Looking for advice on replacing coupling capacitors in this circa 1964 N.Y. built amp. I picked it up some 20 years ago in a pile of stuff and it wor ked when I tried it, but my son wants to use it with a turntable and she ba rely makes a peep now. I found a whole batch of 4uf W.German electros total ly inert, and need to replace them. I'll need at least 15 but don't want t o break the bank on an amplifier of dubious value, particularly since it's all germanium and some blown outputs would probably end it's useful life. My son loves it because of it's looks, and it is very well made otherwise.
So instead of putting electrolytics back in, I was thinking of putting in s ome film caps. Is there a relatively cheap film cap or should I just stay w ith electrolytics, and if so, which? I found these on DigiKey which are re asonable:
Another anomaly is that while the schematic calls out mostly 4uf caps, this particular unit has two locations that have 10uf installed on each preamp board, everything is the same as the schematic. Strangely, although they're the same 10uf value and voltage, the two locations have two different manu facturers. The other twin preamp board has the same exact two caps in the same exact spot, as if they were selected for voicing reasons. Service man ual here:
And since 4uf caps are pretty much made of unobtainium, should I go to 4.7 or 3.3, or should I cobble some together?