lound crackling sound on clean channel

[kenny9a9o]

I've bought a new Hot rod Deville about 2 years ago and its been working fine so far until...
The first time it did it was at a live show at the end of the gig every time I did a F# on the guitar (basy note) I would here a very loud crackling/distortion noise. A week after at the practice it was working fine and then the same thing happen again at the end of the practice (F#). It didn't do it for a while after so I thought it might just be some bad cable or something but then the nightmare, at a live show, again in the middle of the second set the noise came back this time it was doing it all the time, had to go direct with a 30 sec sound check, lets just say I didn't enjoy the rest of the gig. I brought it back home and it was fine again but cannot trust this amp anymore. The common thing seem to be heat since it always happen after I play for a while. could this be the plate resistor R57 acting up?

ken

[52 Bill]

The common thing seem to be heat since it always happen after I play for a while. could this be the plate resistor R57 acting up?

ken

Ken: Welcome to the board.

First question is: How old are the tubes? This could be caused by a bad tube.

Beyond that, while it could be R57, I'd be more inclined to first check for cold solder joints on the two output tube sockets. I've seen quite a few broken connections on the power tube sockets that will cause this or similar problems.

If you purchased the amp new 2 years ago, you should still be under warantee.

[kenny9a9o]

Thanks Bill,

My tubes are the original one.
I've check for cold solder but did not find anything unusual. I'll replace the hot plate resistors anyway while I've got the amp open. I'm a tech so i've done this before. I had ordered some power tube JJ 6L6GC to replace mine like you just recommend from the tube store and I just receive them and they are E34L. After checking the spect I'm not putting those in my amp (will have to order again), I've also installed a small 12V fan that run's on 9V in the amp to get the air cerculation going cause I play with my amp tilted back. Will see if all these change fix my problem.

Thanks

Ken

[Enzo]

As a Fender warranty station myself, I also would suggest that your 5-year warranty covers this. ANY Fender waranty repair facility can handle this.

The fact it has been resoldered doesn't matter. The repair tech will not know it was you and not an authorized shop unless you tell him or your work is horrid. ANd he is not going to waste any time trying to find out.

If you are absolutely stuck on fixing it yourself, then ball up your fist and whack the top of the amp. If it responds with the noise, then there is a loose connection somewhere. The two dropping resistors for the zener supplies are most suspect, R78,79, but the solder on the power tube sockets also fails more than it should on that series of amps, as Bill points out.

While possible, R57 usually just opens. That leaves you with weak crappy sound, not crackles and noises.

[kenny9a9o]

Thanks guys,

you were right
I've actually look with a magnifing glass at all my solder and the ones for the power tube had all a tiny fracture in them that the other solder didn't have. I've resolder all of them and played for more than 3 hours with no problem. I think I've found it.

Ken

[Enzo]

And there's another $50 I didn't make...