Tube Amp Archive

You may well read those MEF topics to get well balanced PI outputs without mess with plate loads

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even though I don't understand how a cap from input ground lug to chassis could be lower impedance than the straight wire right next to it. Dave The chassis is "0" potential for the inside circuit as time main star ground is tied to it .the buss wire have some "resistance" for certain frequencies d...

I tried to imagine using this cap preventive to suprime posible oscilation in first stage which is most sensitive. the signal grounds wire I consider more important than supply ground return and in normal way the decoupling cap(usually not too good in HF range) should be as close as possible over th...

pretty similar versions:
komet
[img733]http://i66.tinypic.com/dh6bdt.jpg[/img]
and lite
[img749]http://i66.tinypic.com/34p064o.jpg[/img]

Speaker won't measure as 8Ohm at all frequencies, it will change. So don't worry its perfectly normal. You're right and I allready said that. speaker impedance will change-but just in one way: up. So, that means more reactance in parallel with 25ohm shunt resistor rising the attenuator impedance mo...

Just pondering this. A centre-tap (or artificial centre-tap) on the winding ensures that both sides of the winding will see equal voltage swings on either side of a neutral reference point. If you don't have this neutral reference point in your P-P amp, then won't one side of the OT primary see a h...

Hi That's the best way I found to keep the filament noise to absolutely none: sparate heater windings: one for PI & power tubes and one for the rest of preamp circuit. You need a dc reference for both 2 x 100 ohm resistors for each section and separate leads from each mid junction to main star. Don'...

Hello all I just finished an airbrake project intended to use for severe attenuation for a non MV amp. Did not found a 150ohm reostat, used 100ohm instead. Now, the dc resistance readings in "bedroom mode" (with 8omm speaker conected) shows between 13.5 - 20.5 ohm. and will be a litle higher in real...