Why don't Mesa amps feedback?

[JakeAC5253]

Don't know if anyone else has experienced this, but I have hit the front end of the Recto and Mark V with a huge amount of boost with a large amount of gain already dialed in on the amps and they refuse to feedback. At least that's been my experience with the amps. Why are these amps different from all other amps out there on the market? Is the input gated or something? Do they have a ton of power conditioning in there? If it's not either of those then I have no idea what could be the cause of this.

Also, side question that's not really worth an extra thread. The Mark V has that 'Variac' mode, what exactly does that do? I've switched from Full to Variac and back and only can detect slight differences mostly headroom related. Does the Variac mode engage more power conditioning or what?

 

[hunter]

In my experience amps tend to feedback less if they are biased cold, but they tend to sound a bit sterile.

I have a VariAC in my Bogner, it reduces the internal volume in the amp by 10-20%, reduces volume, adds sag/hair and some more trebly/less bassy.

 

[Valtiel]

Don't know if anyone else has experienced this, but I have hit the front end of the Recto and Mark V with a huge amount of boost with a large amount of gain already dialed in on the amps and they refuse to feedback. At least that's been my experience with the amps. Why are these amps different from all other amps out there on the market? Is the input gated or something? Do they have a ton of power conditioning in there? If it's not either of those then I have no idea what could be the cause of this.

Also, side question that's not really worth an extra thread. The Mark V has that 'Variac' mode, what exactly does that do? I've switched from Full to Variac and back and only can detect slight differences mostly headroom related. Does the Variac mode engage more power conditioning or what?

"Power Conditioning" would not have anything to do with feedback. John Petrucci shows in his more recent gear demo that his Mark IV feedbacks back a ton on his highest gain setting, and that is without boost I think. So there is nothing special about Mesa Marks in terms of feeding back.

 

[TX6Strings]

My Mark IV will feedback like crazy if I've got the gain diemed and am standing close to it.

 

[HerbieTheRadDorklift]

I never get bad feedback with my Mark IV, but I get tons of good feedback if I vibrato the note near the speaker.

 

[ACShreds]

my mark IV feeds back easily.

 

[spawnofthesith]

How high did you have the volume? Mine only starts feeding back when I am approaching band volumes with higher gain settings

 

[GuitarGoat]

Variac mode drops the power coming into the amp. I don't remember exact voltages though...

 

[jmgman69]

I will find out later today when the brown truck stops by

 

[Shask]

My Mark III will feedback pretty easy. My Recto is harder, but still will when you try.

 

[Atropos_Project]

You need to plug the guitar cable in.

Seriously, I can make mine howl like a banshee rather easily.

 

[JakeAC5253]

Well I am referring to bedroom volume, but all my other amps feedback regardless of volume (as long as it's not in the 'dismal' area)

 

[mixeduplydian]

Don't know how you set your amp, but if you cut the shit out of your mids and/ or treble, it makes it a lot harder to get "musical" feedback.

 

[JakeAC5253]

"Power Conditioning" would not have anything to do with feedback.

The reason I mentioned power conditioning is that the wall power is the basis of the gain in a tube amp and if you chop and compress the large random peaks of the power AC wave and condition it to linger in the area that you want it to be, it may stop the gain from being so chaotic and in my mind that could have had something to do with feedback.

 

[JakeAC5253]

I will find out later today when the brown truck stops by

 

[JakeAC5253]

Don't know how you set your amp, but if you cut the shit out of your mids and/ or treble, it makes it a lot harder to get "musical" feedback.

My Marshall is set with gain at 3 bass 5 mid 2 treb 7 vol 3

Recto Red Channel gain 2:30 bass 9:00 mid 11:00 treb 3:00 pres 12:00 vol wherever output full

Mark V chan 3 Extreme gain 2:30 bass 9:00 mid 11:00 treb 3:00 pres 12:00 vol wherever EQ sliders (10, 5, 0, 5, 10) fx loop bypassed

Yeah that's pretty much everything. My Marshall feedsback uncontrollably if I hit the front end with an OD808 with the gain/volume maxed and I did the same with the Mark and it didn't even think about feeding back. I can't explain it, it just didn't feedback.

 

[locoed]

I noticed that to,and like "hunter" said,cold amps etc.
Boogies are set up cold when they leave they're shop.

 

[Mailman1971]

I love that feature or whatever it is.
I can play the Mark IV SUPER LOUD....and its quiet when I stand near it.
Gain up high......dead quiet.
But i can get all the CONTROLLABLE feedback I want.
My 5150 I cant get the gain past noon......still loud but in between songs I have to roll the guitar volume down or it bucks and squeals like a pig.

 

[droptrd]

all the mesas ive owned fedback fine. is that right - fedback?

theyre not as warm as a marshall but they can easily squeal, howl and sustain for me.

Have you tried using a high gain 12ax7 in V1? Try a mullard RI. If that doesnt get you squealing you might have other things going on.
Assuming your tubes are all good

 

[locoed]

Mesa isn't as warm as a Marshall? ^ huh?