Something is not right here though. Two things specifically. First, there should not be much difference, certainly not that much difference, between those JJ 5Y3s. The JJs drop about as much or even more than NOS 5Y3GTs. 340ish volts sounds more correct. What power transformer do you have?
Second, your 6V6s should be cooking at -23 on the grids, even at around 315V on the plates. So again, something doesn't seem right here. How old are your 6V6s? What were your initial voltage and bias numbers when you completed the amp? How exactly are you measuring the plate (or cathode) current?
Hi and thanks! I am going to leave it with the 390V tube. All of the voltages are more in line with what they are supposed to be. The old original schematics do show 340V at B+, but I'm considering that when that was done the wall AC was running 110V. My wall AC varies between 119/123V. That equates to between 30 and 40 VDC higher than the original. As far as voltage on 6V6's, my PRRI is running at 427VDC, and that was what the original 1965 schematic is showing when wall AC was 117VAC.
As far as plate current, I'm dividing the V drop on the primaries of the OPT by the resistance of the same primary leads.
It sounds killer with the higher 5Y3. Thanks!
Really not trying to piss anyone off. I bought the transformer from AES back in 2017. They sold trannys by unbranded ClassicTone I believe. Classictone went out of business so I can't find the exact tranny. I bought the one for a 5E3 along with the OP tranny also for a 5e3, which is what mojotone uses in their kits for a 5F11. I believe they are rated at 384-0-384 with a 50V bias tap. 5VAC.You're not listening.
Your 6V6s, again, based on the numbers you are providing:
-23V grids 17mA at 315V. That should be closer to 30mA with those voltages!
-28V grids 24mA at 390V. That should be closer to 40mA!
Something is wrong! You either have some extremely cold 6V6s, or they are nearly cathode depleted.
You're not helping me help you either by not answering my questions about the power transformer, or your original voltage and bias numbers with those tubes.
Do whatever you want to do, but I think you're ignoring problems, and they aren't just going to go away.
Really not trying to piss anyone off. I bought the transformer from AES back in 2017. They sold trannys by unbranded ClassicTone I believe. Classictone went out of business so I can't find the exact tranny. I bought the one for a 5E3 along with the OP tranny also for a 5e3, which is what mojotone uses in their kits for a 5F11. I believe they are rated at 384-0-384 with a 50V bias tap. 5VAC.
This amp started as a 5e3 deluxe back in 2017 but it was too much amp for me so I converted it to a 5f11 with the same chassis and parts. I had to do some PTP wiring for the tremolo and bias circuit. It's been a while but I think it was putting out 383 VDC on the plates. The 5e3 was cathode bias and I don't remember what the bias was at that time.
Uncle Doug's work on YouTube is a treasure trove of information. If it were me, I still would do a pt in the amp that was lower vac if I was able to. But with it running as it is, I'd have a tough time justifying the extra cost.
Would love to see a gut shot of your amp!
24ma at 390Pv is about 67% of max plate dissipation…which is right where I would want it for a 5F11 fixed biased circuit. Ommv.
If you can't hear enough difference in tone to decide which to use,
I would go with the lower voltage for two reasons:
Lower voltage stress on all the parts in the amp = better reliability
Lower voltage on the power tubes = Earlier breakup at lower volumes, which I happen to like
Just make sure to bias the wattage dissipation within the rating of the tubes you are using...
I had it figured at around 77% based on 12 watts. I guess nowadays we base it on 14 watts? Either way it's pretty good and it sounds wonderful. Thanks Wally!