mark iv-can you try this?

[rich]

Hi, I've been having a problem with bad feedback with my Mark IV. I saw people using settings similar to mine on the forums and the amp settings section. But, when I use these settings, I get crazy ringing feedback. I brought my brand new mark iv to a repair shop, and they said its fine. the settings i have are lead channel: gain-8 pull fat, treble 7.5, bass 3, mids 3.5, drive 7.5, presence 1.5, master 3, output 2.5-3 GEQ= 3rd line, center line, 1st line, above center line, 3rd line.

Can somebody tell me if they experience the same thing with these settings? I'm very curious, maybe the tech was wrong. i also changed tubes and guitars and the same thing happens

thanks a lot

 

[Platypus]

Are you using the midgain toggle?

 

[Platypus]

From the manual:

As the setting of the LEAD DRIVE control is increased, the MID GAIN continues to add huge amounts of extra boost, which at some point will become overwhelming and will cause unnecessary noise, squealing and feedback when used in conjunction with the LEAD BRIGHT and LEAD FAT switches.

Otherwise I would check your guitar cables and your guitar itself if you already replaced the preamp tubes.

 

[rich]

hi, when i first got the amp i posted something along these lines and you helped me out a bit. i was still having problems and took it to a shop. they said its fine its just normal feedback, but i can't see how everyone can own this amp and use similar settings and not have a problem with this. i do not use mid gain nor the lead bright pull switch. i use only monster cables and tried several, along with 3 of my esp guitars with emgs, 1 esp with duncans. still the same...ringing feedback unless i turn the volume off on the guitar.

 

[Platypus]

Hmm that's very strange. That kind of squealing feedback is typically preamp related, I vaguely remember your previous post so forgive me if I am repeating myself here.

If you've taken it to the shop and replaced tubes/cables/guitars then I would put a call into Boogie right now and explain all that you've done. Since it's new there may just be a problem with it that they'll be able to fix. Depending on the shop you bought it from you might be able to just get a new one while they send that one back to boogie.

Hopefully one of the mark series pros here can point you in the right direction if it is indeed a bad component in the amp

 

[rich]

yea it didn't seem like normal operation to me...yet the tech said it was...if you think its strange and it shouldn't be doing it, I guess I'll have to call up mesa like you said. I waited like 4 months for this amp from mesa, and it has a problem haha that sucks

 

[Machine Gun]

I personally think that it's fairly normal for the Mark IV to feed back like that. I think both Marks I've owned have done that, and it's either turn the volume down when you're not playing or mute the strings. When I've demoed other Marks, they've done the same thing.

There's just so much gain in those amps and those settings just help it feedback more. Just my opinion, but I think you're amp is fine. I just got my new Mark and it produces feedback very easily just like you're getting. I don't know if a noise gate would help, I never tried one?? But I think it's just the nature of the beast.

 

[Platypus]

My marks have NEVER squealed.. I can imagine some ground hum type noise or hissing but squealing is definitely not part of the normal operation.

 

[Shep]

It sound's like a microphonic V1... but you say you have changed it.. thats a pickle..

 

[Herbie the Rad Dorklift]

Sounds dumb, but you aren't sitting directly infront of your amp facing it while you play are you? Like playing while fiddling with the amp?

 

[ANIMATED SUSPENSION]

If it stops with the guitar's volume off it's not a mcrophonic tube problem. Welcome to the world of cascading gain pre amps and Simul Class power ! I bet it only happens on the lead channel and in Simul Class right ? Try backing off the gain and drive slightly, and learn to mute strings when not playing them. It's always worse the nearer you are to the amp and can vary depending on where you stand in relation to the speakers. The treble control also gives more gain, so you could reduce that slightly and compensate on the graphic (which is post pre amp so makes little difference to the gain) Watch the John Petrucci rig video on the Boogie site and he has the same problem on high gain settings !!

 

[Restless Rocks]

Sounds dumb, but you aren't sitting directly infront of your amp facing it while you play are you? Like playing while fiddling with the amp?

That's exactly what I was thinking too!!!

 

[Tre4J]

The only time I get squealing on my mark iv is after I set it up at my drummer's place...it may take a couple minutes to dial in a tone for jamming levels and then another few to fine tune it and dial out the squeal.

Usually, happens on RHY2 with my OD-9 on. Simply, roll back the treble, presence or gain just a tad until its gone. Also, as others mentioned, sitting close to it will certainly cause some squeal, especially at high gain/drive settings.

 

[demonofthefall]

I had some feedback issues a while ago with the Lead channel set for high gain stuff. Switching from Pentode-Midgain to Triode-Harmonics cured it all ...

 

[Machine Gun]

Exactly, Mark IV's have a lot of gain and it's all in the settings. I always had to back off the volume in between songs on gigs, just in the settings I preferred. But that's just the amp. You either get used to it or try different settings. It's not really an issue when you're playing.