Cap upgrades (bear with me)

Hey Adam - These guys are a good place to buy wire IMO. I have used their silver wire for everything. Their prices are reasonable (I guess thats relative).

http://www.homegrownaudio.com/
 
So.......there is good news, and there is bad news.

The good news is that I am almost certain that I know what the problem is.  :D

The other piece of good news is that it wasn't due to me having any bad solder joints.  ;D

The bad news is....I think one of my very expensive caps is broken.  :'(

When I desoldered the caps to allow me to remove the chassis from the frame, I noticed that one of the leads to one of the caps was, for lack of a better word, limp. The ClarityCaps have fairly stiff solid core copper leads, but one of them was limp. I think the solid core of the lead broke within the insulation sleeving, very, very, VERY close to the cap itself (although the insulation is still intact). This is a real problem. If it were further from the cap, I would just cut the lead where broken and solder a new fly lead to the remaining piece of good lead on the cap. But the break in the lead on the cap is so close to the cap, that I suspect there is hardly anything left for me to solder a new lead onto, and I'm worried that the heat from the solder iron would damage the cap even if I tried.

That basically means I have no option but to try and return the cap, but I have doubts that they will accept a return where the tips of the leads show evidence of having been soldered. That probably means I spent $90 for a paperweight.

Since the lead is still in the insulation, which itself is intact, I think that when I turned the Crack over, the broken lead moved a bit within the insulation. Just enough to make contact. But when I turned it over and started playing music, after 10-20 minutes, the lead or cap would settle just enough to lose contact again.  The cap would slowly discharge, which would explain why the sound would gradually fade out, rather than being a sharp break. Every time I turned the Crack over to try and diagnose the problem, the lead and/or cap would shift again, just enough to make contact. Then the cycle would start again: I turn on the amp, listen to music in both channels, but then the lead/cap settles in and contact is lost again. Etc., etc.

Grrrrrrrr.....I really hope Madisound stands behind their goods and sends me a replacement....
 
You can't know that the cap is bad till you have it in the circuit.  You might have a chance with a return.

THHN, IIRC, has thicker strands than SJO.  The smaller the strand the more flexible the wire.  At Alcoa and K-C we ran multi-conductor cables of THHN.  So it pulls well and terminates easily in an industrial situation.  As Paul points out larger stranded wire is a booger to get into a small terminal strip hole.
 
I broke off a lead like that on one of my big caps. I guess I bent the wire too many times. I think the copper leads are very fragile that way. That explains your symptoms. Bummer!
 
BIG props to Madisound! I just called them and they agreed to send me a new cap without any hassle whatsoever. Nice to get good service like that. The guy I spoke to (also named Adam) was very friendly.

I think the lead must have been damaged/weakened in transit. It was EXTREMELY cold last week, and I suspect that the leads became brittle, then got jostled enough in transit to create a problem.

Anyway, I can't wait to get the new cap and finally be able to enjoy the Crack again. I took the opportunity to also order a 2.2uf ESA ClarityCap, so I can bypass the last transformer cap, too.

Thanks to everyone who has been patiently helping me diagnose this problem!

Best,
Adam
 
Adam,

Yes, I've never had anything but first rate service from Madisound.  Also, congrats on nailing down the problem -- that was some nice detective work there!

-- Jim
 
crackcap2_zps52e6d5b7.jpg


This is how I mounted my caps the top plate. I used a glued a PVC end cap to a wire tie holder. As you can see from the picture I drilled a hole in the PVC end cap so that I could use a wire to secure the cap. In the past a I had a big motor run cap with a Russian Teflon bypass cap on this holder.

This way the caps clear everything and I can still get under the hood.
 
Just a quick update: I installed the new ClarityCap ESA 100 uf output cap I got from Madisound. I took the opportunity to also order an ESA 2.2 uf cap to bypass the last cap on the power supply. Installing that one was...um...not fun (its getting #%^
 
When I OD on my stereo it usually means passing out only to be jerked awake at 4:00AM by a particularly dynamic passage.
 
I know the feeling! Its always a bit mind boggling to me how other male creatures of my generation do not at all get this addiction. My 'seestum' and I are in a zone right now. We are in a discovery mode. No desire to 'upgrade'. A very nice zen if you will.
 
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