S1200 problem

I have six S1200 amplifiers replacing six 700’s. I now have had to return four of the six due to the tube staying lit after the unit is turned off.

I cannot believe that I am the only person that is experiencing this problem. I have the MarantzAV8805 processor from which each of the six amps are on “trigger” status; when I turn on the Marantz, all six amps correctly turn on. BUT when I turn off the Marantz, so far, four of the six have had to be returned due to the tube remaining lit. NOW, just yesterday, I find an amp that did not have this problem suddenly having the tube lit after shut off. I turned off the amp via the back of the unit’s switch which resulted in the tube light disappearing. BUT when I switched the unit back on several hours later, the tube again lights even though the unit itself is not on.

I’m almost at my wit’s end with all this. The concept of just turning on my home theater sound and enjoying is out the window. I now have to watch each of the six to see if the tube light remains on even though the unit itself is turned off.

Does any one with the 1200’s have this problem? I can’t believe I’m the only one.

What happens to the sound if I just ignore the problem and let the unit(s)'s tube light stay on until the tube burns out?

Do the 1200s properly turn off and on from the front panel switch?


The four remaining amps that I have do turn off and on from the front panel switch except for the one that I experienced yesterday which keeps the tube lit when turning off the front panel switch. Again, I have to turn off the unit via the rear switch which does turn off the tube light.

I might try removing all the triggers from the Marantz and see how things are then.


I only removed the trigger from the one amp that was tube-lit. I then put on the Marantz which switched on all the amps except for that one. I then pushed the back/ front buttons and turned it on. I decided to re-enter the trigger from the one amp in question and when I turned off the Marantz, all the amps turned off without the tubes remaining lit, and that includes the one that was the problem.

So…what does this say?

It might be an issue with one or more of the relays on the Marantz. Can you daisy chain the +12v signal between the1200’s so a single output from the Marantz turns all of the 1200’s on and off?

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Baldy,How do I daisy chain the +12v signal beteen the 1200"s? Right now I have the trigger “out” from the Marantz to the first amp “in”, and “out” to the second amp “in” and so forth.

If you have the connection from amp to amp with only one output from the Marantz then you have them daisy chained already. I wasn’t sure how many outputs the Marantz has and whether the 1200’s have a trigger in and a trigger out.
You might try physically disconnecting the trigger wire from the Marantz and see what happens to the line of 1200’s.

I know what will happen: the Marantz will go on, the amps will not until I switch each one on via the front switch. The disconnect of the trigger from the Marantz disconnects all the 1200’'s from turning on due to the daisy chain set up.

I just returned two more amps to PS Audio for replacements (making a total of four returned) but I have a feeling that something else is going on. Kevin, sales manager, contacted the designer of the 1200 and he was as confused as to why the tube remains lit after amp shut down. Kevin was waiting a response from the designer about any suggestions.

For my understanding, if you were to unplug all of the triggers from the amps (just for testing) and turn them on/off with their front logo button, the troubled amps would still have the tubes lit? More specifically, I’m wondering if the trigger cables are causing any weirdness with the on and off sequence.

Does it matter how close or far the amps are in the line from the one connected directly to the Marantz.

i dont know if its the same but i noticed the red lights which i assume are the tubes in a bhk preamp are staying on with the power button on front being off and the power button on back staying on.


You have the same problem as I. Perhaps you should call PS Audio regarding this and see what they have to say.

yes, ive only had the pre amp for 2 weeks and did do the burn in for a week and didnt really think about it till i read your post

The M1200 is a different issue. The BHK Pre light stays on when in standby.

I can confidently say that the red lights in the BHK amp and preamp while in standby mode are not due to the tubes being on - and it’s quite normal. Don’t lose your sleep over this.

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If you leave all the amp triggers connected (and make sure they are all properly connected out to in), then turning on the first in line should turn them all on.

Maybe you could experiment with one of these.

It has two operation modes: in the first one, it is connected to the Marantz, and it will turn everything on with the Marantz. In the second mode, it goes to an outlet, and activates via on/off button. You would bypass the Marantz, and turn everything on with only one button press.

More important: should the amps work normally with the Marantz bypassed, you would have isolated the issue to you pre/pro.

Best of luck.

I am pretty certain the red light you see is an LED and not the tubes. I’ll check to make sure.

It would really be extremely helpful to everyone involved if you posted a picture of what red light you are speaking of, from the exact angle that you’re seeing it from.