Help Mesa Boogie Dual Rectifier is sounding muddy and weak

[bermuda_]

hey everyone im new to this board and to tube amps so bear with me right i just recently bought a Mesa Boogie Dual 3 channel Rectifier of Ebay pre owned and i also purchased a brand new 4x12 oversized mesa cabinet.

Now the problem im having with my amp is when im playing the amp with master volume down to zero i can hear a lovely bit of distortion coming though my amp speakers but when i crank the volume up louder on my amp it starts to sound muddy and weak i was just wondering guys is it normal for this sort of thing to happen with tube amps i really don't know how to fix this problem guys please help me out also my amp is on the loop bypass setting.

 

[nomad100hd]

sounds like a bad pot!

 

[bermuda_]

any way to fix a bad pot :lol: oh and if your active pickup battery is running low on power can that cause your amp tone to sound muddy and weak :?:

 

[nomad100hd]

i think it's a pot because you hear sound when masters is on zero, but it could even be in the power supply. Better take it in to be fixed.

 

[bermuda_]

alright cool thanks is there any way i could fix the pot myself or should i just leave it to a technician thanks again man for all your help :mrgreen:

 

[nomad100hd]

idk you could just replace the pot but if your not used to working on things you might have a tech do it!

 

[bermuda_]

cool thanks will do man so what will happen when i replace the pot with a new one will the amp sound more distorted and less muddy when i crank the master volume up on it?:shock:

 

[nomad100hd]

if that is the problem it's hard to say without really experimenting with it myself.

 

[bermuda_]

i know what you mean im just curious about this problem i take it you have never experienced this problem with your amp before man :?: I doubt it's normal for it to happen otherwise people woudn't be buying tube amps :lol:

 

[nomad100hd]

no it's not normal if your not good at trouble shooting you should take it in.

 

[bermuda_]

will do man thanks soo much for your help :wink:

 

[lerxst88]

i dont know if its a pot but us nomad guys are quick to assume its that (since thats the only problems we have really haha)

replacing a pot is EASY!!! if that is really all it is youre going to pay a tech at least $50 to work for 5 minutes on your amp and snicker at how easy this repair was. to put in a new pot, buy the correct value and taper replacement (can be found at radioshack) and a soldering iron. unscrew the chassis and take the amp out. remove the knob and unscrew the nut under the knob to remove the original pot from the chassis. unsolder the wires (make sure to remember which one goes where!!!) and add some solder to the new pots lugs. that last step isnt entirely neccesary but i like to so you know that the solder is completely melted and the wire can poke through thus avoiding cold solder joints. resolder the new pot in and maybe test it out to make sure the pot is in correctly before you pack the thing back up.

if you have never soldered before or arent much of a handyman it might be best to let a tech do it but if you have ANY soldering experience (including understanding basically how one works) you should be able to pull this off.

another thing i should stress is DO NOT TOUCH THE FILTER CAPACITORS!!!!! theyre the big cylindrical things that sorta look like batteries. THEY WILL KILL YOU!!!! however you can safely discharge them by touching the red probe to the end with the little notch in it and the black probe to the other end. set your multimeter to read volts! you cant miss them theyre the biggest things in the amp (roughly the size of a 6L6 tube).


techno gargle aside maybe your settings are just set up for minimal power tube distortion. try turning gain down a bit and give it some mids. mesa's are kinda weird how they react to EQ changes. think of the EQ as a shower with hot and cold faucets. if you want a hot shower you dont just turn on all hot and zero cold. same with a mesa. so since now youre letting more "water" flow you dont need as extreme settings as you had when the volume was down.


ok that was probably my longest post ever. back to chem homework

 

[bermuda_]

thanks again man for all your help you certainly know alot about tube amps :lol:

 

[Slanderous666]

Just curious how high do u put the volume on the amp because you kind of need to give the volume a good amount of kick to let it really open up from what I've heard.

 

[nomad100hd]

oh i say at least to 10 oclock before it sounds okay i prefer half way!

 

[bermuda_]

eh usually crank the volume up to about 9 or 10 oclock. but heres a qustion man i have to ask you just out of curiousity here

do you play your amp with loop bypassed or with the loop on

also does your speaker cable go into the input our the output jack on your cabinet

I always have my speaker cable plugged in to the input jack on my cabinet but im not sure if that's the right jack it should be plugged into? :lol:

 

[lerxst88]

i always have my loop on with just a delay in it.

on my 2x12 recto cab theres only one input so the guesswork is down to a minimum for me haha