Can someone please help out with my noise problem?

dannybuoy · #1 03-29-2008, 03:19 PM

I'm not sure where the best place is to ask this question, but since a lot of you effects heads are probably used to having to deal with noise issues I came here!

I have a Squier Vintage Modified Precision, a Line 6 Lowdown 300 amp, and various pedals, latest of which is a Zoom B2. I've got some kind of grounding problem giving me noise hell and I can't figure out how to sort it out, it doesn't quite add up for me...

- If I plug my bass straight into my amp, with the tweeter on and the treble turned up (I don't normally set it like this, it's just to help me detect the relative noise levels) I get a lot of noise. This noise increases if I hover my hand over the pickup, and cuts down by about half if I touch the bridge/strings/jack plug.

- If I plug straight into my computer's firewire audio interface and turn everything up, I get a hardly any noise, and there is no kind of interference generated from me touching the metal parts or waving my hand over the pickup.

- If I plug into my Zoom B2 and use headphones, powered by either my johnnyshreadfreak power supply or the one I got with my DHA pedal (both supposedly high quality noise free regulated supplies) I get the same kind of noise again. It's pretty quiet when touching the strings, but let go and there's a nasty buzzing sound.

- If I do the above but use the cheap looking little 9v 300mA supply that came with the unit, it's completely silent whether touching the metal parts or not.

This is rather annoying, as I would like to use my amp and the Zoom B2 with my pedalboard daisy chain. I've tried different rooms and plug sockets etc, to no avail. Can anyone step in and help me out here?

bongomania · #2 03-30-2008, 09:56 AM

Doesn't add up for me either, I'm mystified. Are you using the same cables each time? What happens when you run the Zoom into the amp, the Zoom into the computer, or the amp's line out into the computer?

baalroo · #3 03-30-2008, 10:13 AM

Is there a guitar player around? I find that they are usually the cause of annoying noise.

i2k · #4 03-30-2008, 10:23 AM

I've been on the similar situation, when the symptoms was unpredictable and normal troubleshooting was not able to find the source of the noise. At the end I realized that somehow I had the noise only when my washing machine is on. Go figure !!!

Choosh · #5 03-30-2008, 03:50 PM

Learn to enjoy it?

niftydog · #6 03-30-2008, 04:54 PM

Quote:

Originally Posted by dannybuoy

- If I plug my bass straight into my amp, with the tweeter on and the treble turned up...

This is a very extreme setting and I think most of us would find the noise objectionable if we did this to our amps. Not so sure this is really a fault, per say.

Quote:

Originally Posted by dannybuoy

- If I plug straight into my computer's firewire audio interface and turn everything up, I get a hardly any noise, and there is no kind of interference generated from me touching the metal parts or waving my hand over the pickup.

No replication of the extreme treble boost of the above scenario? I know it's more difficult, but try comparing like to like - set everything flat and then compare, or if you can, monitor the audio interface using the amplifier so you can see if there is any noise being added to the circuit.

Quote:

Originally Posted by dannybuoy

- If I plug into my Zoom B2 and use headphones, powered by either my johnnyshreadfreak power supply or the one I got with my DHA pedal (both supposedly high quality noise free regulated supplies) I get the same kind of noise again....
If I do the above but use the cheap looking little 9v 300mA supply that came with the unit, it's completely silent whether touching the metal parts or not.

I'd be suspicious of any switch mode power supplies. Not sure what the johnnyshreadfreak and the DHA supplies are, but I'm almost willing to bet they are switch mode supplies. Are they significantly lighter than the "cheap" supply?

bongomania · #7 03-30-2008, 05:58 PM

FWIW DHA ships both kinds, traditional and switch mode. I've gotten both from him.

cheapbasslovin · #8 03-30-2008, 06:51 PM

Unless I'm greatly mistaken, wouldn't some shielding ala this thread help with the floating hand noise problem? The symptoms may not be consistent all across the board, but I'm pretty sure that may fix part of the issue.

