Sorry, yes of course to the tone pot, I just naturally saw it with the volume pot I never bothered to mention it. As far as the low voltage it all depends what you are looking for in an amp. I built a small amp that switched between a cathodyne and a paraphase PI. the paraphase thickened up the sound a bit. The low voltage on the tube will give the amp more of a bluesy sound which would probably go well with the paraphase. Now your cascoded triodes will give a pentode type of sound which might work with the combination you have. If it does not have enough cleans you can change the dropping resistor value to increase the voltage to these stages.
It really depends what kind of sound you are looking for. If you are looking for a sparkling clean sound this combination may not be ideal. Mind you since you are not short of other amp I figure you could give this a shot and if it does not work for you then you could make some changes. If you want to go in another direction that is fine also.
It really depends what kind of sound you are looking for. If you are looking for a sparkling clean sound this combination may not be ideal. Mind you since you are not short of other amp I figure you could give this a shot and if it does not work for you then you could make some changes. If you want to go in another direction that is fine also.
there was some versions of this amp that was a 34 watt it came with a pair of 6l6's but you can plug in a quad 6v6 set (extra two sockets).
Sorry, I totally fail to see your point?.
The circuit the OP posted looks perfectly viable to me - the first triode, with an active anode load, feeding the differential amp phase splitter (long tailed pair if you like).
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Just noticed a mistake on his drawing, the anode of the active load should go to the +ve of C70.
I have clean amps out the yin yang... i want something different. Whether that's Vox AC15 sorta 'chimey' or whether that's 2x6L6 tweed style 'bluesy' ( which is what i THINK i have right now )....i don't care. It's a blank slate. I just want an amp i can say i converted, and that ultimately sounds and works well. 🙂 ( and i hope to learn something in the process )
The other thing i was wondering about, is that i have what is clearly a Fender Tweed style tone stack. Can and should this be swapped for a more versatile Baxandall tone stack?
ala this pic...by just subbing it in after the bypass cap and before the PI ?
An externally hosted image should be here but it was not working when we last tested it.
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That will probably drop the gain considerably, in which case (and if you're wanting more gain anyway) I would suggest dumping the active anode load, and using the second triode as a further gain stage.
Don't have a problem with the preamp circuit. If you care to explain how that PI will work better than the original paraphase or the LTP I am willing to learn. I missed where the high voltage was taken for the first stage, good call.
You could try that but I think the previous version would sound a little more different as you already have a good palette of Fender tones.
You're still connecting the new preamp power supply to the wrong place, it needs to go to the positive of C70.
AHHH!! I get what you mean, now. I couldn't figure out what you meant by C70... but it's C7. Got it.
See attached changes to my 2nd revision
1) is this new schematic feasible? ( with the obvious needed addition of a plate load resistor in between C7 and the new 12AX7 stage 2)
2) any ideas on the value of that plate load resistor?
3) Say i want to run the PI with a higher plate voltage, but leave the 6L6's alone. That would require adjusting R3 and R8 to lower value resistors, right?
4))And by changing the plate voltage, would i also not have to rebias by adjusting R7 to match ? ( commenting only on the components of the original leslie, not on my bodged on front-end )
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Not quite the right place, the other side of R10 (where the existing triode is fed from).
You don't need an anode load for the circuit, the top triode is an active load.
I don't see why you would want to alter the phase inverter voltages?.
You don't need an anode load for the circuit, the top triode is an active load.
I don't see why you would want to alter the phase inverter voltages?.
Roger on the power for the active load. I think i understand now.
I was asking regarding the PI as a theory question...because i may want to do it to the first 12AX7 at some point.
Just a matter of changing things and see if you like the resulting distortion, there's not really any way to calculate what the distortion might sound like.
Thread re-opened on request.
Did This thing ever fly?
I just got my self a Leslie 25 with the booster amp and am trying to do the same thing.