Harman Kardon Citation 17 Upgrades

[AmCan]

Actually it's just outside 2%, but within 2.5%. Maybe I am a purist, after all. This preamp's designer clearly thought that tiny 2% difference was important enough to have a non-standard value of capacitor manufactured especially for this application, despite the extra cost. I rest my case.

That's why it is one of the best preamps ever made, less then .001THD.
However, both Bob and I agree that the phono stage sounded poor (choked is how I would describe it) and now mine doesn't. :yes: I am pinning it on those designer poly caps or whatever poor quality part was used. I can't wait to see what Bob's impressions are of the capacitor upgrades. If at least we will have a confirmation on the quality of the part selected.:thmbsp:

I have put so many quality parts in this pre who knows how it measures anymore but it sure sounds good to me. Anytime you are in Toronto Mike please come over for a listen to see how much your ears are offended. :smshot:

 

[BinaryMike]

Thanks for the invitation, but I have an absolute personal rule: I don't engage in critical listening tests until I first confirm by measurement that the equipment is free from gross technical defects. It prevents a lot of wasted effort and disappointing dead-ends in circuit development.

If I felt compelled to hack on this preamp, I would strongly consider replacing the discrete devices with a high-performance audio op-amp (socketed), and perhaps switching to a split-gain setup of some sort. Power supply voltage would have to be reduced a bit, which will cost some headroom (~2.5dB) unless gain is reduced proportionately. HypnoToad, here on AK, has a lengthy thread on one design that has been very well accepted. It was derived almost directly from a National Semiconductor app note or datasheet on one of their newer audio op-amp chips, and probably has excellent RIAA accuracy. You might easily try out this design as an external attachment, to keep all of your options open. It's especially simple if you go with battery power.

If you find that hijacking RIAA equalization is the only thing that yields satisfactory results, then you should consider measuring the original factory EQ to see if it's truly incorrect. Simulation didn't reveal a major problem, but simulation does have its limits, and the existential hardware might not match the schematic.

 

[BinaryMike]

The thread I mentioned is here: http://www.audiokarma.org/forums/showthread.php?t=371889

It was started by Fasterdamnit, but HypnoToad designed a compatible PCB.

 

[bobrown14]

The thread I mentioned is here: http://www.audiokarma.org/forums/showthread.php?t=371889

It was started by Fasterdamnit, but HypnoToad designed a compatible PCB.

I'm pretty familiar with the 17. My phono stage after re-cap and all new metal film resistors (I left in those red poly caps) sounded dull compared to the CNC. I then built my ESP P06 pre and it sounds better by a little than the CNC but walks all over the 17 phono stage. I did replace the 17 phono stage with all stock sized replacement parts, no messing with the design. I will have to see what those relcaps sound like but again I will not be changing any stock sizes cept for the 2350 to 2400pF sized cap which is well within the margin for error. Parts are on thier way. We will see if that makes a difference but I really have my doubts. I left in all those old transistors (about 24 of them). Me bets they won't sound as good as say AD823's which I'm running in my ESP phono board.

Cheers,
Bob

 

[BinaryMike]

I will not be changing any stock sizes cept for the 2350 to 2400pF sized cap which is well within the margin for error.

I ran the simulation again with just that 50pF change in isolation, because it's easy to investigate small differences after the chore of initial setup is completed. I couldn't predict the audibility of this change, but you could certainly eliminate it by using 2200pF and 150pF in parallel.

 

[AmCan]

Good News Mike! I have found a place to put those .01uF on the EQ boards, which I haven't done yet so I am going to switch them out off the preamp board for the correct value just to make you happy. You can sleep easy tonight knowing that there will be a little more order in the Hi-Fi World.

2400pF is .021% more than 2350, which is within tolerance. The REL RTEs also have a +/- 2%, so if you really wanted to be anal about it you could have Parts Connexion measure them for you for a dollar ea. I am not going to change the 2400pF though unless Mike wants to send me the money for the 2 x 2 caps I would need to parallel. Then I will do it to make Mike happy.:yes: (They have to be RELs too) Whataya say Mike?

