#1
Hi there,

I bought an ISP decimator a few weeks back, and recently I've noticed a bit of hum has crept into my signal path on the OD channel

My efects chain is like this:

Guitar > Crybaby 95Q > ISP Decimator > JCM 900 ( I sometimes use a CS-3 before the Crybaby, but I've also noticed that this pedal whether on or off kills the tone of the wah somewhat)

(With a DD-5 and MXR Micro Amp in the FX loop)

I haven't actually tried the decimator in the effects loop yet, but I have read in numerous places that this pedal has no such effect when placed there. I have isolated the power supply to my pedals so they are not power by the same socket etc, nor have I actually tried this without the decimator as again I have read of some cases where the decimator adds noise to the effects chain.

Can someone help me with any solutions or advice? Is it possible something is wrong with my amp? The decimator does actually work - in that it does stop any noise getting through when I'm not playing, but I am still getting this persistent, fairly loud hum. Because we play at low volumes in practice I have the preamp gain on the OD channel on 12 or above just so I can get some decent overdriven sounds - before I had the decimator in there, I never noticed any hum of any kind because I find this is a fairly quiet amp in some regards, even with the pre amp gain maxed out, it doesn't tend to hum as much. I intend to get a THD hot plate at some point so that I can back off the pre amp gain and drive the amp more using the master volume and really get to hear some proper tube OD coming through.

Any help or advice would be gladly appreciated.

Steve