Other Equipment

Rig cutting out

1

My guitar rig has started to cut out at the end of the night.

I’ll be playing and during the last set my guitar signal will sometimes get faint, to the point of no signal at all. I’m wondering how to diagnose it.
Last night when it happened the band took a break and I switched out amps.
Seemed better but than I thought I heard it happen again.

Can a pedal do this to a signal?

it’s either something on my pedal board, my Shure wireless or my Vocalist Live Pro processor, which my guitar signal runs through.

Any ideas? It seems to only happen at the end If the night when things are good and warm.

It’s a little tough to figure out because it only happens during a long gig, and I don’t have time to mess with things at a show.

2

Spray the pots with contact cleaner and wrap some ultra fine sandpaper around a 1/4” dowel and insert into the input jack of the guitar a few times.

3

Had a similar issue, and it stopped after I removed all pedal cables, sprayed generously with Deoxit, and put it all back together.

4

Cleaning connections is always a good place to start. It does sound like it could be a heat issue, or a component going bad. Eliminate one piece of gear at a time, or, reverse the process and add one piece at a time. Troubleshooting electronics can be a nightmare.

5

My guess and starting point would be the battery on your wireless system. Can you play a gig fully connected by leads and see if it happens?

6

I had a similar problem, it turned out to be one of my patch leads. It tested fine cold but it was breaking down after being used over a few hours.

7

I found the culprit a few gigs ago, it was a patch cable on my pedal board. All was fine until last night when it started happening again. Drives me crazy!

8

Dang, depending on how much stuff you are running that is tough to track down. Glad you nailed it!

9

I'm happy to hear that you figured it out Hipbone. That was a tough one, I've had similar experiences, they're very hard to troubleshoot especially at a gig. I'm glad you found it!

10

Ya I thought I found it a couple months ago, replaced a patch cord but it popped up again last night at a show. I’ve got a big show tonight and I’m bummed.

It is incredibly stressful when this happens at a show. Used my backup amp and it still reared it’s ugly intermittent self. I was able to rule out my wireless system and amp. It’s either something on my pedal board or my vocal processor/ pre amp that my guitar signal passes thru.

11

I read that wrong, then, I thought you figured it out.

I have a similar situation, but it hasn't happened in a while so I'm still not sure where it is and if it's still a problem.

12

Sometimes if you wiggle each patch lead in turn the dud reveals itself. But you are correct - the gig is not the place to try and fault-find.

I guess you could try replacing all the patch leads at the same time. If it happens again then at least you know the patch leads weren't the problem.

It's a bit weird - are there any tubes in the pedal board? Because pedals don't normally get hot - not hot enough to change things anyway. I wonder if the power supply is being over-stretched?

13

My rig tapped out halfway through a song at our gig last night. The volume dumped to about a third of where it should have been - luckily I have a boost pedal on my board and cranked that and the master volume up and was able to muddle through the rest of the night.

I'm replacing all the patch cables first (especially the ones that were in an "estate sale" - I think they're haunted).

14

sigh

I think it's my bridge pickup.

After spending the afternoon re-cabling my pedalboard, I was noticing a real volume drop while I was fooling around so I plugged guitar direct to amp bypassing the board. The volume picked up (some) but started getting distorted and clippy. I've already had the pots replaced on this guitar, and it's a brand spanking new cable so I think I've got a bum pickup.

sheesh

I mean, the good news is that at least I've got it narrowed down.

16

I just pulled the back panel off, the rectifier tube isn't seated right. I've never touched the tubes on this amp so that's interesting.

17

I had a Synchromatic Jet that would routinely cut out on me. Infuriating. Lots of trouble shooting my gear didn't help. Turned out to be a cold/loose solder joint on the guitar's pickup selector switch. It "looked" fine, until I touched the wire and realized that it was loose as a goose.

It took longer to heat the iron up than it did to resolder the connection. Go figure.

