Problem with Input on Tube Amp
Ok, heres whats goin on:
I broke one of the input jacks on my sovtek mig-100, so I decided to just replace both of them. I wired it up the way it was originally wired up but now I am having a problem.
The low input gets sound but it is very low and not what it is supposed to sound like. The high input does not work at all and i just get a really offensive buzzing. Both channels buzz when I insert the tip of the plug.
My guess is that I messed up with the little jumper cables that connect the two inputs. Can anyone help? I could provide pictures if that would be better.
thank you very much for any help!
-RJ
Ok, heres whats goin on:
I broke one of the input jacks on my sovtek mig-100, so I decided to just replace both of them. I wired it up the way it was originally wired up but now I am having a problem.
The low input gets sound but it is very low and not what it is supposed to sound like. The high input does not work at all and i just get a really offensive buzzing. Both channels buzz when I insert the tip of the plug.
My guess is that I messed up with the little jumper cables that connect the two inputs. Can anyone help? I could provide pictures if that would be better.
thank you very much for any help!
-RJ
Ok, heres whats goin on:
I broke one of the input jacks on my sovtek mig-100, so I decided to just replace both of them. I wired it up the way it was originally wired up but now I am having a problem.
The low input gets sound but it is very low and not what it is supposed to sound like. The high input does not work at all and i just get a really offensive buzzing. Both channels buzz when I insert the tip of the plug.
My guess is that I messed up with the little jumper cables that connect the two inputs. Can anyone help? I could provide pictures if that would be better.
thanks so much
-RJ
I broke one of the input jacks on my sovtek mig-100, so I decided to just replace both of them. I wired it up the way it was originally wired up but now I am having a problem.
The low input gets sound but it is very low and not what it is supposed to sound like. The high input does not work at all and i just get a really offensive buzzing. Both channels buzz when I insert the tip of the plug.
My guess is that I messed up with the little jumper cables that connect the two inputs. Can anyone help? I could provide pictures if that would be better.
thanks so much
-RJ
ooops, forgot the links.
http://www.ftwcw.net/amp1.jpg
http://www.ftwcw.net/amp2.jpg
http://www.ftwcw.net/amp3.jpg
http://www.ftwcw.net/amp1.jpg
http://www.ftwcw.net/amp2.jpg
http://www.ftwcw.net/amp3.jpg
I'm sorry I don't know what's going on in your amp. I looked at the sovtek schematics and all sovtek amps use mono jacks.
So me thinks your amplifier is modded in a way I have never seen before.
Please let me know how you fixed it and maybe what the input switching is like. Good luck!
So me thinks your amplifier is modded in a way I have never seen before.
Please let me know how you fixed it and maybe what the input switching is like. Good luck!
Not Stereo Jacks
They are not stereo jacks. They do have 3 connections but 1 of them is a shorting switch that contacts the tip connection when a jack is not inserted. Have a look at the schematic and you will see this- http://www1.korksoft.com/~schem/newamps/sovtek_mig100h.pdf
The reason you don't have any sound out of the "High" input is because you have not closed the circuit to your first potentiometer. A good musical instrment store should be able to sell you a couple of the correct jacks and then it's just a matter of tracing the wiring in amp and soldering away!
As stated beore, please be very careful while working on this one. They have power supply caps in series to handle the high voltage and that means you could expect to find >450 volts on the B+ rail! Even in standby mode, the first pair of caps are going to be charged and the 220K equalizing resistors on the second pair will not be in the circuit. If none of this makes sense to you, please take this to a qualified tech to have it repaired. It's just not worth risking your life to save a few bucks.
T
They are not stereo jacks. They do have 3 connections but 1 of them is a shorting switch that contacts the tip connection when a jack is not inserted. Have a look at the schematic and you will see this- http://www1.korksoft.com/~schem/newamps/sovtek_mig100h.pdf
The reason you don't have any sound out of the "High" input is because you have not closed the circuit to your first potentiometer. A good musical instrment store should be able to sell you a couple of the correct jacks and then it's just a matter of tracing the wiring in amp and soldering away!
As stated beore, please be very careful while working on this one. They have power supply caps in series to handle the high voltage and that means you could expect to find >450 volts on the B+ rail! Even in standby mode, the first pair of caps are going to be charged and the 220K equalizing resistors on the second pair will not be in the circuit. If none of this makes sense to you, please take this to a qualified tech to have it repaired. It's just not worth risking your life to save a few bucks.
T
Does it do this in both inputs? If it's only on the High input, look at the shorting portion of the Low jack. Other than that, you might try cleaning the tube pins and sockets. If the tubes are ones that have been in there a while (or just really old...I mean vintage, like in my case) they could have some oxidation on the pins. It's simple, and cheap. If you can tap the tubes and get the noise to occur, it's time to replace that one. I have more than my fair share of old triodes that are just plain noisy. I hope it solves your problem!
T
T
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