Paramount runs at nominally 350v (plate to cathode) and 70mA, which is 24.5 watts plate dissipation. You can probably run a Sovtek 2A3 that way for a while - better have a spare set on hand though. Smoke 'em if you got 'em! Don't do this with anything that's out of production though, that would be a crime against posterity. :^)Fullrange said:Thanks Paul for your answer.
Could you please tell me how much dissipation the 300b uses, hope I am using the right term, if it is 22 watts or less it might be possible to run the 2a3 Sovtek also, the idea of using 2.5v AC filament appeals to me.
I was thinking of the EXO-050. Kind of overkill, but has excellent sound, at least the nickel-core ones that Doc has used. I'm not sure but I think it's a bit larger than the TFA-2004 and might be a very tight fit.Fullrange said:... you mentioned Magnequest 5k OT or others to be used in the Paramount, which are the ones to be appropriate.
Your guess is correct. You can't get more voltage because of the power transformer limitations. It runs at 360v (300v plate to cathode plus 60v bias) in 2A3 mode, which is a bit higher voltage than the usual 2A3 amp. (You could probably run a 2A3-40 at higher current, but you'd need new output transformers - lower impedance - and plate chokes. The power benefit would be modest, maybe 5 or 6 watts at most.)Also liking the Stereomour because it looks simple to built, is it possible to increase to voltages and currents to run the OT tubes at higher operating conditions, guessing that it is limited do to the Power Transformer and OT's, looks like it is easy to wire up for one input only and owing a very good tube preamp which I like to use as source input.
Power predictions are difficult. Looking at the WE table of operating points, the stock 2A3 Paramour should make over 5 watts before clipping; I still rate it at 3.5 watts and we generally see about 4 watts before visible distortion of the waveform. Dropping the load impedance to 3K (with a current increase to keep the distortion low) ought to give you about 4/3 the power, or another 1.5dB. Whether that means 4.5 or 6.5 watts is an unanswerable question until someone tries it and does the measurement. A lot depends on how strictly linear the individual tube is.Fullrange said:...
Paul, coming back to what you said, is it possible to use the TFA-2004 and an appropriate plate choke in the Stereomour to be able to increase the current for the JJ-2a3-40. How many watts would I be able to increase to approx., a 2 to 3db gain to 5 to 6 watts would be perfect.
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