View Full Version : Does recapping make an audible difference? The shoot out & you're invited


w1jim
01-09-2011, 10:49 AM
Does recapping result in an audible difference?

I have a Pioneer SX-850 receiver that I've fully recapped with Nichicon electrolytics (excepting the 2 large PS caps) and all of the 1uf and below electrolytics have been replaced with poly film caps. All tantalums have been replaced with electrolytics as well.
I was recently given a very nice SX-850 that had a blown fuse. I've recapped the power regulator PCB but left everything else original.

The question is can we discern a sonic difference between the recapped and non-recapped receivers?

I'm going to do a shoot-out on February 12th at our New England Winter get-together. (http://www.audiokarma.org/forums/showthread.php?t=343338&referrerid=41196) Everyone is invited.

I'm very interested to see if we can determine if there is a sonic upside to my OCCRD (Obsessive Compulsive Capacitor Replacement Disorder).
JimB


http://www.audiokarma.org/forums/attachment.php?attachmentid=249140&stc=1&d=1294591408

trutrent
01-09-2011, 10:59 AM
OCCRD (Obsessive Compulsive Capacitor Replacement Disorder).
:thmbsp:

I'm interested in the results

istariknight
01-09-2011, 11:17 AM
IMO the answer to your question is no. However I recap nearly everything that comes into my hands for reliability which is very worthwhile.

Hyperion
01-09-2011, 11:32 AM
Whether you and others will be able to detect an audible difference between those 2 SX-850's is one thing - who knows ?

However, in general I think re-capping makes a huge audible difference - I speak here as a veteran of 4 full re-caps :D - 5 if you include my oscilloscope - which now 'sounds' just peachy :D :smoke:

My experience suggests that - If you cannot hear a difference, you have
a). used poor replacements,
b). you are hearing challenged,
c). the old caps were not that bad in the first place.

And the audible difference may not so much be the caps themselves - but being able to reliably set the equipment to manufacturers specs in the case of Bias and offset for example.

(Retreats to underground bunker protected by 20' of reinforced concrete, flame suit on, beer in hand :beerchug: :para: :D )

Sadly, I won't be able to make it to the shoot-out to be shot down.
:D

ChrisMarantz
01-09-2011, 11:54 AM
I fully admit that I believe that recapping is necessary due to the age of components, I also believe that the perceived end result is tainted by a variation of the Observer Effect.

Thierry
01-09-2011, 12:03 PM
Not only you can hear a difference but you can also measure it :

http://www.dcx2496.fr/2220BL/Comparaison%20Marantz%202220BL.htm

I measured those two Marantz 2220BL the same day, using the same procedure.

One was completely restored to new condition with quality parts (capacitors, power supply rectifiers) and the other one stayed in original condition. Have a look athe results, they speak for themselves.

http://www.dcx2496.fr/2220BL/P1030192.jpg

w1jim
01-09-2011, 01:57 PM
The condition of the unrestored SX-850 is quite impressive - there were no signs of heat damage to the power supply regulator board which makes me think this has lead a very pampered life (even though it was originally purchased as a high school graduation gift which guarantees it's been cranked).
The major degradation to the original caps would therefore be age related (IMHO).
The data on the Marantz restoration is quite impressive - gives credence to my aforementioned OCCRD.

I was thinking that set up would be critical, especially regarding the volume. My intention is to use a signal generator and a SPL meter set up on a tripod to insure that the volume levels of each receiver is the same.
BTW, the amplifier idle & bias have been set to the same values for each.

I've always felt that higher quality / modern capacitors should give superior sound and there is certainly no ignoring the fact that recapping will result in more reliable service, I'd just like to confirm this with a variety of different listeners.

BTW, while I'll be listening to these receivers individually prior to the shoot-out I will not be comparing them - just confirming that they seem to be functioning properly.

gyrene
01-09-2011, 02:10 PM
Thierry thank you so much for posting the graphs.
Very enlightining to see the difference.
I never doubted that capactiors wear out especially after 35 years!!!
But seeing it is very educational

mashaffer
01-09-2011, 03:47 PM
With my 40s vintage Sparton radio it definitely made a difference. Of course it was inoperable before I did the recap. :D

mike

w1jim
01-09-2011, 04:03 PM
With my 40s vintage Sparton radio it definitely made a difference. Of course it was inoperable before I did the recap. :D
mike
I think it's a whole different world - comparing those waxy caps from the 40's with the caps from the 70's. I want to see if there's a difference with modern caps.

grateful
01-09-2011, 04:21 PM
It should be interesting to find out.

Nikko75
01-09-2011, 04:25 PM
Excellent work, w1jim. There are those who say that modern capacitors aern't as good, my experience warrants dissagreement as do the results provided by Thierry. I've recapped speakers and the sound does change in some cases too. There was one set however that performed best with the originals, but I think that's relative.

Rybeam
01-09-2011, 06:41 PM
I had Ecowars completely re-cap a SX-950, including the two main caps. He found that one of the power transistors was not working. He thought since nothing else was blown that it may have always been that way. He replaced it with a transistor from a Marantz. Yes, it still has Marantz printed on it.

I had been using the Pioneer off and on for a year or so after finding it at a thrift. I never heard any problem with it. I only took it to EC because I always wanted a SX-950 and decided I wanted a restored example. I have used almost daily for the last 4-5 years. I think it and the 850 are among the best buys in vintage receivers.

Point is, it sounded great with a blown transistor!

BinaryMike
01-09-2011, 07:22 PM
Not only you can hear a difference but you can also measure it...

Great, but where are the measurements for those SX-850s? Will we see them after the shootout?

w1jim
01-09-2011, 07:47 PM
It should be interesting to find out.
Dave - think you can make it?
Great, but where are the measurements for those SX-850s? Will we see them after the shootout?
Nope, this will be a highly subjective event, possibly enhanced with responsible levels of alcohol.

BinaryMike
01-09-2011, 08:01 PM
A single uncontrolled attempt to confirm or deny the audibility of differences among electrolytic capacitors, whatever the result, will be strictly anecdotal. That's fine, as far as it goes, but it's disappointing to see a good opportunity for correlation with measurement go down the drain.

superdog
01-09-2011, 08:04 PM
Interesting to be sure.I'll be looking forward to the results.By the way those Pioneers look really good.

Switchblade
01-09-2011, 08:15 PM
Whether you and others will be able to detect an audible difference between those 2 SX-850's is one thing - who knows ?

However, in general I think re-capping makes a huge audible difference - I speak here as a veteran of 4 full re-caps :D - 5 if you include my oscilloscope - which now 'sounds' just peachy :D :smoke:

My experience suggests that - If you cannot hear a difference, you have
a). used poor replacements,
b). you are hearing challenged,
c). the old caps were not that bad in the first place.



I think c) will be the most important point. Either way it will be a fun thing to try!:D

Arkay
01-09-2011, 09:04 PM
Be honest now... you've already done a little un-official comparison and know which one you believe sounds better, right? :D


Whether a recap will make a sonic difference depends overwhelmingly on what condition the old caps are in, to begin with; that is, how much deterioration-from-new has occurred. Most of the time, with 20+-year-old caps, it will make a significantly audible difference... but with a well-preserved example, less so. Some caps age better than others.

