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RE: Futterman H3 stereo amp parts list?

Posted by AJ (A) on February 21, 2018 at 09:12:24

In Reply to: Futterman H3 stereo amp parts list? posted by waldenpuddle on January 24, 2018 at 17:55:50:

You won't find a parts list anywhere. The machine is over 50 years old.

For curiosity you could look to SAMs folders- I'm not sure if they ever developed one for this model.

Futterman used many different output tubes for this model including the 6FW5, 6HJ5 and even 6LF6 - they all have similar characteristics and are mostly electrically equivalent- different basing etc.

He also used different screen regulators and combinations - sometimes not even relabeling the chassis or doing so and then having the stick on label fall off due to heat leaving the question as to whether the right tube was ever in there to begin with- ask me how I know.

I have totally rebuilt mine. Last thing to do is replace the huge electrolytic couplers with poly I will have to devise a mounting system and bracket that is unobtrusive and reversible to do this as the those parts are a huge form factor outside of the dimensions of the original parts.

Rebuilt it is a great and reliable amp...it sounds great on the ESLs

You'll find a schematic on the web if you search well -- you might also find the bias instructions for the amp which contain a couple of errors but is mostly correct- its about 3-4 pages long as I recall.

Good Luck.

Edits: 02/21/18

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