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Replacing Sherwood power supply caps with standard radial instead of Snap-In - Bad idea?

B

bccbass

New Member
Hi All,
First time poster, long time lurker. I believe the title says it all - I'm having some trouble with my Sherwood S7100 with a scratchy volume pot that is VERY loud on power up. I ordered new PSU caps, but foolishly ordered radial leads instead of snap-ins - the amplifier just has wires soldered directly on to the terminals. Is it foolish to use the radial leads? I've been googling and not been able to find anyone with a similar query.

Many thanks!!

-Ben
 
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No issue using a different lead style. The issue could be if the cap is the correct type for the application.
 
Thanks for the responses!

I'd actually took it apart last night and cleaned the infamous volume/on/off switch and the loud static pop is much better, now its just a little scratchiness in the left channel, which I can live with. I may forego recapping the PSU after reading the myriad pros/cons. The caps I ordered are Nichicon Fine Gold with the same spec as original - 2200uf 63v.

Perhaps I should have led with this, so might need to start a new thread- this whole project started because the right channel is not as brilliant and a bit muddier than the left. The problem is present using phono or aux. It is also like this through speakers and headphones. I've recapped the preamp and phono preamp with Nichicon FG and Elna Silnac II's with no luck. If anyone had any suspicions or guidance that would be quite helpful. Thanks!!
 
You have the caps might as well put em in. if you have questions about how to install them post pics. Need something to hold them in place with the wires attached to the leads. Everything starts with the power supply. Are the voltages the same for the L and R channel power?
 
I will check - would that be a dmm set to voltage on dual 2200uf caps?

Was scheming to use zip ties to secure caps to the board if I do it. :)

Also, even with being very careful, my volume knob/switch JUST bit the dust. I think I'll bite the bullet and purchase the replacement vs. fixing. Perhaps thats a culprit as well.
 
Update: I fixed the volume/On-off knob with a locking washer - worked great. It was very noisy when I turned it on, thought maybe there was some arcing due to dirty contacts in the switch mechanism. I took the switch apart, cleaned it and was struggling to get it put back together. In doing so I broke the retaining tab off the pot. I can't stress this enough - don't take the back section with the power switch off if you can avoid it. Ended up ordering a new one on eBay.

The good news: I Recapped the phono preamp, preamp and the main amp section and it sounds amazing. I used mostly Silmic ii's and Nichicon FG. I'm actually surprised at how much better it all sounds - it sounded good before but now there is so much more clarity and energy. Also I think I was not getting a whole lot of highs, and very muddy lows before. Now its very tight and sparkly. I can hear detail and separation much better: reverbs, brushes on snares and bass all sound lovely. Ironically after reading many opinions on AK I did not recap the power filter caps. Thanks for the previous guidance!
 
The small caps die first, so I suspect the filtering caps for the secondary power supplies (for the pre-amp and phono amp) were getting high resistance and impedance. Any coupling caps going bad (usually for the phono amp in my experience and the tone amp board) will muddy the sound quite a bit as the impedance and capacitance drift off spec.

Using one of those inexpensive component testers will often show the old ones to be just a little high in ESR and maybe high (or low) in capacitance, but in fact they are NOT in good shape due to drying electrolyte. The low voltage and signal in the cheap tester isn't the same as operating voltage and signal.
 
Most of the caps were at least %25 and up to %35 out of spec for capacitance. Everything else seems to be working great and there is only about 35mv DC at the speaker terminals so I opted to just leave the power filter caps as I read they can heavily impact the sound and are probably the last to die.
 
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