So new update. Only had time to populate the outputs Yesterda. I do them all a one time now.
today set up for testing. Set out with dim build and all sorts of meters hooked up.
now to be humble
i started the varic and as I bought up at about 30 volts the unit was drawing about 1 amp. This is not right so as I thought about it the neg 1/2 watt left channel fuse blue on the back plain. This was troubling as everything had gone text book perfect. The funny thing is I powered to fully without fuses and no fuss. Spent 2 hours checking my work and perplexed as to who this came to be. Well it was operator error. The meter I used for the measure negative supply voltage on the control board had probes connected to it prior to testing. I replace them with a mini grabber setup. I plugged into the amp circuit instead of the everything else circuit. Well that’s behind me and the rest of testing went well.
so here are the numbers.
right channel
dc offset .40 mv
bias as run in .362v
output into 8 ohms at 110 volts input. 54.67 v &@120 v 56.6 v
output distortion .006 thd+n
residual noise connected to 8 ohm load and 1k on imput 172uv. And 120uv without 8 ohm load
left channel
dc offset .22mv
bias as run in .362v
output into 8 ohms at 110 volts input. 54.42 v &@120 v 56.1v
output distortion .0068 thd+n
residual noise connected to 8 ohm load and 1k on imput 190uv. And 135uv without 8 ohm load
so this may be the quietest amp I’ve built. thanks to some tips along the way.
shout out to Joe who had added an extra fuse in my order. What a guy.
The test drive went well tonight with about 6 hours on it. I have a set of Joe’s meters to build and will upgrade to those soon. Next up is of coarse another dual 500. It’s on the bench now.
So new update. Only had time to populate the outputs Yesterda. I do them all a one time now.
today set up for testing. Set out with dim build and all sorts of meters hooked up.
now to be humble
i started the varic and as I bought up at about 30 volts the unit was drawing about 1 amp. This is not right so as I thought about it the neg 1/2 watt left channel fuse blue on the back plain. This was troubling as everything had gone text book perfect. The funny thing is I powered to fully without fuses and no fuss. Spent 2 hours checking my work and perplexed as to who this came to be. Well it was operator error. The meter I used for the measure negative supply voltage on the control board had probes connected to it prior to testing. I replace them with a mini grabber setup. I plugged into the amp circuit instead of the everything else circuit. Well that’s behind me and the rest of testing went well.
so here are the numbers.
right channel
dc offset .40 mv
bias as run in .362v
output into 8 ohms at 110 volts input. 54.67 v &@120 v 56.6 v
output distortion .006 thd+n
residual noise connected to 8 ohm load and 1k on imput 172uv. And 120uv without 8 ohm load
left channel
dc offset .22mv
bias as run in .362v
output into 8 ohms at 110 volts input. 54.42 v &@120 v 56.1v
output distortion .0068 thd+n
residual noise connected to 8 ohm load and 1k on imput 190uv. And 135uv without 8 ohm load
so this may be the quietest amp I’ve built. thanks to some tips along the way.
shout out to Joe who had added an extra fuse in my order. What a guy.