Pioneer sx-1080 - advise on re-cap.

ultrasparc

Active Member
Hi

I would like to ask a few generel questions regarding my upcoming re-cap of my dear sx-1080, and please forgive if they have been answered in other threads - I haven't seen them the places I have looked.

I have had it worked on a couple of times before. About 10 years ago it needed new main (22000uf) capacitors, plus some other components was burnt on the power supply assemply. Then about two years ago it needed some more repair (one lead-print on the board had broken loose at soldering point and was disconned, causing serious scratching).

During the past year I find that the sound quality has degraded, to the point where my CD-player in my car sounds better. More specifically there is total lack of treble, bass is OK, and I am hoping to regain the fantastic sound this unit has proven to provide.

I plan to renew the caps on the Tone Control Assembly.

Before I start I'd like to ask if anyone will share their opinion on this:

1) Having taking it apart, is it worthwhile to do a complete renewal of ALL component (resistors, caps, transistors) on the Tone Control Assembly board?
Same question for all boards? Some boards?​

2) What is the best way to deal with the fact that boards are interconected by wires that are wrapped? I find it rather difficult to work on the boards, while they are connected. I don't have the wrap/unwraping tool, so the only alternative I see is to cut the wires and re-connect them by soldering. What is the right tinhg to do?​

I am not deterred by taking it apart, if I have a safe way to connect the board-wires back.

Also I comtemplate to overhaul the tuner (left channel is weaker than right), but from what I have read here and there, it isn't trivial to do?

Best regards
Ole
 
There's no reason to disconnect any wires and is absolutely not recommended to fool with the wire wraps. Pioneer left enough slack in the wires that you should be able to work on every board in the unit once they're lifted from the risers or loosened from the front panel. You may have to get creative about how to situate the unit, horizontal/vertical etc., but it can be done.

You will get differing opinions about whether or not to recap the tuner section since there are proprietary chips on this board. You may need to do so if there is a weak channel issue you are having. Recapping the rest of the unit is the preferred method. I would recommend replacing also transistors and diodes on the power supply which runs hot in this unit. Other replacements might be a good idea on the protection board as well depending on how the unit behaves. It's also a good idea to apply new thermal compound to any transistor having a heatsink.

Ask for further specific help when the time comes regarding these things.
 
There's no reason to disconnect any wires and is absolutely not recommended to fool with the wire wraps. Pioneer left enough slack in the wires that you should be able to work on every board in the unit once they're lifted from the risers or loosened from the front panel. You may have to get creative about how to situate the unit, horizontal/vertical etc., but it can be done.

Thanks, that was my basic conception, that these wrapped wire should be left, but from previous experience I know that it requires - as you say - some creativity to get the boards in a position that is nice to work with. I'll take your advise as my guideline.

You will get differing opinions about whether or not to recap the tuner section since there are proprietary chips on this board. You may need to do so if there is a weak channel issue you are having.

I was thinking only replacing standard/"off the shelf" components, since I assume they must be as tired as all the rest, and that I may get an overall improvement on the FM part, by doing that. I haven't considered fiddling with proprietary chips - I don't think I could find them in denmark at all, anyway.

Recapping the rest of the unit is the preferred method. I would recommend replacing also transistors and diodes on the power supply which runs hot in this unit.

Right, that was the answer I kind'a was hoping for - might as well do a complete overhaul and hopefully have working unit for a few more years :music:

Other replacements might be a good idea on the protection board as well depending on how the unit behaves. It's also a good idea to apply new thermal compound to any transistor having a heatsink.

The protection board was what broke the first time, ten years ago, and then I exchanged the heatsinks with a homemade model I did from some other PC cooling, and then also applied new compund.
But I might as well renew everything now that I decided to go ahead with the business.


Ask for further specific help when the time comes regarding these things.

But, just for clarification: Should I only replace capacitors, and, if any obviously damaged, resistors/transistors?
 
