Popping pedals and other noises...

Ché

My friend plugged into my board with a balanced TRS cable the other day and it took me ages to find out why my rig was so noisy, anyway, after swapping the lead I noticed my rig still had quite a lot of nose and I noticed all the pedals on my board pop very loudly (a mixture os Strymon, EHX, MXR, Ibanez etc.). 

Noting this was quite strange I auditioned each pedal separately with an MXR Isobrick, Voodoo Lab PP2 and a signal wall wart. 

All pedals produced a loud pop regardless of amp gain. I first thought it was the high volume/gain combination of my Marshall Plexi (20w Studio Head) but I tried the same test through my Vox AC15C1 and while the pops was nowhere near as loud, they were still there. Granted most are true bypass I tested them enough to discharge any static build up to no avail. 

Is there a grounding issue I'm unaware of or is the electricity in my place really bad? The Marshall does have a lot of idle hiss when off standby with even the smallest amount of volume. 

I'd normally be able to diagnose this but I'm having a tough time isolating the cause of it. 

I beseech your wisdom.

ICBM

Try putting a buffered pedal last in the chain before the amp. If you don't have one, any of your pedals left 'always on' will do for the test. If the other pedals in front of it now don't pop, the problem is a DC leak from the first valve in the amp - this is quite common.

p90fool

Yep, another symptom of the same thing is crackly guitar volume pots. 

Ché

Thanks for the advice, as always. 

I put my Strymon Flint last in the chain, my EHX Electric Mistress XO and MXR Phase 95 still popped but my Boss CE-1w is silent. There's a pop when I turn the Flint on and off. Same thing happens with both amps but its more pronounced on the Marshall.

ICBM

The Boss will be silent, as it has proper buffered switching.

What happens if you put the Boss last?

Ché

Unfortunately the popping is still there with the Boss pedal last in the chain. Really confused now. Could it be an issue with power?

What's weird is there's now an audible ticking coming through the amp from the rate of the Electric Mistress. 

ICBM

Ché said:

Unfortunately the popping is still there with the Boss pedal last in the chain. Really confused now. Could it be an issue with power?

Yes, it must be.

Sounds like you may have poor earthing in the mains supply.

Ché

ICBM said:

Ché said:

Unfortunately the popping is still there with the Boss pedal last in the chain. Really confused now. Could it be an issue with power?

Yes, it must be.

Sounds like you may have poor earthing in the mains supply.

Well that sucks. Good time to be broke, know any good electricians Yorkshire way?

Is there anything I can do in the meantime to alleviate the issue or find out myself if it is poor earthing?

ICBM

Ché said:

Well that sucks. Good time to be broke, know any good electricians Yorkshire way?

Is there anything I can do in the meantime to alleviate the issue or find out myself if it is poor earthing?

Replace all the pedals with Boss ones...







That will work, but if you like the pedals you've got, perhaps not the best suggestion .

How are you plugging it all into the wall? If you're not using an extension strip, try getting one with surge/spike protection built in and run everything from it - that might be enough to stop it.

Ché

Haha, Boss pedals are good.... 

I've tried various extensions strips that all have the same issue. Amp and pedal power always on the same extension. The kitchen is a separate ring so I could try running it from there...

...same issue, louder pops in fact.

I've noticed my amps hiss a lot aa well, could that be a symptom of poor mains ground also?

Would something like this be enough to determine an issue or is it that the earthing is there but just that it's poor?

p90fool

Check the earth in your extension lead.

They're frequently thrown together as piecework by home workers with no interest in or knowledge of things like strain relief. 

Ché

p90fool said:

Check the earth in your extension lead.

They're frequently thrown together as piecework by home workers with no interest in or knowledge of things like strain relief. 

I tried two different extension leads just to make sure and both had the same outcome.

ICBM

Yes, it's worth checking the mains earth with something like that as a first step. The problem is that it might not be conclusive - if the earth is only poor rather than missing altogether it will still show as connected.

Ché

ICBM said:

Yes, it's worth checking the mains earth with something like that as a first step. The problem is that it might not be conclusive - if the earth is only poor rather than missing altogether it will still show as connected.

I have a feeling that may be the case. Is that something an electrician can test? (I imagine so). I tried my Ditto X2 Jam and that pops when starting a loop and also pops when clearing a loop. There's a relay click in the pedal when the loop is cleared but I can hear it coming through the amp which I assume it shouldn't do.

BigMonka

Can you try any of the pedals with batteries to help with diagnosing if it’s the mains bringing in problems?

Ché

Haven’t been able to test with batteries but took my pedals home along with my PP2+ and wall wart and tried the ditto looper again. Popping when engaging the loop means there’s an audible pop every time it loops, same thing with it’s own power supply. Can’t believe this. Gonna have to send it back. I’m using different cables as well... today has been so depressing. Are all my pedals faulty?! Or do I need some sort of buffering system for all of them? Does anyone else have these issues? Feel like I’m loosing my mind. 

Simon_M

Electrician response:

Socket tester like the one show above will verify if a voltage can be made across the live and cpc terminal of the socket outlet being tested. Generally any voltage will result in a positive led as the current used to determine this connection is incredibly small and therefore a much greater than acceptable impedance to earth is tolerated (Ohms law). 

Where a house doesn’t have rcds installed for fault protection and fuses or mcbs are relied on for fault protection, typically an acceptable earth impedance at the socket outlet should be no greater than approximately 1ohm. Professional electricians have equipment to test this and any competent spark will be able to verify if your earth connection is satisfactory or not. 

Different earthing facilities will be different with the most common in the UK being PME where outside the installation the earth and neutral are combined. noise on the neutral could be introduced on the cpc and generate noise within your installation.

if you do suspect there’s an issue with your earthing though I would recommend you get an electrician soon as an earth problem can be seriously bad for your health!!!

Ché

Thank you for the response

I’m having the same popping issues with pedals in both my studio and my home. I can’t imagine there’s serious earth issues with either and there’s RCD’s in both premises. 

I’d be more inclined to know why a poor ground would make pedals pop and what actually constitutes poor grounding. I’m under the impression a circuit is either grounded or it isn’t?

joetele

Does this narrow it down to an amp valve then? I'm intrigued 

ICBM

What makes pedals pop is DC voltage present on the signal path, which produces a sharp transient when a mechanical switch is engaged or disengaged. This is caused either by a leak from the first valve in the amp, or a poor ground which will allow any stray voltage to not be fully drained away.

A small amount of resistance in the earth connection can be enough. Many modern amps in fact intentionally have this, in order to prevent ground loops which cause hum - it may be enough to be causing this problem, although I wouldn't have expected it to. If so, you could try using a mains-powered effect unit of some sort which is definitely fully grounded, and see if that fixes it - if it does, it would be fairly easy to modify the amp to connect the signal ground directly to the chassis ground. (Many bass amps have ground switches to do that because ground loops are a common problem when DI'ing.)


[Rant] Fundamentally the problem is pedals with mechanical switching in the signal path! Dinosaur technology that's been obsolete for forty years, and one of the reasons proper buffered switching was introduced in the first place... [/rant]

Ché

joetele said:

Does this narrow it down to an amp valve then? I'm intrigued 

I’m using a different amp at home. Still valve, Blackstar HT-1r.