I'm trying to salvage a bad first build with a bit of a redesign and numbers I'm getting from my volt meter are not matching what I'm being told should be there by the PSUD software. For example, based on measuring the voltage across my 6L6GC's cathode bias resistor (SE design) I am running them at 65ma. But, if I put that value (x2) into the PSUD software, along with appropriate pre-amp tube draw I'm not getting very accurate B+ results. Now, if I drop the draw to something much lower (on the order of 50ma per channel) then the voltages line up spot on with what I'm recording on the volt meter, given the rest of the parameters being accurate.
Seems simple to me that 21.5 volts divided by 330 ohms (small design change from original) equals 65ma but I'm wondering if I'm missing something. The design (attached) plays incredibly quietly at something a bit north of these B+ voltages so worried my bias is off.........then again, could just be those 6sn7s.
Seems simple to me that 21.5 volts divided by 330 ohms (small design change from original) equals 65ma but I'm wondering if I'm missing something. The design (attached) plays incredibly quietly at something a bit north of these B+ voltages so worried my bias is off.........then again, could just be those 6sn7s.
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You don't want to say what your meter or PSDU is telling you? Not even how far off it is?
Have you entered transformer resistance? Choke resistance?
Welp, used a different layout for the power supply and didn't want to get into it. Bridge rectifier on a 250 VAC supply with an CRC filter produced very different results but swap a choke for the resistor and it was more or less bang on with what PSUD calculated. Trying not to drown a potentially tired audience in data points, just seeing if the the issue had occurred before with the software.