Mark V turns extremly quiet when the footswitch is connected

The Boogie Board

Help Support The Boogie Board:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Hektor

Member
Joined
Feb 3, 2024
Messages
8
Reaction score
4
My Mark V turns extremly quiet when i connect the footswitch. As soon as i disconnect it, everything goes back to normal volume.
If i disable the fxloop the problem does not occur.
the footswitch itself seems to work normal.

what could be the problem?
 
Is this with nothing in the FX Loop?

When the footswitch is connected the FX Loop switch has no effect?

Hard-bypassing the loop removes all the FX Loop circuitry, including the loop driver 12AX7 tube. Could be a bad tube.

You could also try putting a patch cable from FX send to FX return to see if you can further narrow it down, but I’m guessing it’s tube related.

Dom
 
On occasion (more often than I’d like to admit) I’ve accidentally flipped the cables so FX out of amp goes to output of pedal board on occasion. The result is as you described. So, if something is plugged into the loop when your issue is happening first thing is to check the cable routing.
 
Is this with nothing in the FX Loop?

When the footswitch is connected the FX Loop switch has no effect?

Hard-bypassing the loop removes all the FX Loop circuitry, including the loop driver 12AX7 tube. Could be a bad tube.

You could also try putting a patch cable from FX send to FX return to see if you can further narrow it down, but I’m guessing it’s tube related.

Dom
Yes nothing in the fx loop.

If i connect the footswitch, ecerythibg is fine as long as the fx loop is bypassed. As soon as i want to use the fx loop (to be able to use the output knob for volume) the amp turns quiet and no volume related knobs have an effect except adding fizz to the unusable tone.

I will try the method - connecting fx send and return with a cable - later today.

Which tube powers the fx loop?
 
On occasion (more often than I’d like to admit) I’ve accidentally flipped the cables so FX out of amp goes to output of pedal board on occasion. The result is as you described. So, if something is plugged into the loop when your issue is happening first thing is to check the cable routing.
I have nothing in the fx loop
 
I am assuming this is a Mark V90? If so, you can leave the FX loop in active mode on the back panel, it is the same switch that places it into hard bypass. So turn it on. Then select the FX loop channel, you can leave it set to FS for now. Play through the amp as you normally wood, if that works, it is likely the V6 tube is not the issue. Since there is a relay that will disconnect the internal jumper on the FX circuit, try changing the rotary knob for the FX assignment to all channels. This will activate the relay. If there is nothing in the FX jacks, you should still have some sound since there is an internal disconnect in the return jack. If no sound, do as what Dom had recommended. Insert a jumper in the FX send/Return jacks. When ever the amp is placed in the FX active mode (not the hard bypass mode) the V6 tube will be active and the output volume master will do what it is supposed to do.

If that works without the footswitch connected, and then when you install or connect the footswitch, you may have a bad cable, (check to see if it has all 8 pins). Also since the Footswitch also has a mute circuit, there could be an issue with that circuit in the cable, or the footswitch. If not mistaken, I believe the front panel has a light for the mute when it is active. It is right above the standby switch. If that turns on when you plug in the footswitch, I would assume it is footswitch or cable related. The front of the amp has a pull switch on the solo control, if you pull it out it also puts the amp in mute. I believe that is the same circuit. Sometimes all it takes is a few turns on the rotary knobs on the back as the movement cleans the contacts. I believe they are sealed switches but I could be wrong on that. May as well pull out the solo knob a few times. Not sure on the other Mark V amps like the V:25 or V:35, I am not sure if those amps have a mute feature or hard bypass function.
 

Latest posts

Back
Top