Hi all! I posted about a year ago while I was doing my Aleph J build and received some great help from y'all. For the past year I've been greatly enjoying my amplifier, though I seem to have some sort of gremlin somewhere. This is / was my first build so thanks in advance for your patience.
The problem I am having is intermittent loss of output in both channels. This occurs perhaps once every hour or two for about 10 seconds at a time. The output cuts out in both channels after a few blips, is completely silent for ~10 seconds, then comes back. DC offset and bias have been confirmed to be in the desired range when the amplifier is functioning. The instability makes it a bit hard to measure for, though I could probably leave a multimeter hooked up and try to get some measurements in the blackouts. I'm assuming it's in the power supply. Operating temperatures seem within normal range, and this problem has occurred in cold and warm surrounding temps.
Thanks a lot!
The problem I am having is intermittent loss of output in both channels. This occurs perhaps once every hour or two for about 10 seconds at a time. The output cuts out in both channels after a few blips, is completely silent for ~10 seconds, then comes back. DC offset and bias have been confirmed to be in the desired range when the amplifier is functioning. The instability makes it a bit hard to measure for, though I could probably leave a multimeter hooked up and try to get some measurements in the blackouts. I'm assuming it's in the power supply. Operating temperatures seem within normal range, and this problem has occurred in cold and warm surrounding temps.
Thanks a lot!
You could try pushing on wires and components with a chopstick to see can you force the fault?
Could it be something heating, cutting out and then coming back in when it cools?
Could it be something heating, cutting out and then coming back in when it cools?
And if using the Universal PSU with euroblocks, just start with them. They are complete crap in the long run.
Thanks for all of your suggestions so far! Here are a few pictures of the power supply - unfortunately can't get a perfect angle on the PS board.
I traced the entire power path from wall to amp boards with a stick and was unable to trigger a fault. Some of my soldering is definitely suspect (I needed some help from this board the first time around as well!), so that is certainly an option. The timing is regular enough that I am inclined to believe some part is overheating and cutting out though. Due to the sporadic nature it's hard to measure during the failure, but maybe I'll set up some leads and wait.
I traced the entire power path from wall to amp boards with a stick and was unable to trigger a fault. Some of my soldering is definitely suspect (I needed some help from this board the first time around as well!), so that is certainly an option. The timing is regular enough that I am inclined to believe some part is overheating and cutting out though. Due to the sporadic nature it's hard to measure during the failure, but maybe I'll set up some leads and wait.
There has never been made a connector that will not eventually be a problem. Ditch all those connectors in the PS section and solder them directly is what I would do. Even solder joints in old equipment fail with expansion and contraction due to heat cracking the solder. I hard solder almost every project I have made. Not a fan of connectors being old and seeing too many issues caused by a bad connection. Most likely your problem but not the only one. Go over all the solder joints in the power supply as well with an iron. More problems are caused by not using enough heat when soldering than too little. Very unlikely a component problem.
Both channels, something with PS wiring. I had a similar issue with mine. Only cropped up when I moved them. Studying PS, I had a wire that had not been soldered!
Russellc
Russellc