Magnatone weirdness

[Valvehead]

Is that plate or cathode current? What is the 6V6 cathode voltage?
You could lower the cathode resistor to 220R, aiming for a cathode current of 50mA.



Does that include the cathode bypass cap?

Best measure output power.
Should be around 4W.

6v6 cath is 10.6v
257 ohm cath resistor
10.6 ÷ 257 = .041ma
cath bypass cap new
i swapped the 3 tubes and got some slightly higher volts

[mozz]

Put a 220k plate resistor for the 6sj7.

[Valvehead]

About what acv should i see at the output of this 5y3 ? Pin 8 is 41vac . 317vdc is there

[Helmholtz]

Generally your voltages look ok.
What is the remaining problem?

What is the HT winding AC voltage?
What is the heater voltage?

Can you measure output power?

[g1]

41VAC on 317VDC B+ seems high. I wonder if the 317 is not really all there but fooling your meter. Do you have a scope?

[Helmholtz]

As there's is a 1k resistor before the reservoir/first filter cap, I'd expect high ripple voltage at the 5Y3 cathode/heater.
But as that node is not used to supply the circuit, it's not relevant.

A (say 10µ) cap there would decrease ripple and increase B+.

[Valvehead]

Sorry been busy...i tried adding the 10uf filter as Helmholtz mentioned and the amp is hum free ! Sounds ok through my 4x12 , but more raspy with stock 70 year old speaker when cranked up.