How to address hissing.

[pholli00]

Hi, I am playing a warwick wa 600 amp out of a ampeg svt 410.

I play off a passive single coil in the bridge position and crank the hi's and mids on the amp.

It sounds great but there is alot of noise coming out of the cab.

What can I do about this, besides eqing differentl?

I'm not an electronics guy myself, but I noticed my combo amp hissed a lot. Then I moved. Hiss was reduced considerably in the new place. I have no idea what that means or why that would be, except that I personally think electricity is magic. Does the source for the electricity have anything to do with hissing? Has anyone else noticed that?

 

[rwkeating]

Hissing doesn't usually bother me much, but when they start booing, then I get worried.
Uh ... wait, you were talking about your amp? Never mind

 

[DInfrasound]

Have your bass professionally shielded, that should dramatically reduce the notice that your pickups collect. I remember with my old passive jazz bass if I stood in my practice room just right I could tune in to a spanish radio station

 

[ddnidd1]

Maybe I missed something in this thread, but it seems at this point you're just guessing where the problem is.

Disconnect everything from the input of the amp. Don't have anything in the effects loop.

Now set your amp as you've described initially. If the hiss is still there, the problem is internally with the amp and its components.

If there is no hiss or the hiss is reduced, plug in your bass and see if/how the hiss changes.

Until you do this, you're just chasing your tail as to whether the cause is your amp, your bass or both.

And is it a high frequency hiss or a lower frequency buzzzz.....

 

[Ewo]

Treble cranked? My guess is there's not a lot of top end coming out of the bass (dead strings, passive tone rolled off). Jacking up the treble EQ is just gonna give you hiss.

 

[David Jayne]

He says the bass is passive so it's not coming from there.

 

[yodedude2]

Maybe I missed something in this thread, but it seems at this point you're just guessing where the problem is.

Disconnect everything from the input of the amp. Don't have anything in the effects loop.

Now set your amp as you've described initially. If the hiss is still there, the problem is internally with the amp and its components.

If there is no hiss or the hiss is reduced, plug in your bass and see if/how the hiss changes.

Until you do this, you're just chasing your tail as to whether the cause is your amp, your bass or both.

And is it a high frequency hiss or a lower frequency buzzzz.....

yes, process of elimination. seconded.

 

[GreyBeard]

A while back, I had an Ampeg SVP pre-amp that was super noisy. I used the noise gate feature from a DBX compressor to quiet it down until I got it fixed. (bad tube). It actually worked pretty well. Maybe look into a noise gate pedal. Behringer makes one for about $30 that isn't all that bad, might just do the trick.

hope this helps

 

[physics]

As others have alluded to, at this point you don't know what the source of the noise is, internal to the amp or external magnetic fields, and so what I would do is methodically test each possible source until you pinpoint it and can then fix it. I found that my TBird, with dual HB pups, would hiss noticeably when I operated the pups in single-coil mode. That was a clue to me that I was picking up stray magnetic fields from either wiring in the walls of my apartment or from electronic equipment in my neighbors apartments. I eliminated the possibility that the hiss was coming from my amp or speaker by varying my distance from the amp and orientation with it and observing no change. I confirmed that it was external noise by moving the rig somewhere else and noticing that the hiss was greatly reduced. My fix has been to operate in HB mode when I'm in my apartment. An alternative fix might have been to have shielded the electronics cavity and the underside of the pick guard with a sheet of grounded copper foil, a Faraday shield.

Another possibility is that it could be generated within the circuitry of the amp itself. I have a cheap battery operated headphone amp for when I'm mobile and when I monitor the bass with headphones through that amp it produces a lot of HF hiss. I rolled off the highs on the tone pot of my bass and it made no difference, hence the hiss was being generated downstream of the bass and could only come from the headphone amp that I was using. I wound up rolling off the highs on the amps tone control and the hiss went away. Since there was no real bass signal at frequencies that high, there was no noticeable degradation in my tone.

Again, the idea is to isolate and identify the source of the problem before anything else. I used to do troubleshooting diagnostic work on Ham radio rigs and communications gear when I was young and got into the habit of approaching problems this way, it saves time and reduces frustration in the long run. I hope this helps.

 

[JollySpudd]

Thanks I'll try. It's fine while playing. I want it for basically, talking while at band practice QUOTE]

Just to clarify for a newbie what WayneP said "Send is the output. Return is the input" that's for the loop - The loop send (output) will go to your denoise unit's input, then your denoise out goes to the loop's return (input). - Good words from WayneP