The zoom R24 can record 8 tracks simultaneously onto SD card , and that's what I wanted it for. It works as described. The pre-amps are a bit hissy on high gains, so it'd NOT be much good for quiet acoustic stuff, (big shame really) but for a live rock band it ROCKS!
I got one of the recommended 32Gbyte SDHC cards from amazon.co.uk [sandisc ultra SDHC about 56 quid inc vat] and it records 8 channels simultaneously without glitches. (32Gbyte = approx 13.3 hours 8-track at 44.1kHz).
CAUTION ! Getting the right recording media is ESSENTIAL for this unit. You CAN'T just use any old SD card if you want to do 8-track recording successfully.
www.zoom.co.jp has a list of SDHC cards that HAVE been tested and proven to work with this unit. Searching for the exact SDHC card numbers on their list revealed that Amazon.co.uk has several of these exact cards in stock and I was able to choose one from the several that they had in stock, based on reviews and price).
When you purchase your Zoom R24, YOU WILL FIND THAT IT CANNOT READ USB data sticks (like the one it comes bundled with) UNTIL YOU HAVE UPGRADED THE R24s FIRMWARE to V1.01.
This is rather annoying, they could have at least shipped it without an important part of its functionality broken....
Headphone output is very quiet.
I haven't tried mixing on it, I do that on a PC. It's easily portable, great for getting usable multitrack recordings in rehearsal rooms.
The 'sample player' functionality seems a bit weird, I couldn't figure it out properly, it seemed a bit rubbish, maybe I just need to get the hang of it. The manual is quite big!
The built in mics are okay, the phantom power is okay, (phantom power is a bit noisy but my Fostex MR8mk2 was a lot worse), and being able to have 0, 2, 4 or 6 channels of phantom power is VERY USEFUL once you are in a studio with misc microphones and a bunch of scruffy musicians wanting to get started.
Oh, and it is TOTALLY silent in operation, no moving parts AT ALL, so if you got a classy (low-hiss) pre-amp and a posh mic then you could take this to your desert island and do your 24 track solo acoustic album very nicely.
Overall I'm very pleased with my purchase.
4/5