Reading and commenting in this post, I have an Aleph J in its build stage at the moment so I am taking an interest in this thread.
Correct me if I am wrong.
With no load connected to the amplifier I cannot see a mode of failure from connecting a single rail power supply. OK it wouldn't work but I can't see any component that would be put under duress.
Correct me if I am wrong.
With no load connected to the amplifier I cannot see a mode of failure from connecting a single rail power supply. OK it wouldn't work but I can't see any component that would be put under duress.
...other than the speakers, since there will be a heck of a DC load on the output.
there was a load ; #1:
"If I turn the source output up to the extreme, I'll hear some muffled, highly distorted sound."
"If I turn the source output up to the extreme, I'll hear some muffled, highly distorted sound."
I also said it wouldn't work.
My point is that I can't see why components would fail.
OK, he had a load. Yes, the MOSFETs would be under duress trying to destroy the speaker.
If you get a gate to substrate short on the MOSFETs, yes that could destroy the driver stage.
My point is that I can't see why components would fail.
OK, he had a load. Yes, the MOSFETs would be under duress trying to destroy the speaker.
If you get a gate to substrate short on the MOSFETs, yes that could destroy the driver stage.
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Zen Mod: I want to make sure I'm taking this measurement correctly before powering up. I have the positive lead of my meter clamped to the collector on Q3 and the negative lead clamped to the V- pad. I can observe between 1R and ~60R between these connection points during the full range of the pot. When you say "minimized", do you want me to set it at the minimum or maximum resistance? I'm guessing minimum - but I don't want to make any mistakes.
minimum means 0 ohms
if you rotate place of probes , do you have same 60R in max position ?
how that compares with same measurement on functional channel (without touching any setting, just as is now?)
60R for max seems fishy, at least now when I'm sleeeeeepy
if you rotate place of probes , do you have same 60R in max position ?
how that compares with same measurement on functional channel (without touching any setting, just as is now?)
60R for max seems fishy, at least now when I'm sleeeeeepy
The other possibility is that it was first run without any Keratherm or other insulator beyond the anodized layer on the heatsink. If a shaving or burr scratched through the anodized layer, it may have introduced a short.
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I re-tested with probes rotated (then again as originally placed). I stand corrected. The range is 1R - 73R, regardless of probe orientation.
The functioning side reads 69R.
The functioning side reads 69R.
Upon power-on, voltage on speaker output went to +20.4V.
No current was observed across R16.
Rails were 23.4V (+/-) referenced to ground.
Voltage across R8 was 8.42, but I need to figure out if it was positive or negative.
No current was observed across R16.
Rails were 23.4V (+/-) referenced to ground.
Voltage across R8 was 8.42, but I need to figure out if it was positive or negative.
Update: I fiddled with R7 trying to see a change in voltage. I'm now able to get to zero; but, unlike the working side, a slight movement of the pot (1/16 of a turn) will change 2-4V. The voltage can be adjusted negative, as well.
R27 will make the output voltage change, but I haven't been able to adjust it to cause a voltage reading across R16.
R27 will make the output voltage change, but I haven't been able to adjust it to cause a voltage reading across R16.
that's irrelevant how you oriented probes across R8
when you set output offset near 0, is there anything measurable across source resistors (mosfet sources)?
when you set output offset near 0, is there anything measurable across source resistors (mosfet sources)?
power off, and do everything in your powers to be sure that R27 is set to max settable value, for start
then it's easy to dial down
then it's easy to dial down
I'm assuming those are R9, R10, R11, & R12?
Nothing registers with the meter in the 200mv range.
Also of note, the output was 13v when power was turned on again. It falls steadily. I was able to force it down to 0 by adjusting R7 for the test.
There is a smell - of hot electronics, for lack of a better term; but not burning/smoke.
Nothing registers with the meter in the 200mv range.
Also of note, the output was 13v when power was turned on again. It falls steadily. I was able to force it down to 0 by adjusting R7 for the test.
There is a smell - of hot electronics, for lack of a better term; but not burning/smoke.
output source resistors, again for ooomteeenth time, are R16,R17,R18,R19
power off
move R7 to 0 ohms, do what I said with R27 trimpot - max it , then power up again, try setting procedure again
R27 for coarse Iq (reading across any of said source resistors) , R7 for offset and fine set of Iq
power off
move R7 to 0 ohms, do what I said with R27 trimpot - max it , then power up again, try setting procedure again
R27 for coarse Iq (reading across any of said source resistors) , R7 for offset and fine set of Iq
Zen Mod: THANK YOU! Thank you, so much, for being patient with me!
R7 is very, very sensitive compared to the other side; but I can get close to 0V on the speaker output w/ 354mv across R16.
The voltage on the speaker out is slowly climbing. When I started typing this, it was +.1. It's now -2.1.
R7 is very, very sensitive compared to the other side; but I can get close to 0V on the speaker output w/ 354mv across R16.
The voltage on the speaker out is slowly climbing. When I started typing this, it was +.1. It's now -2.1.
observe it, and be careful
if you can't achieve same ease of setting as functional channel , do not connect speaker in any case
take reading across all 4 source resistors and write down and post here
see ya 'morrow
if you can't achieve same ease of setting as functional channel , do not connect speaker in any case
take reading across all 4 source resistors and write down and post here
see ya 'morrow