This rack is a "psycho equalizer"
It allows you to add serious harmonic (sub bass) or acute, there is also a setting that plays on the stereo image
the connection is only XLR, good for the quality of sound, sometimes annoying when you want cable or faster with other devices that are not symmetric connectivity.
I bought this mainly for use in mastering, so a stereo signal, a feature I would have AIM Link (there's not too many buttons to move either ...)
At manufacture, is of German high-end metal chassis, XLR connectors with metal rivet indestructible We can see by the gates a ring transformer for power, a priori, no worries in perspective. (My model is already old and no button crack)

UTILIZATION

I do not have the manual, so the grip is necessarily intuitive,
the sound setup is relatively simple, there is a single player to listen to the channel on which we work and how active / bypass channel
There are two modes of sub bass: tight or soft (the tight punchy bass gives the soft envellope more)
for acute, we can select the frequency for which it intervenes, but the button is reversed with respect to frequency (22 KHz to 1 KHz) is quite bizare ...
there is a button "deep" certainly associated with the sub bass but I can not quite identify the exact action (I hear no difference)

SOUND QUALITY

The settings really get along (this is not always the case for other devices ....)
especially the adjustable harmonic acute. The sub bass is more discreet
the stereo expander works well also
a stereo mix, the sound is really more intelligible.

OVERALL OPINION

I use it for 3 days
ca Lightens really sound, even on the mix that was already coherent front, the contribution is very positive
I never tried other similar devices. is quite different from a conventional EQ since it does not increase the amount of bass or treble but it adds harmonics.
I bought this unit in order to bring more coherence to lose a little cot multitrack and "mix" a little more sound sources after mixing. the stereo expander is also involved in that.
I think this device fulfills its role. it is found used sometimes not very expensive.
The greatest difficulty in this type of effect is the right amount of what we provide. It can certainly become a bit faster on some aggressive monitoring system. I think it takes some time to put just the right dose.
I do not own a long time but I was happy with my first purchase order. I think I would do it without problem.