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The power supply is working now. I used the BUZ80 instead of the Ixys 10M90S with some modifications: But the amp makes problems. The problem seems to be also the Ixys parts. I measured ~9V across R12/R19 only at one transistor. I guess this is ok? The other 3 seems to be defective (~0V across the R12/R19). I guess nearly all the Ixys parts from Littlediode were defective. Or they are fake parts. I will complain about the parts.

The printing on the power supply board for BR1 is wrong. The "+" is at the wrong side. I guess it's a board from the current group buy (Production Rev 0.6). So be carefull if you have one of these boards.

Thanks, this answers my question

Nobody any idea?

How do I build the Power Supply v8 as simple version (only zener diodes)? I guess there is a connection between the Cathode of D5 and the Gates of Q1/Q2 missing. In version 4 was there a 250kOhm resistor (R23). Should I add it also in v8?

@livewire The insulation is ok now, I used the thick insulators and plastic screws. Also all traces were cut. The problem is really the current source. A friend showed me an alternative current source with the BUZ80, which is easily to get here.

The voltage is much too low, only some mV. The strange thing is that in the working part it's also too low. I really have no idea why they are defective. I changed Q8 and Q17 already. I bought them from littlediode. I hope they don't sell faked parts. Is there any alternative for the 10M90S which is better available and not so expensive in Europe? They cost > $10 and it takes two weeks to get them

After having no success at all I tried this today with 3 x 160V zeners. It's still not working. The output voltage raises slowly. After 10 min it reaches 285V. Is it normal that the voltage across the zener diodes drops instantly if I want to measure it? Also the voltage across D7-D10 is IMHO too low. I get only 98V and not 580 V as expected.

Was anybody successfull to build the PSU version 3 at the corresponding PCB? I have still problems, livewire had problems too. Perhaps there's something wrong with the PCB? Or this version was not the best solution. Version 4 has some changes.

Thanks for your help I measured Q4-7 (all voltages to GND): Q4 (B/E/C): 46,15/46,60/30,1 Q5 (B/E/C): 54,7/47,3/17 Q6 (B/E/C): 27,8/30,4/0,6 Q7 (B/E/C): 27,8/16,8/0,02 Output voltage was ~56V. The voltage is not stable and fluctuates a little bit. I didn't matched the transistors in the power supply. Only in the amp section.

At the LM4040 I can measure 10V. I will measure at the other points tomorrow. Yes, I read it. The only question is if I should leave the cap in parallel to the zeners. I guess yes because I saw it in other power supplies. Thats the problem. Generally some more information and help would be nice

My power supply is still not working. Could any of the changes between Version 3 and 4 help? If I change to the simple version with zener diodes I would only need the diodes? Also the cap in parallel (C5, C6)? I get ~60V from the positive rail. I changed all semiconducters already

Not yet. I'm still struggling with the power supply

What did you do? It's possible This was done with a cordless electric screwdriver and a hand thread cutter. It's a Pesante Dissipante 2U:

Thanks for your reply. I will try changing the parts first.

My power supply is still not working Q8 and D1 were fried at first test and had a short. I changed them and also Q1/Q2. But Q1/Q2 were ok, no change. I get ~50V output voltage at the positive rail. The negative rail is working. The other transistors in the positive rail seem to be ok. A diode test was ok and there're also no shorts. The LM4040-10 has the desired 10V. What should I try next? My next idea is changing all the other transistors. Is there a schematic with operating points like AMB has?

I used a fiber-glass reinforced silicone foil which is rated for 4kV. Mouser is too expensive to order only some small parts. Is this also ok: http://de.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2182609? The 7721-3PPSG will fit? It has a inner diameter of 2,84 mm for the screw. I still had to tap the heat sinks for M3 because they have 6-32 UNC, which is a little bit thicker than M3 and was too thick for my insulating shoulder washers (these one: http://www.reichelt.de/Waermeleitpaste-Iso-scheiben/IB-2/index.html?;ACTION=3;LA=444;GROUP=C88;GROUPID=3384;ARTICLE=8713, the IB 2).

No good news. The power supply makes problems. The positive rail is not working proberly. First it had a very low output voltage, ~80V. After some testing the output voltage was the same as the input voltage and two parts are defective: D1 (zener diode 24V) Q8 (IXYS 10M90S) Both have a short. The other parts seem to be ok. I made a diode test at the bipolar transistors. The FQPF8N80 are not shorted. I hope there's noting else damaged.

The boards will be mounted with a little overlap to fit in the case. So this capacitor had to be mounted at the back side.

I finished the PCBs today and will start to test the amp tomorrow. The pots at the power supply board have to be set fully counter clockwise for initial setup?

I'm not sure. Here are the datasheets: http://www.st.com/stonline/books/pdf/docs/10850.pdf and http://www.st.com/stonline/books/pdf/docs/11781.pdf.

Is there an alternative for the IXTP01N100D? I guess the drain to source voltage is the most important point? What about the STF5NK100Z or STP8NK100Z from ST? They have also 1000V and 30V gate to source voltage. And are easier to get outside the US.

Thanks for the quick answer. Is 40VA per winding sufficient? P.S. A info for the guys from outside the US. Littlediode also has the IXCP10M90S. The price is

I have a set of PCBs here and have still a question about the transformer. I read earlier in the thread 475 volt and 39VA each winding. Is this still up to date? The board is marked with 485V. I guess this is for 500V DC? How much voltage difference does the regulator need?