AMB Laboratories DIY Audio

[lgulyas]

Plastic.

[lgulyas]

I thought it over and the only difference between the working and not working setup was that the interconnection cable(to the KRK Rokit GP6 active monitor) was not pluged in. I also added some new picture:
https://plus.google.com/photos/10771701 ... 5mrufHW0AE

Any idea?

[lgulyas]

Between pin 4 and 7 the voltages is 4,7V and between pin 4,7 and IG is half of that value on each OPAMP so the TLE works.
Between gamma 2RCA out ground(M3 IG) and v-(M3) there is a short circuit.
Q5+ CE 18,6V --> blown... but why?
Q5- CE almost 0V

[amb]

What power supply are you using for the M³ and for the γ1/γ2? Is the one for the M³ fully isolated from AC ground? (i.e., neither of the two contacts at its DC output should have continuity to the ground pin on its AC plug.

[lgulyas]

I am using a MikroTik 24HPOW adapter (24V 1,6 A)http://routerboard.com/24HPOW. Is it possible that I am orientating the Q5+ reversily (I forgot to check the transistor collector emiter base legs)? But if I orientated wrongly. Is it possible thet the M3 work for a while and than Q5+ gives up and die because of wrong orientation?

[amb]

I am using a MikroTik 24HPOW adapter (24V 1,6 A)http://routerboard.com/24HPOW.

Measure the resistance between the AC ground pin and either of the DC plug's contacts. Are any of these showing a short?

Is it possible that I am orientating the Q5+ reversily (I forgot to check the transistor collector emiter base legs)? But if I orientated wrongly. Is it possible thet the M3 work for a while and than Q5+ gives up and die because of wrong orientation?

If you're using the proper 2N3904 transistor for Q5 (not 2N3904Cxx), then it should be installed according to the board silkscreen outline.

[lgulyas]

AC ground and dc plug has a short on v- side of the plug.

[amb]

AC ground and dc plug has a short on v- side of the plug.

OK, there is a problem right there. You need an isolated adapter (see the description in the M³ website parts list section).

[lgulyas]

Can I just cut the ground wire of the AC cable or I have to buy another one?

[amb]

Can I just cut the ground wire of the AC cable or I have to buy another one?

I wouldn't recommend cutting the ground prong off without knowing what's inside the supply, the ground connection may be necessary for it to work properly.