Other Amps

Can Some Amps Not Be Fixed :(

1

I have had a Red Knob Fender Champ 12 for about 6 months now. I had started a thread here about the reverb tank a while back and actually had that solved by Billy Zoom. The short version of this is I have had this amp with 3 different amp technicians in NYC. 2 recommended by guitar players in other bands I know who have private businesses and 1 tech from a prominent guitar shop.

The issue is a rattling or distortion and it makes it so the amp cannot be used for recording a guitar take with out some crappy noise coming in. I love everything about this amp but nobody in NYC seems to be able to fix it. It is a cheap amp but I want it fixed but wonder if it can be fixed or if I just have a lemon and that this is a scenario when there amp JUST CANT BE FIXED

AHHHHHH

2

Is it mechanical?

It has a line-out, is the noise on the line-out? Is the noise in the headphones?

Or, if you used a different speaker cabinet, is the noise there?

[Intuition tells me the sound is coming from a nut, somewhere.]

If it's mechanical, you need to put a finger on every nut and screw in the cabinet, on the feet, chassis straps, knobs, speaker screws, handles... Just don't kill yourself.

3

While you're at it, have a small tube of Loc-Tite handy.

I think hammerhands is on the right track, usually a rattle is mechanical. Plus, if true, it is about the least expensive fix you will find.

4

I had a MusicMan RD 50-112 on the bench a few years agoo that had such a rattle problem. It took me a few days to find the issue.

FIrst I thought is was a rattling PCB board or components on the PCB, but it ended up being the thin steel chassis resonating on the transformer bottom on a certain pitch. I put a thin small sheet of packaging foam between the chassis and the transformer and the rattling was gone.

5

Have you tried Blackie Pagano?

Hopefully, you aren't spending a dollar to save a dime!

6

Lots of lower end amps these days can't be fixed -- they're essentially disposable. I know a Fender service guy and if it breaks under warranty they just send a replacement. Still some older stuff including a red knob Fender -- it just might cost more that it's worth. And some problems are hard to trace-- some are electronic, some mechanical.

7

some problems are hard to trace-- some are electronic, some mechanical.

That's the first thing to look at. A mechanical rattling can do weird things with the whole amp.

I assume you and the techs checked the obvious stuff like tubes etc.

Often these amps have crappy reverbs and faulty ones can mess with the sound. Try to unplug the reverb unit and bypass it. Good luck.

8

I tend to agree that some amps are just going to have issues. Things techs have told me: - vintage amps hum, that's all there is too it. - can't remove the pop from the footswitch due to the circuit design. - tubes are rattling because they're too close to the speaker. - cabinet is rattling because the amp is too loud.

I suppose an argument can be made that these are common problems, and the trick is to find a good tech who can resolve them. My best success was fixing a rattling cabinet (perhaps like what you're experiencing). After days and weeks of trying, I found the back panel screws did not have enough wood to grab, and so the screws could not hold the panel tight enough against the rest of the box. I filled the holes with toothpicks and glue, screwed the back panel on, and viola! .... rattling gone. It was frustrating that I had found that, but the guy that made the amp could not.

9

I had a MusicMan RD 50-112 on the bench a few years agoo that had such a rattle problem. It took me a few days to find the issue.

FIrst I thought is was a rattling PCB board or components on the PCB, but it ended up being the thin steel chassis resonating on the transformer bottom on a certain pitch. I put a thin small sheet of packaging foam between the chassis and the transformer and the rattling was gone.

– MaBerY

THIS SOUNDS like something. I dont want to turn into some curmudgen and say all amp techs in nyc suck but the rattle/resonance/static whatever comes only after amp has been on for a while and is being played and certain frequencies make it show up!

10

some problems are hard to trace-- some are electronic, some mechanical.

That's the first thing to look at. A mechanical rattling can do weird things with the whole amp.

I assume you and the techs checked the obvious stuff like tubes etc.

Often these amps have crappy reverbs and faulty ones can mess with the sound. Try to unplug the reverb unit and bypass it. Good luck.

– sascha

So after talking to 2 of the amp techs the diagnosis was mechanical. basic stuff like tubs had all be checked an not the culprit. the last guess was that the faceplate was coming unglued and that there was resonance coming from there... and there was SOME... but now the faceplate has been torn off and is not replaceable and the rattle is still there. facepalm kinda stuff.

I just want this to be fixed

11

On some Excelsiors, there was an odd rattle causes by the inner and outer wood parts of the grille vibrating, and/or due to the armored cable that connected both halves of the amp. Mechanical vibrations can be a nightmare to hunt down.

Some amps have parts that are impossible to find, I hear. Old, esoteric tubes and components will stop you in your tracks. Some amps have sections sealed in resin so they couldn't be copied---or repaired.

Good luck sorting out yours.

12

is there anyway to upload a video file here thta is not a youtube link? I took video of the noise and sent it to a tech on youtube who thinks it is bad solder or possibly debris in the voicecoil of the speaker.

never ending

13

It's easy enough to try another speaker. Bad solder joints can be the devil to find, tho.


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