Hi omri

Hi Ole
Replace all electrolytic caps .
No need to change any resistors if unit works and It's not fried anywhere.
If you want to go further , replace transistors .
Here you have the re-cap list

Thanks, that does make the work quite a lot easier


Thanks for the link - I have all ready noticed it when I searched AK. Impressive effort some folks put in to this site, for guys like me benefit from.

/ole
 
My first version of a caps parts list.

Hi

After having read through a number of posts mainly here and on Tapeheads, I finally feel somewhat comfortble with the capacitor partslist below here.

I must admit I was tempted to use MUSE caps, but in some posts I have read, that they don't improve the sound, so I decided to stick with what people have tried, and what is known to work.

However I'm not certain that I can be fully confident in my conception of what exactly designates as capacitors in the "signal path" or "power path" but I am assuming these to be "power boards":

AWH-071 Power Amplifier Assembly
AWR-152 Power Supply Asembly
AWM-120 Protection and Surge Killer Assembly


and these to be "signal boards":

AWE-092 Tuner Assembly
GWS-125 Function and Equalizer Assembly
GWG-112 Flat Ampifier Assembly
AWG-056 Tone Control Assembly
AWT-001 Filter Assembly
GWS-124 Speaker Selector Assembly
Miscellaneous



Based on this assumption I have come up with this parts list: (attached as an Excel- and a text-file.)
Since spaces in the text in the post are gobbled up, columns don't show, a txt-file is atatched for easier reading.


Pioneer SX-1080 Capacitor Requirements
AWE-092 Tuner Assy
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
AWE-092 C27 0.1 35 CSZA Cornell Dub 598-DSF050J 50
AWE-092 C28 0.47 50 CEA Cornell Dub 598-DSF050J474 50
AWE-092 C32 1 50 CEA Nichicon 647-UKL1H010KDDANA 50
AWE-092 C35 10 16 CSZA Nichicon 647-UKL1E100MDDANA 25
AWE-092 C36 220 16 CEA Nichicon 647-UKT1E221MPD 25
AWE-092 C37 1 50 CEA Nichicon 647-UKL1H010KDDANA 50
AWE-092 C38 0.1 25 CSZA Cornell Dub 598-DSF050J 50
AWE-092 C39 10 16 CSZA Nichicon 647-UKL1E100MDDANA 25
AWE-092 C40 6.8 6 CSZA Nichicon 647-UKL1E6R8KDDANA 25
AWE-092 C42 3.3 16 CSZA WIMA 505-MKS23.3/50/10 50
AWE-092 C43 3.3 16 CSZA WIMA 505-MKS23.3/50/10 50
AWE-092 C44 0.56 35 CSZA Cornell Dub 598-DSF050J564 50
AWE-092 C45 0.56 35 CSZA Cornell Dub 598-DSF050J564 50
AWE-092 C46 47 10 CEA Nichicon 647-UKT1C470MDD 16
AWE-092 C47 47 10 CEA Nichicon 647-UKT1C470MDD 16
AWE-092 C49 10 16 CSZA Nichicon 647-UKL1E100MDDANA 25
AWE-092 C61 3.3 50 CEA Nichicon 647-UKT1H3R3MDD 50
AWE-092 C62 4.7 35 CEA Nichicon 647-UKT1H4R7MDD 50
AWE-092 C67 10 16 CEA Nichicon 647-UKT1E100MDD 25
AWE-092 C70 4.7 16 CSZA Nichicon 647-UKL1H4R7KDDANA 50
AWE-092 C73 10 16 CSZA Nichicon 647-UKL1E100MDDANA 25
AWE-092 C76 4.7 16 CSZA Nichicon 647-UKL1H4R7KDDANA 50
AWE-092 C78 220 16 CEA Nichicon 647-UKT1E221MPD 25
AWE-092 C79 33 16 CEA Nichicon 647-UKT1E330MDD 25
AWE-092 C81 100 16 CEA Nichicon 647-UKT1V101MED 35
AWE-092 C83 100 6 CEA Nichicon 647-UPM1A101MED 10*