I belong to the camp that says it's better to recap than not, since all electrolytics gradually dry out and change (for the worse) sonically over time. Carbon resistors get noisier over time, too, so I usually change those. Solder joints deteriorate, too, so re-flow those. I'd rather take time to do everything at once, and do it right the first time, than to have to repeatedly open up a case and do more work, then yet more, then again more, etc... as a series of old components I didn't bother to replace decide to give up the ghost, one after another.

w1jim
01-09-2011, 09:30 PM
A single uncontrolled attempt to confirm or deny the audibility of differences among electrolytic capacitors, whatever the result, will be strictly anecdotal. That's fine, as far as it goes, but it's disappointing to see a good opportunity for correlation with measurement go down the drain.
There is no denying that this will not be "the" defining test to determine that worthiness of recapping for sonic purposes.
And, it's not like I'll be burning or selling one of these units after this exercise so the opportunity will continue to exist and if anyone has the test equipment I'd be very happy to have them document for us.
Be honest now... you've already done a little un-official comparison and know which one you believe sounds better, right? :D
Nope, I want to believe the recapped one will sound better and I certainly have pride in the work I performed to make it a "better" unit but I honestly don't know if the difference will be discernible to my aging ears or those of the other attendees.

Arkay, if you want to hop a jet I'd be more then happy to pick you up at the Boston (or Worcester for that matter) airport.
JimB

Thierry
01-10-2011, 04:03 AM
Thierry thank you so much for posting the graphs.
Very enlightining to see the difference.
I never doubted that capactiors wear out especially after 35 years!!!
But seeing it is very educational

Thanks,

I think that apart from ageing leading to performance loss, capacitors are the electronic parts that have seen the biggest performance improvement during the past 15 years. Reliability, size reduction along with ESR (equivalent series resistance), leakage current, ripple current, all of these essential parameters have seen tremendous improvements, at least for respectable manufacturers like Vishay (Philips / BC Components, same group), Panasonic, Elna, Rifa, Nichicon etc..

First of all you don't need to replace ALL of the capacitors. You must first study the device schematics to determine which capacitors will bring a real improvement when replaced. Some are obvious, some are less obvious : by instance, a decoupling capacitor located in an area of the circuit may influence a remote part of it because of a feedback loop. Thus I would say that recapping shall be done with discernment. Of course if you have time (and money) you can replace all of the electrolytics and enjoy a nice result but personally I prefer to think first and act accordingly.

generally I don't touch any other capacitor other than electrolytic and tantalum ones. I may also use bypass film capacitors in selected areas but then whe are not speaking about restoration anymore, rather about modifications.

Hope it helps

Thierry

Jon_Logan
01-10-2011, 07:52 AM
Not only you can hear a difference but you can also measure it :

http://www.dcx2496.fr/2220BL/Comparaison%20Marantz%202220BL.htm

I measured those two Marantz 2220BL the same day, using the same procedure.

One was completely restored to new condition with quality parts (capacitors, power supply rectifiers) and the other one stayed in original condition. Have a look athe results, they speak for themselves.

http://www.dcx2496.fr/2220BL/P1030192.jpg

Generally speaking, I am against the wholesale replacement of caps (Electrolytic). But, I can also say I appreciate this kind of depth and making the measurements. I am not sure if the cap/no cap graphs are from the same unit, but these noise floor issues due to lost filtering performance is one of those things that might go un-noticed after repairing another part of the set.

Whether the difference in S/N, TIM, IMD, etc is enough for somebody to pick up in a listening test??? .... that's another thread.

Kudos for making the measurements. :thmbsp:

Thierry
01-10-2011, 08:11 AM
Measurements were made on two strictly identical units, one restored and the other one in original condition.

Did the same thing on a Marantz 1040 :

http://www.dcx2496.fr/marantz1040.php

You can compare reports BEFORE/AFTER :


BEFORE http://www.dcx2496.fr/1040/Comparison.htm
AFTER http://www.dcx2496.fr/1040/1040.htm


However you have to know that this project was not only a simple restoration but included some deeper modifications (mainly about the power supply). In fact I always measure a device before I work on it and measure it again once the project is completed. That helps me a lot to decide if specific attention is needed on some areas or not for future projetcs.

Here's another example on an analog 2 ways active crossover : http://www.dcx2496.fr/CX2300m.php

I never came accross a measurable improvement that wasn't detectable when listening carefully.

merrylander
01-10-2011, 08:58 AM
Whether you and others will be able to detect an audible difference between those 2 SX-850's is one thing - who knows ?

However, in general I think re-capping makes a huge audible difference - I speak here as a veteran of 4 full re-caps :D - 5 if you include my oscilloscope - which now 'sounds' just peachy :D :smoke:

My experience suggests that - If you cannot hear a difference, you have
a). used poor replacements,
b). you are hearing challenged,
c). the old caps were not that bad in the first place.

And the audible difference may not so much be the caps themselves - but being able to reliably set the equipment to manufacturers specs in the case of Bias and offset for example.

(Retreats to underground bunker protected by 20' of reinforced concrete, flame suit on, beer in hand :beerchug: :para: :D )

Sadly, I won't be able to make it to the shoot-out to be shot down.
:D

Glad to see that you included c). because after recapping the audio path of my CR-2040 I could not really hear any difference. However all the old caps tested good on my ESR meter.

dspear99ca
01-10-2011, 09:37 AM
I've done full re-caps on several receivers, among them the Marantz 2250 in my livingroom. I fell in love with this receiver the first time I hooked it up to my test speakers on my bench. If there was ever a receiver I would re-cap just because I wanted it to live forever, this was it. I went the full monty, but honestly I could hear NO DIFFERENCE before vs. after. My bench speakers are NHT Super Zeroes which are pretty gosh-darn revealing in this near-field listening application. Just for fun I tested all the caps I had replaced and, wouldn't you know it, they all tested fine on my ESR meter. Given that the spec on most electros is +/-20% value, I highly doubt any of them would have drifted that far, in fact I find that it's extremely rare for even very old caps to change value appreciably and stay low ESR. The only location where I've really been able to tell a difference in any receiver is with coupling caps and, to a lesser extent, power supply caps if they're real old to start with.

My take on re-caps is to do it selectively... sure go ahead and do the signal path caps, if there are any. But I tend to test the caps rather than go wholesale replacement. If they're low-ESR, in a non-signal path location, and they don't have a hard high-ripple life, they generally stay.

Just my 2 cents.

w1jim
01-10-2011, 10:21 AM
First off, while I am not a professional audio technician, I have extensive experience over the decades and have personally recapped to the order of 20 pieces of audio gear.

My main goal is to determine if there is an audible difference between the stock and recapped unit. Audible being the important factor. Even if one could measure a difference that looks significant on paper if a group of audio enthusiasts (notice I didn't say "audiophiles") can't tell the difference then the justification becomes one of reliability and not superior sound.

I think there is a general consensus that recapping is a good thing in regards to assuring the long term reliability of older equipment - providing you don't screw something up in the process of course.

The other thing that is important in the A/B test is that one's hearing memory is not very good. Hopefully the live comparison will be a more reliable / objective methodology.

