I do
not like building preamps for the fact that the jacks and the input
selection always carry along a lot of boring work. So I prefer using
existing units or bases from integrated amps.
The
Fisher integrated amps are real classics. When I started with tube gear in
the mid 80s I really loved them and optically my favourite unit always was
the X-101-C (technically I prefer the early X-100 with EL84s and tube
rectifier).
I got this X-101-C
without output transformer, so it was an easy decision to convert it to a
preamp. I carried out the following changes:
- tube rectification with 6AU4
(on the original 7591 sockets) = rectifier tubes with 6.3V heaters
- Tape Head input is now a
Moving Coil cartridge input (very nice as the MM input still works)
- Siemens T-41 input
transformers for MC
- Siemens choke (from 6SELA
amp) and more filter caps (some had to fill some original holes...)
- cathode follower output
stage (original phase splitter tubes) as in McIntosh C-20 or C-22
- treble / bass control bypass
possible
Avery Fisher already
used a lot of German parts in his amps (as ERO caps, Telefunken tubes and
German resistors), so I only added original 1960s Siemens parts.
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