audio-talk

As discussed briefly on the 6.3V heater reg thread it's a bit of a challenge fitting the HT trafo, rectifiers and raw DC filter, HT shunt reg, heater trafo and regs into the same box as the audio circuit. The jfet MC pres have been a success and I want to include one with PS and trafo too, just for ...

Thanks for sharing your experience Mike. I'm struggling to get my head around AC umbilicals tbh, my hurdle to climb.

Moving the HT and heater transformers to a separate box would make a big difference to the space available. But it just doesn't feel right having the rectifiers so far from the transformers. Presumably each individual wire, or at least the same pair, in the umbilical needs screening? And even the ch...

Back to a one-box phono I think, it has a simpler set of problems to solve I think. Unfortunately space is the main one for me at the moment with the single box approach.

Mmmm, food for thought...

I was thinking more about potential issues with a single raw DC supply feeding multiple regs connected by an umbilical.

Andrew's design and specification works well for me, but I can accommodate your suggestions in the pcb.

I'm considering putting the C3g Aikido in two boxes, power supply on one and audio in the other. The HT shunt reg can go in the power supply box as it has sense wires, but the two heater regs should go in the audio box. I want to pass DC, not AC, through the umbilical so thought I'd have a common ra...

You like a challenge . Andrew's or Rod Coleman's filament regs would do it, probably.

Surely it's got to use 45s Steve!

good find!

Does this also hold if AC heaters are used i.e. no following rectifiers?

Thanks Morgan, good info.

It's too much work for me though, maybe when I retire. TBH though I can't imagine ever having that much time to wind my own. Maybe I'll be surprised?!

What a splendid idea, that didn't occur to me when you mentioned the two 10nF caps.

Is 10nF critical? Mark suggests 10nF for Cx, the cap across the secondary, so two in series would become 5nF. Or if 20nF is okay I can stick with my existing Cx and Cs.

I thought this was an interesting piece on Don Garber and Fi, and the NY valve scene back in the day. It really made me wish I could find my Sound Practices CD.

https://jeffsplace.positive-feedback.co ... -godspeed/

I've even started adding the two caps and resistor to PS PCBs now, to make it easy to implement