Noise/Hum coming from my SansAmp BDDI

[mcbn]

I have been auditioning for different bands recently and have noticed that I have a bit of noise. I think this noise is coming from my BDDI.

 

I have had this problem before, but I know for a fact that the room I was playing in then had serious grounding issues.

 

My signal chain is as follows:

 

Bass --> EBS Multicomp --> BDDI --> True-Bypass Loop pedal

 

On the parallel out of the BDDI is my Boss TU-2 tuner.

 

I keep a couple of different effects in the true-bypass loop. Last night it was an EH BassBalls and a Digitech Bass Driver.

 

All pedals are powered by a Godlyke Powerall and are well within the 1.7 amp rating of that unit.

 

All of my patch cables are fairly new and all are tested.

 

I have individually tested both basses, the EBS, and the T-B Loop and all are very quiet/noiseless.

 

If I am not touching the strings, I get a hum from the amp. As soon as I touch the strings, this goes away.

 

My BDDI is an older model with only 1 switch on it (phantom/ground connect). It is set on the "SVT" setting with a little added bump on the drive. The "level" is set for unity gain.

 

This happens with either of my basses (Warwick Streamer STD (passive) and US Fender P). I really don't think the problem is with either bass.

 

My guess is that I have a grounding issue. This may come from one of the following reasons:

 

1) The parallel output I'm running the TU-2 on is causing some interference

 

2) The SansAmp doesn't like to share power

 

3) There is a grounding problem in every room I've played in recently

 

4) My SansAmp has an internal issue and needs to be sent in for servicing

 

Please provide me with your thoughts.

 

Thanks to all.

[Fred TBP]

Originally posted by NUTT:

My guess is that I have a grounding issue. This may come from one of the following reasons:

 

1) The parallel output I'm running the TU-2 on is causing some interference

 

2) The SansAmp doesn't like to share power

 

3) There is a grounding problem in every room I've played in recently

 

4) My SansAmp has an internal issue and needs to be sent in for servicing

1) not likely

2) you're right about that. battery, AC adapter or phantom power? the latter fried my BDDI.

3) (assuming you're using a 2-prong AC adapter) are your outlets sharing circuits with flourescent lighting or another household appliance? microwave? motor? TV set? hair dryer?

4)(if all else fails) Tech21 support LINK - look under "Repairs". Make sure you can provide them a copy of the sales receipt and be careful to mention that you're only using their "authorized" power supply or it'll be on your dime.

Good luck with it.

[MvW]

Definitely sounds like a grounding issue somewhere. Have you tried running the BDDI on battery to see if there is a difference?

[Mike Bear]

Maybe try running the BDDI before the EBS Multicomp then into your amp. Many rehearsal spaces I've been in don't have the greatest grounding. My Furman power strip comes in reading very low under 120 most of the times. So that can be an issue too.

[Big Daddy from Motown]

Try plugging in your bass and than turning the volume on the guitar all the way down. Did the hum go away? If it did the hum would be from the guitar.

A slight hum is not all that unusual.

 

P.S. low AC voltage will not cause a hum.

[PhilMan99]

Battery idea may be good. Try running from batteries on everything you can. If hum goes away, find which device(s) causes hum adding A/C adapter(s) back one at a time.

[mcbn]

Fred - I'm running on an AC adapter. I don't run phantom power.

 

Mike - I'll try switching my signal chain around and see if that works.

 

Posted by Big Daddy from Motown

Try plugging in your bass and than turning the volume on the guitar all the way down. Did the hum go away? If it did the hum would be from the guitar.

A slight hum is not all that unusual.

I'm thinking the answer is yes. When I turn the bass down the hum goes away. I didn't think this automatically pointed out the bass as the problem though. I can run my entire signal chain without the BDDI and have no hum.

 

To eliminate the slight hum I've spent a decent amount of cash on a completely silent compressor and run everything else in a true bypass loop. I'm quite particular about being whisper quiet. However, this is a very noticeable hum, even to the non-particular types.

 

Keep the ideas rolling in, I'm going to do a little testing Saturday.

[Big Daddy from Motown]

OK it could be a bad shield in the guitar cord, but not very likely.

 

You haven't mentioned what amp you are using. Is it a single amp (pre+power) or just a power amp?

Try running the volume higher at the amp end and lower at the sansamp. If's it a power amp run it flat out.

 

The first thing you should try if it's a integrated amp (pre+power), is plugging the guitar straight into the amp to see if the buzz is still there.

 

To avoid ground loops and hum in general make sure that your entire system has only 1 grounded outlet, typically at the power strip.