 

[bobrown14]

Good News Mike! I have found a place to put those .01uF on the EQ boards, which I haven't done yet so I am going to switch them out off the preamp board for the correct value just to make you happy. You can sleep easy tonight knowing that there will be a little more order in the Hi-Fi World.

2400pF is .021% more than 2350, which is within tolerance. The REL RTEs also have a +/- 2%, so if you really wanted to be anal about it you could have Parts Connexion measure them for you for a dollar ea. I am not going to change the 2400pF though unless Mike wants to send me the money for the 2 x 2 caps I would need to parallel. Then I will do it to make Mike happy.:yes: (They have to be RELs too) Whataya say Mike?

Do you have an older brother?

Cheers,
Bob

 

[BinaryMike]

I am not going to change the 2400pF though unless Mike wants to send me the money for the 2 x 2 caps I would need to parallel. Then I will do it to make Mike happy.:yes: (They have to be RELs too) Whataya say Mike?

Well, I was going to offer to hand-select some caps for you, but I just discovered that my trusty old ESI 296 has bit the dust. Okay if I send you a bill for professional services, so I can go shopping for a new LCR bridge?

Cheers,
Mike

 

[AmCan]

Do you have an older brother?

Cheers,
Bob

YES

 

[AmCan]

Well, I was going to offer to hand-select some caps for you, but I just discovered that my trusty old ESI 296 has bit the dust. Okay if I send you a bill for professional services, so I can go shopping for a new LCR bridge?

Cheers,
Mike

The check is already in the mail. Keep a look out for it things usually get lost between here an Canada. LOL

Sorry to hear your ESI 296 broke down that bites.

 

[TerryS]

Good News Mike! I have found a place to put those .01uF on the EQ boards, which I haven't done yet so I am going to switch them out off the preamp board for the correct value just to make you happy. You can sleep easy tonight knowing that there will be a little more order in the Hi-Fi World.

2400pF is .021% more than 2350, which is within tolerance. The REL RTEs also have a +/- 2%, so if you really wanted to be anal about it you could have Parts Connexion measure them for you for a dollar ea. I am not going to change the 2400pF though unless Mike wants to send me the money for the 2 x 2 caps I would need to parallel. Then I will do it to make Mike happy.:yes: (They have to be RELs too) Whataya say Mike?

2400pF is 2.1% more than 2350...

 

[AmCan]

2400pF is 2.1% more than 2350...

Yes, I forgot to move the decimal point. Now you know the quality of my math skills, which is why I could never make it into med school or engineering. Mark Twain Once said "Be careful of what you read in health books, you may die of a misprint."

 

[AmCan]

Power Board Upgrade

Having had such great success adding the Mundorfs to the power board I came across this Black Gate for a $5 so I though it would make a great addition to the power board. This 330uF 50V replaces a 220uf 16V Elna. It is amazing to me to see how this Black Gate towers over the Elna for just an extra 100uF. This was another great upgrade with and made an instant improvement on resolution. Everything was brought more forward and made clearer. Again I used a custom made silicone pad under the Black Gate to support it since the cap is a little over sized for the space.

 

[AmCan]

Hi/Low Cut Board

Can one of you HK experts tell me what kind of effect the HI/Low Cut Subsonic Filter Board will have on the overall sound in general? Is this the equivalent of the input board? Is this a coupling board, meaning does the audio signal go through this board regardless of engaging the filters. Is it linked to the input selector knob? I am curious because I bought a Citation 11 that was upgraded by a real reputable tech here in Toronto and he paid a fair bit of attention to the "Input Board" on the 11. Its the only place where he changed the film caps, even leaving the Mylars on the output board. I am going to post on that separately but was curious if I should pay more attention to this board. I did replace the lytics and thought that the noise floor dropped when I did it. Perhaps I should upgrade the films on this?

