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RE: There are always solutions.

Posted by Ralph (M) on December 23, 2020 at 10:54:10

In Reply to: RE: There are always solutions. posted by airheadair on December 23, 2020 at 09:24:31:

Filter caps are the thing that limits the life of almost any electronic circuit that uses a power supply.

I can't speak for Roger's reasoning at the time so I'll put it this way:

Electrolytic capacitors have a sort of 'half life'. Depending on the application, usually after about 20-25 years, half of the filter caps installed are defective in some way. This idea falls apart after that, because by the time you hit 40 years its more than 75% of them have failed. Now if heat is involved, the caps fail sooner; this is why filter caps last a little longer in solid state equipment. The quality of the part makes a difference too, as well as the age of the part prior to installation.

I mention this last bit because Harvey Rosenburg told me that he was sourcing a lot of his filter capacitors from a surplus source for the NYAL amps. That source was (Bill) Godbout Electronics. These parts, if in your amps, were photoflash capacitors and not well suited for use in a tube amplifier (not good at ripple current), although they were very good at having a lot of capacitance for their size. Harvey also told me that he stripped the casing off of the part, since they were made in Japan (by Rubycon) and the Japanese didn't like to see Japanese parts in their amps at the time. By stripping the plastic case off, the parts looked American unless you looked closely. This part BTW is a 600uf 360WV capacitor, slightly over 1" in diameter and about 4" long. This is an unusual form factor and might be part of the reason Roger didn't want to mess with them.

Harvey also told me that the source dried up (I didn't tell him that I knew the person that bought out the remaining stock) so he had to find something else. The point here is that filter cap was used when it was installed. Its also possible that your amp does not have this part if it was made a bit later.

Roger was a great guy and very competent. But in his last years (and I don't know how long because he kept this under wraps) he was in pain dealing with cancer and this affected his mood and judgement.

So you might want to revisit this issue. Put another way- 'nice amp you got there- it'd be a real shame if something happened to it'... :)

I can also tell you that we used brand-new parts in our amps and any of our product made in the early 1990s is needing new filter caps at this point.

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Kimber Kable

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