I am aware that new batteries can and will create an excess of the spec'd voltage. From what I observed most who have had problems with this unit were using Tekeon like devices.

Personally I just went with a 12v lead acid battery to power my rig. It is a painless powering option that cost me 20$ plus some minor soldering. Of all the recorders it is the best for me because it can be adapted to bag work so well. It's a great compromise between performance and cost.

@andyharris

I found my DR680 also to eat (new 2700mAh) AA cells way to fast, so I built an external power pack:

This V-mount plate for LED-lights:

http://www.ebay.de/itm/Sony-V-Mount-Akku-Adapter-fur-NANGUANG-LED-Flachenleuchte-H-Vers-/141330210773?pt=DE_Elektronik_Computer_Foto_Camcorder_Foto_Camcorderzubeh%C3%B6r_PM&hash=item20e7efdfd5

and this step-down converter (high switching frequency!):

http://www.ebay.de/itm/DC-DC-3A-Mini-Konverter-Einstellbar-Step-down-Power-Supply-Modul-Ersetzen-LM2596-/171366746667?pt=Wissenschaftliche_Ger%C3%A4te&hash=item27e6410a2b

Open up the plastic of the V-mount, solder the step-down converter inbetween the wires (you will need some extra wire), adjust the voltage to 12V, close the plastic cover (the converter fits easily inside) and...

...yes, the powerplug is just the right one for the DR680! :-)

I have not tested it yet, but a 100Wh V-mount battery should last....for ever. And a short test confirmed, that the Tascam will instantly switch to the internal batterys without stopping to record if you pull the plug (have not testet undervoltage, but should work the same way).

I have a DR680, it eats AA cells. So I investigated external battery power. I found much mention of failures with various supplies.

I've contacted Tascam and the party line is that there are no approved external battery supplies and that the input specification is 11.5V through 13.5V.

You are very welcome, what little I know I am happy to share. It's a handy machine, so don't think twice abaout buying it if you have the $$$. You will need XLR to TRS if you plan to use tracks 7 & 8 with XLR cables.

@matt_gh2 Assuming you want a backup level at a lower gain, you can use a simple Y cable to connect one mic to two of the xlrs (or trs) inputs on the 680. You could then use a different gain structure on the backup channel, or add a limiter, or route the signal to the stereo pair using the internal mixer, or combination of all three. Plus you could, for example, create a submix, either digital or analog, and route this to a backup stereo recorder, a laptop, ipad, etc. The 680 can be configured to use all eight channels, or engage a submix from line 1-6 to lines 7-8, internally and externally, digital, analog and internal recording.

For example, you could split the signal (and this is a simple Y cable, although you could use other kinds) into two equal streams, and plug one into a high gain input, and the other into one that has the limiter on, and set 6dB lower. Then you would have a simple system for concerts that guarantees no overs. Assuming the limiter does not kick in, the recordings would be identical except that at 6dB lower gain, you would effectively be recording at 23 bits instead of 24 bits, which of course is inaudible for our purposes. You could also simple record everything 6-12 dB lower, which is what many ppl do, effectively recording at 22 bits. You recapture all the gain at mixdown if you are using more than two mics, or simply boost the gain, which is more or less lossless for 16 bit output, aac, MP3, etc.

I myself use the same Y cables, but feed for example two identical 24 track systems, so that if one fails, the other continues. You could do the same with two 680s, or use a 6+2 combo or a four+four combo on a single 680.

This is how expensive gigs are recorded, where it would be impossible to raise the money to reshoot or rerecord the scenes, or where for example the performers would be unavailable to redo a scene, event, film, concert, etc. It does not address the all too common problem of overloading the mic capsule, upstream of the gain structure, for which you would need two mics, one with a pad circuit between the capsule and the electronics.

However, if you have such a "once-in-a-lifetime" event, then it is interesting to consider redundancy at all the levels of the recording, including hanging two sets of identical microphones. The failure rate for Schoeps mics is close to zero (I have never had one in the set fail in thirty years, but it could happen, for sure), so one option is to split the mic cable, but not duplicate the mics (keeping one spare on the set), and this is one typical system.

At half the price (or less) than what I paid for the 680 when it was released, it is a no brainer. However, unlike the Fostex FR2 LE, it does not always keep recording if you yank the power cable out, so in my backup I split the main pair into the Fostex (with batteries as well as plugged in) instead of using the submix on the 680. Statistically, the likelihood that the power will fail, or the cord will be pulled, is higher than the failure rate for the other elements in the system.

However with two recorders, the 680 could fail--like in a power outage--but the Fostex would seamlessly switch over to battery backup and keep recording on the other end of the Y cable.

@Vitaliy_Kiselev Thanks.

Tascam DR680 looks like good value. Can this record 8 stereo tracks (or only 8 mono track)? Also, can I plug in 3 XLR mics and record each mic to 2 separate levels, so I'd have 3 tracks at -12 and then an additional 3 tracks recorded at -30?

@Psyco

I have no idea. Usually it is quite useless to spend your emotions. You can just buy it using Shipito intermediate, ask them to remove invoice and all original papers and write your own :-)

Thanks @Azo I used exactly that chart to make up my mind - but that was before the price drop. Now the Tascam looks really like the best choice, even on a budget.

Yes, please - if someone could compare the Tascam DR 680 to the Marantz PMD 661 that would be great (as I'm using the Marantz and I'm very pleased with the quality, but beeing only a two track recorder sometimes sucks).

some compared this vs the Marantz PMD 661 in audio quality??