Deepdark
Well-known member
Hi guys
Some questions aout the amp section. I plan using it on a eqp1a, but had some questions.
1. The first stage (12ax7) looks to be some sort of phase splitter stage, according to Morgan jones valve amplifier book (4th edition). Page 459, figure 6.19. Never seen it before. Any things I should take in consideration/take care of to avoid any trouble?
2. The output transformer is fed by the cathode of the 6aq5. At the node before the 18K - 5W resistor and the primary high, it shows +160v!!! Is it a typo? straight into the transformer??? looking at the 18k resistor, if we need to drop 160v throughit, it gives us about 8.8ma, about 1.5W, so our 5W looks logical.
3. 1k resistor between heater ground and B+, heater elevation I guess? essential in this topology to avoid hum?
Thanks guys!
Some questions aout the amp section. I plan using it on a eqp1a, but had some questions.
1. The first stage (12ax7) looks to be some sort of phase splitter stage, according to Morgan jones valve amplifier book (4th edition). Page 459, figure 6.19. Never seen it before. Any things I should take in consideration/take care of to avoid any trouble?
2. The output transformer is fed by the cathode of the 6aq5. At the node before the 18K - 5W resistor and the primary high, it shows +160v!!! Is it a typo? straight into the transformer??? looking at the 18k resistor, if we need to drop 160v throughit, it gives us about 8.8ma, about 1.5W, so our 5W looks logical.
3. 1k resistor between heater ground and B+, heater elevation I guess? essential in this topology to avoid hum?
Thanks guys!