• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Old Fisher SA-300 Amp help!

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Hi Gang!

A friend has found a Fisher SA-300 Tube Power Amp that is without tubes and he needs a Schematic to get some help from an experienced Guitar Amp friend.

Can anyone make any recommendations for the Schematics and/or Tubes and/or Gotchas.

Thanks as always in advance! 😀
 
You can get the schematic from HIFI Engine, after registering.

The tube complement is 2X 12AX7/ECC83s, 2X 12AU7/ECC82s, 2X matched pairs of EL34/6CA7s (4X power tubes total), and 2X 5AR4/GZ34s.

BTW, Fisher's 45 WPC claim is HIGHLY optimistic. That comes from before FTC rules were put in place. A yield of 35 WPC RMS is about right from a PP pair of EL34 family tubes.
 
Thank you Eli.

Always a Gentleman here!

I saw 30 WPC in a few references. They seemed to held in high regards for an early 60's amp.

Hopefully, he'll join HiFi Engine and download it but I think he might have tried that and found what they had wasn't complete.

I'll check with him.

Thanks again!

Regards//Keith
 
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