You should post the updates on the web page Gio, and I'm still patiently waiting for information page on the amplifier I made.
You should upgrade the old cathode carbon resistors you have in your amplifier to the Riken 62 ohm types, not shure what kind of improvement they make but they have a 1% tolerance and 62 ohms is the exact bias value.
A small update on the preamp stage... I tried a 6CG7 instead of the 12AX7, and it worked real nice, it looked nice too. The only difference is that the filament is wired differently and uses 600mA, I have a switch in the power supply so I can swap between the tube types.
So 12AX7, 12AT7, 12AU7, 6CG7, and with an octal socket you can use the 6SN7 or 6SL7. I find the preamp to be very convenient because I can use my ipod with the amplifier without a seperate unit like the Mini Tube Preamp which still gives me allot more gain, but could easily be integrated with the amplifier.
The addition of a headphones jack is is also convenient, and this amplifier has more than enough power to drive 16 and 32 ohm headphones, and because it is so simple I find recordings to sound so pure from this amplifier, personally I think it works better as a headphone amp.
A later update will be to upgrade the 50EH5/25EH5 filament power supply into a smaller one with a switched power outlet on it, I have sometimes forgotten to heat up the 50EH5 tubes before applying the HV, amazingly nothing visually happens but I know its not a good thing.
Bye for now!
