so i has teh Flashback for a couple of days now, and though i haven't taken it to Paris and everything i've given it a few hours' workout. some thoughts:
modes:
2290: i would buy a box just for this delay sound. combines the best of both worlds, a clean digital repeat that goes for days with just a hint of warmth to chase away that bleak Baltic chill.
Analog: seems to overload on strong pick attacks awfully easily. this is characteristic of digital emulations of analog chip-based delays in my experience. great dark mush of moody repeats that deteriorate fairly quickly to vaguely electronic sounds. ALMOST self-oscillates.
Tape: a better tape sim than i expected. if one could tweak the parameters this could be top, but as-is it's still very nice. sneaks up on Space Echo territory if you use the dotted-eighth setting on the toggle switch. great for simulating the Fripp/Eno tape loop thing with the time maxed out. after a minute or so going around on 7 second repeats clean electric guitars sound like Rhodes pianos.
Lo-fi: i like to use this interchangeably with "Tape" for dark extended repeats. i haven't really analyzed to it in detail, but it strikes me as having the audio qualities a cassette loop would have but without the associated wow/flutter/artifacts, having instead a flatter analog-delay type response.
Dynamic: this is supposed to work as a sort of delay + gate/mix function which lowers the level of the delay signal so it doesn't conflict with picked notes. if you play quietly, keep the level of the delay signal low relative to the clean signal, and you don't have too dense of a delay stratum built up, it works fine, but if you hit things too hard or the volume level of the delayed signal gets too high the gate function cuts the delay signal in and out like a very stupid noise gate and makes this function totally unuseable for normal playing. this is an uber-example of the type of frustrations engendered by the unavailability of TonePrint software for home patch editing...without the ability to alter the gate threshold this function is of no use at all.
Modulation: analog-esque repeats that almost immediately deteriorate into a huge wash of barely pitch-valued fog. this setting may not be the most obviously useful, but boy is it going to be great for ambient stuff and for creating atmosphere in places where it's barely noticed. noir soundtracks, here we come!
Slapback: sounds like it's based on the Tape echo model with some room-esque EQ tweaks. as is it's a pretty decent one-trick setting; with some ability to tweak settings it could be an awesome chamber echo for the 50s enthusiasts.
Ping-Pong: haven't used it yet since i only have one amp set up. i want to see if i can use the Ping-Pong setting in mono for more Space Echo trickery, but i suspect that it's just a standard one-echo-on-THIS-side, one-echo-on-THAT-side deal.
Reverse: well, it definitely does reverse your phrase and play it back to you. how exactly i can apply the result, which consists of the original phrase PLUS the mirror-image repeat(s), is another question. this function is going to generate some very cool riffs, though. i suppose the ideal here would be to use the internal dip switches to set the Flashback to 100% wet since you don't seem to be able to set it to take the non-delayed signal out using the external knobs; this would allow you to play backwards stuff that would appear out of nowhere.
Looping: works quite well, better than i'd anticipated for what is, after all, an ancillary function for this pedal. i find it simple to create loops and punch in/out of them to add more parts. would i try to use it for the kind of "i'm constructing a whole song on the fly" stuff some people use loopers for? no...i need an UNDO, kthxbai. but is it entirely useable for, say, the kind of thing Jonny Greenwood uses the Head Rush for on the coda to "Where I End And You Begin" where he loops an ambient phrase and then stacks additional loops over it? you betcha!
i haven't used the TonePrints other than dialing up the one that's pre-loaded, so i have no comment on the additional TonePrints, the software, the ease of downloading, or anything about that.
generally:
when i don't use the audio-tap to set the delay time, there's a noticeable change in the sound when switching from the quarter-note to the eighth-note settings on the toggle switch that makes me think the switch changes the recording resolution in manual delay time mode...it's particularly audible on the Analog, Tape, and Lo-fi settings.
the audio-tap works quite well, and i like it...i find it easier to stand on a switch and pick a few notes in consistent tempo than to step on a switch in dependable time.
on some settings there's an odd sort of quality to the sound when a large number of complicated repeats build up which i can best describe as "crowded": slightly compressed and blurred, lacking in audio detail. it may be a phase-cancellation thing with multiple layers of signal, or it may be a sample-rate thing related to that toggle-switch thing mentioned above, but it's there, and audible in the PGS demo, and i'd be remiss not to note it as well though it wouldn't keep me from recommending the Flashback.
like everything i've ever seen from TC, the Flashback looks great and appears to be built like a tank...if not for that toggle switch and the risk of scratching the rather groovy sparkly blue paint i would have no fear of throwing the Flashback at naughty squirrels in the yard and then retrieving it and plugging it in. extra points for making the type on the labels legible to old people with spectacles AND typographically attractive
if only it came with a thumb drive with editing software or had one more parameter-tweaking knob per model it would be a 9.5 of 10. and the critique above that without the ability to edit it's essentially a series of presets is 100% correct. but they include some of the best presets you're ever going to hear in a stompbox delay that regular common folk can afford. if you can say to yourself "aah, i can buy a Echolution or an El Cap instead" then God bless you. otherwise, if you're terminally on the fence, go ahead and buy one. the 2290 and Tape settings are worth $169 all by themselves.