My Aleph 5 isn't working

[DJG]

Yes, all the transistors gets warm in a few minutes, except for the BC 550. I will definetly have to check that.
Where could I get datasheets of BC 550 and MPSA 18(I don't have any literature at home and it's weekend... so I need it for the pin check).

thx,
DJG

 

[DJG]

Never mind about the datasheets. I've found them on google.
I will go check it out right away...
Will report further.

Regards,
DJG

 

[DJG]

OK, I have checked the pin layout and find out that both BC 550 are inserted wrong. So I have turned them and try again...
Now the whole output part(fets and 3W resistors) is boiling. Literaly. When I turn it on it takes about 10 seconds before the heatsinks goes hot, hot, hot! What could be the reason? IRF9610 are only warm(working temperature).

regards,
DJG

 

[MikeW]

Check you voltages across the source resistors if possible. If not check to see if you have a shorted Mosfet. Check the circuit around Q5, R17,18, and 19 they set the current. Let someone else take a look at it. It will give you a break and maybe they will find something you were not looking for. Good luck, Mike

 

[DJG]

I've had it and I made another Aleph 5 by air and it works perfectly on it's first start. The sound is great, etc.

I would like to thank all of you who helped me at solving my problems.

I will send pics of my finished A5. Can't wait...


Best regards,
DJG

 

[jleaman]

We all love pic's : O )

 

[dodonoid]

Hi, DJG

I'm happy, that you resolved the problem.

I just finished a tube preamp for the alephs (60), and sounds GREAT!!! Alephs needs preamp (this is my oppinion...), and a tube one makes the sound more warm and "sophisticated". You know what I mean... .

I will soon post a schematic and some pictures...

Regards,
Miki.