A old one - where to start?

[Gingertube]

Jeff,
If you can tell us what the tubes are we may be able to find a schematic.
Cheers,
Ian

[jeff mills]

Jeff,
If you can tell us what the tubes are we may be able to find a schematic.
Cheers,
Ian

Ian thanks

The PS has one tube the number unreadable

The Amp has 5 tubes:
2x 6AU6
2x 5881
1x - number unreadable, it's a little larger than the 6AU6's but smaller than the 5581's

[Gingertube]

Jeff,
Sorry I was unable to track it down - the schematics I was thinking of were from the RCA Receiver Manual (RC17 or RC20) of about 1954-55.
There were 2 variants (both published as variants of the Williamson)
1st:
7199 Triode pentode input (pentode common cathode preamp to triode as concertina splitter) to 2 x 6au6 diffamp driver
2nd:
Very similar circuit but a 12AU7 twin triode input (common cathode amp to concertina splitter) to 2 x 6AU6 diffamp driver
Look at that unmarked tube - if it has 2 identical structures in it then it is the 12AU7 twin triode, otherwise it is probably the 7199.
Sorry I could'nt be more help,
Cheers,
Ian

[jeff mills]

Jeff,
Sorry I was unable to track it down - the schematics I was thinking of were from the RCA Receiver Manual (RC17 or RC20) of about 1954-55.
There were 2 variants (both published as variants of the Williamson)
1st:
7199 Triode pentode input (pentode common cathode preamp to triode as concertina splitter) to 2 x 6au6 diffamp driver
2nd:
Very similar circuit but a 12AU7 twin triode input (common cathode amp to concertina splitter) to 2 x 6AU6 diffamp driver
Look at that unmarked tube - if it has 2 identical structures in it then it is the 12AU7 twin triode, otherwise it is probably the 7199.
Sorry I could'nt be more help,
Cheers,
Ian

Ian thanks for your reply - the unmarked tube has the 2 identical structures inside like you said. That would make it a 12AU7