19

It can be a nightmare to diagnose. I had a patch chord issue and then later discovered my Vocal processor was cutting out later on in gigs. Good luck and just keep eliminating gear until you find it.

20

It is. For sure.....

Since the rectifier is power and not audio I don't think it would be causing what I heard - I'm on the fence on if I should just bring my other amp and plan on playing my spare guitar instead.

It wouldn't be so bad except it usually takes about an hour of playing time to have it happen.

21

The rectifier could be the cause - modern rectifier tubes are not all that good. If you can, try a new rectifier and see if that helps. They're not expensive and having a spare is a VERY GOOD IDEA. If it takes an hour to manifest it is extremely unlikely to be a cold solder in the guitar or a "burnt out" pickup - pickups don't generally go bad unless messed with. They certainly don't burn out. The voltages and currents involved are so miniscule. And when they do have a cut in the winding they either cut out altogether or they have a very weak signal. They don't make the sound clip or get distorted.

What happens when the voltage drops in an amp is that things get quieter and more distorted. They also get "spongier" in feel. It is possible that a rectifier could heat up and start to drop the voltage, as it is possible that other parts of an amp could behave in a similar way, especially plate resistors. Plate resistors can burn out. I once fixed an old Super Reverb where the plate resistors had gone rather darker in colour and measured around 1M rather than 100K - no wonder the amp was quiet!

Sounds to me like a dodgy tube or possibly a dry joint in the amp. How long have the tubes been in the amp? Do you use the amp a lot? If you are gigging weekly then don't expect more than about 12 months from modern power tubes.

22

Great info Jimmy - it's a pretty new amp (2017 or 2018), it's got stock Groove Tubes (Princeton Reverb), I do use it weekly.

I've got an A/B splitter box, I could run two amps and then when it starts happening switch to the other amp and that would tell me too. The rectifier wasn't seated properly so I don't think it is necessarily going bad, but not making good contact on the socket, which heat/time would cause (I think).

I'll definitely pick up another rectifier, they're cheap (relatively speaking) and the peace of mind for a gig is well worth it.

23

Just to update - while the Deoxit sits on the input and output jacks of three pedals.....

I've got a pretty big gig on Friday and today is the first day this week that I've had a chance to plug in. I popped in the new rectifier tube, and I started playing and the volume started getting goofy pretty quick.

Lesson for today: The Mix knob on a Topanga is ON regardless of if the pedal is on or in bypass mode. Turning mix full on when the pedal is off will kill your signal (don't ask me why). My set-point on that pedal was super close to where it cuts out, so I backed it off.

Once I got past that, I played for about an hour and caught a break. The volume kept jumping way down or cutting out. I plugged straight into the amp, volume went back to normal, plugged back into the board, the volume dumped. I very quickly got my A/B box and fired up my deluxe reverb - ruled out the amp quick - popped on another guitar and isolated it down to the board.

Then I started unpatching pedals from the end of the chain one by one and going from each back to the amp. The volume then started doing a weird swell like a really slow tremolo (it wasn't on at the amp, and all the pedals were in bypass mode....in theory). Ruled out my reverb, trem, boost, limiter and now I'm down to three pedals. All three I bought off Reverb - so of course I don't know how reliable any of them are. A Fulltone, Frantone Peach Fuzz and that infernal B9.

A Fulltone is easy to get - the Frantone Peach Fuzz is not. For some reason they've all disappeared off the market, even the recent ones. I sprayed a cable with deoxit and jammed it in and twisted it on all three.

I honestly suspect the B9 - I originally had problems with it engaging when I turned it on - I had to unplug it and then plug it back in to get it to work some times. All three jacks on the B9 were loose so I tightened them up.

To be continued.....likely....

24

Well it sounds like you are on your way at least.

25

I work in I.T. so troubleshooting and isolation is part and parcel of what I do all day. Just caught a lucky break where the problem happened long enough that I could switch stuff around.


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