Incidentally, for set up I will be feeding each with a sine wave from a signal generator and verifying the SPL with my db meter (on a tripod to insure a constant measurement) to insure that the volumes are the same. This is important since the louder one will generally sound superior (given fairly equal signal "quality").

And as always, YMMV!

thefragger
01-10-2011, 10:34 AM
I think it's a whole different world - comparing those waxy caps from the 40's with the caps from the 70's. I want to see if there's a difference with modern caps.

Not really--my Sony TA-F6B (1977) produced terribly, unlistenebly poor music (well, mostly static) before I recapped mine. I'd say it's a measurable difference :)

Yggdrasill
01-10-2011, 10:39 AM
Last year member Sir Byrd recapped two pieces of mine, a Sansui AU-9900 and a Marantz 2270. The Marantz sounds much better all around, especially the tuner section. The Sansui has a more resonant bass but otherwise sounds mostly unchanged (to me).

Nikko75
01-10-2011, 11:07 AM
Be honest now... you've already done a little un-official comparison and know which one you believe sounds better, right? :D


Whether a recap will make a sonic difference depends overwhelmingly on what condition the old caps are in, to begin with; that is, how much deterioration-from-new has occurred...
Well that's completely relative to the circuit too, and is common sense. Previously nobody said it, because everyone knew it.

stereofanboy
01-10-2011, 11:34 AM
Will this be a blind comparison?

w1jim
01-10-2011, 12:05 PM
Will this be a blind comparison?
Yes. I won't even identify which receiver is stock vs. recapped until after.

Bigears
01-11-2011, 12:19 AM
Wholesale recapping of vintage receivers is a lot of work. The few that I've completely recapped did not produce an audible difference. However the caps were bulging and over 30 years old, so I was looking to preserve rather than restore something that was lost. I have heard a difference doing audio path caps in some high end amps.

This comparo will be interesting.:yes:

Soundcraftsmn
01-12-2011, 12:10 AM
This should be good. My own experience is that it does make a difference, but most of my recapped gear was buggered up to start.

Layoutpad
01-12-2011, 12:26 AM
This should be good. My own experience is that it does make a difference, but most of my recapped gear was buggered up to start.

I think a good re-cap (with upgraded main caps) makes a huge difference in sound.

I have all of my vintage gear gone though and getting the power-supply, amp boards and especially the pre-amp board (receivers and integrated)
makes a huge difference in soundstage, bottom end and over-all presentation of music.

But transistor issues can be (and are sometimes more)
important than caps as well.

Maybe I'm weird but there has been more than one occasion
when I have heard weak main caps, sloppy power-supply issues
or odd transistor/sotter issues and been proven correct
by measurements on the offending suspects by my tech.:music:

Just my 2 cents.


---------------------------------------------------------------------------

Accuphase.....P-300 amp / Sony TA2000 pre-amp
Classé..........Cap-151
HKardon........HK730 / 930
Holfi………..…..Integra 5.1 amp / Xara CD transport
Kenwood.......KA-907, KA-801 / KT-615
Luxman........R-1120
Marantz........2230, 2240B, 2250, 2270, 2285B, 2325, 4240, 4270, 4300, 4400
Nikko............Alpha II amp / Beta II pre-amp (Silver)
Onkyo...........M-508 Amp / Perreaux SX1 pre-amp
Parasound......HCA 2200II AMP / Sir Byrd passive pre-amp
Pioneer..........SA-9500II / TX 9500II, SX1250, SX1010, SX980, SX950, 9930
Rotel.............RB-991AMP / Acurus L10 pre-amp
Sansui...........9090 / 990DB / AU717
Sony.............TA-3200 amp / 2000F pre-amp (x2), STR-6065, 7065, STR-V7
Yamaha........CR-1020 / 2020 / 3020

DAC's............Music Hall 25.2,,Music Hall 25.3, PS Audio DLIII, Xindak 5,
....................Fubar IV, Firestone Audio TubeHead pre-amp

Speakers........Pioneer HPM-1500's, HPM-900's, Klipsch Forte II's,
………………..KG-2's, Infinity RS1000, JBL 4412A / S-38's, Ohm Model L,
....................Norman Labs Model 8's, "New" Large Advents & KEF 103.2's

MisterFishey
01-12-2011, 12:46 AM
With just anecdotal evidence, I can say that recapping makes a huge difference. The sound after recapping is, to my ears, invariably better after a recap, especially in crucial places like speaker crossovers.

However, even ignoring sonic benefits, IMO all vintage electrolytics should be replaced solely for safety reasons, as previously stated. :yes:

crazyjeeper
01-12-2011, 01:15 AM
I would say that the recap of my sansui made a huge different in the sound. It no longer pops loudly. :D

str8tlk
01-12-2011, 01:36 AM
I just replaced the huge main caps and PA board in my Pioneer SX-1010. It sounds like a 300 watt receiver now and dosent clip under heavy loads. The sound is so much clear.

Zeke
01-12-2011, 11:07 AM
In my limited experience, the expensive re-capping of a Sansui G9000DB most definitely resulted in wholesale improvement: night versus day.

Of course, things required power supply rebuild because the unit was already in oscillation...

313guy
01-12-2011, 04:25 PM
Will you be publishing charts and graphs of the test results? Maybe one axis could show number of alcoholic beverages consumed and the other the ability to discern a difference in the two receivers.:lurk:

bluesky
01-12-2011, 05:02 PM
OCCRD (Obsessive Compulsive Capacitor Replacement Disorder). :thmbsp:


That's pretty funny!! I like that one! Way cool!! :thmbsp:

Svt
01-12-2011, 05:17 PM
Wow what an interesting debate! Here is my take on recapping....

I have a Sansui 9090 that is uneven between channels when cold, but evens out once it warms up. Do you think a recap will fix it? Yes. Will the sound quality improve? Absolutely. But it 100% has some bad caps.

I also have a SX-1250 that is on "loan" from a fellow AK'er. It just sounds terrible. Not distorted, but just kinda lifeless. Dull. I found one of the big caps leaking all over the place inside. Will it sound better after a full recap? Absolutely! But again it 100% has at least one bad cap.

I have a G9000DB. It functions 100%, and sounds amazing. There is no distortion, uneven channels, tone controls work great, etc. Will it benefit from a recap? Only for piece of mind and reliability. Will it sound better after a recap? I bet noone could hear a difference. But remember this one probably does not have any bad caps.


Summary: If you hear a difference in sound after a recap, then you had bad/out of spec caps.
If you do not hear a difference, there was nothing wrong with the caps that you replaced beside being old and probably near the end of the life span.

w1jim
01-12-2011, 06:54 PM
Wow what an interesting debate! Here is my take on recapping....
Actually, I never meant it to be a debate but rather an opportunity for people to compare these two in a casual setting and perhaps draw conclusions of their own - pro, con or indifferent.

