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^ Yes, I also noticed that. I thought my Epcos caps’ leads were large but they fit all Kevin’s boards.

While waiting for the delivery of the heatsinks, I built 2 short DC umbilical cables using 18awg wires. I experimented with new cable sleeve and the result is just great, very soft and flexible.

The large cap version seems to take 35mm power caps. Would suit your need if you want to use large ones.

It’s great to see more people working on the CFA-3, it should get more attention! Regarding the GRLV, this is the one I have been using in the Dynalo, Dynahi and forthcoming CFA-3. It’s version .47, dated 2018 with small caps (25mm diameter). I’m not so sure about the name because I downloaded it and renamed to something easier to remember.

I also had the protector powered off the GRLV in my Dynahi. It worked fine but the Dynahi itself is very stable. I'm not sure with stock parts on the silkscreen, what's the dc offset trigger value? I know amb's e12 will do at 80mV.

There are still missing parts but so far so good, transistors will be all mounted directly on the heatsinks. This is gonna be a dual chassis setup with custom cut heatsinks. I have some balanced headphone protector boards, not sure it’s worth adding the extra wirings... still waiting for Kevin’s ZF/SS switch board anyway.

I suppose we still have the same transformers specs like the full-sized GRHV? 330vac for 400vdc and 360vac for 450vdc outputs?

Thank you. Seems much cooler than I thought.

How hot does the heatsink get? Seems to me it's like 220-250mm long? That power hole seems to be meant for the 12mm Bulgin-like switch...

With my own machined aluminum buttons, they are quite smooth. You need to press a bit harder than the illuminated switches though. They also sell plastic buttons but the feeling was not so great.

You meant this? The button diameter is either 5mm or 10mm. I got bored of the illuminated switches after using so many of them and changed to this simple switch a while ago.

@RudeWolf How did you adjust the input trimpot? Also, what’s the part number of the 47uf ceramic cap on the CFA3 are you using? Great looking build, btw. I’m thinking of building the CFA3 with shorter heatsinks (300mm).

Great guide, thanks! What's the value of C1,C2 are you using?

The resistors sparked to the ground plane. I spent a good whole day elevating all of them. Also fixed the PSU, all voltages are ok now. (*wheww) Now back the amp section, the same thing happened. I couldn’t get the trimmers as low as 6.55V. Same as 740V. The LED at +500V didn’t lit. I wonder if the sparkling to ground plane affected the board itself?

So I swapped out the parts and fooled around with the trimmers, got all the batteries dialed correctly, offset was ~10V. Plugging the headphones and got sound! My Carbon definitely felt threatened. This was at 2am and I was both excited and sleepy, listened to it for a bit and turned off the amp. Next morning when I got it up again, some resistors in the amp sparked. Looks like I didn’t elevate them high enough 😕 Also the +250v rail went bad and couldn’t regulate, outputting +320v now. Been checking around but still couldn’t find the culprit. I wonder what would be the root of this?