 

[bobrown14]

Can one of you HK experts tell me what kind of effect the HI/Low Cut Subsonic Filter Board will have on the overall sound in general? Is this the equivalent of the input board? Is this a coupling board, meaning does the audio signal go through this board regardless of engaging the filters. Is it linked to the input selector knob? I am curious because I bought a Citation 11 that was upgraded by a real reputable tech here in Toronto and he paid a fair bit of attention to the "Input Board" on the 11. Its the only place where he changed the film caps, even leaving the Mylars on the output board. I am going to post on that separately but was curious if I should pay more attention to this board. I did replace the lytics and thought that the noise floor dropped when I did it. Perhaps I should upgrade the films on this?

Here's the block diagram for the Citation 17 Hi/Low filter board. If you follow the input from the EQ board to the on/off switch, you can see the signal will bypass the board when not engaged.. I've not looked at the block diagram for the Citation 11 enough to make any conclusions.

Follow the line going into S8 (L/R) (switch), not engaged the signal path goes thru to VR1 and on out to the output amp. That's the way I see it.

If it was me, I would replace all the caps on your board probably with the exception of the little green (mylar) ones. Of course you could replace the mylar but a better cap is pricey, diminshing returns takes hold there for me at least.

Cheers,

Bob

 

[AmCan]

Here's the block diagram for the Citation 17 Hi/Low filter board. If you follow the input from the EQ board to the on/off switch, you can see the signal will bypass the board when not engaged.. I've not looked at the block diagram for the Citation 11 enough to make any conclusions.

Follow the line going into S8 (L/R) (switch), not engaged the signal path goes thru to VR1 and on out to the output amp. That's the way I see it.

If it was me, I would replace all the caps on your board probably with the exception of the little green (mylar) ones. Of course you could replace the mylar but a better cap is pricey, diminshing returns takes hold there for me at least.

Cheers,

Bob

Thanks Bob! I see that now whereas before I wasn't sure what to even look at but this schematic makes a lot more sense to me now. I am going to take a look at the diagram for the 11 now and see why the tech put M Caps on that board.

Did you ever insert those REL caps on the phono board?

 

[bobrown14]

Thanks Bob! I see that now whereas before I wasn't sure what to even look at but this schematic makes a lot more sense to me now. I am going to take a look at the diagram for the 11 now and see why the tech put M Caps on that board.

Did you ever insert those REL caps on the phono board?

Funny you asked... I did just that last night hooked up the 17 and powered on the TT a few minutes ago... I'll put a LP on the platter and let ya know what's what. I also replaced all the ceramic disc caps on the EQ board that I missed as well and noticed right away a difference. I have one left on those boards (EQ), its a 47n470... on the schematic it's C29 and listed as not used. I for the life of me cant figure out what the 47n470 is equivalent to for a ceramic disc... anyone? I still have all the stock resistors in there (EQ board) and will replace them with all 1% MF next time I take the hood off.

So I'm about to test... stay tuned. I'll compare that mod to my DIY phono pre and see if it holds the mustard, I'm skeptical at best.

On your 11, where on the hi/lo board did he install the M caps?

Cheers,

Bob

 

[AmCan]

Funny you asked... I did just that last night hooked up the 17 and powered on the TT a few minutes ago... I'll put a LP on the platter and let ya know what's what. I also replaced all the ceramic disc caps on the EQ board that I missed as well and noticed right away a difference. I have one left on those boards (EQ), its a 47n470... on the schematic it's C29 and listed as not used. I for the life of me cant figure out what the 47n470 is equivalent to for a ceramic disc... anyone? I still have all the stock resistors in there (EQ board) and will replace them with all 1% MF next time I take the hood off.

So I'm about to test... stay tuned. I'll compare that mod to my DIY phono pre and see if it holds the mustard, I'm skeptical at best.

On your 11, where on the hi/lo board did he install the M caps?

Cheers,

Bob

On my schematic and circuit diagram I show C29 as 10uf 25V. Are you sure about the C#? I think you mean C28, which is 470pF. I replaced all of my ceramics with silver micas. Here is a color chart for the ceramic discs http://www.electronics-tutorials.ws/capacitor/cap_5.html.

