Effects loop squeal, now and then

[jamminforever]

I've researched some prior postings on the Line 6 message boards about my issue with squealing when my effects loop is activated running my pod hd500. I only use the pod for effects only, in 4 cable method, connected to my Mesa Mark V head. ( I've posted this issue on the Mesa boards, to see if they can give me any tips on the mesa end... POST COPIED BELOW )

 

As I've said above, I did research the issue with other users on this forum, but I have a rather unique situation. Sometimes the POD 4cm works great, and once in a while, I get this loud as heck squeal when engaging the effects loop on my mesa pedal. I cannot replicate this issue. Either it works most of the time and there's that once in a month or 2 where it craps out with that squealing. Nothing is changed on the pedal or the amp. I don't understand how this can happen. Either it works or it doesn't!

 

Any tips or suggestions appreciated.

 

( posted on the mesa boards )

 

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I'm using a 4 cable method to hook up my effects board ( Pod HD500 ) to my Mesa Mark V head. I am not using any cab sims nor am I using amp models. This is strictly for effects only.

Problem is, every once in a while, ( did it last 2 practices ) when activating the Mesa loop on my Mark V pedal, I'll get this extremely load squealing sound and I will have to rehearse without the POD. THE FUNNY THING is, I'll come back next week, and without changing ANY settings on the Pod or the Mesa, the amp and the Pod will work fine. I cannot replicate this issue on demand.

Some things I've tried.

All new tubes
plugging the pod and the amp into different outlets
turning on either the amp or the pod first
tried the pod in 2 cable method ( just thru loop only, still got the squeal )
I'm at a total loss here, and would like some other diagnostic suggestions to try.
 

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[jamminforever]

••• BUMP •••

 

Also, is there a way to measure the signal level coming out of the pod, going into the mark v head?

[panaman]

i havent seen this problem reported related to the fx loop.

usually the socalled tuner noise bug seems to me happens when using the pod as a soundcard. (and why would you want to do that, with all the other digital and analog connections available on the pod.)

[jamminforever]

More and more I think about this, I wander if it is the way things are plugged in to the same outlet or not plugged into the same outlet. I will have to experiment further.

[panaman]

you  want eberything on the same outlet to avoid hum. for your problem probably not relevant, but who knows until you try.

are you using the pod as a soundcard or standalone when it happens?

[jamminforever]

I using the POD as an effects unit only for my Mesa Mark V head, so I guess you could say standalone????

 

When you say use as a sound card, do you mean like sound card as in a computer?

[panaman]

i was probably wrong assuming the squeal happens only when using the pod as a (external) pc soundcard over usb.

because it never happened here where my pod has been on for the last 3 or so years straight, and i do use the tuner frequently, with the last 4 firmware versions.

maybe there are certain pod hardware revisions more suseptible to issues.

since the squealing issue was supposedly fixed in the latest firmware versions (see sticky on top of the forum about the tuner bug), you should check und update if not yet done.

after reading your post again, im not sure what your setup is when you call it a mesa pedal.

anyway, if you disable the effects loop on the amp when the squealing happens, and if it works when playing the guitar directly, turn down the volume and gain and connect the pod to amp guitar in. if the squeal is still there and cannot be silenced it means the pod crashed. power cycling should help.