gig tomorrow and a Mark IV FX loop problem...

[Fronzil]

basically when the loop is active/on, i get massive gain/volume loss..so much that i cant hear it...ive heard cleaning the FX loop can be a solution for this...any other suggestions? if that is the way, how do i clean my FX loop? have a gig tomorrow so any help is much appreciated

 

[ryjan]

Preamp tubes most likely. I'd clean the fx loop's connectors just because but I wouldn't imagine that the would be so dirty to drop the volume, scratchy maybe. Swap out cords in the loop if the tubes dont fix it. I've had more problems related to bad cords than anything else. Hope this helps.

 

[Fronzil]

how do i clean the connectors? and why would it be the preamp tubes if it only happens when the loop is active? i can switch it on and off with the footswitch and the amp goes from fucked to normal

 

[ryjan]

If memory serves one of the pre's serves as an fx return. If your loop is bypassed then you are not using the effects return. You can clean the jacks with any electronics contact cleaner. Also, verify that the components in the loop aren't at fault.

 

[Geiri]

I'm having similar problems with my mk4 a. I was beginning to guess it was them preamp tubes since they are the same age as my amp and probably about time to swap them out for new ones.

 

[ryjan]

I'm having similar problems with my mk4 a. I was beginning to guess it was them preamp tubes since they are the same age as my amp and probably about time to swap them out for new ones.

I looked it up and its the V2 tube. Swap it with V3 and see if the problem at least changes. It's a free test that only takes 20 seconds.

 

[Geiri]

thanx dude

Will try that.

 

[Fronzil]

If memory serves one of the pre's serves as an fx return. If your loop is bypassed then you are not using the effects return. You can clean the jacks with any electronics contact cleaner. Also, verify that the components in the loop aren't at fault.

so i just stick some cleaner in the FX jacks? and ya ill do some cord swapping and see if i can trouble shoot the problem a bit

 

[primeholy]

If memory serves one of the pre's serves as an fx return. If your loop is bypassed then you are not using the effects return. You can clean the jacks with any electronics contact cleaner. Also, verify that the components in the loop aren't at fault.

so i just stick some cleaner in the FX jacks? and ya ill do some cord swapping and see if i can trouble shoot the problem a bit

Here is what I did. Make sure amp is unplugged. Spray contact cleaner in one of the loop jacks, repeatedly insert a patch cable in that jack. Repeat with next jack.

 

[Fronzil]

If memory serves one of the pre's serves as an fx return. If your loop is bypassed then you are not using the effects return. You can clean the jacks with any electronics contact cleaner. Also, verify that the components in the loop aren't at fault.

so i just stick some cleaner in the FX jacks? and ya ill do some cord swapping and see if i can trouble shoot the problem a bit

Here is what I did. Make sure amp is unplugged. Spray contact cleaner in one of the loop jacks, repeatedly insert a patch cable in that jack. Repeat with next jack.

you saved me man, gig went killer..thanks a bunch I effin love this site. (except i sprayed it on the cable itself, then did the in and out)

 

[Fronzil]

speaking of which, video of the show...last tune of the night..little intoxicated on a few things..but it went well..first show as a band..we first jammed 12 days ago..playing my bfr into the mark iv b /w a recto 2x12

http://www.youtube.com/watch?v=MB3HGaPc8O8

 

[ryjan]

Glad we could help.

 

[GD_NC]

My Mark IV just started doing the same thing. The volume drops everytime I turn on the FX loop. It even happens when nothing is plugged into the loop. The amp works perfectly as long as the loop switch is off. I replaced the V2 with another tube but that didn't help.

I don't have any contact cleaner on hand so I can't try cleaning until I can get some tomorrow. Can dirty contact cause this if it still happens with loop unplugged? Are contacts engaged when you pull the plug out???

 

[Fronzil]

my amp had the exact same thing..no matter what, if the loop is on, it died...i narrowed it down to 2 problems..faulty cables, and then the contact cleaner...spary it on your cable..**** the **** out of the jack whole..if it doesnt work, spray directly into the jack.

 

[GD_NC]

Perfect I'll give it a try. Thanks!!!!