Posted on 3rd Aug 2010 @ 10:27 AM

DR-680 Hands on Review : Field and Sync Tests

The DR-680 from Tascam is being offered at a very irresistible price. It claims to be a full 8 track recorder for under $1k street price. The question is, it worth adding to your gear ?  Does it really perform or is it overspec'd and under performing in reality? Here is my take.

First you can check out my video review of the device. I used it to record my sound while shooting on a EOS T2I. I went a full 12 minutes so you can see how it starts, and how it ends. You can also get an idea of the sound quality of the unit as well.

Review of the Tascam DR-680 8 Track Audio Recorder from Steve Oakley on Vimeo.

Specs:

Its really a 6 analog channel recorder with option to mix down 6 to 2 stereo. Yes it can record 4 digital channels on the TRS inputs making the total 8, but how many of us have stereo or even mono AES mics yet ?  or are connecting to AES/SPDIF 2 channel feeds ? not many. So lets count the inputs you can actually use: 4  dual XLR and 1/4" TRS Mic or Line Level inputs, 2 1/4" TRS  mic or line level inputs all with phantom power. You can use TRS->XLR adapters for powering mics that need power. The unit specs do not state what the total phantom power available is so I can't say if you can really plug 6 phantom power mics in at the 20ma max power spec and Be Happy‚Ñ¢.  Since most mics only use about half of that, you might be ok. I don't have 6 phantom power mics to confirm or deny if the unit can power them, nor do the specs state if it can. I had no problems powering 2 phantom power mics. All inputs can take also take line level. Each input in mic level also has a High-Low switch. As far as I can tell this is a -20db input pad which is handy to have when working with loud sounds.

PreAmps:

Does anything get audio people more animated in a conversation besides the quality of preamps ? probably not. When I first powered the unit up out of the box, I was not thrilled. It seemed noisy, and some quick test recordings somewhat confirmed this. My first tests were done with a Sanken COS-11 powered via Emule XLR power module plugged directly into the unit.

Now having been around gear for a long time, I wasn't ready to throw in the towel and send the DR-680 back. Instead, I put the unit into pause record over night. This forces the preamps to be on. The good news is that the unit will stay in pause record indefinitely which is great. I truly dislike gear that drops out of pause record after a certain amount of time, which is usually 30 seconds less then what you need. Even if it did, it went into record almost instantly anyway which was fine. I will say the Pause button acts far more like a Record Cue then pause button, its a little bit weird how it works. You can also just  hit the record button and start rolling pretty much instantly. Last, the unit does have a pre-record function you can engage in a menu for just in case.

So back on topic, despite all the digital parts, there is still an analog front end here. What I have found from many years of experience is that gear right out of the box often isn't quite hitting spec. It needs "on" time to burn the components in. Various parts settle into their ideal values, and suddenly the unit is hitting its specs. The DR-680 was no different. After an nearly 24 hour burn in, I redid my tests and got much better results.

The preamps are reasonably quite. They aren't Sound Devices quite, but they are good enough for most people's needs if you aren't working high end broadcast or film work. For web, corporate, cable TV type productions, more then good enough to use direct. I'd say that its preamps are better then most cheaper cameras have which are shooting half of these shows in the first place, so you are ahead of the game here.

I also tried feeding line level from my FP33 running on 24V into the mixer. The FP33 running on 24V is a much better sounding mixer then if you have ever run it at 12-14V where it is barely functional. Its a very different mixer at 24V where the limiters function correctly, and the headroom is there. Overall I found the FP33 preamps made for a bit warmer sound which could well be in part due to its transformer inputs and outputs. Either way, the DR-680 worked well being fed by the mixer at line level. If you have a mixer you like the sound of, you can certainly use it as a front end to the DR-680.

One Knob, Many Channels:

It works. Ok, lets be clear here, it works fine for reasonably controlled shoots where you don't need continuos level fiddling on everything. You can certainly use the one knob to ride one channel without a problem. If you really need to ride the levels of 4-6 channels at once, then you need a mixer that lets you do so. With some practice, you could get a bit quick hitting the input channel selector ride levels if things aren't too crazy.

Limiters :

They are there, but don't work great. I could yell into the mic up close and clip input levels. It seems the limiters may stop a peak or two, but if you are hot on your overall levels, they won't save you. Then again, lets ask the question, how much does this thing cost ? perhaps some firmware update might make for better limiter handling.

Lowcuts :

The low cuts are settable for 60/80/120hz. The LC can be enabled for each input, and seems to work ok. I left it at 80hz which seemed ok when using direct ins.