I especially related to your response because I have those 3 receivers.
My recapped SX-1250 and 9090db have me in a quandry - both are in the bedroom (oh, such a tolerant wife) and I can't decide which I prefer; both look and sound wonderful.
And then downstairs I have a 9000db which I don't want to touch - it's perfect as is!

w1jim
01-12-2011, 07:01 PM
Will you be publishing charts and graphs of the test results? Maybe one axis could show number of alcoholic beverages consumed and the other the ability to discern a difference in the two receivers.:lurk:


Here some of my earlier research in that regard...


http://graphjam.files.wordpress.com/2008/04/funny-graphs-beer-bottle-distribution2.gif

RebelKat
01-12-2011, 07:05 PM
:lurk:

w1jim
01-24-2011, 12:41 PM
I built an A/B switcher this weekend to use in the SX-850 comparison test.
It is basically 5 DPDT relays. One is used to switch the RCA signal source and the other 4 are for the speaker connections - I have paralleled the contacts for the speaker switching (overkill with 10 amp contacts).
This will allow for the 2 receiver outputs to connect to a single pair of speakers and a single RCA source to go to the individual receivers.
The LED on the board switches between green and orange to indicate which is selected.
I still need to construct a simple remote box with a toggle switch to alternate between the selections.
I built this with parts from a scrap alarm system relay panel.



http://www.audiokarma.org/forums/attachment.php?attachmentid=252053&stc=1&d=1295894350

BinaryMike
01-24-2011, 04:33 PM
Neat work, but power relays aren't reliable when switching small signals. You will need one that's rated specifically for 'dry circuit' or small signal service, which generally means that it has gold contacts and a very low limit on contact current. Also, avoid routing low-level signal anywhere near power output circuits. There's way too much risk of hostile feedback.

w1jim
01-24-2011, 04:52 PM
Hopefully I'm good on keeping the signals isolated from one another but I'll use some copper tape around the preamp level signals to maximize the isolation.
I'll verify that the relay with the low level signals works properly - otherwise I'll replace it with something more "delicate".

Copa1934
01-24-2011, 05:32 PM
old woodworking adage, but along the same thought. It would seem that if DC-offset and bias can't be adjusted correctly that would be cause to consider re-cap? Anything else that would be a subtle sign?

w1jim
01-24-2011, 06:51 PM
old woodworking adage, but along the same thought. It would seem that if DC-offset and bias can't be adjusted correctly that would be cause to consider re-cap? Anything else that would be a subtle sign?
Subtle signs would be a general dulling of sound. I would think an inability to properly adjust the amplifier stage could also be attributable to bad transistors, inadequate / unbalanced rail voltages dirty trim pots and I'm sure a bunch of other stuff.

Gang-Twanger
01-24-2011, 08:23 PM
Will this be a blind comparison?

Yes... Blind-drunk.

I read the results of a similar test last year, except instead of re-capping, I think they simply measured the 'aged' performance of 2 different receivers - One was a Sansui, and I think the other was the comparable ******. Anyway, they found that the Sansui was still putting out it's rated wattage while the other receiver's measured output had dropped several watts. I was sold after that... Scientifically-proven or not.

Dawgme85
01-24-2011, 08:58 PM
My experience after having my amp re-capped was a subtle, but noticable improvement in sound quality. The slight sibilance (that I had to listen for prior to the rebuild) was totally gone when I got it back, replaced by a cleaner, more detailed sound. That was 2 years ago. Now, I'm sure it's just like that super-fast computer that I bought and 2 weeks later was just a computer! Still, I wouldn't trade this system for anything (at least when it comes to listening to vinyl). YMMV.

BinaryMike
01-24-2011, 10:50 PM
Hopefully I'm good on keeping the signals isolated from one another but I'll use some copper tape around the preamp level signals to maximize the isolation.
I'll verify that the relay with the low level signals works properly - otherwise I'll replace it with something more "delicate".

I think it's important to pursue a higher standard. Here's how I see it: Without an upgrade, this will be pseudoscience at best. If you're going to invoke the concept of scientific inquiry, then you ought to observe the fundamentals instead of running roughshod over them. Experiments with major uncontrolled variables resulting from abandonment of engineering principles have only entertainment value. If that's the goal, then I'll butt out permanently. If not, then I'll try to offer constructive criticism because I hope to learn from the results of well-constructed experiments.

w1jim
01-25-2011, 05:06 PM
OK - here's my redesign.
I replaced the power relay for the RCA level switcher with a sealed dry contact DPDT relay. The modification also required a simple 7812 voltage regulator (the other relays are 24 volts).
Also shown is the remote handheld A/B switcher.

I may make the LED larger or brighter as well, got to think about that.

I'll put together some simple forms for people to comment on the A/B comparison.




http://www.audiokarma.org/forums/attachment.php?attachmentid=252283&stc=1&d=1295996475

BinaryMike
01-25-2011, 07:19 PM
The relay change certainly helps this project look serious, but unfortunately, the proximity of low-level signal wiring to high-power speaker circuits will never be acceptable. It's pretty much imperative to use a separate enclosure for the low-level signal relay and its wiring. Good work on that pickle switch, by the way!

princeoftides
01-25-2011, 07:23 PM
I don't know about receivers but one capacitor in a speaker can make a huge difference, Just a cheap orange drop instead of an electrolytic will do wonders for a good speaker.

princeoftides
01-25-2011, 07:28 PM
The big problem with this shootout is that you aren't dealing with brand new equipment versus "BRAND NEW" capacitors. What would if sound like if you got an SX-850 off the showroom floor in 197? and then recapped it? You will never know. The test is flawed.

w1jim
01-25-2011, 07:45 PM
The big problem with this shootout is that you aren't dealing with brand new equipment versus "BRAND NEW" capacitors. What would if sound like if you got an SX-850 off the showroom floor in 197? and then recapped it? You will never know. The test is flawed.
The test isn't flawed, it isn't even a test - it's more a casual demonstration to see if various individuals can determine (for themselves) if they can hear a difference in the sound and thereby get a feeling for what a recapping might do (or not do).
I'm not trying to make this the definitive test. Just a shared experience.

Frank Sol
01-25-2011, 08:32 PM
I'm not trying to make this the definitive test. Just a shared experience.


and undoubtedly fun :thmbsp:

Looking forward to the 'results'

cdfac
01-25-2011, 09:16 PM
the Omron (and similar) relays people are using for the DIY B1 preamps would be idea for this. i think this is an example:

http://www.mouser.com/ProductDetail/Omron/G6H-2-100-DC5/?qs=eORE%252bZ%252b0Crs5ZfdQaEiSCQ%3D%3D

i also googled and read that "reed relays" are common for blind tests.

Isotonic
01-26-2011, 02:50 AM
There are so many variables in comparing audio products that a strict test is impossible anyway. So what's left? The subjective. We all use subjective impressions and analysis everyday in our everyday lives, though we would never question ourselves like we do when we have conversations about audio. Why is that?

BinaryMike
01-26-2011, 12:54 PM
There are so many variables in comparing audio products that a strict test is impossible...

This is a myth propagated by those who find themselves and others unable to design good experiments, and sometimes by those who profit from a widespread belief in mumbo-jumbo. As in medicine, it is sometimes exceedingly difficult to tease out the truth, but it is far from impossible. I think it's important to pursue and encourage any efforts to uncover the facts, however modest. The other path ultimately leads to madness.

hellhound94
01-26-2011, 12:55 PM
I fully admit that I believe that recapping is necessary due to the age of components, I also believe that the perceived end result is tainted by a variation of the Observer Effect.

