I hope this is the right sub-forum to post. I'm in doubt as this project also involves solid-state components and it's an instrument amplifier. Feel free to move it to the most appropriate space.
I would like to build a guitar practice amplifier for a friend of mine. He would rather play with his headphones in order not to bother his flatmates.
Having a spare 12AX7 tube on hand I though I could go with a tube preamp section and a solid state final stage to drive his headphones (they should be low impedance, certainly below 100ohm).
Using the schematic I have attached * I would only need to buy some passives (I already have a suitable HV power supply) and I already have the tone controls sorted out.
So I guess what I am missing is a solid state final amplification stage to drive a pair of headphones. My aim is to use a single rail 12V supply which I already have on hand, but for other voltages I am open to using a buck converter.
I am asking for your advice on two topics:
* The schematic attached comes from here, but I've uploaded a copy for future-proofing.
I would like to build a guitar practice amplifier for a friend of mine. He would rather play with his headphones in order not to bother his flatmates.
Having a spare 12AX7 tube on hand I though I could go with a tube preamp section and a solid state final stage to drive his headphones (they should be low impedance, certainly below 100ohm).
Using the schematic I have attached * I would only need to buy some passives (I already have a suitable HV power supply) and I already have the tone controls sorted out.
So I guess what I am missing is a solid state final amplification stage to drive a pair of headphones. My aim is to use a single rail 12V supply which I already have on hand, but for other voltages I am open to using a buck converter.
I am asking for your advice on two topics:
- What driver circuitry should I use for the headphone amplifier?
- Do you have a different/better tube preamp schematic (using the 12AX7)? is there anything you would change in the current design?
* The schematic attached comes from here, but I've uploaded a copy for future-proofing.
Attachments
The 12AX7 is going to need a High Voltage B+ to work well.
You will need a 12V supply for the solid state amplifier, and a 12V to B+ Boost convertor for the 12AX7 or other tube stages.
You could say this belongs as a tubes / valve thread.
You could say this belongs as an instruments and amps thread.
Or . . . because you already seem to have most things worked out other than the solid state output amplifier . . .
You could say it belongs as an Solid State thread.
40 Years ago, I would just have used an LM386 8 pin dip solid state amplifier.
After all, this is a guitar amplifier, not a high end Hi Fi Stereo amplifier, Right?
The solid state thread fans should be able to suggest some sort of simple IC audio amplifier chip.
Just my opinions.
You will need a 12V supply for the solid state amplifier, and a 12V to B+ Boost convertor for the 12AX7 or other tube stages.
You could say this belongs as a tubes / valve thread.
You could say this belongs as an instruments and amps thread.
Or . . . because you already seem to have most things worked out other than the solid state output amplifier . . .
You could say it belongs as an Solid State thread.
40 Years ago, I would just have used an LM386 8 pin dip solid state amplifier.
After all, this is a guitar amplifier, not a high end Hi Fi Stereo amplifier, Right?
The solid state thread fans should be able to suggest some sort of simple IC audio amplifier chip.
Just my opinions.