Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Diverted on November 23, 2018, 09:38:32 pm
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Hi all,
I have a ton of 6SF5s laying around and I've never used them. I'm planning on putting together a stripped down Princeton Reverb on a small chassis. No tremolo allows me to dump V4A, leaving half a 12ax7 for the phase inverter.
Looking at 6SF5 vs 12AX7, they look nearly identical spec-wise (6SF5 is a single triode). Any reason why I shouldn't use this tube in the PI circuit?
If there's no issue I'd like to try. I have a bunch of these and I was hoping to use all octals in the old chassis I'm using, which has octal socket holes — I hate making plates to mount noval tubes in them. With the lack of a good equivalent for the 12AT7 and no 6SL7s on hand I probably won't do that. But if I can get away with at least an octal PI, that would be OK with me.
Thanks!
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yes: obviously you need two of them. ground pin 1 of both tubes. pin 1 is the shell and that's equivalent to running with a shield. there are glass versions but they are rare.
--pete
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Thabks Pete. But why would I need two 6sf5s for v4? With the tremolo circuit cut out there’s only one triode of V4 12ax7 being used. Seems like the remaining triode would be an even swap for a single triode 6sf5. Thanks.
Ted
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Shouldn't be a problem since it's a cathodyne, Do what DL suggested though on pin1