The Microcab is a fully analog guitar cabinet with mic simulation. Connect it like this: guitar > preamp > Microcab > line input (mixer, sound card, etc.) or power amp.
The device has two channels so you can use it in stereo mode. It also has Dry outputs for A/B signal comparison.
This unit has few competitors in the analog world since most simulations are now digital. With this device you don't have any AD/DA conversion which is an advantage. Moreover, very few digital units can successfully apply digital modeling to a guitar signal except for high-end products (TC Electronics hardware, etc.)
The unit is very easy to use once you understood the role it plays in the sound chain. It's not an analog POD since it doesn't emulate amplifier heads or effects. So you must have a good guitar preamp (a Marshall JMP1 for example) or an excellent tube preamp (Universal Audio LA-610 for example) to get the best performance out of it because it is this device (along with the guitar and the musician) that gives some color to the sound! If you have a cheap preamp you won't get good results!
After that just choose a cabinet type (one speaker, two speakers, four speakers, open, closed, vintage, modern...). Two additional controls adjust high and low overtones created by the mic's proximity effect.
Effective sound tool! You get the silky, thick and somewhat dark sound of the speaker and mic combination. BTW the emulated mic is a Shure SM57, a standard mic for guitar amps... Its sound can be easily recognized. With a LA-610 preamp you get a Fender-like sound.
How does it sound compared with a software tool like Guitar Rig*? The sound difference is not huge but clearly audible especially within a mix. It's the same difference as a real MXR Phase90 and its emulation in Guitar Rig. It sounds pretty similar but the sound of the real unit has more character and is easier to use in a mix. It's the same here!
I even tested it with a bass and the result was also very good! The sound was warm and smooth...
Like with most good analog devices it doesn't alter the sound!
* For the sake of comparison just change a cabinet and mic in the software, but not the whole amp)
The unit is quite difficult to find! Go look on ebay and the like! I found mine for a very small price without external PSU! And considering the device requires 16 volts AC the PSU wasn't easy to find! Remember this if you see it without a PSU.
ADA ceased to exist a long time ago (because of some fire) but there still is a user community, and their products became cult because of their high quality and original concept! Many musicians still use this product and look for them because they prefer its natural sound to a POD, Zoom and other digital solutions... THE reference homepage for ADA products is:
Update from 12/03/08: it's really a great product. I can't make a recording without it!!! It never disappoints me (neither with guitar nor bass)! A great deal!!!