I love your comment!

w1jim
01-26-2011, 01:41 PM
This is a myth propagated by those who find themselves and others unable to design good experiments, and sometimes by those who profit from a widespread belief in mumbo-jumbo. As in medicine, it is sometimes exceedingly difficult to tease out the truth, but it is far from impossible. I think it's important to pursue and encourage any efforts to uncover the facts, however modest. The other path ultimately leads to madness.
Perhaps we're starting from madness, what with our obsession with this kind of thing in the first place.

IMHO, when it comes to something that is subjective in the first place, it is unlikely that a test could be construed that determines what is "best" when we can't define what is in fact best.
My best may not be your best.
We could test for what sounds the closest to the original source or has the lowest distortion but again - that may not sound the "best" to me.
And keep in mind that many guitarists strive for a "likable" form of distortion in their amps in the first place - because they like how it sounds.

Again, we're not sending a guy to the moon (and back) here - just an excuse to have fun and drink more beer (and we're not even sure what the best beer is either - but we have our people working on it).

Thierry
01-26-2011, 01:50 PM
This is a myth propagated by those who find themselves and others unable to design good experiments, and sometimes by those who profit from a widespread belief in mumbo-jumbo. As in medicine, it is sometimes exceedingly difficult to tease out the truth, but it is far from impossible. I think it's important to pursue and encourage any efforts to uncover the facts, however modest. The other path ultimately leads to madness.

I fully agree with this.

Everyone should read this : http://www.enjoythemusic.com/magazine/viewpoint/0601/audiohell.htm

Thierry

BinaryMike
01-26-2011, 03:49 PM
IMHO, when it comes to something that is subjective in the first place, it is unlikely that a test could be construed that determines what is "best" when we can't define what is in fact best.

As I understand it, this experiment has just one simple goal: to establish whether wholesale capacitor change in a typical vintage receiver, by itself, is clearly audible to some fraction (hopefully documented) of a large sample of listeners in various states of inebriation. I'm perfectly happy to have just this one simple but reliable datum, even though I would like to see more detailed data on the cap changes actually involved and any measurable difference in performance between the two receivers. If one listener choice is consistently preferred over the other, then it would be nice to find some correlation in the data, but this result couldn't possibly be meaningful without further investigation.

w1jim
01-26-2011, 04:50 PM
...this result couldn't possibly be meaningful without further investigation.
I don't know that I am striving for meaningful. Really just to share a unregulated experience.
The clear reality is that even though one was recapped we won't know the condition of a myriad of other variables within either of the samples.

BinaryMike
01-26-2011, 05:13 PM
The clear reality is that even though one was recapped we won't know the condition of a myriad of other variables within either of the samples.

Well, that's a good point. Ideally, a similar product comparison party should have occurred before the recapping. Still, distortion measurements after the fact would help to establish that gross defects didn't color the results.

Thierry
01-26-2011, 07:09 PM
Well, that's a good point. Ideally, a similar product comparison party should have occurred before the recapping. Still, distortion measurements after the fact would help to establish that gross defects didn't color the results.

Did it many times. Here are a few examples :

Marantz 1040 before : http://www.dcx2496.fr/1040/Comparison.htm
Marantz 1040 after : http://www.dcx2496.fr/1040/1040.htm
The work is documented with what has been changed and why : http://www.dcx2496.fr/marantz1040.php

Another example, a Marantz 2220BL before and after : http://www.dcx2496.fr/2220BL/Comparaison%20Marantz%202220BL.htm

Did it also on an analog active crossover :
Behringer CX2300 low output before :http://www.dcx2496.fr/LOW.htm
Behringer CX2300 low output after : http://www.dcx2496.fr/TWEAK%20LOW.htm
Behringer CX2300 high output before :http://www.dcx2496.fr/HIGH.htm
Behringer CX2300 high output after :http://www.dcx2496.fr/TWEAK%20HIGH.htm

In all cases the improvements were audibly noticeable.

Isotonic
01-26-2011, 08:56 PM
This is a myth propagated by those who find themselves and others unable to design good experiments, and sometimes by those who profit from a widespread belief in mumbo-jumbo. As in medicine, it is sometimes exceedingly difficult to tease out the truth, but it is far from impossible. I think it's important to pursue and encourage any efforts to uncover the facts, however modest. The other path ultimately leads to madness.

Nope, not a myth. Speakers and room placement are widely variable and differ from living room to living room. Different runs of old stock capacitors, transistors, or even production runs might yield subtle variations. Even measuring instruments yield different responses based on factors such as humidity, atmospheric pressure etc. We cannot live in a vacuum, nor should we attempt to measure in a vacuum.

It is not always possible to design a perfect experiment. And science doesn't require it. There is a universe of methodologies perceiving shades of understanding in every science.

Just because mumbo jumbo exists, doesn't mean that all perception that is not provable within a known scientific framework leads to mumbo jumbo. All science is first an act of creativity. If you don't understand that, then you need to bone up on the your science history.

That last statement regarding madness strikes me as extreme and naive. In the social sciences it was long ago established perception itself is widely variable and largely constructed within the context of language and the historic origins of the given culture. And in the present time, homogeneous culture is long lost.

Isotonic
01-26-2011, 09:06 PM
You guys act as if you need a measuring device to determine weather you can perceive an improvement. The measuring device is mode of perception, but the end result is squiggly lines and numbers. I don't listen to lines and numbers. I listen to music. When i recap, and do the other things I do during a restoration project I do it to ensure that the unit works as it was designed, with parts that are known to be in spec, and I do it to preserve the unit.

IF I want to listen to a before and after, that could be fun too. And why wouldn't I be able to perceive a difference? All the numbers and squiggly lines in the world don't change the limits of auditory perception. And ultimately a receiver is an instrument designed to be heard, not measured.

Isotonic
01-26-2011, 09:16 PM
As in medicine, it is sometimes exceedingly difficult to tease out the truth, but it is far from impossible.

Actually medicine is in a constant state of evolution. What was believed to be true 20 years ago was found to be true using strict scientific method and state of the art research methodology, yet here we are doing things very differently using the same data viewed from different paradigms, and new methodologies that transcend strict testing. Meta analysis and bundling show that unprovable methods can show statistically significant results despite lack of concrete evidence.

Isotonic
01-26-2011, 09:20 PM
Bottom line: Concrete perception is a myth propagated by those that lack the creativity to perceive beyond a limited set of variables floating amidst an ocean of variables that are right under their noses. Not to mention the ones that we are simply not equipped to perceive.

EPI-Center
01-27-2011, 12:58 AM
do "better" or newer capacitors affect the THD numbers? I'm just curious if the topology of the amp determines distortion or if it's better components or a combination.

I'm wondering if you're exceeding factory spec, assuming they weren't being conservative with cap replacements.

