Hello, can anybody help? I have a Marantz PM-47 Amplifier. I think i have a problem with the right stereo output. I have change all the wires over, and eliminated any speaker and wiring problems, it seems to go back to the unit!!! I would be most greatful if someone could shed some light.

You, sir, are a rare adherent to stereo-only electronics. Are you replacing it for cause (showing its age)? The PM7003 is only 2 x 70 watts like the JVC but it also has separable preamp/amps so you COULD upgrade or augment the power output with external amps and still control it all locally.

Of course, any current AVR's do that too and bring digital sources and multichannel audio to the mix for as little as the PM7703 may cost.

Hi mas_66,
Make sure that the fuse is the same rating with the old one.
If still symptom persist, I've suspected that your output IC is shorted.
You may hang this IC, then power up the unit.
Observe what will happen, if this cure the symptom then this is a clear indication that this IC is shorted and made the fuse blown while it is in the circuit board.
Hope I helped you.
Have a nice day!
Thanks for using Fixya.

The easiest thing to do would be to put high wattage level controls at your speakers
Parts express sell them and MCM electronics

The symptom sounds like a feeback loop. As long as that indicator is showing near maximum output on one channel AVOID ATTACHING ANY SPEAKERS TO IT!!!! You'll cook the tweeters.


Turn it off and manually operate every control, knob and pushbutton throughout its range many times to wipe oxides away from their conductors.

Set all EQ controls to their midpoints and re-evaluate.

We don't know if it's an input or output problem yet. Does it do that with all inputs?

There really is no point in  connecting the two components with an optical (=digital) cable, if you didn't want to use the SA-15s DAC- and analog output section you might aswell have bo bought the chiepest one you could find...

To get better sound than the SA-15s analog outputs can provide, you would have to spend a load of money (not as much as for the SA-15 but quite a bit) on a DAC - and the DAC would only work with CDs, you would still have to use the SA-15s analog outputs to listen to SACDs.

So in conclusion:
-Use the SA-15s analog outputs

-If you have other digital sources that you want to use - if you care about their sound quality - you can sell/return the SA-15s, buy the chiepest CD-Player you find (only look and feel matter) and spend the rest on a good DAC. (note: SACDs won't play on this setup)


I'm using a PM-15S1 with a DAC (Apogee Mini DAC, Studio-Equipment, nominal price ~1000$, got mine 2nd hand for 400€ ) myself. A DAC is usually the better choice over an expensive CD-Player - especially if you've got other digital sources (PC, ...) - but you'll probably lose a lot of money if you sell the SA-15, so think about it (IF you're still thinking about it, I realise that your question is 8 months old...)


anyway... have fun with the PM-15, it sure is beauty

Jan (Hamburg, Federal Republic of Krautistan)

the input selector switches if they are dirty can make the amplifier sound like it has a blown channel.
compare voltages from the left and right channel and make sure they are identical as well as the power supply,typically + and - 65vdc .check the regulators for the pream,they run panel lights off the same circuit + - 14vdc

hmmm. Let's start by swapping the wires you are using for your speakers. Double check the wire connections first, then take the left and place iton the right and vice versa.

HI...
You need an 8 ohm stereo "L-pad"
Try partsexpress.com
or
mcmelectronics.com

Hi there

The part that you speak of is called the emitter stabilizer resistor. It is common to the output pair on one channel. You will find that the large "output" transistors mounted to the heat sink either side of this resistor will most probably be faulty.

Best not to run the amp at all whilst in this condition.

To be sure that you have an effective repair, you will need to change both these parts, and also the "driver" transistors that connect to the outputs. They too are in symmetrical positions close to the the output transistors. You should also check that the 3 legged resistor you mentioned is measuring its correct value, and check all other low value resistors in the output stage area to that channel.

If you are not familiar with repairing this sort of equipment, perhaps you can find a repair guy with some experience on audio equipment, then this work should be all he needs to do to repair the amp. I would also ask him to "blanket resolder" the output/bias stages and power regulator stages in the amp as problems with heat stressed cracked/failed soldering and dry joints often cause these amps to blow the output transistors.

BE SURE THAT THE CORRECT PARTS ONLY are used for the repairs. Different transistors could cause future problems with the amp. The parts can be obtained relatively easily from a marantz distributor(we can find one in a country near to you). OR if you can give me the markings to each of the parts you need, I can provide you with an international source to get them from.

The amp is decent HiFi, and worth repair. Happy to provide you any assitance I can, Good Luck

regards
robotek

look on the back of the TV and there should be L/R audio outputs (white & red), connect this to a spare input of your amp via a connecting lead eg. AUX or any other input except PHONO.

hope this helps.