I owned a rectoverb series 2. I could never get the loop to work with any delay or any other modulation pedal for that matter. Specifically, for me the problem was I had to mix it in all the way (pedal on max) and mix 100% but then in just a minute of playing a terrible feedback loop would occur. It seemed to be timed with the delay repeats. I went to a store and tried different delay pedals (line 6, and numerous boss's including the giga delay) and the combo rectoverb in the store did the exact same thing. The store employees were stumped. I've also tried the same thing on the single rectifier amp heads . . . same results.
I've talked to Mesa and all they say is that I have to get the levels right. Well, the problem is to get rid of any feedback, I have to set the levels to the point you can barely hear the effect!
Moral of the story is that your rectoverb WORKS JUST FINE but the loop Mesa put in these amps is awful and worthless! Mesa just needs to change the loop design. I really like Mesa and the tone out of the rectoverb is fantastic but they just dropped the ball on that amp's loop. I found that any effect you run must be infront of the amp which means no modulation after the preamp.
Check out Harmony-Central.com reviews on this amp. People talk about the terrible loop.
I have a dual rectifer now and it's loop is great. I don't have any problems.
