i have the 222 since quite some years now and love it. nice preamps, nice limiter, great internal mic and speaker (i did some crude “reamping” through it for degradation, great stuff).
i started using is as a tape echo without mods like this:
- post fader aux send from mixer into line in
- line out into one mixer channel (return)
- use the same aux send on the “return” channel to create repeats (feedback)
- monitor set to “tape” on the 222
- hit rec+play and you’re good to go
- even without the varispeed mod you still have two speeds: normal and low, and the tone control to sculpt the sound of it, plus you can saturate easily
then i did the mod, its pretty easy, you just have to cut one trace with a sharp razor or knife or cutter and solder a jumper cable from one specific point to another (only two solder joints) and that’s it. then you can use the varispeed also in recording mode!
have to say the sound of this cassette echo is great! i have a korg stage echo se-300 and strymon magneto to compare, all three of them sound absolutely gorgeous, three different characters 
i acquired my unit for very cheap on ebay after a two years hunt (no way i was spending the ridiculous amounts you see on reverb and such), it came from a very nice Ukrainian seller (its shop was mainly old soviet photo cameras), no bag, a lot of scratches but fully working. i have some transport noise on it, i’ll probably have to change belt and lubricate some parts, other than that its just fantastic. the heads are in very good shape, frequency response is still awesome. i have of course cleaned them with isopropylic alcohol (98%) and demagnetized them.
only thing i noticed after the mod is that it seems to draw a bit more power, now it works better on batteries than with the universal PSU i was using. perhaps i have to give it more milliamps…