MK 3 noise

Replace most of the preamp tube out... running only on outer 2 power tube.. Lead channel too noisy...

I am tempted to have main volume lower may be 5 ... and loose the clean crunch... but it cleans up more when lead is selected.. less noise..

I do not understand everyone says MK3 is dead quiet..

not mine..

i see you've got a lot of effects. Have you tried just a guitar -> m3 signal chain?

Or try a recap. Eliminated ALL of the noise in my purple stripe

droptrd said:

Or try a recap. Eliminated ALL of the noise in my purple stripe

Click to expand...

What is a recap.. ??? replacing all the capacitors??

The big filter caps. Big blue guys. I replaced mine with F&T caps. dead quiet

Is this user serviceable,,, I heard that caps must be shorten to drain the charge before handling it..

what are the values?? in faret? and where can I get them?

well, its not hard but if you are unsure, id recommend taking it to a tech. Yes the caps MUST be drained before working on the amp. some of them have over 400 volts stored in them.

I got my caps at tube depot.com

Have you exhausted all debugging yet? Do you have any of the footswitches connected? Do you run your amp out of a Furman or other power regulator?

Have you made a call to Boogie support? Mike can probably walk you thru a debug in his sleep.

Replacing the filter capacitors isn't a horrible job if you're electronically handy. If not, step away from the bench and let a pro do it.

Today I tried something - I plugged my Line 6 XTL into Mesa Boogie 3 FX return. It sounds amazing. a combination of Amp modeling with real tube power amp. Also, this experiment narrowed by noise issue to be related with Pre-amp section. It was dead quiet with master vol all the way to 5-6.

Did you use new preamp tubes or old spares you had laying around? Sometimes even new tubes can be noisy.

V1 (the one in the metal shield) is very crucial, also V3 is the lead tube.

If you used the FX loop, we know that its not a dirty jack or the phase inverter tube. I guess not V1 either since you were probably using R1 for your lead tones with the line 6.

I'd say V3 or V2 is suspect. What brand tubes are you using? It matters alot. Cheap chinese sinos/ruby = garbage. Most of us prefer RFT, Tungsram or Russian high gain stuff for the lead tube (and V1). I accidentally left a Sino in V3 and V4 last week during shakedown and it had no gain and sounded fuzzy and messy. Turned out it was just cheap tubes.

I replaced all preamp tubes - with Mesa brand. I went to their Hollywood Store. They did suggest start with V1.

So when I am using FX in... I am bypassing all pre-amp tubes.. right?? the Vol. Tre, Bass, MId had no effect. The Master Volume was in control the graphic EQ worked also.

Also,

Is there such things as Simul-Class Mod??

I been relying on Pedals for few years on my MK3. Mine is not a Simul-Class. It used to take pedal well. I started using.. EP SP SL..from Xotic and OCD M3 takes it very well...then .. from last week it started to fizzel... sounded like there is already pedal on with vol on 5. T 5 B3 M5... First I thought it was my guitar,, because I am usually strat guy.... but I started using PRS.. and I know it has break point that is lot earlier then Strats..I kind of suspect if there was a power issue.. where voltage was low.. is tube amp sensitive to voltage changes??

kdorsey said:

Have you exhausted all debugging yet? Do you have any of the footswitches connected? Do you run your amp out of a Furman or other power regulator?

Have you made a call to Boogie support? Mike can probably walk you thru a debug in his sleep.

Replacing the filter capacitors isn't a horrible job if you're electronically handy. If not, step away from the bench and let a pro do it.

Click to expand...

i agree, especially recapping with F&t or TAd or whatever actual cheapy ones, i experimented, and nothing sound better than Mesa genuine replacement parts !