Good Morning IloveHiFi,
I’m building a 6V6 with a Baxandall Tone Stack Pre-Amp in in one chassis. I’m using an adapted 6V6 Power Supply to run both. See the adapted PSU here in the 6V6 V.2 thread.
viewtopic.php?f=9&t=5736&start=220 You and Matt steered me in the right direction. (13th April 2019).
I have the 2k7 resistors but can’t get the 47uF caps to finish the pre-amp/tone stack legs of the PSU as we’re on a four week lockdown here in Spain, so I decided to just fire up the amp with the pre-amp/tone stack hooked onto the B+ of the 6V6. With the ‘scope and signal generator connected I couldn’t find a clean signal anywhere.
Once you had informed that I could test the pre-amp/tone stack stand alone without any load, I tested it and it worked fine. I also tested the 6V6 on it’s own and it worked fine.
I hunted around and managed to find two 68uF 400v caps which I used to finish the modified PSU and connected up again. Everything is now working fine.
Matt did say that I would likely have problems without the extra stage of power supply filtering and he was 100% correct.
I would like to understand about PSU filter isolation if anyone could explain it to me in laymans terms or point me towards a good article on it.
I will change the 68uF caps to 47uF when I can get hold of them. How does using larger caps affect the PSU and/or Amp?