Did it many times. Here are a few examples :

Marantz 1040 before : http://www.dcx2496.fr/1040/Comparison.htm
Marantz 1040 after : http://www.dcx2496.fr/1040/1040.htm
The work is documented with what has been changed and why : http://www.dcx2496.fr/marantz1040.php

Another example, a Marantz 2220BL before and after : http://www.dcx2496.fr/2220BL/Comparaison%20Marantz%202220BL.htm

Did it also on an analog active crossover :
Behringer CX2300 low output before :http://www.dcx2496.fr/LOW.htm
Behringer CX2300 low output after : http://www.dcx2496.fr/TWEAK%20LOW.htm
Behringer CX2300 high output before :http://www.dcx2496.fr/HIGH.htm
Behringer CX2300 high output after :http://www.dcx2496.fr/TWEAK%20HIGH.htm

In all cases the improvements were audibly noticeable.

Gibsonian
01-27-2011, 06:20 AM
When are you drunks, er, I mean Science Audiophiles gonna get this contest rolling? Alot of pregame hype, I think we're now ready for the rumble!

Isotonic
01-27-2011, 07:01 AM
!!!!!!!!!!!!!!!!!!!

w1jim
01-27-2011, 07:35 AM
When are you drunks, er, I mean Science Audiophiles gonna get this contest rolling? Alot of pregame hype, I think we're now ready for the rumble!
I concur - Saturday February 12th.
I'm happy to pick up any of you guys who'll be flying in with your test gear.
http://www.audiokarma.org/forums/showthread.php?t=343338

w1jim
02-13-2011, 12:33 PM
Yesterday we had the comparison between my stock and recapped Pioneer SX-850s.

The goal of this comparison was to have fun and interesting experience - by virtue of those goals I declare this test a success.
If anyone wants to criticize any aspect of this exercise then I can only say - chill out and learn how to have fun!

We had about 25 attendees at the get together of which most had the opportunity to listen to the 2 receivers.
11 people opted to listen critically for between 5 minutes and perhaps an hour and also fill out the questionnaire.

Each receiver was volume matched using a audio frequency generator and an inexpensive SPL meter (this to avoid the situation where the louder unit will often sound better).
Sources were a new NAD 515BEE CD player and a Teac 2300S reel-to-reel half track machine playing some jazz at 7.5 ips. This was a very high quality recording but did exhibit a little bit of tape hiss during quiet passages which is to be expected.
I did want to also compare FM signals but due to the poor reception in our semi-rural location that wasn't feasible. Also the recapped receiver had a more sensitive FM section - most likely due to differences in alignment parameters.

Speakers were my Polk Monitor 7A's with an auxiliary ribbon tweeter with a 6db crossover that permitted frequencies above about 10khz. I decided that for this critical listening having a system with strong high frequency response would be a plus.

Each receiver was only identified as "ORANGE" and "GREEN" - nobody knew which was which. I was the only one to adjust the levels so someone couldn't determine which was which by seeing which one changed.

Below is the text of the form and the 7 parameters I asked people to consider.

Does recapping a piece of vintage gear change it’s sonic characteristics? Who knows - but let’s perform a completely non-scientific test and see if we can tell the difference and if it is for the better.
We have 2 – Pioneer SX-850s – one has been completely recapped except for the main power supply caps – the other has only had the power supply regulator PCB (which had issues) recapped.
Each will have a colored LED to identify the one you’re listening to. Which sounds better to you?


BASS
Recapped - 4
Stock - 2
No Diff - 5

MIDRANGE
Recapped - 7
Stock - 1
No Diff - 3

TREBLE
Recapped - 9
Stock - 1
No Diff - 1

SEPARATION
Recapped - 9
Stock - 0
No Diff - 2

BACKGROUND NOISE
Recapped - 3
Stock - 0
No Diff - 8

IMAGING
Recapped - 8
Stock - 0
No Diff - 3

SMOOTHNESS / MUSICALITY
Recapped - 7
Stock - 2
No Diff - 2


---------------------------

In my experience some people could form an opinion right away whereas others could discern no difference. Obviously everyone has different listening skills and abilities. Everyone seemed to be impressed with the sound of each system and the consensus was that the lesser system would have been fully acceptable in the absence of the comparison.

Also important to note was that the differences here were not "night and day". Even when a participant could quickly discern a difference nobody thought the difference's were extreme.

Additional comments from participants:

Regarding the recapped - Bass comparison was perhaps limited by source material and speaker size. Midrange very smooth, treble nice detail. Very musical.
Non recapped - sounds slightly grainy in the background noise.
Recapped - Bass is tighter, midrange effortless, treble smoother - non-recapped was a bit shrill.
Recapped - I think the bass was improved simply by everything being clearer, the treble was smoother with more detail and 'air'.
Both - no perceived difference, both sound fantastic in any case.


There were no hanging chads and all ballots have been destroyed by order of the officiating body (me).

donberry
02-13-2011, 12:53 PM
Just my opinion - when re-capping a receiver, amp etc, I feel you are restoring it back to at least new performance, which makes an audible difference mainly because I am comparing something that probably has at least some caps which are not performing as they should.

I feel the biggest difference is when you get into the more expensive film caps such as Dynamicap, Mundorf, Sonicap etc. Usually it seems I see these caps used more in speakers and preamps. You could use them in the preamp section of a receiver, but the biggest problem you get into is space and trying to make room. These are not your tiny orange drop caps. The caps in my CJ preamp are mostly the size of 1/2 a roll of quarters and there are a bunch of them in there.
As I have mentioned to many times, I splurged (for me) and put this type of capacitor in a pair of speakers I really, really like. I do not think it was just me wanting them to sound good because they also made me a believer in burn in because after the initial sweetness - they did not sound all that great for about 50+ hours....
I know there is quite a debate about burn in, yet all I can do, for me, is go by my experience and what I believe to be a huge difference.

As for replacing electrolytics, I tend to believe it sounds better mainly because it has restored the receiver/amp etc to it's original specs.

I think if you really want to have a cap shoot out, it would be best to gather up some of the better reviewed film caps and swap those in as I tend to believe each of them does impart their own sound characteristic....
As a side not, I am a big Dynamicap fan.......

x_25
02-13-2011, 12:56 PM
Cool, so the consensus is there is some difference.

It definitely wasn't much. Listening to material I didn't know made it very difficult to hear any difference, although when I put on my reference album (reference because I have listened to it so much) I could discern a subtle difference between the two. If jim did not have it set up to switch instantly and seamlessly though I could not have heard a difference. Switching wires back and forth would have just taken too long.

thedelihaus
02-13-2011, 12:59 PM
Jim- I would have loved to have participated- I'm terribly sorry I missed this opportunity!

DENNYDOG
02-13-2011, 01:31 PM
Thanks for the great read and all your effort. I thoroughly enjoyed it!

mrbruce
02-13-2011, 01:49 PM
Thanks for the great read and all your effort. I thoroughly enjoyed it!

+1! Jim, thanks for your efforts there as well as the posts.
Can you shed any light on why more than half the attendees didn't want to document what they heard in the comparison?
Beer usually reduces inhibitions!:D

Bruce

EPI-Center
02-13-2011, 01:55 PM
I A/B'd a sansui amp once that I had recapped with one that wasn't but didn't have the awesome A/B switch that jim had so by the time I frantically replaced the speaker wires..could I really "remember" what I just heard 45 seconds ago? I've had some amps that I could definitely cop a difference between them with the speaker wire switching deal...I wonder if I would have been able to tell yesterday with a 45 second delay between listening.

