Hi @b_force
Thanks for the suggestions.
I have a 100V line transformer too, for push-pull amps. However, now, these transformers are getting too expensive (in the UK, at least).
It would be great if you could help me with this one. I did recently a self-inverting push-pull amp and thought of using a transistor to act as a phase inverter for a "normal" push-pull stage.
Another idea that I had, in the use of transistors in valve amplifiers, was to put a boost circuit (or overdrive/distortion/fuzz) done with transistors at the front of the pre-amp and have a switch to commute from normal pre-amp (valve only) to "boosted" pre-amp.
The only thing is that the 6P30B-R is more powerful, but I don't really care. In push-pull the EL91 should be able to deliver 4W or more. and if I wanted more power I could do what you've suggested which is to go for the EL-95 instead.
To be honest I like the idea of using the EL-91.
I was thinking of doing a Princeton 65 in subminiature. That could be fun too.
Thanks a lot for your comments and ideas.
Kind regards,
Pedro
Thanks for the suggestions.
I have a 100V line transformer too, for push-pull amps. However, now, these transformers are getting too expensive (in the UK, at least).
Ohh, I wanted to do that too. I was thinking to use a JFET, but didn't know how to use it. I don't know the supply to use (12V, 15V, 30V, ....) and how to bias it.I often use something like a LND150 as a simple phase inverter.
It would be great if you could help me with this one. I did recently a self-inverting push-pull amp and thought of using a transistor to act as a phase inverter for a "normal" push-pull stage.
Another idea that I had, in the use of transistors in valve amplifiers, was to put a boost circuit (or overdrive/distortion/fuzz) done with transistors at the front of the pre-amp and have a switch to commute from normal pre-amp (valve only) to "boosted" pre-amp.
Great piece of information! The 6P30B really sucks a lot of current and using an EL91 would be a great alternative.Although strictly not sub-miniature, this works great with something like a EL91.
Which are tiny as well, same height as the 6P30b, only 19mm diameter instead of 11mm of the 6P30B.
Heater current is only 200mA compared to 400mA of a single 6P30B.
The only thing is that the 6P30B-R is more powerful, but I don't really care. In push-pull the EL91 should be able to deliver 4W or more. and if I wanted more power I could do what you've suggested which is to go for the EL-95 instead.
To be honest I like the idea of using the EL-91.
They look the same but they've introduced a tone stack. Very nice.Btw, obviously totally personal and subjective, but I think the AA764 Champ circuit is a little nicer.
Better is even the AA764 Vibrochamp.
The regular AA764 uses the same amount of tubes, just in a slightly different configuration.
I was thinking of doing a Princeton 65 in subminiature. That could be fun too.
Thanks a lot for your comments and ideas.
Kind regards,
Pedro