AWG-056 Tone Control Assy
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
AWG-056 C01 4.7 25 CEANL WIMA 505-MKS2-4.7/50/10 50
AWG-056 C02 4.7 25 CEANL WIMA 505-MKS2-4.7/50/10 50
AWG-056 C03 4.7 25 CEANL WIMA 505-MKS2-4.7/50/10 50
AWG-056 C04 4.7 25 CEANL WIMA 505-MKS2-4.7/50/10 50
AWG-056 C17 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
AWG-056 C18 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
AWG-056 C19 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
AWG-056 C20 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
AWG-056 C21 100 10 CEA Nichicon 647-UKT1E101MED 25
AWG-056 C22 100 10 CEA Nichicon 647-UKT1E101MED 25
AWG-056 C23 47 35 CEA Nichicon 647-UKT1H470MED 50
AWG-056 C24 47 35 CEA Nichicon 647-UKT1H470MED 50
AWG-056 C25 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
AWG-056 C26 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50

AWH-071 Power Amplifier Assy
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
AWH-071 C01 2.2 25 CEANL Nichicon 647-UKL1H2R2KDDANA 50
AWH-071 C02 2.2 25 CEANL Nichicon 647-UKL1H2R2KDDANA 50
AWH-071 C11 0.22 25 CSSA Panasonic 667-ECQ-E2224KF 250

AWM-120 Protection and Surge Killer Assy
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
AWM-120 C01 220 35 CEA Nichicon 647-UBW1H221MPD 50
AWM-120 C02 100 16 CEA Nichicon 647-UPM1V101MPD 35
AWM-120 C03 10 16 CEA Nichicon 647-UKT1C100MDD 25
AWM-120 C04 47 16 CEA Nichicon 647-UPW1V470MED1TD 35
AWM-120 C05 47 16 CEA Nichicon 647-UPW1V470MED1TD 35
AWM-120 C06 1 80 CEA Nichicon 647-UPM2A010MDD 100

AWR-152 Power Supply Asembly
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
AWR-152 C11 220 100 CEA Nichicon 647-UPM2A221MHD6 100
AWR-152 C12 220 100 CEA Nichicon 647-UPM2A221MHD6 100
AWR-152 C13 220 35 CEA Nichicon 647-UBW1H221MPD 50
AWR-152 C15 220 80 CEA Nichicon 647-UPM2A221MHD6 100
AWR-152 C16 220 80 CEA Nichicon 647-UPM2A221MHD6 100
AWR-152 C17 47 16 CEA Nichicon 647-UPW1V470MED1TD 35
AWR-152 C18 47 16 CEA Nichicon 647-UPW1V470MED1TD 35
AWR-152 C19 4.7 50 CEA Nichicon 647-UPW1H4R7MDD 50
AWR-152 C20 4.7 50 CEA Nichicon 647-UPW1H4R7MDD 50
AWR-152 C23 2200 35 ACH-060 Nichicon 647-UPM1H222MHD 50
AWR-152 C24 47 25 CEA Nichicon 647-UPW1V470MED1TD 35
AWR-152 C25 47 25 CEA Nichicon 647-UPW1V470MED1TD 35

AWT-001 Filter Assy
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
AWT-001 C01 0.47 35 CSZA Cornell Dub 598-DSF050J474 50
AWT-001 C02 0.47 35 CSZA Cornell Dub 598-DSF050J474 50

GWG-112 Flat Ampifier Assy
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
GWG-112 C03 0.1 35 CSZA Cornell Dub 598-DSF050J 50
GWG-112 C04 0.1 35 CSZA Cornell Dub 598-DSF050J 50
GWG-112 C05 1 25 CSZA Nichicon 647-UKL1H010KDDANA 50
GWG-112 C06 1 25 CSZA Nichicon 647-UKL1H010KDDANA 50
GWG-112 C13 100 10 CEANL Nichicon 647-UKL1E101KPDANA 25
GWG-112 C14 100 10 CEANL Nichicon 647-UKL1E101KPDANA 25
GWG-112 C15 100 10 CEANL Nichicon 647-UKL1E101KPDANA 25
GWG-112 C16 100 10 CEANL Nichicon 647-UKL1E101KPDANA 25
GWG-112 C17 100 25 CEA Nichicon 647-UKT1V101MED 35
GWG-112 C18 100 25 CEA Nichicon 647-UKT1V101MED 35
GWG-112 C19 4.7 25 CEANL WIMA 505-MKS2-4.7/50/10 50
GWG-112 C20 4.7 25 CEANL WIMA 505-MKS2-4.7/50/10 50

