Aleph 5 help

MikeW · 24th October 2002, 01:11 AM

I plugged in my 1st half of my first Aleph 5 and the led went on. No music, but no smoke either. I think the input is working ok. I have no voltage drop across R14. The voltage on my output mosfets is drain +33, Gate -34, source -34. I took out Q 4 and checked it with a meter. It looked ok. Any idea of what i could have blown up? At least the power supply is working.

Mad_K · 24th October 2002, 07:59 AM

check q1-q3

PedroPO · 24th October 2002, 12:05 PM

I had exactly the same problem. It was the R17 221k resistor that I mistook by 22k! the dam red strip did seem orange actually.

I changed itt and music is flowing perfectly!!!!
good luck!

MikeW · 24th October 2002, 03:32 PM

I will take out the Q1-Q3 and measure the Vds. I tried the other main board with the same outputs and it has a 9 volt drop across R14.I just ordered some more IRF9610 and IRFP140n's. It is always good to have some extra parts. I am sure something is not right. Thanks for your help so far.

MikeW · 5th November 2002, 02:33 AM

Has anyone finished with Harvardians boards? I have ordered more IRF610's and still can't get them to work. Any help would be welcome. In the mean time I built a Zen 4 and it is working fine. I will give it one more try. If I can't get this Aleph 5 working by the end of the week is anyone interested in the boards?

mefinnis · 5th November 2002, 10:27 AM

Hi Mike,

Don't give-up too soon. I appreciate it can be near soul-destroying when these things don't work but it will be worth the effort.

Pedro's comment about R17 is valid ..... I actually did this myself also .... doh! This produced exactly what you are describing for both Pedro and myself.

Failing this, what is Vgs across (1) the current source, (2) the output stage, (3) Q3.

Can you get a friend to look over your circuit. Trying to debug your own creations is often clouded and a fresh pair of eyes will find something you have overlooked.

Best of luck.

Mark

PedroPO · 5th November 2002, 11:07 AM

LOL Mark!

It was my most stupid mistake EVER!!!

It happen to every body I guess, not just me ..

mefinnis · 5th November 2002, 08:41 PM

Actually, as I try to help Mike off-line, it is R19 in my diagram.

cheers, mark

MikeW · 7th November 2002, 11:44 PM

Mark and Pedro, thanks for the help. I have one channel working. Hopefully the next channel will be easier. I must have blown a transistor. There are only 5 on the board so I changed them all and beautiful music.

PedroPO · 8th November 2002, 10:39 AM

I'm glad for you

24th October 2002, 01:11 AM	#1
MikeW diyAudio Member Join Date: Sep 2002 Location: North of Boston	Aleph 5 help I plugged in my 1st half of my first Aleph 5 and the led went on. No music, but no smoke either. I think the input is working ok. I have no voltage drop across R14. The voltage on my output mosfets is drain +33, Gate -34, source -34. I took out Q 4 and checked it with a meter. It looked ok. Any idea of what i could have blown up? At least the power supply is working. __________________ MikeW

24th October 2002, 07:59 AM	#2
Mad_K diyAudio Member Join Date: Sep 2002 Location: Norway	check q1-q3 __________________ Mads K

24th October 2002, 12:05 PM	#3
PedroPO diyAudio Member Join Date: Jan 2002 Location: Lisbon,Portugal	I had exactly the same problem. It was the R17 221k resistor that I mistook by 22k! the dam red strip did seem orange actually. I changed itt and music is flowing perfectly!!!! good luck! __________________ Pedro Oliveira

24th October 2002, 03:32 PM	#4
MikeW diyAudio Member Join Date: Sep 2002 Location: North of Boston	I will take out the Q1-Q3 and measure the Vds. I tried the other main board with the same outputs and it has a 9 volt drop across R14.I just ordered some more IRF9610 and IRFP140n's. It is always good to have some extra parts. I am sure something is not right. Thanks for your help so far. __________________ MikeW

5th November 2002, 02:33 AM	#5
MikeW diyAudio Member Join Date: Sep 2002 Location: North of Boston	Harvardian Boards Has anyone finished with Harvardians boards? I have ordered more IRF610's and still can't get them to work. Any help would be welcome. In the mean time I built a Zen 4 and it is working fine. I will give it one more try. If I can't get this Aleph 5 working by the end of the week is anyone interested in the boards? __________________ MikeW


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5th November 2002, 10:27 AM	#6
mefinnis diyAudio Member Join Date: Feb 2001 Location: Adelaide, Australia	Hi Mike, Don't give-up too soon. I appreciate it can be near soul-destroying when these things don't work but it will be worth the effort. Pedro's comment about R17 is valid ..... I actually did this myself also .... doh! This produced exactly what you are describing for both Pedro and myself. Failing this, what is Vgs across (1) the current source, (2) the output stage, (3) Q3. Can you get a friend to look over your circuit. Trying to debug your own creations is often clouded and a fresh pair of eyes will find something you have overlooked. Best of luck. Mark

5th November 2002, 11:07 AM	#7
PedroPO diyAudio Member Join Date: Jan 2002 Location: Lisbon,Portugal	LOL Mark! It was my most stupid mistake EVER!!! It happen to every body I guess, not just me .. __________________ Pedro Oliveira

5th November 2002, 08:41 PM	#8
mefinnis diyAudio Member Join Date: Feb 2001 Location: Adelaide, Australia	Actually, as I try to help Mike off-line, it is R19 in my diagram. cheers, mark

7th November 2002, 11:44 PM	#9
MikeW diyAudio Member Join Date: Sep 2002 Location: North of Boston	Mark and Pedro, thanks for the help. I have one channel working. Hopefully the next channel will be easier. I must have blown a transistor. There are only 5 on the board so I changed them all and beautiful music. __________________ MikeW

8th November 2002, 10:39 AM	#10
PedroPO diyAudio Member Join Date: Jan 2002 Location: Lisbon,Portugal	I'm glad for you __________________ Pedro Oliveira

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