6SQ7 Tremelo
Moderators: pompeiisneaks, Colossal
6SQ7 Tremelo
Has anyone attempted a 6SQ7 Tremelo, such as those in the late '50s Gibsons, or some Valco amps?
BLT
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Stevem
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Re: 6SQ7 Tremelo
What do you mean by attempt, those circuits did work fine in those amps?
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: 6SQ7 Tremelo
A 6SQ7 is an octal tube with 2 fairly useless diodes and one triode that is nearly identical to half of a 12AX7. In a tremolo circult, you need a high gain, high Ra to properly trigger oscillation. Since this tube is a perfect sub for the 12AX7, it will work fine in any one-triode tremolo circuit. As Steve says, it worked fine in those old circuits. If it is a 2-section tremolo, you'll need 2 tubes. This could be a lot of chassis space to take up where you could just use one noval dual triode. There is no "tone" riding on a tremolo circuit. You can use a cheap Sovtek or one of those other similar Russian tube types. I have a box full of them, but can't recall the tube designation - a momentary brain fart. If you have one or two of these and have the space on your chassis, go ahead and build it. It should work fine in any tremolo circuit as long as the tube isn't spent.
Re: 6SQ7 Tremelo
Attempted to build one. Anyone know what the actual minimum plate voltage the 6SQ7 operates at?
I don't necessarily trust the Gibson datasheets. I've tried 3 different tubes, all seem to test strong
but it won't oscillate. I'm using a 6SJ7 in the first preamp position. This is an all octal rebuild using
an old Masco PA amp chassis. V1-6SJ7, V2-6SN7 2nd stage with cathode follower, V3-6SL7 paraphase,
2 6L6Gs, and a 5U4G. The amp itself sounds great. It sounds like it going to come down to tube rolling.
I don't necessarily trust the Gibson datasheets. I've tried 3 different tubes, all seem to test strong
but it won't oscillate. I'm using a 6SJ7 in the first preamp position. This is an all octal rebuild using
an old Masco PA amp chassis. V1-6SJ7, V2-6SN7 2nd stage with cathode follower, V3-6SL7 paraphase,
2 6L6Gs, and a 5U4G. The amp itself sounds great. It sounds like it going to come down to tube rolling.
BLT
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Stevem
- Posts: 4750
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: 6SQ7 Tremelo
But what are you building , a TREMOLO circuit like a Les Paul amp?
What is the voltage reading on the tubes Cathode?
It would seem in that amp that 130 volts with the Tremolo clicked off is what your looking for.
What is the voltage reading on the tubes Cathode?
It would seem in that amp that 130 volts with the Tremolo clicked off is what your looking for.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!