GWS-124 Speaker Selector Assy
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
GWS-124 C01 4.7 6 CSZA Nichicon 647-UKL1H4R7KDDANA 50
GWS-124 C02 33 10 CEA Nichicon 647-UKT1E330MDD 25
GWS-124 C03 4.7 6 CSZA Nichicon 647-UKL1H4R7KDDANA 50
GWS-124 C04 33 10 CEA Nichicon 647-UKT1E330MDD 25
GWS-124 C05 100 6 CEA Nichicon 647-UPM1A101MED 10*

GWS-125 Function and Equalizer Assy
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
GWS-125 C03 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
GWS-125 C04 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
GWS-125 C09 470 6 CEA Nichicon 647-UKT1C471MPD 16
GWS-125 C10 470 6 CEA Nichicon 647-UKT1C471MPD 16
GWS-125 C11 100 25 CEA Nichicon 647-UKT1V101MED 35
GWS-125 C12 100 25 CEA Nichicon 647-UKT1V101MED 35
GWS-125 C17 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
GWS-125 C18 2.2 50 CEANL Nichicon 647-UKL1H2R2KDDANA 50
GWS-125 C19 220 6.3 CEA Nichicon 647-UKT1E221MPD 25
GWS-125 C22 10 16 CEA Nichicon 647-UKT1C100MDD 25

Miscellaneous
Assy Symbol uF Volts Prefix Manufacturer Mauser# New Volts
CEA010P80 C09 1 80 CEA Nichicon 647-UPM2A010MDD 100



Perhaps the two 647-UPM1A101MED* should be 647-UKT1A101MDD ?

I'm hoping someone more experienced than I will take the time to skim through it, and hopefully catch any significant errors. I'm begiing to feel the urge to move forward with project but on the other hand I'd like be make sure I do not goof up too badly, by stating with the wrong components :nono:

Mean while I have been able to dis- AND re-assemble one of the push-button on the seelctor board and the tone selector toggle switch, for cleaning. I hope the cleaning also will contribute to less crackling system.

Thanks
 

Attachments

  • Cap list assembly ordered.txt
    5.9 KB · Views: 44
Too bad - I can't upload the *.xlsx file:

Pioneer SX-1080 Cap list.xlsx:
Invalid File
 
Last edited:
I have a recent SX-1080 restoration thread you can compare your parts list to that may help. The parts list shows the original specified part from the same thread you were linked and if those were unavailable I listed the part I actually ordered in parentheses (). The list also includes diode and transistors which aren't necessarily in need of replacement outside of the power supply, where I would recommend them be replaced wholeheartedly.
 
zip up an .xls file and upload the zip

BTDT...

Right, You are, Mark, thanks :)

BTW, I will take (yet) another look at list you posted to hopjohn's project.
And, I'd like to acknowledge all your contributions to the community as well - I have read many of them and leaned a lot:thmbsp:

/Ole
 

Attachments

  • Pioneer SX-1080 Capacitor Requirements ordered list BOM.zip
    52.4 KB · Views: 41
I have a recent SX-1080 restoration thread you can compare your parts list to that may help. The parts list shows the original specified part from the same thread you were linked and if those were unavailable I listed the part I actually ordered in parentheses (). The list also includes diode and transistors which aren't necessarily in need of replacement outside of the power supply, where I would recommend them be replaced wholeheartedly.

I did take more than one look at your project (VERY usefull post :thmbsp:), actually I have copied more than one of choices (WIMA).

