OK, my bad on the previous.  I did NOT do enough testing in different configurations to really check out the Constrictor.  This time I tested the following:

- Setup: Fender American Delux Tele playing directly through the pedals into a Fender 65DSP (no effects loop and with amp effects both on and off).  Spectraflex Fatso 10' cord from guitar to Behringer PB1000 pedal box and 14' cord from pedal box to amp.  Pedals generally arranged in order of tuner, distortion effects, then modulation effects with the Constrictor either at end of chain or directly after tuner.  Pedals connected with Hosa pedal couplers.

- Power: Power adapters either plugged directly into wall AC outlet or run through a Tripp-Lite UPS with power conditoning & noise filtering.

- Effects plugged either into the Dunlop DC-Brick with individual power cords or the Behringer wall wart, distrubution block, and daisy chain power cord.

All the Hardwire pedals and the Line 6 Echo Park and Otto behaived very well with supprising little noise reguardless of setup (no more than going straight from the guitar to the amp and usually less, especially if I kick the Hardwire Reverb on -plesant side effect is that it distinctly reduces high freq hiss).  The DC-Brick did produce a lttle less high frequency hiss (only a few percent) on some settings, but not worth the $110 bucks.  The UPS did supprise me though dropping the hiss about 10%, but I would dread dragging a heavy UPS around.  Could probably get the same effect from something like the little Tripp-Lite ULTRABLOK that provides 40-80 dB of noise filtering, will fit in your hand, and only costs a little over $30.

The Constrictor; however, is a whole different story.

- Located at end of effects chain, Behringer wall wart plugged into UPS:  If you set the Level (and in some instances, the Sustain) to more than about 70% and reduce the gate to less than about 30%, the hiss and feedback are ungodly.  This is especially true if I try and use any of the distortion effects like Metal Distortion or Tube Overdrive.

- Located at end of effects chain, DC-Brick plugged into UPS: With the DC-Brick, again there's somewhat less hiss, but still totally unacceptable and lots of feedback, severly limiting the usefulness of the Constrictor in this location.

In both cases, it also severly dampened/fuzzed the sound of the Metal Distortion pedal where it was almost useless.

- Locted after tuner and before other effects:  Much better here with ability to gererally take Level/Sustain all the way up without severe feedback at fairly high guitar volume knob levels without distortion pedal effects on and at moderate guitar volume levels with them on (pretty bad at higher levels).  Still can't drop the Gate below about 30% or get intolerable high frequency hiss.  Also has a bad habit of generating a strong sharp pulse whenever you turn it on that is very audible.  Same result if Constrictor is only pedal hooked up to DC-Brick and all others are powered by Behringer wall wart.

All-in-all, not impressed in any of the configurations I messed with, but it could be result of not having a true isolated power source.  If I build the isolation circuits, I'll see if it improves.  Right now, I think I would have liked the Boss CS-3 Compressor/Sustainer or something else better.