Marantz Model 1200 Left Channel Issue

[rBuckner]

I wonder about the whole 'Hfe matching' thing after reading this.

Tom

Interesting indeed!

 

[lo-d dad]

I couldn't touch the amp for days. Today, I tested "Pre Amp out" and "Amp in" again. "Pre amp out" is still not working, but "Amp in" works for the both channels now. Last week, the only right channel was working. I also noticed when I turned on the amp after putting on the jumpers, the light came on and the relay clicked, but if I switch Tone Control knob to "Out" position, the relay goes off. Then, when I switch Tone Control back to "in" position, the relay clicks in again. Is this normal?

 

[MarantzRefrb]

Glad to hear you got both channels back with 'Amp-In'.

No, the relay shouldn't click in and out when switching between Tone Control modes. Did you recap the relay board already?

For the pre-amp, I just had a problem with my stock jumpers on my 1200, where the jumper would cause a low frequency oscillation significant enough to prevent the relay from staying closed. In my case, the relay kept clicking open and closed, like an old telegraph. Do you have an RCA cable to swap in place of both of the jumpers?

 

[lo-d dad]

Glad to hear you got both channels back with 'Amp-In'.

No, the relay shouldn't click in and out when switching between Tone Control modes. Did you recap the relay board already?

For the pre-amp, I just had a problem with my stock jumpers on my 1200, where the jumper would cause a low frequency oscillation significant enough to prevent the relay from staying closed. In my case, the relay kept clicking open and closed, like an old telegraph. Do you have an RCA cable to swap in place of both of the jumpers?

I recapped the relay board in 2011. I have RCA cables and will try that to see if that makes any differences. Thank you for your reply always.