Martex M200 amps

No changed with the 10k in . I had -150mV on turn on and DLT is out of circuit . Both sides DC offset are negative on turn on .I have to call it a night I get up early for work.I'll check in tomorrow
 
It "was" actually working .It was -16mV on turn on it went to 0 and then up 6mV and was going up slow . Then the VU pinned and there XXVDC on the speaker terminals . No fuses blew .I have replace everything except that zener .I put it back on the DLT and it now stays bright . So I'm thinking shorted output transistor(s)
 
And it's Q9 again. What can I look for to fix this. this is the original problem. this board has been worked on before I got it. I was thinking about having new boards made. I don't what these amp sound like so I don't know if it's worth the time and money.
 
Have you checked out Ampslabs kits?? Damn good stuff there..
 
I'm going to try two of these china boards. The build looks good so does the price. I'm just not sure how the units power supply is going to behave? or the VU meters (they're feed right off the speaker output jacks.
 
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Nope, just those specs. Connection seems straight forward. The DC + & - voltages, input + & - and ground and speaker - is CT of secondary . There is not much info on either amp board or unit so not sure it will work or not. If it does I will have to mod the heatsinks
 
I'm ready to power up this new board. I have still have the original board connected to the right and the new board on the left. I need some advise . Should I put and amp meter in series with the AC main(or + & - DC) and bring it slow on a Varrac . or use dim bulb tester (100watt) ? I can monitor the DC offset and power supply voltages . I have no heat sinks connected or input . What do you think ?
 
calman46 said:
I'm ready to power up this new board. I have still have the original board connected to the right and the new board on the left. I need some advise . Should I put and amp meter in series with the AC main(or + & - DC) and bring it slow on a Varrac . or use dim bulb tester (100watt) ? I can monitor the DC offset and power supply voltages . I have no heat sinks connected or input . What do you think ?
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Bring it up on tha variac in series with the DBT, ac mains in on the amp.
 
OK nothing bad happen. The bulb was dim and I watch + DC go up to 50V the DC offset was 8mV . Now I checked my the Variac with AC meter and my dial is off I had 137vAC at 120 mark . The voltages of the amp will be off with the DLT is circuit so do you think its safe to turn on without DLT and variac ????
 
From my Variac ,it will output 140vAC . I will monitor the AC on the units line cord
 
I'm going to take the DLT out and just bring it up slow with the variac .I'll watch the AC voltage along with the offset and + &- DC voltages
 
Sorry calman, I didn't notice you posted. So you use the 140 scale so you get full voltage in spite of the DBT in line?
 
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