Definitely go for the 680.
It's the newer design.
Edirol will probably bring out something to rival it soon.
In 24 bit mode once levels are set there is no need to ride levels.
I just recorded a six piece funk band with one. 4 instrument mic's, 2 room mic's, 2 di's.
Could never have done that with a 4 track.

What is the downside to doing a sample rate conversion from 96 to 44.1, vs the preferred 88.2 to 44.1?

I realize the math is more simple, but is there actually a sonic difference, or is it just an unfounded concern?

Like with 16bit: A well recorded 16bit file can not be discerned from a 24 bit recording by human ears (Ethan Werner proved that) but the benefit of 24 bit is that there is more headroom, enabling one to record at a lower level without dipping into the noise floor. But some people still claim that 24 bit sounds better to them. Is the asymmetrical math of the 96 - 44.1 sample conversion really going to adversely affect the sound quality? Or maybe just take a few more seconds to process the conversion?

Inquiry minds want to know, because I record for CD release too.

Depends on the software used for the sample rate conversion. Anti-alias filters and such. I would not trust a low-end video editing program with it.

I would be using a professional NLE - Cubase. So I guess it's really a non issue as I suspected.

The issue with 24 versus 16 bit isn't with any audible difference with the source files themselves so much as it is that 24 bit stands up to more multitrack mixing and processing in the digital domain before the noise floor starts to creep up. For most video soundtracks it probably doesn't make any difference but what the heck, disk space is cheaper 'n dirt these days. Might as well use it.

reality is at 24bits you are are best really getting 20 bits of resolution, but I'll take it ! any more headroom and better S/N is a good thing. 48K sounds nice on the unit as I spent a couple of days shooting interviews, better then the native sound of the HD100 I've been using for years, and no one has ever complained about its 384kbits MP3 recording ! so as always, YMMV. don't get so hung up about Nth degree of qaulity because unless you are using top end mics, and everything else, the difference is often too small to matter in the finished product.

a case!
 

This finally was released. sweet.

PortaBrace - Product Detail:AR-DR680

Are you going to actually USE an uninterrupted 12 minute clip in a real production? This is so rarely needed that the question is essentially moot. Anywhere you make a video transition is an opportunity to pull-up the picture sync to match the audio track. It is so easy to do that I don't even think about it anymore.

Sometimes I'm asked to do a one camera shoot of a band performing or a play. I have used an Edirol R-4 Pro for the audio in those situations, and at least with the R-4 Pro I can get through a whole set without needing to adjust the audio sync. So I would expect the same out of the DR-680.

yes, sometimes. or put another way, I should be able to lock a clip up once, and not need to re lock it thru a take. thats a waste of time, and clients can freak out. also I have been making TC burns of EOS clips to DVD... where again, clients don't want to see drift or they have a problem...

I do a lot of theater shows that run over 1 hour per act. I've had good experiences with the Tascam HD-P2 which has a lot more features than this unit when it comes to sync. For instance, you can lock the Tascam to the camera's vertical sync pulse and there are at least 2 to 3 other methods of sync. I would have traded 2 of the 6 mic channels for these features. 4 channels is ideal for my work.

I love the DR-680 but you should read...
 

A review of my experiences with the TASCAM DR-680 at over 100 degrees operating temperature:

I chose the DR-680 because it recorded to a flash drive, I used 32gb sd cards, rather then to a hard drive, I felt the flash drive would be less likely to fail due to rough roads, airline travel, dust, and wind, with varying humidity. I also liked the 6 channels available for discreet recording. I did not need time code, as we were not using a clapper or sync time code, we were shooting on two 5d’s.

Things I loved: Portable, very light, the flash drive performed excellently, it has 48V Phantom for my boom mic (see also things I didn’t love). It ran almost nonstop for two 36 hour shifts

Things I Didn’t Love: Heat not so good! The manual says its maximum operating temperature is 104 degrees Fahrenheit. Let me tell you what happens after that. My DR-680 was in a portabrace bag with air space all around on the left and right sides, it was hugged close to the case on the bottom and had some air space on its top, then on the other side of a divider were 4 lectrosonics receivers. In the first days of shooting we were told the ground temp got to around 109, after quite a while I noticed a buzz in the boom, I turned off the 48 Volt power supply and that eliminated the buzz. I had to run without the boom for a little while to let it cool off. The other channels that didn’t require 48volt power would operate fine. A day later we had another shoot and we were fine until the temp reached close to 115, I had learned just to take breaks inside the air conditioning, but this time we had to run for an extended time outside shooting a scene. So up pops an error message that says “device error”, no other remedy would work, I tried cooling it down, the only way to get rid of the error message according to the manual was to unplug it, I lost all the files since the last shutdown. This device has to be shutdown and given time to complete the writing of the files to the sd card otherwise if you just pull the power you are not saving your files. Lesson learned, from that time on I frequently in between scenes shut down and then started up again in order to save the files.

Ed Anderson
Ronhillimagery.com

Luckily it rarely gets over 70 degrees up here in Humboldt! It is humid though.

Ed...
Do you mean turned off/powered down? The manual says it can be set to start a new TAKE if the REC button in pressed in REC mode. That should start a new take...? If the power is lost will it loose ALL the takes since it was turned on? Or just the current take being recorded?

Thanks

Doc

Re: Tascam DR680 recorder thoughts ? long sync ability ?
 

Well, I just finished a shoot today in Montana on a 13 degree snowy day. My DR-680 performed flawlessly, except the LCD screen seemed a tiny bit slow to react at times. I guess it likes cold better than heat. I have mine set so PAUSE creates a new take...it saves and creates a new file every time I pause. Never had any problem with not saving files, sounds like the heat could be the problem. I've had mine since May 2010 and had only good experiences.