Hi guys.
I have a Hafler P3000 power amp that blew the MOSFETs on one channel, quite a while ago. These are the famous 2SJ162 and 2SK1058. So I bought the exact same parts on eBay, 2 pair of each. When they arrived they didn't work, complete crap. Someone sold me fake parts. Now I ordered (and already received) the EXICON 10P20R and 10N20R replacements, they work right away. I readjusted the bias from 400 mA with EXICON ICs to 200 mA (as specified in the manual).
Now I ran into a new issue: when I connect the 2 wire link cable for bridge mode, a noise (half way between hiss and hum) comes out of the speakers. Probably some ground loop but I cannot figure out whe it is.
Another thing is that on the channel with the new ICs now the signal LED is always turned on, even with input vol turned all the way down. So there must be some signal present that is higher then the other untouched channel, but I can't hear anything.
I have a Hafler P3000 power amp that blew the MOSFETs on one channel, quite a while ago. These are the famous 2SJ162 and 2SK1058. So I bought the exact same parts on eBay, 2 pair of each. When they arrived they didn't work, complete crap. Someone sold me fake parts. Now I ordered (and already received) the EXICON 10P20R and 10N20R replacements, they work right away. I readjusted the bias from 400 mA with EXICON ICs to 200 mA (as specified in the manual).
Now I ran into a new issue: when I connect the 2 wire link cable for bridge mode, a noise (half way between hiss and hum) comes out of the speakers. Probably some ground loop but I cannot figure out whe it is.
Another thing is that on the channel with the new ICs now the signal LED is always turned on, even with input vol turned all the way down. So there must be some signal present that is higher then the other untouched channel, but I can't hear anything.
You can't replace a tire without a jack.....
If the unit originally worked properly, the fake parts may have caused other damage.
If the unit originally worked properly, the fake parts may have caused other damage.
I am getting a P3000 shortly. Could you please tell me the measured DC voltage on the output rails? Thnks
Do you meant DC millivolt on the (+) and (-) output posts? On the "good" channel with original MOSFETs, no input signal and no load connected, input control turned all the way down, it oscillates between 3.8 and 6.3 mVDC.
I you a different measurement, please tell me.
I you a different measurement, please tell me.
no, the power supply voltages.
either at the level of the large capacitors (in DC), or before the diode bridge (in AC) .
Before the rectifier it has 49.1-0-49.1 VAC, after the rectifier at the large cap its +66.5 / -66.5 VDC.
There are actually 2 separate transformers on one metal core in this unit. The primary windings have no center tap, but each secondary winding (49.1-0-49.1 for the power and 15-0-15 for the preamp section) does have center taps. That 4 secondaries in total, 2 for each channel.
There are actually 2 separate transformers on one metal core in this unit. The primary windings have no center tap, but each secondary winding (49.1-0-49.1 for the power and 15-0-15 for the preamp section) does have center taps. That 4 secondaries in total, 2 for each channel.
