mark v and mxr phase 90 issue

[ave]

Hello from England where it's taken 8 months to finally receive this magnificent mark v head which I run through four EV12L loaded boogie 1x12s (2 thiele and 2 halfbacks). I am only just beginning to scratch the surface of the seemingly myriad combinations of soundscapes available. My only concern is the loop and in particular my mxr phase 90 (which has had the ubiquitous R28 mod). In front no problem, however in the loop I get an almost 'bad piezo' quacking tone however much I try balancing the rear panel level knob from my preferred slot at noon. My other pedals in the loop (mxr micros chorus and flanger plus boss dd7) are perfectly happy in the loop. The in front chain is boss tu2,dunlop 535q wah and mxr supercomp.The guitars are a 62 strat and a 75 les paul deluxe. Anyone help with advice ?

 

[Hörman]

I tried it for you with my evh pase 90 and couldnt make it sound good in the loop too.
Anyway, the phase 90s are imo made for preamp use.

 

[eudaimonia02912]

I couldn't make my Phase 90 sound good anywhere with this amp, so it's gone. Even in front of the amp, it tended to sound distorted.

 

[screamingdaisy]

Phase 90s sound better before distortion.

 

[mejoshee]

phase/wah filter type effects should be the first thing in your chain before most everything else. part of the problem is the transistors used are running with relatively low headroom so they tend to clip pretty early. putting it in after a buffer may or may not help, i'm not entirely sure.

you can read this discussion from robert keeley (keeley effects):
http://www.robertkeeley.com/faq.php#Effect Order

other than that, there's pretty much little else you can do except find a way to auto level before input to the phaser, or use a digital phaser or something.