sorenb

looks like the T2Shrunk

If you look at the schematic, one resistor string reference O+ whereas the other reference O-

The BH or T2?

My experience with Phoenix connectors is that you can actually put in a wire, and tighten the screw with out getting a proper connection. I usually check the connection from somewhere else on the boards than the actual connector. Since you have been fiddeling with the wires I guess the Phoenix connector is the culprit here rather than something more serious.

in terms of "learning" something here, can you be more specific to what might be wrong in your view? in rgrds to the Blue Hawaii I guess the "what the fuck were they thinking bits" must be the found in the third of fourth stage of the Blue Hawaii? what should be different or improved upon in those stages?

Can you elaborate a bit on the reason why you believe that the circuit design is flawed? does it include both PSU and AMP board from the Carbon Group Buy?

So you are talking about noise you've discovered using your custom boards rather than the GB boards? Can you elaborate a bit on the reason why you believe that the noise your are measuring is caused by leaking resistors?

Glad to hear, although it took a very loooong time to arrive.

Will there be new V5 and GR HV boards with ground plane? I guess, if people mount the components raised and stick to boards of good quality it shouldn't be a problem?

Meaning that any Carbon build will be "severely compromised" just by using the boards from the Group Buy?

That looks like your own personal edition of the "kgsshvpssicfetsmall3" having 330uF pre-reg, and 220uF post-reg - but as you like mini, you've replaced those 220uF for 100uF and shrinked it a bit to go from small to mini. The only schematic the other persons did publish has 680uF pre- / post- reg, so how are people to know that 680uF caps is NOT what the PSU is designed for?

Meaning that the GND from the PSU are connected two times at each AMP, and uses the signal GND for ref for the HE90 voltage divider?

Thanks. How does the Carbon compare to your BHSE?

Appriciate your description, thanks. In terms of change in sound, have you noticed any difference during the time you've had it?

I'm sure it does ... a pretty fine amp that is ;o) Have you notice any change in how the Carbon presents the deep end during the time you've had it?

Nice build you've got there Purk :o) Un-twisting the output wires, isolating the AC wiring and some hot snot to further secure the caps would be an easy fix.

Fiat lux ... Fiat musica

If someone wants to power up the Circlotron using a variac it might cause a bit of trouble. When powering up the driver it has B+ at the output until the driver output stage begins to conduct current, then it drops to some ~0V (if proper adjusted that is) Having B+ at the input of the Circlotron output board will turn on the SiCs at full throttle going for 7,5Amps (900V/120ohm) ...however limited by the HV900 current limiter. Better to power up the driver at full mains, and afterwards dialing in the output boards + HV900's using a variac. That approach seems to work out pretty ok. Only applies to the HV900: For anyone building this Kevin recommends to increasing the current sensing resistor from 5,1ohm -> 12ohm to further protecting the output if something should go wrong. /Edit: as per Kevins comment below.

I'd rather change the values off the zener-string a bit an tap the NB from there. Then you only need to add three resistors and a couple of caps. Like Kevin has done here: As you may notice, there are two NB BIAS connections corresponding to the two pins on the jack. /S

for the amp @20mA they seem to be a bit on the small'ish side

You have been added to the sheet here

probably the BIAS ... the HV has balast resistors that will burn the energy

it comes and goes ... I often loose it when changing into the DIY section ...a refresh however solves the problem in my case

everyday is a Black fried day