Quote from: Littlewyan on August 13, 2013, 05:44:00 PM
Here is the amp as it stands. I have added the two zener diodes to protect the JFET and increased the voltage from the PSU to 30volts to increase the volume. I may change the JFET source resistor to 5K6 to lower the gain slightly, which may also give me a fuller tone.Do you think I will benefit at all from changing the 10K Pot to a 100K Pot? I should see an increase in volume shouldn't I?Actually I think the preamp will just be stupidly overdriven.
I would say that the thing to do is to revise the impedances so as not to have to use these ridiculous 22 uF capacitors in the signal path.
They are actually already too large. You have a 22 kOhm impedance into the TDA stage input. If the coupling capacitor is 22 uF, the -3dB frequency is 0.33 Hz, which means you have nearly flat frequency response down to 3.3 Hz (10X the -3dB frequency: this is a rule of thumb).
That is ridiculous even for hi-fi, let alone guitar.