Hi,
I have Onkyo Integra M 508 power amplifier, and left channel is blown. Even if all transistors are changed, i.e. power out stage, drivers, small frequencies trans. etc., it will work just few minutes and everything will die again.
There are 8 big capacitors 10000uF/90V and seems they are fine, though.
My question is, does anyone has schema or similar documentation for onkyo, or any kind of help will be appreciated.
Thanks in advance
I have Onkyo Integra M 508 power amplifier, and left channel is blown. Even if all transistors are changed, i.e. power out stage, drivers, small frequencies trans. etc., it will work just few minutes and everything will die again.
There are 8 big capacitors 10000uF/90V and seems they are fine, though.
My question is, does anyone has schema or similar documentation for onkyo, or any kind of help will be appreciated.
Thanks in advance
hi netlist,
can i have the schematics too? thanks...
how about an onkyo integra m510, i believe their top of the line way back then...thanks
you may send to rodenbarca@yahoo.com or jbuenotecson@yahoo.com
thanks a lot,
tony
can i have the schematics too? thanks...
how about an onkyo integra m510, i believe their top of the line way back then...thanks
you may send to rodenbarca@yahoo.com or jbuenotecson@yahoo.com
thanks a lot,
tony
I have the M510 Integra on order and it was ONKYO's 1995 Flagship Amp.. Waiting for it to arrive.
This amp claimed 0.003 IM and .005 THD at rated output..
300watts/ch into 8ohm. 750watts/ch into 4ohm.
1Hz-100KHz +-.1db
120db SN
If anyone wants to look i'll try and post.
The M508 is no slouch though.. Look at the following specs.
The M508 claims 200W/ch into 8. 460W/ch into 4
Same frequency responce as above but has lower distortion .003 for both IM and THD at rated output.
This amp claimed 0.003 IM and .005 THD at rated output..
300watts/ch into 8ohm. 750watts/ch into 4ohm.
1Hz-100KHz +-.1db
120db SN
If anyone wants to look i'll try and post.
The M508 is no slouch though.. Look at the following specs.
The M508 claims 200W/ch into 8. 460W/ch into 4
Same frequency responce as above but has lower distortion .003 for both IM and THD at rated output.
i was reveiwing a Stereo review magazine for all products created in 1995 and was reviewing specs on Power amps. I was so curious on the technology they used that I just ordered the service manual. Maybe one day i'll have the chance to work on one of these animals. 
The only amp that comes close to these specs was a McIntosh MC500 that had a output autoformer. I'd like to see a schmatic of this too, and try to figure out how they did it..
I have a fealing that they are blowing a bunch of smoke. Review of the amp will tell the story.
The only amp that comes close to these specs was a McIntosh MC500 that had a output autoformer. I'd like to see a schmatic of this too, and try to figure out how they did it..
I have a fealing that they are blowing a bunch of smoke. Review of the amp will tell the story.
Thanks netlist
For others who may want this complete service manual for the M 508, I have put this on: www.audio-circuit.dk for free download. Just look under >Schematics< ......
Just a small warning to those using slow band ... Size is almost 5 mb
For others who may want this complete service manual for the M 508, I have put this on: www.audio-circuit.dk for free download. Just look under >Schematics< ......
Just a small warning to those using slow band ... Size is almost 5 mb
"it will work just few minutes and everything will die again. "
If R423 is dirty the amplifier will blow up.
D423, a dual diode, frequently goes intermittent in Marantz gear of the same era, and a big puff of smoke follows.
I would make a bias clamp from seven series connected 1N4148 and wire across the bases of Q435 and Q437. That way if the bias malfunctions the unit will get hot but not blow up (right away).
I run units like this with a 100W lightbulb in series with one side of the line. Adjust the wattage of the bulb (use a smaller bulb for smaller units) until the DC voltages are about 2/3 of normal. Just enough for the unit to come out of protection and work.
The unit will be able to drive a load at a low level to verify normal operation. The bulb will glow dim and become brighter if you try and play it louder. If the bulb flashes or goes full bright you have a fault.
Run the unit with the bulb for hours or even days until you are SURE it is OK.
I had a big Robertson amp blow up after a re-build. After the second re-build I used the bulb. After about four hours it started to flicker and flash. The bulb protected my work while I found out what was wrong and repaired it.
A Variac offers no protection.
If R423 is dirty the amplifier will blow up.
D423, a dual diode, frequently goes intermittent in Marantz gear of the same era, and a big puff of smoke follows.
I would make a bias clamp from seven series connected 1N4148 and wire across the bases of Q435 and Q437. That way if the bias malfunctions the unit will get hot but not blow up (right away).
I run units like this with a 100W lightbulb in series with one side of the line. Adjust the wattage of the bulb (use a smaller bulb for smaller units) until the DC voltages are about 2/3 of normal. Just enough for the unit to come out of protection and work.
The unit will be able to drive a load at a low level to verify normal operation. The bulb will glow dim and become brighter if you try and play it louder. If the bulb flashes or goes full bright you have a fault.
Run the unit with the bulb for hours or even days until you are SURE it is OK.
I had a big Robertson amp blow up after a re-build. After the second re-build I used the bulb. After about four hours it started to flicker and flash. The bulb protected my work while I found out what was wrong and repaired it.
A Variac offers no protection.
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