They way you managed to fix the 3 dial lamps are just so smart! I also wanted to cut the wires to the dial and function lamps, but unfortunately mouser don't seem to carry the JST-plugs you used. I'll have ge some elsewhere, but it would be nice to place the order with only one supplier.

I will also follow your advice and replace trans on the power supplys, and I take a few more looks, and grab the items for for my order.

On the power amp. assy board (AWH-071) I did take measures for DC offset and bias, but only from the right ch. It seems to be very difficult, due to the very limited space between the main caps and the board (AWH-071) to get to the leads/pins on the left ch without shorting something, but I suppose it can be done with the proper insulated probes.

One other thing about your restoration w. regard to the power supply (AWR-152). That board was repaired in my unit about 10 years ago, where it was fried pretty bad. I also replaced the two transistors (Q1,Q4) and heatsinks. To get better cooling I wanted to replace them with bigger ones. I took a PC CPU-heatsink and modified it to fit. They are screwed tightly on to the trans. However this fix caused another failure last year.

What happened was, that because their weight was carried by the 3 pins of the trans (not resting on the board), over time, one of the pins pulled a small piece of the print-lead off the board, which obviously caused some problems :tears: . I managed to fix it, by placing a piece of wire between the broken lead-print and the corresponding pin at the connecting end of the print-lead (I forget wich one). All this only because it looks like the black heatsinks on your photo are also carried by the pins, and aren't resting on the board, just like on mine. Mine are bigger and heavier than yours (heatsinks, of course ;) ), so hopefully it won't happen with yours, but I wanted to draw your attention to a potential future problem.

BTW: Do you find that your 1080 sounds significantly better after restoration?

/Ole
 
zip up an .xls file and upload the zip

BTDT...

Mark, If can ask your opinion (I know you are busy) on this comment:
http://www.tapeheads.net/showpost.php?p=400486&postcount=15 in particular the first part:
Hi Ole,
If the lack of frequency response of a product is noticed, I have to say that electrolytic caps aging may not be the problem. As the caps decay and shrink in size they then lose their ability to handle the lower frequencies first. If a coupling cap in line with the Hi end EQ opened then certainly that would cause a loss of high end or clarity at that point. If the high end problem was to be determined directly I would sweep the unit form 30 Hz to 20KHz and see where the signal diminished and then look into that.

Since I'm not able to follow the suggestion to do at freq sweep and such, I only try my best shot ie. do a re-cap.

I must admit that I am only hoping that a re-cap will bring back the missing mid and high tones, but from reading hopjohns project I have pretty much decided to replace all the transistors while I'm at it.
Does it make any sense to ask if replacing all of the caps and trannys will have a high probability to fix the sound issue?

I'm not an electronics technician/engineer, just a guy that has some general fixing skills :rolleyes:
 
They way you managed to fix the 3 dial lamps are just so smart! I also wanted to cut the wires to the dial and function lamps, but unfortunately mouser don't seem to carry the JST-plugs you used. I'll have ge some elsewhere, but it would be nice to place the order with only one supplier.

I couldn't find anything at mouser that I liked either. Get them here.

On the power amp. assy board (AWH-071) I did take measures for DC offset and bias, but only from the right ch. It seems to be very difficult, due to the very limited space between the main caps and the board (AWH-071) to get to the leads/pins on the left ch without shorting something, but I suppose it can be done with the proper insulated probes.

Invest in some mini grabbers. It's too risky to use anything else here.

Mine are bigger and heavier than yours (heatsinks, of course ;) ), so hopefully it won't happen with yours, but I wanted to draw your attention to a potential future problem.

I wanted to free up some "breathing" space between the part and the board for better ventilation. The heatsinks I used are very light, but I'll keep that in mind.

BTW: Do you find that your 1080 sounds significantly better after restoration?

/Ole

Yes it does. The sound seemed veiled before, bass garbled. It just opens everything up, more clarity and definition.
 
