Tube preamp modded to use in transistor power amp! Help?

[Frankli]

(Original Project: http://www.projetg5.com/Projets/G5/G5V3/G5V3officielle.pdf)
I need mod for these preamp (see schematic) to use in mosfet power amp.
Because high impedance in out and high sinal i dont have use with transistor power amp. Any ideas to mod?
Thanks

Franklis

[Frankli]

 

[km-r]

isnt this a class-A tube amp?
why do you want to connect it to a mosfet amp?
more power?
you may want to:
1. connect a dummy load at the 8ohm output and tap your input for the mosfet amp there...
or,
2. delete the EL34 stage and couple the output of the 12ax7 preamp to your mosfet amp...

[Frankli]

Isnt this a class-A tube amp?
Yes.
why do you want to connect it to a mosfet amp?
more power?
No. I made the test and sound is good (very very good!!wow) and price to build low

you may want to:

delete the EL34 stage and couple the output of the 12ax7 preamp to your mosfet amp...

Yes.    
The ideia is this. But the output impedance and signal is very high to transistor amp.
With high signal is bad because it can damage the transistor amp.
With high impedance he is not so critical, but the sound it lacks some power and it has some noise.
The "problems are detected", but i do not know to modify the original schematic diagram of preamp to make this adaptation.

Thanks one mor time

[Ben N]

Maybe change the second 12ax7 stage to a cathode follower to lower the output imedance and reduce the second stage gain to unity (slightly less, actually). If the signal is still too hot, insert a voltage divider ahead of the power amp to shunt as much signal as you need to. Better yet, change the second stage to a follower direct coupled to the inut stage AND move the tone stack and the volume control after the tube so they can act as the shunt.

That second stage as it is in the preamp is designed to add voltage gain after the lossy tone stack so that the signal is hot enough to drive the power tube. As is, it really is not designed for the purpose you have in mind. The unbuffered fx loop wont work very well, either, and that configuration wont give you much distortion, so why do you want to use this particular preamp? (Just wondering--it's your choice, of course.)

Have you asked ths question at Ampage/Music Electronics Forum (or whatever it is called these days)?

Ben

[Frankli]

he unbuffered fx loop wont work very well, either, and that configuration wont give you much distortion, so why do you want to use this particular preamp? (Just wondering--it's your choice, of course.)

Yes. I need clean preamp, clean sounds. These preamp have good sound and nice options (loop, tone stack) to my necessities.

Have you asked ths question at Ampage/Music Electronics Forum (or whatever it is called these days)?

No.not yet i made these questions in this forum. I will make soon

if mosfet amp found other clean preamp already suitable to use in one, already it decided my problem.

Thanks