On the Citation 11 he put 1uF 250V MKP on the Tone Control Board at C 516, C 518, C 522, C 524. If you always keep the circuit engaged I guess it would act like a "Input Section" as he called it on the invoice. Just like you were saying that you get a nice result from having your EQ engaged but leaving the sliders flat. I always thought that a high/low cut truncated a vinyl analog signal. I will have to go back and try the 11 with with the circuit engaged.

Thanks for telling me what you are going to use for the resistors. How does upgrading the resistors effect the perception of the sound? That is something I need to do too. Next time you have the board out take a pic and post it. What did you use for C,9,13, 14, 18, 19, 23, 24? I am thinking I might use the Multicaps there unless you have a better suggestion.

 

[bobrown14]

On my schematic and circuit diagram I show C29 as 10uf 25V. Are you sure about the C#? I think you mean C28, which is 470pF. I replaced all of my ceramics with silver micas. Here is a color chart for the ceramic discs http://www.electronics-tutorials.ws/capacitor/cap_5.html.

On the Citation 11 he put 1uF 250V MKP on the Tone Control Board at C 516, C 518, C 522, C 524. If you always keep the circuit engaged I guess it would act like a "Input Section" as he called it on the invoice. Just like you were saying that you get a nice result from having your EQ engaged but leaving the sliders flat. I always thought that a high/low cut truncated a vinyl analog signal. I will have to go back and try the 11 with with the circuit engaged.

Thanks for telling me what you are going to use for the resistors. How does upgrading the resistors effect the perception of the sound? That is something I need to do too. Next time you have the board out take a pic and post it. What did you use for C,9,13, 14, 18, 19, 23, 24? I am thinking I might use the Multicaps there unless you have a better suggestion.

Yes its C28 ... it's marked as not used on the scematic. I've looked at that link you sent before and it really didn't seem to me to answer my question about the markings on my disc cap. Well at least not real clear TO ME. I guess disregard the 47n and go with the 470 code? Or 47n and 470 both mean 47pF? or 47n=? and 470 is the voltage?

Testing the phono and I have a loud hum (TT ground wire connected) something amiss with the ground, probably at the RCA/ground connect... I'll have to take the lid back off, could be a loose ground somewhere on the case.

I'll take a look on those caps you asked about. I replaced them all but don't remember what I used for each. Some were lytics just replaced with audio grade and some were polly caps, not sure exactly what I used. I'll check again tonight when I get in there.

Cheers,
Bob

 

[AmCan]

Yes its C28 ... it's marked as not used on the scematic. I've looked at that link you sent before and it really didn't seem to me to answer my question about the markings on my disc cap. Well at least not real clear TO ME. I guess disregard the 47n and go with the 470 code? Or 47n and 470 both mean 47pF? or 47n=? and 470 is the voltage?

Testing the phono and I have a loud hum (TT ground wire connected) something amiss with the ground, probably at the RCA/ground connect... I'll have to take the lid back off, could be a loose ground somewhere on the case.

I'll take a look on those caps you asked about. I replaced them all but don't remember what I used for each. Some were lytics just replaced with audio grade and some were polly caps, not sure exactly what I used. I'll check again tonight when I get in there.


Cheers,
Bob

Check to see if your solder is overlapping 2 traces. It just happened to me last time.

I looked at the Service Manual again because the C28 not being used is some sort of circuit thing. My manual does not have a capacitor list so I had to constantly check between the schematic of the PCB layout and the circuit diagram. Ultimately I found the circuit diagram the easiest to read for correct values. C28 is not a designation on the board at all. I could not find it labeled there at all. I think you pulled the brown ceramic disc out from C26 slot, which on the circuit diagram is 15pF 500V.

I find the conversion on the 47n470 a little confusing too. Here is a better conversion chart, but still is n the same as nF? Anyway it is not on the board so don't worry about it but a 47nF converts to 4700pF and the voltage should be 470 (I assume)

http://www.justradios.com/uFnFpF.html