Valco Gretsch 6150 Voltages Values

[K Teacher]

Greetings,

Based on measurements from a Valco 6150 clone, I was able to estimate the circuit voltages (see below), assuming nominal component values.
However, I would like help to validate (or not), the estimated voltage values, with real-world measurements from a Valco 6150 (or similar Airline/ National/ Oahu/ Supro made by Valco) ...

If anyone have one of these in good working condition at hand or on the bench, could you please be kind enough to post the voltage values?
The ones I've seen on schematics that are circulating in the web, vary a lot and some do not even make sense…

Thanks in advance for your help.

[K Teacher]

Plate_dissipation = (Plate_voltage – Cathode_voltage) x Plate_current
P_diss = (302 - 14.8) x 41.0 mA
P_diss = 11.8W (98% of 12.0W)

[K Teacher]

Anyone?

[K Teacher]

Wow !!! … I guess all of the amp experts are out to lunch !!!

[The Dude]

Or, nobody has a Valco Gretsch 6150 laying around. The voltages on your schematic look reasonable to me.

[Helmholtz]

Agree, your voltages look reasonable and should ensure perfect operation.
As always, actual amp voltages may vary by more than +/- 10%, due to tube variations, resistor tolerances and actual line voltage.

What's the problem?

[K Teacher]

Hi Helmholtz,

Thanks for the feedback.

There is no problem... just want to confirm the estimated circuit voltages with the real deal…

Like I mentioned before, Valco assigned different numbers for the same schematic they used on Airline/ National/ Oahu/ Supro amps. But they have the same circuit, same PT, and the schematics show different voltages… that is puzzling…

But if you guys say the voltages are good, then they are good !!

Thanks again…

[K Teacher]

Just for the record, these are the amps (that I know of) which use this same circuit:

1. Valco 6150
2. Valco / Airline 62-9022A (same as 6150 plus tone)
3. Valco / Gretsch G6150 (same as 6150)
4. Valco / National 1210 (same as 6150 BUT 6EU7 in V1 instead of 12AX7 -- same tube, different pinout)
5. Valco / Oahu Practice Amp (no number, same as 6150)
6. Valco / Supro S6606 (same as 6150 plus tone = Airline 62-9022A)

Other differences between them are only cosmetics of the cabinet…
Also, for some reason I am not aware of, some of them were made with oval 6x9 in speaker instead of 8 in…
But none of them have influence on circuit voltages…

[K Teacher]

I think the estimated voltages I got are the closest to the real-deal...

Thank you all for your input…