Could I use these tubes from a radio?

[Dixie]

I recently bought an old Farnsworth phono/radio for dirt cheap, and I'd like to use the vacuum tubes in a project. They appear to be working right now.
Anyways, the tubes are as follows:
two 6SK7 Remote Cutoff Pentodes
6SA7 Pentagrid Converter
6X5GT Full-Wave Rectifier
6SQ7 Twin Diode - High-Mu Triode
6V6GT Beam Power Amplifier
It looks like the 6SQ7 is the only tube here I'll actually find useful, but I'm not sure what modifications I'd have to make to an existing schematic to use it in place of a 12AX7, for example. Could I just get away with changing the heater voltage? Any advice would be appreciated.

[Zben3129]

6v6 is a very common output tube ala fender,
6x5 is a rectifier, and I especially like it because it runs the 6.3 heater voltage

lets put it this way,

You could make an amp out of those for sure, but I would never try it as my first project, as you would have to design the entire preamp from scratch around those other tubes, which is no easy feat. You need to know how to look them up, find the info on the datasheet, bias, etc etc etc

try something over at ax84 for a good first build, there awesome!


Zach

I recently bought an old Farnsworth phono/radio for dirt cheap, and I'd like to use the vacuum tubes in a project. They appear to be working right now.
Anyways, the tubes are as follows:
two 6SK7 Remote Cutoff Pentodes
6SA7 Pentagrid Converter
6X5GT Full-Wave Rectifier
6SQ7 Twin Diode - High-Mu Triode
6V6GT Beam Power Amplifier
It looks like the 6SQ7 is the only tube here I'll actually find useful, but I'm not sure what modifications I'd have to make to an existing schematic to use it in place of a 12AX7, for example. Could I just get away with changing the heater voltage? Any advice would be appreciated.

[Dixie]

6v6 is a very common output tube ala fender,
6x5 is a rectifier, and I especially like it because it runs the 6.3 heater voltage

lets put it this way,

You could make an amp out of those for sure, but I would never try it as my first project, as you would have to design the entire preamp from scratch around those other tubes, which is no easy feat. You need to know how to look them up, find the info on the datasheet, bias, etc etc etc

try something over at ax84 for a good first build, there awesome!


Zach

Thanks for the help! I've taken a look at ax84, and it looks like a very useful resource. I'm thinking I might start working on one of their guitar amps.

[petemoore]

Could I just get away with changing the heater voltage? Any advice would be appreciated.
  First thing to check out on it if it were me.mine, is the power supply grounding.
  If that's 'good' [as in IEC with chassis to E], then...
  It's worth looking at using as an...amp...probably much the same as it was, perhaps identical.
  I've had fine luck with old amps, put a boost or dirtbox on it...shizamm there's the tone ! Mods can be cool...
  And building somehting out of what's there but a different circuit is certainly a possibility.
  On my one amp I didn't tear everything out and that saved me having to wire up the heaters [and some other stuff like grid leak resistors, some of the 'to function' stuff was alread there !].
  I used the PT/OT and tubes that were part of the amp originally, but built the supply circuit and signal circuit..what I wanted..used the old heater and wiring and left some resistors on the existing tube sockets.
  It might just take some light repair to get the tubes lighting up already...they might light up as is !
  filtercaps...