[mro]

I second the motion of NUTT. My battery powered BDDI has the same noise/hiss. Without the BDDI, there are no noises at all. As I either turn up the level or presence knobs, the noise increases. I like the tone I get at these knob positions, I would just like it to be quieter.Same thing, hands on string, ok, when I let go-problem. I'll be reading any further replies.Do other people experience this?

[MvW]

I get some noise running through my BDDI, but it doesn't sound as bad as the rest of you are experiencing (I have both the single channel and the three channel programmable). And the single channel is definitely much quieter when I'm running on batteries as opposed to plugged in with the dedicated power supply.

 

FYI - the three channel programmable is dead quiet running from the battery.

[titrek]

1) The parallel output I'm running the TU-2 on is causing some interference

 

I got rid of some hum when I began not using this parallel out. [i am still thinking why it caused that hum, other than behaving like an antenna.]

 

So maybe you may try not using the tu-2 for a while. [in my case the tuner was a seiko one operating from the batteries]

[Fred TBP]

Originally posted by mro:

I second the motion of NUTT. My battery powered BDDI has the same noise/hiss. Without the BDDI, there are no noises at all. As I either turn up the level or presence knobs, the noise increases. I like the tone I get at these knob positions, I would just like it to be quieter.Same thing, hands on string, ok, when I let go-problem. I'll be reading any further replies.Do other people experience this?

What you're describing is a sensitivity problem caused by your bass acting more like a receiving antenna. Since the BDDI is a pre-amp, it'll amplify any imperfections (noise, hiss) inherent in your instrument.

 

Do you get noises without the BDDI? Is your bass properly grounded and shielded? You'll hear this at stage volume more than in a home practice situation. Also check your cables, patch cables as well; a bad cable will attract noise and hum just like a radio antenna.

[Tom Capasso]

I think Fred's post is it. There is probably always some noise coming from the bass (made better or worse by the room you are in). The noise gets amplified by all of the boxes. I have also used the TU-2 in this manner and feel that it "adds" to the noise a bit. It doesn't take much, because those little boxes amplify it right into hearing level. The proximity of the power supply's transformer may also be part of this (I doubt the noise is coming in through the power line itself).

 

I would suggest Mike's suggestion about lots of "isolation" testing. This includes the cables. If it were me, I'd need a chart to track what you have (4-5 boxes, 6-7 cables).

 

Happy testing!

Tom

[mcbn]

Well I've spent the last hour annoying the ever livin' heck out of my neighbors.

 

I can't reproduce what was happening in the rehearsal studio the other day.

 

Running through my own rig, with my amp and the effects on the same power strip, the "hiss" is about the same level as the fan on my amp if not a bit quieter. That is when the amp is at wall shaking level (around 5 on volume of the Firebass).

 

I think it all has to be a combination of the rehearsal space rigs I've been just plugging my pedal board in to and the poor grounding in the rooms I've been playing in.

 

This ordeal made me think back to the March 2005 Bass Player mag that featured an article on Juan Alderete (from the Mars Volta). This guy is playing vintage Fenders through around 20 effects pedals into vintage Ampeg and Acoustic amps.

 

Is a completely noiseless rig possible? I think I'm going to start a poll.

 

Thanks for everyone's help.

[Fred TBP]

Originally posted by NUTT:

Is a completely noiseless rig possible?

Yes. There are people out there who take your pedals and design custom rigs with regulated power supplies, matching impedance adapters and can put it all into a box for you. The big dogs don't come cheap but with a little searching you might find a local talent who can give you a deal in exchange for some product endorsement. You can DIY but do your homework and purchase top-shelf components for it. I've seen four-figure rigs go bad because of a faulty instrument cord, for instance.

 

Remember that every pre-amp circuit you introduce between your bass pickups and your power amp will multiply your signal noise, not just add to it. In live situations I use three (bass pickup preamp/EQ, amp head preamp and FX preamp) but I'm careful to monitor the noise gain and use extra noise suppresion on the FX pedal to compensate.

[Mike Bear]

Most rehearsal spaces don't have the greatest electricity. I once helped in the construction of a studio and it was very interesting the measures were taken to keep this place quiet. But imagine some guy who buys an industrial building, walls off some rooms and puts a bunch of bands with a bunch of gear in there. Hey on a bad day, I get Radio Disney through on of my pedals. But that's only where I rehearse. Nothing like Britany Spears comming through my Eden, loud and in the middle of some nice soft passage. I do get a bit of air noise when I'm not playing. So I take advantage of my gate on my dbx to just close the signal when I'm not playing. Best I can do. It's not a crazy amount of volume and I know it's not an EQ thing. I hardly EQ anything, and almost never add any high end.