I couldn't find anything at mouser that I liked either. Get them here.
Thanks, allready ordered them :thmbsp:
Invest in some mini grabbers. It's too risky to use anything else here.
Yes. and a screwdriver with a well insulated blade

I wanted to free up some "breathing" space between the part and the board for better ventilation. The heatsinks I used are very light, but I'll keep that in mind.
I suppose you don't have to worry, then. :thmbsp:

Yes it does. The sound seemed veiled before, bass garbled. It just opens everything up, more clarity and definition.

Oh, great , that's good motivation, now I only hope replacement actually will bring mine back in shape, too.
 
What now ?

What is the right choice here:

The C11,C12 caps on the are listed everywhere to be 220µF 100V.
The two at the board are 100µF 100V :yikes:

https://drive.google.com/file/d/0B-K7vfu8iewrYWRMc2JVc05vNjhFUHRsWS1xMm8xRFVTLTM4/edit?usp=sharing

I've read that when what you pull off differs from what is in the SM, replace with what you pulled.

However in this case, the board was repaired 10 years ago, but I do not remember if these (C11,C12) was replaced then.
So either the 100µF 100V has been there from start, or I replaced caps with the wrong value.

I am most inclined to believe that the 100µF 100V was not replaced because:
  1. I'm pretty sure I would have noticed the value and replaced correctly, with a 220µF 100V
  2. There is residue of what looks like glue (to stabilize?) on the board and the cap, and I don't recall apllying glue, then.
  3. The area where C11,C12,C15 and C16 are located was not fried then, thus I would not be inclined to replace them.

So if I am correct, the receiver was born with 100µF 100V and according to consensus I should replace with same value, but I am very much in doubt if I should replace with 220µF 100V.

What should I do?
 
Last edited:
What should I do?

True, in most cases you would use the same values that you pull . For reasons, mainly fit, and the fact that you often can go up a step in capacitance in the power supply with no harm, I use 220uf in place of them. You should be fine with 220uf/100v. The glue is factory applied so I doubt those were ever replaced. Especially if you don't recall adding any glue yourself. Your image links aren't working so I can't see them..doesnt matter just replace them. Even if they are only 10 years on they are reaching the end of their life cycle anyway.

I try and remove the glue once I take the caps out. Some glue can be corrosive over time, so I take no chances with any of it. Scrape it out with something like a popcicle stick, blunt end of a plastic tooth brush or whatever non metal object you have lying around that can be used as a scraper. It also helps the new caps sit in nicely.
 
Bipolar

Well, I discovered another discrepancy last night.

Power amp assy, C1,C2:
No cap in C1 and in C2 there was an Elna ce-bp 1µF 50V. On the board there is what looks like a double '+' on the negative position of C2 (closest to the edge).

I guess this must be a bipolar cap, that I can replace with 647-UEP2A010MDD (bipolar 1µF 100V , 105 C)
 
Order placed (finally)

Phew - finally completed the order and placed it at mouser. Had to change a few components from what was on hopjohns because some items was out of stock, but I trust I haven't made any errors finding siutable replacements.

BTW I figured the project will take a while, so in order to have a decent sound quality, I picked up a Sansui 6060 yesterday - I believe it's from -74, but no scratching, plays beautifully:music:
 
Two boards done

Done with Power supply and tuner boards.

On the tuner there was yet another error since the C67 (10µF,16V) was completely missing, with no trace of having ever been mounted.
I did mount the missing cap, wondering a little how the tuner have been able to work without it :confused:

2c59d4ee-0e2f-44f8-a7aa-20aeae2975a2_zps830baad6.jpg



And I must have been sloppy since I discovered a broken Ceramic C26 (33p, 50V), right there in center:

Tuner-C26-broken-cap_zpsda70a455.jpg


If I'm lucky I can find one at work tomorrow. If I can only find something close to specs, what intervals will be acceptable?

Something like 10p - 0.5n/ 35V - 100V ?

If I can't find one I'm gonna leave it as is.

Long day - I'm turning in :boring:
 
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