Firmware:

Out of the box I had 1.0 firmware. A quick trip to Tascam's website had me downloading firmware 1.1, and updating the unit. Good to know its updateable, lets see what they might add going down the road to add value and functionality to the unit.

Stereo Mix:

You can mix a stereo output with a separate set of menu levels. This is something like a bus mix where you can adjust each input channel into the final mix level, then go to each channel adjust the somewhat mislabeled channel trim which is really input level. You can also disable the recording of the stereo output if you want.

Timecode :

There is none. This is the one single major flaw of the DR-680. You could feed timecode into one of the audio channels and use your NLE to read it, but I dearly wish the DR-680 had some sort of TC chase lock / read / record ability. Working with dSLR's this may be a moot point anyway since dSLR's don't have TC either, unless you feed it to them as an audio channel loosing the in camera sound as a scratch track to sync against. Either way its pretty abysmal that timecode support is such an after thought with lower priced gear when there is no good reason it should be.

Sync:

There is nothing like doing a simple slate clap to check sync at the end of a long roll to check sync. One frame at 24FPS is about .041 sec long. The drift I measured at about 72F between camera audio and the DR-680's recording was about 560-620 samples across several takes, or .012 - .013 sec. This is less then a 1/4 frame of drift. I'd say more then good enough for most of use. This would mean about 1 frame after 40 minutes or so. Pretty solid performance considering there is no timecode, word clock, or video sync locking the unit.

Interesting facts I found along the way with sync :

The  audio  on the EOS 550D is a full frame early from the picture!  Put another way, the picture is one full frame late. This is most likely caused by processing of the image, but the delay hasn't been compensated for in the audio processing. Hopefully a firmware update will fix this. I confirmed this with many slate claps.

For comparison, I also ran a testing rolling my JVC HD100 in 720p24 mode. The HD100 shooting in 720p24 also has early audio as well, but only by about 118 samples which isn't enough to normally worry about.

I used Premiere Pro CS5 for my analysis. The big reason for doing so is that if you toggle the timeline into audio samples, you can literally edit, measure, and even slip / slide / nudge edit audio down to the sample. This made things very simple for measuring drift and aligning things. In order even this out as best I could, I slipped the audio of the EOS 550D 1 frame forwards, and then nudged by samples to get the audio waveform lined up to the slate close on sample one of the slate close frame. I then aligned the DR-680 with the JVC perfectly.  Both cameras now had the slate closing in the same visual frame, and the audio as lined up  within a few samples for an even start.

Lets go to the 12 minute mark and see if sync is there. Drum roll please ! at 12 minutes,  both cameras closed the slate visually on the same frame.  What about the DR-680 ? it was 500-600 samples off from the slate close. Thats a total drift of about no more then 600 samples in 12 minutes ! at 23.976, there are 2002.002 samples per frame, 2002 for quick math. That means a total drift of about 1/4th to 1/3rd of a frame, or way more then good enough for just about anyone.  

Ready for a shock ? Audio on both the JVC HD100 and EOS 550D where different ! they had actually drifted internally despite the expectation that once they were locked at the head, they should come out perfect at the end as well. The HD100 was 1009 samples early, the 550D was about 780 samples early. Remember I had locked the waveform together at the start to match the close frame. So the bottom line is the DR-680 is more accurate for for recording then the cameras ! No one has complained about the camera audio drifting around which it clearly does, so the DR-680 is safe for 12 minute takes for sure. I'd guess you'd probably be safe out to 30 minutes for a total drift of 1200 samples or so, this is  a 1/2frame at 24FPS. At 60i (48,000/59.94) its 800.8008 samples per frame, so your drift would be 1.5 frames which might become noticeable. Even if it was, it would be simple enough to make one or two edits in dead spots, slip the sound a few hundred samples and be back on. However this would only count with video cameras since none of the dslr's shoot this long.

Conclusion:

Its a steal ! the DR-680 runs accurately enough for any dSLR user to be happy. Sound quality is respectable, and the overall ergonomics of the unit are tolerable. Please understand that there are differences between the DR-680 and something like the SD 788T or even 744T, but are they worth 5-10X the price ? That entirely depends on the project, your date rate, and the stakes at hand. In most cases, probably not for low to medium budget work unless timecode is critical. If you have to have BWAV files sync'd to external TC to get the gig, well then you don't have much choice. For the rest of us, the DR-680 should serve as a great audio recorder at a super reasonable price.

 Steve Oakley
Digital Illusionist - DP - Motion Graphics - Editing
http://www.practicali.com