Pilgrim · #9 03-30-2008, 07:04 PM

Quote:

Originally Posted by dannybuoy

- If I plug my bass straight into my amp, with the tweeter on and the treble turned up (I don't normally set it like this, it's just to help me detect the relative noise levels) I get a lot of noise. This noise increases if I hover my hand over the pickup, and cuts down by about half if I touch the bridge/strings/jack plug.

Any time you max out electronic control, you take a chance on adding noise. I'm not sure there's much of a problem. But since you mention the hand thing, I'm thinking that shielding the pickup cavity and making sure you have a good ground to all parts would be worthwhile.

dannybuoy · #10 03-31-2008, 01:39 AM

Thanks for answering guys, I need to spend a little more time experimenting with different situations to figure this one out.

Even without whacking the treble up and at low volumes, I can hear the buzzing from my amp, and it cuts out when touching any earthed metal parts. I realise that adding treble will add noise, but there is still this major difference between touching the metal and not touching it. There's no such effect through the PC or B2 (with correct power supply) which got me thinking that is was to do with a bad ground connection somewhere. Then the fact that I got a similar effect just by using the B2 with a different power supply just completely threw me!

Lots of people have complained about noise from the B2 (there's a whole thread about it) and others insist they have no issues. Seems like it's picky about where it gets it's power.

I'm not sure if my power supplies are switchmode - do I tell by looking to see if it accepts 110v-240v? If so then the cheapo and DHA are not switchmode (240v only), while the johnnyshredfreak is covered in velcro so I can't read the label without removing it!

bongomania · #11 03-31-2008, 02:01 AM

Switchmode is not about switching between voltage ranges, it's about the internal design of the power supply. Switchmode supplies are small and lightweight, while traditional transformers are larger and a lot heavier.

DHA · #12 03-31-2008, 02:02 AM

Quote:

Originally Posted by dannybuoy

Thanks for answering guys, I need to spend a little more time experimenting with different situations to figure this one out.

Even without whacking the treble up and at low volumes, I can hear the buzzing from my amp, and it cuts out when touching any earthed metal parts. I realise that adding treble will add noise, but there is still this major difference between touching the metal and not touching it. There's no such effect through the PC or B2 (with correct power supply) which got me thinking that is was to do with a bad ground connection somewhere. Then the fact that I got a similar effect just by using the B2 with a different power supply just completely threw me!

Lots of people have complained about noise from the B2 (there's a whole thread about it) and others insist they have no issues. Seems like it's picky about where it gets it's power.

I'm not sure if my power supplies are switchmode - do I tell by looking to see if it accepts 110v-240v? If so then the cheapo and DHA are not switchmode (240v only), while the johnnyshredfreak is covered in velcro so I can't read the label without removing it!

I have supplied a switchmode PSU. I would only recommend these for use with my pedals as they work best in terms of low noise.

Try putting the pedals on by-pass and then remove the power supplies, if it still has a hum problem then it's not the pedals or the power supplies that are at fault.

I think you have an poor earth in your amp or even in the room where the set up is. Or, it's a duff or cheap cable.

Dave

niftydog · #13 04-01-2008, 04:08 PM

Quote:

Originally Posted by dannybuoy

Then the fact that I got a similar effect just by using the B2 with a different power supply just completely threw me!

That could be a distinct fault. Many issues with noise manifest as sounding exactly the same, even though the cause is completely different. I'd treat them separately. In this case, stick with the cheap-o supply for the Zoom as it obviously fixes that issue. (some devices just don't like switch modes I guess!)

As for the issue re noise when not touching the strings, that's one very common fault. You could head over to the pickups and electronics forum and have a search around - there's lots of people doing lots of different things to alleviate similar problems.

Also, something DHA said definitely should be investigated. It could well be that your amps input sockets ground connection is a little dubious. While your audio interface has a good ground connection. This might explain why you get noise in your amp, but not in your audio interface.

What happens if you use the quiet power supply on the zoom, and plug into your amp instead of headphones? Headphones aren't a good test in this case because they don't have a ground connection.