Mysterious Buzz

[bassist_lewis]

I've had a read around the internet and can't find this exact scenario, so putting it to you guys.

I'm getting a bit of buzz when I from my setup, which is as follows:

 

Bass (single coils) > pedalboard > amp.

 

When I roll the volume down the buzz disappears, which implies it's something going on with the pickups/wiring. HOWEVER, when I plug straight into the amp... silence. So it's the pedalboard, right? Well, I have a GigRig power supply, so fully isolated, all pedals correctly powered and every pedal is in its own isolated loop using a GigRig QMX. I even have a noise filter (!) I currently don't have a buffer first thing as my Canvas Tuner is away getting repaired (fairly sure the buzz was there before).

 

Hoping someone out there knows electronics better than the internet.

[bassist_lewis]

Additional info:

 

- I use a Y-splitter to power the Generator and a Noble DI. I've tried powering them separately and the buzz is still there

- tried going straight from the switcher to the amp (i.e. cutting out the Noble). Buzz still there.

[pantherairsoft]

A process of elimination is the best port of call… 

 

Do you get the buzz with the pedalboard powered up but all pedals bypassed? If so, start removing one pedal at a time from the set up. In theory, eventually you’ll find the one lowering the noise floor of the setup and probably amplifying the hum in your pickups.

 

As we know that no pedalboard means no noise, at some point you’re going to find the culprit. If you get to a funny point where all pedals are out and you’re basically just powering a switcher, then we can look at other options.

 

The pedals are well powered and isolated, but it doesn’t stop two random pedals refusing to play nice together. As a side note, I also had some noise issues using a gig rig generator and isolators on a larger set up in the past. It was always one random pedal being a pest.

 

Report back after the elimination test is done. Would be great to get a proper run down of the signal chain as well if you are still having the issues (also, solderless patch cables? Another thing I’ve found a cause of random noise!).

[bassist_lewis]

I just powered everything up with the bass plugged in and started unplugging power and audio and didn't notice any significant reduction in noise, even once all the pedals were unplugged and my chain was bass > QMX > amp, which implies its the switcher...?

 

Signal chain is as follows:

 

Bass > Walrus Audio Canvas Tuner (currently crappy mini tuner I can't remember the name of) > QMX (3 leaf Octabvre > 3 Leaf Doom 2 > Origin Effects Halcyon > Tru-fi ghost Vibe > Iron Ether Xerograph Deluxe > JPTR FX Jive) > Noble Preamp > amp

 

QMX is powered direct from the distributer as recommended by Gigrig (had a conversation with them a month or so ago), all connected with Evidence Audio solderless, so that might be the next round of testing.

[pantherairsoft]

4 hours ago, bassist_lewis said:

I just powered everything up with the bass plugged in and started unplugging power and audio and didn't notice any significant reduction in noise, even once all the pedals were unplugged and my chain was bass > QMX > amp, which implies its the switcher...?

 

Signal chain is as follows:

 

Bass > Walrus Audio Canvas Tuner (currently crappy mini tuner I can't remember the name of) > QMX (3 leaf Octabvre > 3 Leaf Doom 2 > Origin Effects Halcyon > Tru-fi ghost Vibe > Iron Ether Xerograph Deluxe > JPTR FX Jive) > Noble Preamp > amp

 

QMX is powered direct from the distributer as recommended by Gigrig (had a conversation with them a month or so ago), all connected with Evidence Audio solderless, so that might be the next round of testing.

Cool, this rules loads out!
 

things to try next, leaving all pedals unpowered/disconnected from the QMX, so it’s just bass, switcher, amp.

1. try a different distributor or isolator for the QMX? Same?

2. as you don’t need it for anything else, try powering it directly from the generator (no distributor etc). Same?

3. do you have a different power supply that you can just power the QMX from? Any 9v supply should be fine. Same?

4. Do you have a different bass you can use. All other considerations remain the same. Same?

5. Take your bass, QMX and amp to a different house/building and this being on a totally unconnected wiring ring. Still the same?

 

I know this is a pain, but if you can let us know the result of these 5 steps we’re probably very close to identifying the exact issue.

[Stub Mandrel]

What happens if you move the bass around or rotate it?

[Stub Mandrel]

And try different PSUs in the switcher.

[PaulThePlug]

Switcher, Simple ABY, Power for LED's?

Check Jack Socket Ground, often paint on the case around the jack can reduce earthing effectiveness.

Edited 23 hours ago by PaulThePlug

[Hellzero]

First question to ask as the pickups are single coils: Is the bass fully and correctly shielded?

[LukeFRC]

17 hours ago, bassist_lewis said:

didn't notice any significant reduction in noise, even once all the pedals were unplugged and my chain was bass > QMX > amp, which implies its the switcher...?

Try taking the switcher out (and stick pedals in series)

 

also the Nobel has a power supply in it, make sure it’s not too close to the gig rig power supply and rotate one to see if that makes a difference