Q for Bruce from Mission Amps- 6V6 Max plate voltage for 5E3?

[RobBozic]

Bruce can you tell me from your experience what is the maximum plate voltage you like for the 6V6's in a 5E3?

I know if you go with too high a voltage with cathode biased amps you get some bias shift which takes away the cathode bias sweet tone.

Right now I got a 5E3 PT from Mojotone and the B+ is very high (around 395VDC on 6V6's with NOS 5Y3).

BTW - I have a 8K OT

Thanks in advance
Rob

[Bruce / Mission Amps]

Bruce can you tell me from your experience what is the maximum plate voltage you like for the 6V6's in a 5E3?

I know if you go with too high a voltage with cathode biased amps you get some bias shift which takes away the cathode bias sweet tone.

Right now I got a 5E3 PT from Mojotone and the B+ is very high (around 395VDC on 6V6's with NOS 5Y3).

BTW - I have a 8K OT

Thanks in advance
Rob

Well, even a real 5E3, run at modern line voltages of 120vac-122vac, will get the first filter cap charged up to around 375vdc to 395vdc... depending on how hard or soft the power tubes are.

I prefer to keep the first cap voltage around 350vdc to 370vdc.

Just lift that red/yellow wire from ground and use two or three, 5 watt 9v-12v zener diodes (reverse biased) in series with the wire and reconnect it to ground or the negative lead of the first filter cap.
With a little B+ massaging, that MOJO PT actually works great in these amps... plus it is slightly over built for a 5E3 and will give the amp more grunt power.

You can use a 330ohm and as high as 360ohms as the 6V6 cathode biasing resistor and still keep a fairly good vintage sound.

[tubeswell]

340-350 at the plates 290 on the screens, with a 250R cathode resistor - my 2CW (But I wanted to wait til Bruce answered, since you were asking him specifically). I have used Bruce's zener trick several times and it works wonders FWIW

[RobBozic]

Thanks guys

Rob