i go from my guitar directly to my stack...i don't plug into the Peavey at all with the guitar! I take the effects loop out from the amp and go into the front of the peavey (its input.) then i go from the peavey's outputs to the amps loop return. i don't use the distortions in the peavey cuz they're not good at all. i mean, they are but not for the stuff i want to play. it all sounds too industrial and fake. it doesn't sound like a natural stack distortion; you can totally tell it's from a rack. there is one distortion on it though that is so heavy and powerfully overdriven...it's one of the factory presets...it's insanely intense. with a little tweaking it would be cool as hell i'm sure. anyway, the only thing i use the rack for is tweaking my sound slightly...just adding color to my stack. the unit isn't noisy at all. the effects always sound great...i'm so impressed! the ones you never want to use are the distortion, the phaser, the wah thing, and all the other little junk you normally wouldn't use. i don't even use its compression unless there is a really noisy effect, which is rare. the effects that are really good are chorus, delay, verbs, stereo sims. all the effects are totally programmable, especially the delays and eq's...man, there are almost too many options! i use it to practice with while wearing headphones in the studio and i still can't get over how beautiful some of the clean sounds sound! FX are powerful. the octaver thing...2 part harmonizer wanna be is pretty cool. i've gotten some interesting things out of it. It doesn't sound like Vai's stuff does but it is cool...puts a smile on your face when you play it....it will work for your needs without dropping $3,000 on an Eventide harmonizer.
I've never had a problem with it, whether in the studio or on stage. i would go to a gig without worrying about a backup! breaking a string is the only thing on my mind. if the unit gave up on me i would be very surprised!
i play metal and classical guitar and this unit fits great. i've also used it to add verb and other fx to drums, vocals, etc. in the studio. i've been playing guitar for about 11 yrs now and have owned a decent amount of equip...this is one of the good ones. i've owned alesis stuff and that is just too weak for me...studio wise is cool but not really in a rig. I would buy it again. In fact, i'm thinking about picking up another one for the studio. i love the clean sounds. i hate the pedal board that comes with it...you really have to press hard to get an effect to work. the editing is pretty good. i can't really can't think of any other product to compare this to...it excels in every area past all the others in its price range. you get a lot for what you pay even if it seems like a lot of money. i wish it had a headphone but oh well. i'm thinking about buying an ADA MP1 guitar preamp...any suggestions to me (email@example.com) would be great. Steve