My first rack compressor . . . not working

[HariKari]

I bought a Behringer MDX1600 off ebay, well used. It was given a good review by bongomania as surprisingly good for the money. I'm using it with a Hartke HA3000, which has a single volume knob vs. gain/master knobs (may be important).

Now, I've tried hooking this thing up every conceivable way--pre and post effect loops and straight into the front input--but the compressor, well, simply doesn't compress. You can twist all the knobs, push all the buttons, and it scarcely affects the tone at all. I have a Digitech Bass Squeeze, so I have some idea what should be happening. And almost nothing is happening. Only the expander/gate has any effect, and it just blows.

Maybe the compressor is just broken, but while some some of the switches are a bit stuffed up, it basically appears functional. And I've tried both circuits; both are the same. The only other odd thing is that the input levels seem very low. They barely crack -18db. And while output levels can be adjusted, input levels cannot.

So, are the input levels coming from my amp just too low for the compressor to compress? Without a separate gain knob on my amp, do I need a separate pre to boost the signal? Or is there something else I'm just missing?

[cliffbass1]

well, i found the manual

http://www.behringer.com/EN/download...P0177_M_EN.pdf

dumb ? but have you tried bass --> Comp --> amp ??? ( i bet you have but i was just curious well if so then idk i guess read the manual its help me a few times. best of luck too you

[bongomania]

Reading the HA3000 manual, the send and return levels of its fx loop (either pre or post) should be perfectly good with the Behringer. The only caveat is that the loop is post the "volume" control, so if you have the volume knob down low, the output of the loop will be low, and the compressor won't get as much signal to work with.

I'm assuming there's no compression shown by the gain reduction LEDs? Because the effect should be much less audible than the obvious squash of the Digitech--there should be no change in the tone. So what you're looking for is a change in the output levels, irrespective of tone.

If you have gone through the Behr's manual, or my FAQ, to learn how the controls operate; and if you've tried everything reasonable based on the info about those controls; then I'd suspect the Behr is not working right. The way to test that is to try a different rack processor in the loop of the amp (to see if the loop is all good) and try the Behr comp in the loop of a different amp or mixer (to see if the Behr is all good).

[HariKari]

Thanks for the help. There is some gain reduction shown when routed through channel one, but unfortunately, there is bad distortion in that channel, so it's difficult to judge functionality. Channel 2 is clean, but registers almost no gain reduction. And several of the push buttons short out. Probably this unit is just borked. I'm returning it to seller.

I'm going to try another pedal. Based in bongo's reviews, I think I may try the BBE Opto Stomp. I'm not looking for major squashing, just a bit of punch and evening of levels without killing my tone. And for a modest outlay.