Nashville 400 problem

[Francis Chamberlain]

I have a problem with my Nashville 400. If I turn the MID up I get a rushing sound. The farther I turn it up the rushing sound gets louder. Another thing, if I leave it on and walk around in the house, I can touch the metal end of the hadnle on the right side of amp and I get a loud pop. If I touch the other end of the handle I don't get the pop. how can this be The handle is only mounted in the wood part of the amp?

[Stephen Cowell]

I have a problem with my Nashville 400. If I turn the MID up I get a rushing sound. The farther I turn it up the rushing sound gets louder.

I'd say you need to see a tech on this one... possibly an op-amp, maybe a resistor.

Another thing, if I leave it on and walk around in the house, I can touch the metal end of the hadnle on the right side of amp and I get a loud pop. If I touch the other end of the handle I don't get the pop. how can this be The handle is only mounted in the wood part of the amp?

It may be that there's some kind of shielding inside the amp... Fenders have screen wire up there. My guess is that one of the handle screws is touching this shielding.

[Francis Chamberlain]

Thanks Steve for your reply but the amp does not have a screen in the top. I thought the pot might be dirty so I sprayed it with tuner cleaner but that didn't solve the problem. It seems to be a ground problem. Like I said I can touch the handle bracket with one hand and touch the metal part of the chassic with my other and that elemates part of the noise.

[Jack Stoner]

Check the AC power receptacle. Check for ground and for proper wiring (hot and neutral wires).

The Mid control cuts or boosts the frequency that has been set. The majority of pedal steel users have it set on the cut side (I ran mine between -2 and -3). If you boost it up very high you can get "white noise".

[Francis Chamberlain]

Thanks Jack, for the info. You are right the noise is more on the plus side. On the minus side there is little or no noisse. But why should I get a loud pop when I touch the handle bracket? Would this be caused by static electricity? I have the amp on sitting in my garage. After wealking around in the house (on carpet)I go out and touch the handle and I get this loud pop and this only happens on the left side of the handle. Would this be due to where a certain component is located on the circuit board being closer to that side of the handle? Note: I might add that I do not have my guitar hooked up to the amp if this would make a difference.

[John Billings]

If it's static electricity generated by walking around on the carpet,,, when you go out into the garage, touch a water pipe or something grounded to discharge yourself. Then see if you still get the pop. This doesn't solve your problem, but it may tell if a static discharge is involved.

[Jack Stoner]

Not having the guitar connected is good, it eliminates that as a potential problem.

I think there is some type of ground shield mounted underneath the top of the amp cabinet. Thus the side you touch that pops is probably the grounded side. It could very well be static electricity. Try grounding yourself to some other grounded device first before you touch the amp and see if makes a difference.

Does it only pop one time when you touch it or can you touch it multiple times and get a pop each time?

The grounding (or lack of) at the AC receptacle is another issue.