Anyone play with the NFB resistor value on the VTA driver board? I just wired this switch in to move between 10k,7.5k and 5k. Although it’s higher gain, the 10k seems to work best for my system, (better bass) but I’m still listening. The lower value has a rolled off sound, but I’m not sure if it’s just gain difference. It’s a nice way to tune the amp.
The amp started as a m125 monoblock. The quad cap and rectifier are no more… bunch of other mods including autobias, snubbers on power tubes and a regulated bias supply. Cosmetics too…
RCA 6sn7 voltage amplifier, Raytheon 12bh7 and tung sol 6550. I played with the Chinese “black” kt88s. They sounded fine, but reliability sucked.
Great amps. A lot of tubes.
The amp started as a m125 monoblock. The quad cap and rectifier are no more… bunch of other mods including autobias, snubbers on power tubes and a regulated bias supply. Cosmetics too…
RCA 6sn7 voltage amplifier, Raytheon 12bh7 and tung sol 6550. I played with the Chinese “black” kt88s. They sounded fine, but reliability sucked.
Great amps. A lot of tubes.