I have a Marshall JVM 410H.

I have the following pedals setup:

For the front of the amp I have:

Guitar > Compressor Sustainer > Chorus > AMP (input)

In the effects loop I have:

Isp decimator --> Harmonizer pedal --> Phaser --> DD3 Delay

The problem is that when I use the OD1 and OD2 channels and turn on the compressor a get a BIG hiss.

I have get rid of the noise if I set the ISP decimator (noise gate) higher, but the playing get's cut off.

What I'm I doing wrong? Do I need to use 2 Noise gates?

  • Sounds like a big part of the problem is the compressor! When you punch it in, you get hiss. A compressor might cause this because it cranks up the gain when the incoming level is low, and turns it down from there in proportion to the signal being louder. If the noise is self-noise from the compressor, then there is no gating you can do in front of it to solve the problem. Get a quieter compressor!
    – Kaz
    Commented Oct 7, 2013 at 23:07

2 Answers 2


There are a couple of possible causes here, so you may need to use trial and error.

First check what happens if you just plug the guitar straight into a clean channel. Any hiss? If so, the problem is with your guitar or amp. Swap one out to try and isolate the issue.

Then use an overdrive channel. This is the most likely steep to introduce noise. If it does, work with your volume controls to minimise it.

Then try adding the compressor - this can dramatically increase the noise floor during quiet parts. If this creates the hiss, alter threshold and gain.

Noise gates can reduce noise during quiet passages, but as you have noticed, thus us at the expense of tone and sustain.


That is a very high gain amplifier and lots of gain almost always means lots of hiss. I think you'll have trouble taming this hiss... Make sure any preamp tubes have a shield on them. You can see an example of a shield here. The shields help remove noise from getting into the tube from outside, which is a real problem for very high gain amplifiers.

Take a look at the amplifier reviews here.

The compressor is also actively working to increase any outside noise that may be coming from the guitar with the way you have it set up (Which is correct, IMO).

Try putting the noise gate after the delay. If that doesn't cut much of the noise, put the noise gate after the chorus and see if that settles it down.

Other than that, I'm out of ideas.

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