clean channel hum

What is the normal level of hum or buzz from channel 1 not set to tweed? I haven't used the none tween modes of channel 1 until after my amp came back from repair. When my amp came back from repair, i'm getting a lot more hum than i'm used to from clean channels on amps and i'm getting a buzz when a passive pickup loaded guitar is connected. The hum is just as loud with no guitar connected as it is on channel 2 and 3. I'm acoustium to getting noise from passive pickups on gain channels but not a clean channel. It's pretty bad in my opinion. Trying to decided if it needs to go back to repair.

Doesn't sound right to me. Mine is dead quiet on all clean modes.

Thanks that's what i needed to know. i guess plugging in a guitar exaggerates it.

jmontgomery said:

Doesn't sound right to me. Mine is dead quiet on all clean modes.

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Same here!

Turns out my wall voltage is at 135, loaner amp causing the same problem... Hope my amp not permanently damaged.

i dont have a hum noise in myMKV combo,,but a hiss noise when the guitar volume is turned down..on channel 1..tweed
never had the amp serviced or anything cause it sounds fantastic in all modes..(except for the hiss)
the hissing sound is prevelent in channel 1 and channel 3 in all modes........channel 2 is dead quiet,and almost no annoying squealing feedback as well
im running the amp through a furman PL-8+.....i think to an extent this 'noise' is normal,
however maybe the preamp tubes has something to do with it...
would like to hear more feedback on this matter!! :?

Swap a good preamp tube in V1. I'm guessing a noisy tube is your problem. Like I said earlier, my Mark V is the quietest amp I've owned. It's remarkable to me how Mesa can build such a high gain amp and keep it quiet.

It's at Sweetwater being "repaired" salesman said it was probably a tube but since they just retubed it they can replace a bad tube.

jmontgomery said:

Swap a good preamp tube in V1. I'm guessing a noisy tube is your problem. Like I said earlier, my Mark V is the quietest amp I've owned. It's remarkable to me how Mesa can build such a high gain amp and keep it quiet.

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this is my current tube setup for now and sounds great,but the hiss is a little annoying,,,ill swap out the mullard in V1,, that could be what is causing the problem,,maybe cause it is a long plate tube....what are you using for the V1 section....everyone seems to like the tung-sol in the V1 spot..
V1--mullard(110/110)
V2--JJ high gain(115/116)
V3--tung sol(110/110)
V4--mullard(115/115)
V5--tung sol(110/110)
V6--jj high gain(115/115)
V7--sovtek lps(115/115)