24.18.227.0
In Reply to: RE: Seduction Transformer Headroom posted by Dr.Toobz on September 07, 2009 at 22:39:01
Possible lack of clarity here.
The high voltage supply puts out 130vDC at 20mA maximum; the Seduction circuit uses pretty much all of that.
The heater supply puts out 5.7 to 6.0 volts DC at 600mA for 6922s, up to 730mA for 6DJ8s. It will give up 800mA if you need it. (The higher currents may need some adjustment of the 1.2 ohm resistor to get the voltage right.) That supply is not very "clean"; the ripple is low enough to eliminate it as a hum source but probably not enough to power an amp directly. And the voltage is low for this project.
It is probably possible to make up a voltage doubler add-on, but I don't know a circuit offhand that will do it. There are chip voltage doublers with DC in and out which would probably also make 12 volts, then a 9v regulator chip could bring the ripple down to a workable amount. So I'm pretty sure this is possible, one way or another - but I don't have a specific circuit in mind.
It does sound like cheap fun - you might start with 9-v batteries and research power supply circuits for use later if you like the results.
Incidentally, there is no rule against turning the knob all the way up. If it's loud enough at 3:00 then it's loud enough.
Finally, yes the stock iron will overload in the deep bass, and more available midrange power will not change the deep bass distortion or increase the deep bass power. The 6DN7 and 6EM7 have about the same total gain; the EM7 just operates at a somewhat higher efficiency operating point so more power is available. My notes say the MQ upgrade will do nearly one octave deeper bass at full power before saturating, compared to the stock outut transformer.
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