First TMB build, final readings
Posted: Wed 05/10/23 8:09 pm
Ok, remember what I wrote about my B+ readings a few days ago? Forget that. Wrong amp. Sorry.
Now then, before B+ zener diode install I had 385 at node A. I ran two 15v/5w Zeners in series and got the A node down to 350.
B=319, C=271, D=236. Line volts 124vac.
Tube V1 remains a 12AY7. Pin 1, 136. Pin 6, 95.
V2… pin 1, 135. Pin 6, 211.
V3… pin 1, 198. Pin 6, 203.
V4… pin 3, 11. Pin 7, 346. Pin 9, 320.
V5… pin 3, 11. Pin 7, 348. Pin 9, 322.
With a 180/5watt resistor for cathode bias, I read 11 volts. My bias meters tell me I’m getting an average of 25ma through the 6N14N tubes. This calculates to 8.65 watts PD per tube, or just north of 17watts output.
Close enough to the bullseye for me. Lol.
I’ll set it up and play through it for a few days before I decide is it needs anything else. I have components for the anti-hiss/snubber mod if needed. Time and my ears will tell.
All opinions welcome. Thanks for providing this website.
Now then, before B+ zener diode install I had 385 at node A. I ran two 15v/5w Zeners in series and got the A node down to 350.
B=319, C=271, D=236. Line volts 124vac.
Tube V1 remains a 12AY7. Pin 1, 136. Pin 6, 95.
V2… pin 1, 135. Pin 6, 211.
V3… pin 1, 198. Pin 6, 203.
V4… pin 3, 11. Pin 7, 346. Pin 9, 320.
V5… pin 3, 11. Pin 7, 348. Pin 9, 322.
With a 180/5watt resistor for cathode bias, I read 11 volts. My bias meters tell me I’m getting an average of 25ma through the 6N14N tubes. This calculates to 8.65 watts PD per tube, or just north of 17watts output.
Close enough to the bullseye for me. Lol.
I’ll set it up and play through it for a few days before I decide is it needs anything else. I have components for the anti-hiss/snubber mod if needed. Time and my ears will tell.
All opinions welcome. Thanks for providing this website.