Trouble with my Aleph-X

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I’m about to start my Aleph-X and having trouble. I’m using a light bulb for inrush current protection.
Without connecting to the board the power supply is ok. The light bulb starts glowing and slowly it’s getting weaker until it won’t glow anymore. But when connecting it to the PCB about halfway when slowly racing using a variac the light bulb won’t totally stop glowing. There’s a faint constant light that won’t go away.
I’m using Kristjans board.

Anyone knows what the problem is?
 
anders.a said:

Without connecting to the board the power supply is ok. The light bulb starts glowing and slowly it’s getting weaker until it won’t glow anymore.

When powering up, the glow of the light bulb is actually the charging of the supply capacitors made visible. When no amp connected, the caps remain charged but have nothing to supply their current to. Hence the light stops glowing when the caps are fully charged.

/Hugo
 
Because this is a class A amplifier it constantly draws a huge amount of current. It is heavily biased, simply explained, it draws the maximum current that it can deliver at all time. Therefore the light bulb will always be able to burn, be it only a little bit. Try increasing the current draw of the amp, you should notice more glow.

/Hugo
 
I’ve just connected the amp. Before testing for DC. Should there be a temperature rise anywhere? Is there any voltage on any component witch would tell me that’s everything is ok? Should I measure the IRF 9610 and IRFP 240 voltage? And if so. How should I measure it? Between G D or S
 
I could go through the whole process of 'How to fire up the AlephX' but you might want to have a look at the WIKI and other very informative threads. Note that at least your big heatsinks should warm up to a reasonable temperature. After say 1/2h you should be able to leave your hands on them for at least five seconds. Hotter is too much.

/Hugo
 
Even without thermistor, it is possible to fire up the AX because you use a variac.
The two 50k pots set the bias and the 200ohm controls the DC.
I'll look at the DC measurements in a moment.
The 0.3V between both halves (differential DC) should be below 100mV. The absolute DC (between out and ground) <1V.

/Hugo
 
I did manage to get current to the PCB and of course I did fry some components T15, T13 and R22,R29 which should corresponded to Q10 and Q11 on Hifizens PCB.
My question is:
What could be the problem? Broken BC550C? Did I turn on the variac to fast?
Also if I try this time without the IRFP 240 to see what’s he problem. What should I look for?
I’m using his PCB http://www.kk-pcb.com/alephx.html
And this power supply http://www.kk-pcb.com/power-x.html
 
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