So my practice 10 watter (an ibanez somthing10g) has been my little practice amp for about 5 years. I recently got a tube driven multi effects pedal(digitech rp7). so far I really like it.

But, one day, they stopped getting along.

now when I plug the pedal into the amp with any distortion running, it sounds like absolute crapp like emitting this verry basssy buzz. initially i thought it was the pedal, but when plugged into my bigger amp it sounds great. and when my guitar is plugged into the ibanez without the pedal it sounds fine too.

any thoughts on this? The cables are fine. I also plugged a small drum machine into the ibanez and it sounded great.

can amps be damaged to only really show it when the signal is over driven?

It worked fine when I just got the pedal about 2 weeks ago
Sounds like you've done the right troubleshooting.

What is your 'bigger amp'?

So the problem is with the RP7 and the Ibanez amp only. My guess is that the little ibby just can't handle the signal from the RP and it's crapping out on you. Not sure there would be a fix.

*runs to search on tube driven Digitech RP7*
Big amp is a peavey bandit 112, just a different amp. and i mean the ibanez is a guitar amp, a decent practice one at that, it should handle it, not like i'm dealing with a cheap stereo here or something. and it sounded great for the first week or 2 with the pedal, and my old distortion pedal before it (sold now).

the one problem is i dont have another distortion pedal to see if thats an issue, the rp7 has both tube and ss distortions and they all sound like ****. although i did find that messing with the eq on the rp seems to help a little, idk what that tells me. but i might crack open the amp and have a looksee maybe something came loose.
somekid, I searched on RP7 on digitech.com and can't find that pedal. Are you sure it is not an RP70 that emmulates disti pedals?

For example, the Tubescreamer setting has nothing to do with tubes.

I have an RP250 and I've used it with Solid State amps with only average results. You will hate me, but I personally would not use a MFX pedal thru either of your amps. If you like it though, that is all that matters.

So in other words, your delay, phaser, chorus, etc functions all work, it's just the Distortion that sounds like crap?
well the whole thing sounds like crap through it. distortion magnifies the crapness... the issue is it sounded great a week ago and i didint change any settings. i think the amp may have had a small fall and knocked something loose on the internals.

I know people hate on multifx but for my level and budget and such it works really well.

its called the rp7 valve, its on digitech website albeit it is discontinued its older like from mid-late 90s. and it has an 7ax12 tube which runs the preamp that it uses for the distortion sounds. i replaced it 2 days ago
Interesting. I didn't see it on the Discontinued list, but I believe you.

Was the new tube you put in brand new? So you're sure it is not microphonic? Also, is the new tube seated down all the way? Is it possible a screw on the speaker came loose or something?

yea it was a new EH tube and I got it in correctly.. I bought it because I thought that was the issue... plus those things come with cheap tubes anyways. i think it sounds more like a loose grounding wire or something.. i just gotta find a free moment and crack it open
SO... I plugged it into the pedal again today... and it sounds great... wtf... I hate electronics

but probably from some loose wire or something