Does anybody have a simmilar problem with Marantz PM7200 output section.
Everything is working fine until I try to switch on loudspeaker ouputs (No speaker connected) , than the quiescent current on both channels rise and i must turn of the output binding posts before mad heat up.
I dont know what can go wrong by switchin on only output relays
.
this only happends when class A mode is used. Help please. I am pretty pist off with that problem😡 .
Everything is working fine until I try to switch on loudspeaker ouputs (No speaker connected) , than the quiescent current on both channels rise and i must turn of the output binding posts before mad heat up.
I dont know what can go wrong by switchin on only output relays
.this only happends when class A mode is used. Help please. I am pretty pist off with that problem😡 .
Hi Gasho,
This amplifier is known to run hot in class-A - it is meant to.
One friend fried a DAC that he had sitting on top !
Cheers ....... Graham.
This amplifier is known to run hot in class-A - it is meant to.
One friend fried a DAC that he had sitting on top !
Cheers ....... Graham.
Graham Maynard said:
Indeed. And, if the heatsinks get too hot to touch more than a few seconds, they may still be less than 50 degrees Celcius. We don't really know what HOT means anymore😉
Jan Didden
I understan that class A means hot heatsink , but this is too much . When I measure the voltage across emiter resistors (0.18 ohm) it is too high , about 490mV . That is not OK.
This only happends when I switch on the output relay for loudspeaker.
Somethig is very wrong here. I must run some tests to locate a problem wich is very srange.
. That is not OK.This only happends when I switch on the output relay for loudspeaker.
Somethig is very wrong here. I must run some tests to locate a problem wich is very srange.
I solve a problem!
I cant belive it! It was the thing with outpur LCR filter. When I remove output coil , the rest of filter have too much of paralel capacitance (about 400nF ). I put the new paralel RC combination of 100nF +10ohm . Now everthig works fine.😀
I cant belive it! It was the thing with outpur LCR filter. When I remove output coil , the rest of filter have too much of paralel capacitance (about 400nF ). I put the new paralel RC combination of 100nF +10ohm . Now everthig works fine.😀
Hi Gasho,
I'd love to hear what you think of the sound of this reasonably priced amplifier.
Reviews say that it has reasonable power, a decent phono input stage and useful pre-amplifier options.
Is it a good basic amp, and has removing the output choke improved it ??
Cheers ......... Graham.
I'd love to hear what you think of the sound of this reasonably priced amplifier.
Reviews say that it has reasonable power, a decent phono input stage and useful pre-amplifier options.
Is it a good basic amp, and has removing the output choke improved it ??
Cheers ......... Graham.
My Marantz pm 7200 does not power up anymore and cannot get the amplifier respond to the remote. Could somebody send me the service manual for this amp ?
Manual
It possible to order from Marantz Service manuals - 5 euro per manual - Marantz, Philips, Denon, Quad, JVC, Akai, Revox, Studer, Sony, NAD, Harman Kardon, Sansui, Onkyo, Krell, Yamaha, TEAC service manuals, schematics, datasheets, diagrams, repairs, schema .
Remeber, some circuit in to protect speakers from deamge!
It possible to order from Marantz Service manuals - 5 euro per manual - Marantz, Philips, Denon, Quad, JVC, Akai, Revox, Studer, Sony, NAD, Harman Kardon, Sansui, Onkyo, Krell, Yamaha, TEAC service manuals, schematics, datasheets, diagrams, repairs, schema .
Remeber, some circuit in to protect speakers from deamge!
- Status
- Not open for further replies.