Dumble voltages?

[Paul Fawcett]

Hi all,

I'm in the process of designing an amp that will have some similarity to the Dumble topologies, but will actually have a very different layout and power supply, among other changes. Still, I'd like to have a sense what to aim for voltage wise for the preamp and poweramp.

I've tried the search function, but am having a hard time finding information about target voltages for the various Dumbles and their clones discussed here.

In particular, I'm after some actual measured voltages (at each B+ node!!) for builds derived from #102, #124, and #183 discussed frequently here.

Also, if there is variation, perhaps some consensus opinion of where the voltage sweet spots tend to fall for each of the nodes.

Many thanks if you are able to point me in the right direction.

Cheers,

Paul

[David Root]

There is all kinds of info here on #124 and #102, also some on #183. General rule of thumb 190Vp V1, 200Vp V2. V3 (PI) 280-290Vp on those designs.

Power tubes vary depending on PT. Twin, 440-460Vp. Marshall 470Vp or so. Music Man, 700Vp, 350Vs.

[Paul Fawcett]

There is all kinds of info here on #124 and #102, also some on #183. General rule of thumb 190Vp V1, 200Vp V2. V3 (PI) 280-290Vp on those designs.

Power tubes vary depending on PT. Twin, 440-460Vp. Marshall 470Vp or so. Music Man, 700Vp, 350Vs.

That's very helpful, thank you. I'm a bit surprised at how low V1 and V2 in particular are run.

Also, my eye popped a bit seeing the 700V plate voltage for the MM tranny. I can't imagine there are too many current production tubes that can handle that...

[Paul Fawcett]

There is all kinds of info here on #124 and #102, also some on #183. General rule of thumb 190Vp V1, 200Vp V2. V3 (PI) 280-290Vp on those designs.

Power tubes vary depending on PT. Twin, 440-460Vp. Marshall 470Vp or so. Music Man, 700Vp, 350Vs.

That's very helpful, thank you. I'm a bit surprised at how low V1 and V2 in particular are run.

Er, scratch that last, for some dumb reason didn't notice you were quoting plate voltages for the preamp tubes, not the supply voltages at the PSU node. I could work backwards, of course, to get the PSU node voltages, but if you know these offhand it would save me the trouble....

[talbany]

There is all kinds of info here on #124 and #102, also some on #183. General rule of thumb 190Vp V1, 200Vp V2. V3 (PI) 280-290Vp on those designs.

Power tubes vary depending on PT. Twin, 440-460Vp. Marshall 470Vp or so. Music Man, 700Vp, 350Vs.

That's very helpful, thank you. I'm a bit surprised at how low V1 and V2 in particular are run.

Also, my eye popped a bit seeing the 700V plate voltage for the MM tranny. I can't imagine there are too many current production tubes that can handle that...

EL-34's 800v on the plates