Direct box problems - NV400 noise UPDATE

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

I have tried several times to run a direct box out of my Nasville 400 preamp out (tried 2 different amps, one with Fox mod, the other stock) and since my amps buzz at various levels depending where I play, this transfers to the direct box and thusly through the PA. Micing doesn't work as I actually sit in front of one of the PA speakers and get feedback.

I have a direct box that has attenuation at 20db and 40 db. If I use these, there is not enough signal to run the input of the PA (Mackie). Also the ground lift on the direct box makes little difference. Straight run from preamp out to PA input causes buzz also.

The direct box has parrallel inputs where you plug the guitar into one and the other to the amp. Then the XLR out runs to the PA. I could try plugging one of the outputs of my volume pedal to my amp, the other output from the VP to the direct box and then the XLR out to the PA. But I will lose my tone and reverb. PA runs delay which I really don't like on steel. I think I could hook my effects rack to a aux output on his PA to get my reverb back and just set the tone on the PA.

What do you think? Any suggestions?

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

Bump...

Please, really need some insight.

Ron Randall · From: Dallas, Texas, USA

Well
Here is a guess. You mention ampS! (plural) If you are running two amps on the same circuit you are gonna get hmmmmmm. (guitar 101) Try the same setup with one amp, and no others on the circuit.

There is a gadget that will let two amps live together on the same circuit, with the grounds intact. I know Furman makes something like this but there are others.Search the forum archives for ground lift or check sweetwater.com

Once you have both amps on the same circuit with the ground loop hummmmmm gone, then you can tackle other problems.

This may not be the problem, I am guessing at the moment. Anyway, you can't do any harm with this ground gadget, and it will one day keep that serious electrical shock from hurtin ya.

After this, if you are using single coil pups, that may also be a problem. Single coil pups humm. guitar 102. You don't have to replace the single coils, just find a place where they don't hum.
Take the guitar about 10 feet out onto the dance floor. (you choose when!)

I started using a power transformer/power factor correction/surge protector/power strip from Furman, a coupla years ago. It will handle four or five 110v amps/processors/etc. with no hum and no risk of shock from lifting grounds. Do this last. about $200?

R2

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

I don't use the two amps at the same time so that's not the problem. I own 2 NV400's and they both buzz. One has the Ken Fox mod and the other doesn't. The modded one is worse than the other (and was that way before the mod - not to imply the mod made it worse).

Guitar has humbuckers.

I use a Tripp Lite power line stabilizer/line conditioner similar to your Furman unit.

I also have the HumX hum eliminators.

I just don't know what to do.

Bryan Daste · From: Portland, Oregon, USA

My suggestion is to have the amp checked out and serviced. A little hum is normal, but not enough that it's noticeable when you're playing with a band.

Jack Stoner · From: Kansas City, MO

The Nashville 400's have the infamous Molex connector for the reverb and if you use the Reverb in the Nashville 400 and there is a poor connection at the Molex connector there can be hum.

If you are using the reverb in the Nashville 400's, turn the reverb off and see if the hum goes away. If it does then the reverb circuitry and/or the Molex connection are probably the problem.

I doubt that a power strip, regardless of the make, has a bearing on your hum issue. A high end power conditioner/strip can remove some AC power line noise but that is not your problem.

Maybe you need those $700 AC power cords Laughing

Johan Jansen · From: Europe

Isn't it something in your steel or volumepedal?
Is the hum away when your steel is disconnected?
JJ

Curtis Alford · From: BastropTexas, USA 78602

When you leave the direct box out of the chain does it buzz? I would look for a defective box.
The amp out on the back of the unit is the proper point of connection to the board. If straight line connection to the board doe not buss then, it's the box.
You only state the buzz is when the box is used. Did I understand you problem correctly?
Curtis

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

The amp buzzes on it's own without the direct box or powered speaker cabinet connected to the preamp out jack.

Lowering the reverb doesn't help.

Of course lowering the pre and post gain controls reduces the buzz, but also reduces volume too much.

The funny thing is that both my NV400's do it.

I haven't tried unplugging my guitar from the amp yet. Will try that.

Have played through other amps (like Fender Deluxe, my Fishman amp) and no buzz like the NV400's have.

Of course when I am playing, the signal is louder than the buzz. The main problem is going to the PA, the volume of the buzz is boosted.

Doesn't anyone else have buzzing problems with their NV400's?

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

Jack, would it hurt to remove the molex plug to the reverb spring to see if it goes away?

My line stabilizer does not make a difference in the buzz. I just use it to keep voltage constant.

Also, I don't know if we all are speaking of the same noise. This is actually a buzzing (Bzzzzzzz) sound as opposed to a hum (Hmmmmm).

Sometimes the guitar players amp will buzz but very minimally.

I can live with the buzz as long as I don't use the preamp out to the PA.

Jack Stoner · From: Kansas City, MO

Richard, it won't hurt to remove the reverb Molex plug. Just turn the Reverb control to 0 (off).

Jim Sliff · From: Lawndale California, USA

Richard, this isn't a suggestion but instead a question.

Is all this happening in ONE location? You mention a board, running through a PA etc - it sounds like it might be in one place. Honestly, you cannot solve a problem this involved until you take the location out of the equation - so if it's in one place my immediate thought is that there is nothing wrong with your equipment at all.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

Hi Jim,

Different locations, different PA systems.

My amps buzz everywhere, just different loudness at different locations. Some places I get hardly any buzz at all.

basilh · From: United Kingdom

It would be a considerable help if you were to record the Buzz/Hum and post an mp3 link on the forum..
Basil

Curtis Alford · From: BastropTexas, USA 78602

Have you tried leaving the power conditioner out of the primary power just to test.
It is extremly unlikely that both amps would have the same problem (cold joints, filter caps, etc) at the same time.
Something IMHO,is causing a cross connection in the signal chain. I once had similar problem with a tube amp, a tooth pick had fallen through the input jack and was across the connections on the jack. My bandmate had a cobweb across two connection points and had a similar buzzing sound.
Let us know the real cause if you find it.

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

I played a gig Friday night and didn't use the line conditioner. Same buzz, although this place has less buzz than my regular places I play.

I plugged each amp (seperately) in at home last night (with nothing connected to them), and while the buzz was there, it was pretty low in volume and I cranked both gain controls all the way up. It's always been low at home even with my guitar plugged in. Lowering any of the tone controls also will lower the buzz.

I'm thinking it's just inherent noise in my amps and are made worse at some locations by some condition in the club or hall.

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

Maybe when Ken Fox gets back from vacation, I will send the one he modded (don't want just any tech messing with his stuff) for him to look at.

Also, if I didn't say before, I removed the reverb spring from the circuits of both last night (with the control knob all the way off, and it made no difference, so I don't think that is the issue.

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

A little update. A while back, I stopped using my George L cables and went to ProCo cables. Reasons: My cords weren't long enough and after years of coiling them in a circle to fit in my pac-a-seat, the cords would no longer lay flat causing trip hazzards (not a fun thing, believe me). I didn't notice any change in my tone.

Well, Sunday I tried my old George L cables. This cut the noise down probably 90%. This is the same place I had the direct box problems and one of the places I have the most noise. Used the direct box and only got some bearable hiss through the PA. Totally different than the buzz saw sound from before.

Forum Index > Electronics		Next oldest topic :: Next newest topic