fender stage 100 dsp 112 combo

[klunk]

I just bought this amp (used) and now realize that it hisses. It only hisses when the cord is plugged in. It is a low volume hiss that is not noticeable while playing consistently at any volume, low or high but i have been playing sparse, mellow, clean, stuff lately and the hissss is beginning to bug me. it also makes it uselesssssssss for close mic recording. any advice? Thanks.

[ricach]

DSP's can inject lots of hiss when you're using several effects. Is the hiss there with all effects turned off?

[klunk]

Thanks for the reply,ricach!...The amp hiss happens without any dsp's in use (clean sound, no effects/reverb) as well as with any effects. it never increases or decreases in volume, unless i turn the master up. when powered on without a cord in the input it is totally silent. hiss occurs as soon as cord is plugged in with or without the other end connected to anything.

[Phostenix]

Input jacks usually have a switch built in to them to either short the input to ground at the jack or activate a mute circuit into the power amp when you pull the plug out. Fender seems to like to mute the input to the power amp. Does the amp have an effects loop? If so, you could try plugging into the effects return jack to see if the noise goes away. That would tell you that the preamp circuitry is noisy.

[klunk]

that killed the noise!.. i ran my volume ped thru the loop. if the noise is in the pre-amp does that mean something is going bad in there? should i even care now that the noise is gone! Thank you very much for sharing that diagnosis technique.

[Phostenix]

I don't know how noisy that particular amp is. Maybe you could go to a music store & check out a different one. Is yours fairly new?

[Enzo]

OK, so the noise is in the preamp. I can;t tell you now if it is excessive or normal, but we CAN locate the source. Plug a guitar into the input but turn the guitar volume to zero. That should "turn on" the hiss, but not add any guitar noise. Now what effect if any do EACH of the controls have?

Apparently the master volume control turns the hiss up and down. Do the tone controls affect the tone of the hiss? Do the pre controls or gain controls have any effect on it?

[klunk]

thanks for your help

sorry to forget to wrap this up...i have been running the amp with the vol. pedal in the fx loop: that killed most of the low volume hiss. there is still some white noise at louder volumes, but nothing like before. It is definitely a pre amp noise problem. i tried another stage 100 dsp combo amp and it was quieter but there was still some light hissing detectable. i also tried another solid state fender that exhibited the same slight hisssss.i think that is possibly a common trait of this generation of ss amp coming out of the factory. Many thanks to you guys for helping me with this problem.

[JoeM]

I think the hiss may just be the nature of the DSP. I owned a Fender Stage 1000 (very similar to the earlier 100 DSP models), with the same problem. There's a mute circuit, so the amp's quiet when nothing is plugged in, but for low level practice or recording the hiss is annoying. I finally built a simple box with two jacks and a pot that could be plugged in the pre-out and power amp in jacks and could reduce the hiss from the preamp, just like you did with the volume pedal. With a band the noise level is well below audible.

[klunk]

dssssssssssp

I figure since i use a vol pedal all the time, i will just use it in the fx loop and live with that set-up. I like the amp well enough: some of the on board fx are cool (although it would be nice to be able to use the footswitch to select between the delay,tremelo,chorus,flange settings)... Now i know better how and when to use this amp AND to be more attentive when checking out amps: when i bought this i was trying it out in a room with open windows facing a busy street. I think the ambient white noise blended with the amp hiss. i dont think the guy selling it intended any misrepresentation (i could have asked to close the windows!) i just did not factor a quiet setting into my checklist. caveat emptor!