High power SE needs big expensive transformers. If you are doing something big and expensive, you might as well use a big expensive valve too.
If you want to use a pair or quad of EL84, better to use P-P and have a cheaper transformer and largely cancel even-order distortion. Also have less audio going through the PSU.
If you want to use a pair or quad of EL84, better to use P-P and have a cheaper transformer and largely cancel even-order distortion. Also have less audio going through the PSU.
Ok 
seems Lundahl LL1627 cost the same whether its PP or PSE version, 190EUR ea
http://www.lundahl.se/pdfs/datash/1620_3_7_9202.pdf
seems Lundahl LL1627 cost the same whether its PP or PSE version, 190EUR ea
http://www.lundahl.se/pdfs/datash/1620_3_7_9202.pdf
But the PP version has much higher primary inductance so handles low frequencies better, and can handle much higher power. So for a given performance, a PP transformer is much smaller and cheaper than an SE transformer.
Push pull operation of a pair of tubes may give you as much as 4X the power of a single tube in SE, whereas PSE will give you 2X the power.
The objection some people have to PSE is that it is alleged to loose something sonically (imaging, timbre, detail) as compared to a single tube implementation. IMLE with some high end 300B amps (very expensive, but to remain nameless) this did in fact seem to be the case.
The objection some people have to PSE is that it is alleged to loose something sonically (imaging, timbre, detail) as compared to a single tube implementation. IMLE with some high end 300B amps (very expensive, but to remain nameless) this did in fact seem to be the case.
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I'm not surprised PSE sounds different from SE given that you effectively have a different tube in there - with two tubes in parallel the average transfer curve isn't the same as either tube, total inter-electrode capacitance will be higher etc.
Ok
seems Lundahl LL1627 cost the same whether its PP or PSE version, 190EUR ea
http://www.lundahl.se/pdfs/datash/1620_3_7_9202.pdf
Sure . . . but look at "Max Power" . . .
hey-Hey!!!,
For Class A operation, two tubes PP deliver the same power as two PSE. Now with PP one can go AB or even B and step power up considerably( though I am not at all convinced it is a good idea). PPP or 4PSE ( each with 4 finals ) does the same thing with a change to the power multiplier over single-final SE.
cheers,
Douglas
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How about just building a P-P amplifier using some EL84 with a usual P-P OT, but connect one side as triode wired (or Schade wired) and the other side as pentode wired (class A operation). OT impedance per the triode side. The lower impedance side then rules the voltage output (sound) mainly, but the pentode side keeps the DC current in the OT balanced. Should come fairly close to SE sound. Could put some degeneration resistance in the pentode's cathode side to raise it's Zo too. This should give about the same power output as P-P too (class A that is).
A further approach is the "anti-triode" or "exact" complementary drive version of P-P that has been discussed in some threads before. That should come very very close to true SE sound using P-P topology and also lowers Zo to the speaker by another factor of 2 beyond the above scheme (without Gnfbk). But more complex to implement.
A further approach is the "anti-triode" or "exact" complementary drive version of P-P that has been discussed in some threads before. That should come very very close to true SE sound using P-P topology and also lowers Zo to the speaker by another factor of 2 beyond the above scheme (without Gnfbk). But more complex to implement.
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I've some Hammond 1K2 xformers sitting - maybe a bit of feedback as in that one circuit they'd make a nice 4x6bq5 SE to play The Ventures stuff - small signal the Hammonds are limited and rough.
sure sure, but high power is not the goal
neither would it need to be exstremely cost effective
I only though about the lower load impedance
and headroom power
maybe with long tube life(in my dreams)
but what about the higher current rating, no advantage ?
or the lower 170V signal voltage, another problem ?
but it does seem obvious why there are none to find
If one is starting from scratch and buying all new components, it would make sense to just go with a bigger tube. But with NOS tubes on sale like 29GK6 (~EL84), 6GF7, 13GF7, 13FM7, 38HE7 .... for 1$, well the equation is different, just an extra socket.
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