The Deluxe Electric Mistress XO is one of seven ways you can currently get flanging from Electro~Harmonix.

The Holy Grail Nano has a FLERB setting that provides a combination of FLanging and revERB – FLURB. The rate, depth (or range), and feedback (or color) are fixed.

The Neo Mistress allows control over the rate and the feedback (color). The rate control allows for a filter matrix, that is frozen reverb, setting.

The Stereo Electric Mistress allows control over the rate and the depth (range), but not the feedback (color).

The Deluxe Electric Mistress XO, the Stereo Polychorus, the Flanger Hoax, and the new Mod Rex all provide control over the rate, the depth (or range), and the feedback (or color).

So, of all the flanger options currently available from EHX, the Deluxe Electric Mistress XO is the least expensive one that gives you control over all three basic flanger parameters. It is also the smallest option that gives you control over all three basic flanger parameters. It also includes a filter matrix option and a dry signal output. The dry output is actually a very powerful feature, but it’s a bit difficult to take advantage of without the right equipment. If you combine the dry and wet signals either as L and R inputs into a stereo pedal or with a mixer (Don’t do this with a reverse Y cable.) you will get a very lush chorus. That’s all most choruses are anyway – a flanged signal combined with the original signal. But, this also allows you to send the dry signal through a different effect chain and end up with something like flanging on one side and phase shifting on the other, or whatever. If you send the flanged signal to one amp, or one recording channel, and the dry signal to another amp, or another recording channel, you will end up with a true spatial acoustic chorus that sounds awesome.

In addition to the smaller enclosure, the XO version that I got adds a couple of other nice features to the original Deluxe EM that came out in the mid 70s. They’ve added a light to let you know when it’s on, and it can run off a 9V battery or a 9V power supply, and it features true bypass.

Overall, I really like this pedal. It’s pedalboard friendly. It has all of the controls that I need, and most importantly, it sounds great.