Polk SRT sub amp capacitors

STLBlues

Hi all, I am going to replace the 10,000uf 80v capacitors in both of my Polk SRT sub amps. Polk used Su'scon 4-pin snap-in caps in these amps (4 in each amp) and I've narrowed my search down to 2 choices (there really isn't a lot to choose from in this configuration). I was going to go with either these Panasonics:

http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=200143903&uq=636020456029669893

Or these Cornell-Dubilier:

http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail&itemSeq=200148413&uq=636020456029669893

These are both good cap brands imo, but I would like to know which one other people would choose? I'm leaning to the Cornells because of their 105c rating at 3000 hours and these are made in the USA. The Panasonics have a 85c rating at 3000 hours and they have a great reputation as well. Thoughts, opinions?

Thanks!

F1nut

Mundorf, worth every penny.

http://www.partsconnexion.com/capacitor_ele_mundorf_ag+.html

FTGV

The Panny's or CDE,s will work fine.The 105c temp rating might be important depending upon actual heat build up within the chassis.

STLBlues

F1nut wrote: »

Mundorf, worth every penny.

http://www.partsconnexion.com/capacitor_ele_mundorf_ag+.html

Mundorf are great caps, I used them when rebuilding my Audio Research SP-3 power supply. But for 8 caps they cost more than I want to spend.

FTGV wrote: »

The Panny's or CDE,s will work fine.The 105c temp rating might be important depending upon actual heat build up within the chassis.

I don't know how hot it gets but the Su'scon caps are 105c, probably only to 1000 hours though. I'll probably go with the CDE, but still open to more suggestions.

Thanks fellas.

F1nut

Ok, if you can find some Kendeil's they are on par with Mundorf and not as much money.

zingo

I have only used 105C caps in past amps for longevity.

STLBlues

I bought some Cornell-Dubilier caps, but not the 105c 80V, I went with their 85c 100V caps instead. These are made in the USA as well. Forum member Gatecrasher who also owns the SRT system was kind enough to send me the schematic for the amps. There is a Potentiometer on each plate amp labeled R28 (why it's listed with an "R" I don't know, it's not a resistor) which I assume adjusts the DC balance or maybe idle current (I'm not an expert), but the schematic has no instructions listed for adjusting this.

I called Polk tech support to ask about this and was transferred to their Senior Tech and I left a voice message but never heard back. I e-mailed them later and again I never heard back. Ever since Ken Swauger retired, who was always so helpful, I haven't experienced good customer service from others at Polk's tech support. If anyone knows about this Potentiometer, please let me know. I won't mess with it otherwise. Thanks again guys.

westmassguy

Try PM'ing Ken. Not to be a stickler, but a potentiometer is a resistor, variable, but still a resistor.

STLBlues

Well that does make sense that it is a type of resistor, thanks. I will try to get in touch with Ken.

heiney9

Is there something wrong with the offset of the amp that you feel the need to twist those pots?

Schematics don't provide step by step instructions. One already needs to know what to do when reading the schematics.

Swapping caps is fairly straight forward, tweaking unknown potentiometers is a recipe for headaches.

H9

STLBlues

I didn't think there would be instructions for this pot I just hoped there would be. I certainly won't touch it unless I know exactly what the setting should be while using my Fluke meter. I had asked Polk if they had a service manual or could tell me more about it. I know it's not necessary to make an adjustment after recapping but I'd still prefer to find out more about it.