Hello Everyone!
After being out of my system a little while I decided to hook up my Aleph J again. Before putting it into my audio rack I powered it back up and let it warm up for an hour to check if the bias or offset had drifted at all and to my delight they were exactly as they were a year ago with a bias of 420mv and almost spot on offset at -0.1mv
The one thing I did notice right away is that all the big 3watt Panasonic source resistors that were once a very light blue were now a light brown colour. There aren’t any burn marks or discolourations that I can see on the pcb, and as per the build recommendations the 3w resistors are elevated from the board for heat dissipation (about 1/4”) and the amp seems to be functioning as expected.
I have read that the J runs “very hot” compared to other FW amps so I’m not sure if this is a problem or not. The amp is well ventilated with nothing on top or around it and the heat syncs are at approx 51deg C. It’s also my first Diy build from a few years ago.
Should I be concerned?
After being out of my system a little while I decided to hook up my Aleph J again. Before putting it into my audio rack I powered it back up and let it warm up for an hour to check if the bias or offset had drifted at all and to my delight they were exactly as they were a year ago with a bias of 420mv and almost spot on offset at -0.1mv
The one thing I did notice right away is that all the big 3watt Panasonic source resistors that were once a very light blue were now a light brown colour. There aren’t any burn marks or discolourations that I can see on the pcb, and as per the build recommendations the 3w resistors are elevated from the board for heat dissipation (about 1/4”) and the amp seems to be functioning as expected.
I have read that the J runs “very hot” compared to other FW amps so I’m not sure if this is a problem or not. The amp is well ventilated with nothing on top or around it and the heat syncs are at approx 51deg C. It’s also my first Diy build from a few years ago.
Should I be concerned?
Since their value is stable, it's probably just the resistor paint turning.
They're only dissipating less than 0.5W each
They're only dissipating less than 0.5W each