Lot of squeeling I didn't have with other amps

[HappyBlues]

My VM loves to squeel... Unmusical feedback. Why is this? No matter what guitar I plug in... Do I stand to close to an amp or what? I usually stand about 2 meters (7 feet) from the amp... And it is close to zero possible to have musical feedback...

To add - amp is behind me facing my back. Feedback happens mostly when I use most of gain found in VM with my LP, or other guitar. DiMarzios in LP feeds back a lot less than SingleCoils...

[gtrman]

Have you tried moving the VM to a different room or location ?

[HappyBlues]

It happens while playing on open air stage...

[Tnjpekar]

Dial back both your preamps
bring each one up individually. see if your squeeling comes back.
sounds to me you may have the gain decked and a dodgy 12ax7

[Terry McInturff]

Sounds like microphonic pickups. Ill bet that you could shout into the pups and hear it thru the amp.....
high gain settings make this happen easily if the pups arent potted.

You may want to remove the pups from the guitar and install a foam pad under each one to mute the bottom plates of the pups...this can help...failing that, using potted pickups is your solution.

[SteveD]

If you didn't have this problem with other amps I suspect you may have a microphonic valve in your Vintage Modern.

Try gently tapping the valves with a pencil when the amp is turned on and up to a decent volume but without your guitar plugged in. Does any valve seem to ring more so than others?

Also, what are your settings on the amp and what pedals if any are you using and what are their settings?

[HappyBlues]

Well I don't really use pedals... only Boss GT-8 for delays... Settings are Body on about 1-2 o'clock, Detail on 3 o'clock, Mid Boost off, HDR, playing on Epi LP vintage output DiMarzios...

I used to have a garage made crap amp and a Peavey Classic 30 and none of them were prone to squeel like VM.

Also, when I used pedals in past (Boss OD-3, BD-2, and DS-1) the DS-1 was really prone to squeel the same way.

I know guitar can squeel when gain is too high, pickups are microphonic, but why is it it doesn't squeel with for example Peavey Classic 30, but rather has musical feedback?

By no means I want to say that I like Peavey more but in this one particular case it behaved better.

Every guitar squeels with my VM... I don't think all guitars I played through it had microphonic pickups...

I will try the thing with preamps valves...

[Bailz]

Sounds like a microphonic valve considering it's only the VM that does this.

[HappyBlues]

So is it possible that a valve is microphonic and somehow when guitar wants to feed back naturally, the squeel kicks in?

[SteveD]

Definately sounds like a microphonic valve. The Vintage Modern is not prone to squeeling.

[Sully]

Just to throw my .02 in, mine does the same thing - so I know what you're talking about. I've had about every Marshall on the planet and the VM is the first one I can remember having feedback issues with. I run a Les Paul Custom with SD's and in HD mode (Detail on 5, Body on 0) with the volume starting on 10 oclock or so it will feedback with a high pitch squeal. If I walk out of the room around the corner it will stop, but if I'm within 10ft it will feedback.

Not trying to hijack the thread, just saying I know what you're talking about.

[mety]

Does this happen when you take the GT-8 out of the signal chain, ie: guitar directly into amp input, FX loop off?

[Anton DC]

I used to have a Peavey Classic 50 and that started to squeal at one point. Got it looked at and that was due to a dodgy preamp valve (my Peavey days are long behind me now though! lol). I run my VM combo and 2x12 cab at similar settings as Freesun and don't have any problems with my '76 Les Paul (or any guitar). Having said that, my Japanese Tele with the stock pickups would squeal like a banshee at the smallest hint of gain but some Custom Shop Texas specials soon sorted that out!

[HappyBlues]

sorry Steve if I offended you. I know amp should not squeel. It turns out one or more valves are microphonic. Will change and inform. Yes squeel is independent of usage of gt-8. Thanks for all suggestions and specially to Steve for most likely solving my problem.

[HappyBlues]

V1 was VERY microphonic. Changed for a new JJ. Got gig today. Will report if solved.