Please help me diagnose my possible amp problem. Video included.

[possum-kingdom]

Hi,

I'm really hoping you can help me diagnose the problem I'm having as it's driving me mad.

For a couple of months I've been experiencing crackling distorting and my sound completely cutting out completely (down to barely audible). I have a Mexican strat, a few pedals and a hot rod deluxe 3. I've sent the amp back to fender twice and they've done various things such as tightening stuff and replacing the power valves. I was sure it was the amp as it did it in the shop I took it back to with their guitar straight away. I also know these amps are notorious for these issues

The issue persists. The confusing part is that it's doing it on multiple amps. Last night it did it plugged directly in to a Peavey bandit. Interestingly it only did it on the low gain input not much (if it all) on the high gain. Also strangely when I played through the hod rod with the peavey on sat next to it the peavey mate weird noises even without anything being plugged in to it but this could be irrelevant. It's also done it on a Laney amp at a gig.

If the amp is the issue why is it doing it on multiple amps?

If the pedals/leads are the issue why is it doing it on multiple amps with different leads both through pedals and directly in to the amp?

If the guitar is the issue (which seems to be the only variable left) why did the amp do it at the guitar shop with a different guitar?

At this stage it seems to be defying logic and I'm considering wiping my savings and replacing my whole set up which is drastic but I've now had two gigs where it's died on me after a few songs which I can't have keep happening.

Here is a video of the noise it makes https://vid.me/yi1C. That video is the strat straight into the front of the amp on the clean channel.

Any ideas? I'm hoping it's something obvious and you will make me feel stupid for overlooking it!

Thanks for your help

[Enzo]

Hi possum, welcome to the forum.

I don't have sound on my computer, so... And the video was a moving image. You did not mention the model amp you have, is it a Hot Rod something fender?

If multiple amps do something with multiple guitars, then there is more than one problem.

If it is a Hot Rod, first thing I'd do is resolder all the pins of the power tube sockets. They tend to crack their solder. have the shop look closely, but resolder them ANYWAY.

Plug the guitar into the FX return to bypass the preamp entirely, does it still do it?

Instead of a guitar, which can pick up noises from your cord or the electrical environment, try playing a CD player or tape deck into the amp. Still do it?

Make sure the speaker is plugged into the correct jack, NOT the extension jack. Now as it plays, grasp the speaker plug and flex it side to side a little. Does that affect the sound?

[Simpson]

cables?

[Tom Phillips]

...If the amp is the issue why is it doing it on multiple amps? ...

One possibility is that there are two different problems that cause the same symptom. One in the amp and one in your cable/guitar/pedals etc. Granted, this is an unlikely situation but it does happen and when it does occur it can be a nightmare trying to diagnose. Part of troubleshooting difficult problems is to be very methodical, change only one thing at a time and keep track of what happens each step of the way. When one or more problems are intermittent it compounds the difficulty tremendously. Anyway, that's my answer to the specific quoted question.

[Mick Bailey]

Agreed. If you've swapped leads, amps, guitars and location and still have the same (or similar) problems then there has to be more than one fault. Stick to one setup and diagnose that.

When you took the amp back to the shop and the fault showed up with their guitar, did you use the shop's cable?

[AmpFix]

I agree on the multiple fault scenario. I've had that happen to me too, so you're not alone.

Take just the guitar and amp for starters. Just there, there could be the cable, jacks on the amp and guitar, selector on the guitar, volume/tone on the guitar as the usual culprits.

[possum-kingdom]

Thans very much for the replies everyone. I decided to just take it back to the store to be sent back to fender (for the 3rd time!) I really hope they resolder or do whatever they do to finally sort it. It's been back twice already and they clearly haven't sorted it. I'm also going to take my guitar for a check up to cover all bases. I'm replacing some of my pedals too just to be sure. Thanks again.