Maverick very noisey in clean channel but not in lead?

[harryjmic]

Hello Everyone,

New poster here. I just got a 2x12 Maverick (Wine red crocadile, killer looking) with the intention of using it as my other amp but am having a problem with the clean channel. What is happening is the clean channel has a very loud hum which does not go away when you turn the guitar volume down. It sounds like a bad ground. I looked inside the amp but didn't see any readily apparent problems.

If I switch to the lead channel there is a slight hum but nothing out of the ordinary. I tried switching preamp tubes and power tubes but nothing works. Does anyone have any ideas? I appreciate your help as I hate to give up on this amp because it voiced somewhat similar to main amp.

Thanks, Harry

 

[harryjmic]

Problem solved. I spoke with Chris at Mesa and he suggested try lowering the reverb volume to see if the hum volume goes down. I did this and it did so with this in mind I opened up the amp and started looking at the circuit board. What I found was that of the 3 wires coming from the reverb transformer (that go to the board) the green wire was not fully seated in the board. In fact it was just soldered with the end of the wire touching. I probably could have knocked the wire loose if I wanted to. I then heated up my soldering iron and seated the wire all the way into the board and put the amp back together. The amp works perfectly now with no more reverb hum on the clean channel, so it looks like it will be a happy ending.

Hope you guys reading find this information useful as it was very easy to repair and took about 40 minutes from tear down to rebuild.

 

[Jops]

Good news!! Glad you got it fixed. It's a great amp it would have been a pity to ditch it for something so simple. Also its good to know that the reverb can cause probs too. Thanks for sharing your experiences.

Jon

 

[PJD]

Hey there. I love my Maverick but when I got mine back from the repair guy (he was changing a relay that went bad) I noticed the rythm channel was noisey. I was wondering if you took any pics of where these wires are when you were in there, I'm thinking I might have the same problem as you since I'd asked the 'repair' guy to take a look at my reverb as it's not working and he claims it's the Accutronics reverb tank but I'm wondering what else he might have screwed up in there. Let's just say the whole thing was not a positive situation :roll:

 

[harryjmic]

Hello PJD,

It's going to be tough to take a picture of the amp because I have returned to Guitar Center and bought a guitar from a friend instead. This being said it is not difficult to describe the problem and what you need to look for.

First thing you need to do is remove the chassis. Once you do this you should see a small transformer along the front side of the amp on the inside where the circuit board is. There will be 4 wires coming from the transformer, 1 black, 1 green, 1 red and (I believe) 1 blue. The black wire goes under the board and attaches to the input jack (for reverb) at the back of the amp, the other 3 travel over the top of the circuit board and are wired up within 1 inch of each other. Green is the ground wire and if this wire seems to be poorly connected it could be the source of your noise. How I could tell is it seemed like the green wire was stripped futher away from the board then the other two wires. Normally, wires are stripped about 1/4 inch and roughly 3/4's of the wire is placed in the board. When I looked at my (green wire) almost all the stripped wire was showing, this is how I could tell something wasn't right.

Heat this wire with a soldering iron and see if it will go into the hole in the board right where it is placed. If it is pops right in (like mine did) this is most likely the reason for the ground type hum you experienced. Good luck and let me know how it turns out.

Harry

 

[PJD]

Thanks Harry I'm gonna try and dig into it over the weekend. Good description, I'll post when I'm done.