PRS SE 50 combo schematic needed

[Godixon]

Hi, does anyone have PRS SE 50 combo schematic? I have problem with reverb. It will help me very much. PRS do not share anything.
Thanks in advance.

All the best
Tom

[Enzo]

What is the problem you are having with the reverb?

Is it a spring reverb like most? If so, does the reverb have a tube drive with its little transformer, or is there a small IC inside?

Reverb systems have two parts, the drive and the recovery. And of course the pan itself. We can test the recovery by turning up the reverb and touching the tip of the return cable. A working return will make hum then. We can test the drive on a transformer based drive by connecting the drive cable to a small speaker and listening.

If the reverb pan feeds back acoustically, we have many measures to take.

The pan itself pretty much will work unless one end or the other is open electrically. And assuming the reverb pan is in fact the correct type for the drive. Bottom line is that in many if not most cases, we can solve reverb issues without a schematic.

[Godixon]

Hi Enzo, thank you for the quick respone See below my answers.

What is the problem you are having with the reverb?
There is no reverb at all. Turning up the reverb pot makes no reverb. I've checked all RCA cables / send and return, tube, reverb tank, especially the resistance.Everything seems to be ok.


Is it a spring reverb like most? If so, does the reverb have a tube drive with its little transformer, or is there a small IC inside?
Tube drive 12AT7 with little transformer.

Reverb systems have two parts, the drive and the recovery. And of course the pan itself. We can test the recovery by turning up the reverb and touching the tip of the return cable. A working return will make hum then. We can test the drive on a transformer based drive by connecting the drive cable to a small speaker and listening.

I connected the speaker to the send jack/drive cable ( red one which goes to the reverb tank input ) and it works. I hear the sound.
There is no hum when I touch the tip of return cable. The return cable is connected to RCA input on the PCB board.

If the reverb pan feeds back acoustically, we have many measures to take.

The pan itself pretty much will work unless one end or the other is open electrically. And assuming the reverb pan is in fact the correct type for the drive.
This is original tank, which PRS put in..
Bottom line is that in many if not most cases, we can solve reverb issues without a schematic.

[Enzo]

OK, so the return circuit doesn't work. Follow the return line from the cable to presumably some tube grid, and see if you lose signal anywhere. Oh yes, apply some sort of signal to the return cable. For that matter check the reverb control and see if it is faulty, and if return signal is getting to the top of it. And the top of the reverb control probably is cap coupled to a plate of the return tube.

The cables may be OK themselves, but measure resistance across the return cable to see if the circuit is shorted inside the amp.

[g1]

Also, some amps use a switching jack for the reverb footswitch. In some cases a dirty footswitch jack can disable the reverb.