Almost There
02-13-2011, 02:16 PM
When are you drunks, er, I mean Science Audiophiles gonna get this contest rolling?

I am proud to say I was one of the drunks, er, I mean Science Audiophiles at yesterday's event. And my analysis of the SX-850 side-by-side, re-cap test is buried somewhere in the above numbers. However, I will leave it to others to debate those numbers, the variables and their opinions.

What I know is that you can't beat good music, good people, and good fun and games (thanks for the demo w1jim!).

Karma at its best... let the good times roll! :music:

w1jim
02-13-2011, 02:45 PM
I think if you really want to have a cap shoot out, it would be best to gather up some of the better reviewed film caps and swap those in as I tend to believe each of them does impart their own sound characteristic...
I believe that this has been done (in depth) on another website.

Again, my goal was to have fun and not have any kind of definitive exercise. That being said I have formed my own opinions (as I am wont to do).

Comparing 2 components by switching wires leaves too much time between the samples and just ends up being an exercise in frustration (IMHO).

Deli - I'm sorry your attention was pulled in other directions and we a only got to chat briefly but still my goal was met because I know you had a good time - but 6 dozen C/C cookies? Who you trying to impress?!
JimB

Rockyhill
02-13-2011, 08:14 PM
So, which was the recapped, orange or green?

w1jim
02-13-2011, 09:12 PM
So, which was the recapped, orange or green?
The recapped one was the green light - the receiver on the right, not that you could tell from the outside.
Thanks for your participation and feedback.

myu701
02-14-2011, 12:41 AM
Thanks so much for posting about this, Jim.

The really good thing is that you can safely say that the sound was definitely not compromised with the recap. That's the thing--there are some people out there who say with recapping you change the character and lose that "original" sound. The most important thing is to find that the change is not for the worse... either imperceptible or a slight improvement. But the biggest gain is the peace of mind that you've got new components in place, so the component is ready for many more years of service.

Based on this test you've done, I think it's a major :thmbsp: sign on doing recaps.
Thanks!

Frank Sol
02-14-2011, 12:55 AM
I love stuff like this. Thanks w1jim and participants!!

w1jim
02-14-2011, 09:19 PM
Some pictures of the setup in action...


http://i442.photobucket.com/albums/qq141/20487/akfest2_11/IMG_2272.jpg


http://i442.photobucket.com/albums/qq141/20487/akfest2_11/IMG_2271.jpg

shacky
02-14-2011, 10:20 PM
Those Polks look pretty high off floor. Maybe effected the bass comparison by reducing bass output? :scratch2:

Great job. Wish I could have have come with my recapped 950 :tears:

Isotonic
02-15-2011, 08:31 AM
Very cool! Well done! Audio with friends is the best!

Gibsonian
02-15-2011, 09:44 AM
Great report and glad a good time was had by all. Only wish I could've joined and contributed some beer, er, I mean scientific analysis to the cause!

jimfet
02-15-2011, 12:41 PM
I agree with what some one else said earlier. Could be a very noticable increase in quality, if you use a higher quality cap. Replacing with the same quality cap less. Or even worse with a low quality one.

HypnoToad
02-15-2011, 12:53 PM
I agree with what some one else said earlier. Could be a very noticable increase in quality, if you use a higher quality cap. Replacing with the same quality cap less. Or even worse with a low quality one.

When I replace the Xunda and other cheap caps in 640P's with Panasonic's there is an audible difference right there. Makes me wonder how much they save by putting in cheaper ones.

When I looked in my Yamaha C4 I was surprised to find good quality caps throughout. The replacements I am going to use are no better than the originals so it will only be age and the risk of breakdown as the reason. If it does sound better that's a bonus IMO.

BinaryMike
02-15-2011, 03:14 PM
Jim, did you segregate the low-level signal wiring from the speaker relay wiring before the event, or did you leave those wires in close proximity as shown in the most recent photos of the switching system in this thread?

w1jim
02-15-2011, 03:28 PM
Jim, did you segregate the low-level signal wiring from the speaker relay wiring before the event, or did you leave those wires in close proximity as shown in the most recent photos of the switching system in this thread?
Mike - The wiring was as shown in the last photo with the smaller relay. While it may not be the best practice I don't feel that it degraded the signal :music:.

awise1961
02-15-2011, 03:54 PM
Jim's system and test set up were piece to behold for sure, and his ability to keep things light and comical kept it all from being too anylitical.
Great job Jim.
We lab rats even had a great variety of cheese to choose from.
Just made sure to stay away from those red hot dogs though.
They looked like they needed a dose of antibiotics.
It was a lot of fun.

Al. Wise

BinaryMike
02-15-2011, 03:59 PM
The wiring was as shown in the last photo with the smaller relay. While it may not be the best practice I don't feel that it degraded the signal.

I find myself unable to agree, because I've seen outright oscillation result from routing small-signal wiring this close to power amplifier output wiring in an amplifier chassis. While I strongly support such attempts to distinguish between perception and reality in sound reproduction, this error is more than sufficient to invalidate the results. Do let me know if you decide to make another attempt. I'll be happy to contribute funds to assist with switch box improvements, if that's an issue. Wish I could be there...

w1jim
02-15-2011, 04:28 PM
I find myself unable to agree, ... this error is more than sufficient to invalidate the results.
Well then so be it.
We had fun and that was our goal so I can only say that I'm sorry for disappointing you. I'm sure it won't be the first time :D.
I don't plan on redoing the exercise and don't plan on having both of these receivers in my collection in perpetuity.

shacky
02-16-2011, 02:44 PM
Well then so be it.
We had fun and that was our goal so I can only say that I'm sorry for disappointing you. I'm sure it won't be the first time :D.
I don't plan on redoing the exercise and don't plan on having both of these receivers in my collection in perpetuity.

Jim,

I applaud what you did. Wish I was there to hear it. I think you did the best real world comparison possible. If the differences were heard in that environment then it's real. Certainly not something to be "invalidated".

Keep the Karma going :thmbsp:

w1jim
02-16-2011, 03:04 PM
:music:/:music:

gogofast
02-16-2011, 03:27 PM
great job! sounds like the whole thing was ton of fun!

from your test results, how can one say that there's still no difference? unless those participants were all drunk or with hearing loss, i think it's clear the recap makes a lot of difference.

w1jim
02-16-2011, 04:22 PM
There was a surprising and disappointing lack of alcohol consumption - I think the tunes and good company was a sufficient high for most.
It is ironic that the more we can afford this gear (as we age) the more our hearing degrades and the less we can appreciate it. Maybe that's the basis of nostalgia.

gogofast
02-17-2011, 12:10 AM
There was a surprising and disappointing lack of alcohol consumption - I think the tunes and good company was a sufficient high for most.
It is ironic that the more we can afford this gear (as we age) the more our hearing degrades and the less we can appreciate it. Maybe that's the basis of nostalgia.

you're right, life IS ironic sometimes....:yes:

i remember back in my younger days when a $20 bill in my pocket and queen's night at the opera cassette tape playing in my friend's crappy yellow pintos was all it took to make me and group of my friends happy.... beer and tacos.

Fast_Eddie
02-17-2011, 12:27 AM
What a cool project! Looks like a lot of fun and sure was an interesting read!

Thanks for the effort that went into this.

Robisme
02-17-2011, 01:02 AM
Did you compare the two before the recap? Just wondering.

Was the bias set on both?

Looks like a fun test.

Having them side by side makes a big difference. I wonder if you would have been able to hear a difference if you only had the one. Before and after the recap. I just did a 100% recap of an HK 330B, and it sounds the same to me now as it did before the recap. That doesn't mean it does though. I used Panasonic FC's for 95% of them. All the originals were the gray Elna's.

Rob

motorstereo
02-17-2011, 03:25 AM
There was a surprising and disappointing lack of alcohol consumption - I think the tunes and good company was a sufficient high for most.
It is ironic that the more we can afford this gear (as we age) the more our hearing degrades and the less we can appreciate it. Maybe that's the basis of nostalgia.

Hey comeon now. I finished up the 3 hard iced teas from the 6 pack that I had gotten for last winter's get together.:yes:
Just like I said at the get together Jim I thought you did a very scientific shoot out with those 2 recievers. Of course some nit pickers will say no but that's their problem. It's really too not hard to criticize most anything in life if you really want to.
I must you did an equally good job on the charcoal grille as well. No criticism from me.:D

w1jim
02-17-2011, 06:28 AM
Did you compare the two before the recap? Just wondering.
Was the bias set on both?
Rob
I recapped the first SX-850 about a year ago and then just recently got the other one which needed some PS repairs so - no, I didn't have the opportunity to compare them before.
Both amp stages had the bias and DC offset set to similar values.
I must you did an equally good job on the charcoal grille as well. No criticism from me.:D
Recapping the grill was a real challenge, those things get nasty hot :gigglemad!

motorstereo
02-17-2011, 07:13 AM
Recapping the grill was a real challenge, those things get nasty hot :gigglemad![/QUOTE]

Was it you that burned the hot dogs?

w1jim
02-17-2011, 07:36 AM
Was it you that burned the hot dogs?
Those nasty red ones that Beemer made from the entrails of his missing neighbor? Delicious!

jblnut
02-22-2011, 12:41 PM
As one of the participants in the shoot-out, I just want to emphasize that this was a very subtle difference. One of the questions we asked each other was "if you walked into the room with one or the other playing, could you identify it?". The concensus was a unanimous "no". Yet, with the very cool switchgear that w1jim fabricated for this test, it was possible to hear some slight differences.

I came away impressed not only with Jim's skill at electronics, but also with the overall sound of the Pioneer and Polks. The addition of the ribbon tweeter was about 10000x the difference of those caps !

It was great to meet you Jim and share in your experiment! This is what makes these gatherings so much fun - the people and their enthusiasm for this hobby...


jblnut

w1jim
02-22-2011, 01:13 PM
Thanks for the kind words jblnut. Did you listen before or after the red hot dogs?

Incidentally, I traded the stock SX-850 for a nice SX-9930 (aka blackfaced SX-939) which I just recapped and updated. This is documented in the Pioneer forum. Anyway, this particular test won't be repeated with those two.

Now I'm thinking what to do next - stock vs recapped SX-1250 or recapped SX-850 vs recapped SX-1250. Or???

vuntruong
02-22-2011, 01:32 PM
U guys are crazy! In a Good Way. I think recapping will make an audible difference. Now, for better or worst? What is better? Cleaner? faster? Wider soundstage? I think the best way to do that is to replace all the aluminium electro caps with film caps. Really expensive, but u can prob hear the diff. better? Worst? Hmm. I really dont know, But i bet ya it will sound diff.

w1jim
02-22-2011, 01:35 PM
Crazy? That ship has sailed as we say.

Happy for you to contribute a receiver for the comparison - I'll even pick you up at the Worcester, MA airport.

How about comparing a Sansui G9000db to a Pioneer SX-1250?
I could l do recapped or stock of each (though I'd have to recap my Sansui).

jblnut
02-25-2011, 06:19 PM
Thanks for the kind words jblnut. Did you listen before or after the red hot dogs?

Incidentally, I traded the stock SX-850 for a nice SX-9930 (aka blackfaced SX-939) which I just recapped and updated. This is documented in the Pioneer forum. Anyway, this particular test won't be repeated with those two.

Now I'm thinking what to do next - stock vs recapped SX-1250 or recapped SX-850 vs recapped SX-1250. Or???

I think before, and I'm hoping that 's not a reference to something else (usually green) in which case I missed out!

Sign me up for the stock vs recapped 1250 session :D

Jblnut

danish guy
02-26-2011, 04:21 PM
Interesting read this! Thanks for that :yes:

patfont
05-23-2011, 09:03 PM
Does recapping result in an audible difference?

I have a Pioneer SX-850 receiver that I've fully recapped with Nichicon electrolytics (excepting the 2 large PS caps) and all of the 1uf and below electrolytics have been replaced with poly film caps. All tantalums have been replaced with electrolytics as well.
I was recently given a very nice SX-850 that had a blown fuse. I've recapped the power regulator PCB but left everything else original.

The question is can we discern a sonic difference between the recapped and non-recapped receivers?

I'm going to do a shoot-out on February 12th at our New England Winter get-together. (http://www.audiokarma.org/forums/showthread.php?t=343338&referrerid=41196) Everyone is invited.

I'm very interested to see if we can determine if there is a sonic upside to my OCCRD (Obsessive Compulsive Capacitor Replacement Disorder).
JimB


http://www.audiokarma.org/forums/attachment.php?attachmentid=249140&stc=1&d=1294591408

Sorry to dredge up this old thread but.............I recapped my Marantz 2220B 1 board at a time and listened after each board was done, you had recapped the P/S board (on the stock unit) and to me sonically that made the biggest difference for me. I now have 2 Marantz 2220B's one untouched and one recapped I am going to do a review when I get a chance.

w1jim
05-23-2011, 10:20 PM
Sorry to dredge up this old thread but.............I recapped my Marantz 2220B 1 board at a time and listened after each board was done, you had recapped the P/S board (on the stock unit) and to me sonically that made the biggest difference for me. I now have 2 Marantz 2220B's one untouched and one recapped I am going to do a review when I get a chance.
Dredge away!
The uncapped receiver had a bad power supply - so I had to redo that board.
Since both PS boards were done the only other variable was all the other "audio" boards. That would be the variation that we were comparing.

If you noticed the biggest improvement after redoing the PS PCB then I would think the original was in particularly sad shape.
Also, you should keep in mind that it is difficult (at best) to remember what something sounds like without a reference point that is readily available.

It would be interesting to hear of your results when comparing the 2 Marantz's. It's important that the volume levels are audible identical (not just the knobs in the same position) - the louder one will sound better.

js1138
05-24-2011, 08:31 AM
I find this interesting, and possibly relevant to this thread. It's not entirely about capacitors.

http://www.parasound.com/pdfs/JCinterview.pdf

rcspkramp
05-24-2011, 09:02 AM
I find this interesting, and possibly relevant to this thread. It's not entirely about capacitors.

http://www.parasound.com/pdfs/JCinterview.pdf

Great read. Thanks for posting this. Always admired JC. Way back when, I owned a JC-1 mc head amp.