Topic: TASCAM DR-680 portable 8-track Part 2

[Chadfish]

What does that mean?

[drewloo]

7200 milliampere-hour divided by 400 milliampere-hour (dr-680 current draw) = 18 hours of run time in theory.  In reality you'd want to multiply that number by .85 since you don't want to run the battery down to empty so you're still looking at at least 15 hours from it.

[Todd R]

7200 milliampere-hour divided by 400 milliampere-hour (dr-680 current draw) = 18 hours of run time in theory.  In reality you'd want to multiply that number by .85 since you don't want to run the battery down to empty so you're still looking at at least 15 hours from it.

I'd be a little wary of these numbers.  You're math is right (I'm willing to concede anyway, but isn't the 680 more like a 750ma draw?), but I'm afraid there might be some marketing hype in their reported specs.  One part says 26 watt-hours and 12volts, the other just says 7200mah.

26watt-hrs = 26000 mW-hrs, divided by 7200mah = 3.6v, which is suspiciously close to what a single li-ion cell provides.  Alternatively, 26000 mW-hr divided by 12v = 2167 mah, not 7200mah.

I'm wondering if the 2167mah at 12v is really what the battery has, and the 7200mah spec is just marketing BS, meaning the battery internally uses 7200mah of 3.6v/3.7v li-ion cells, that then need to be stepped up to 12v using a step up circuit.  If this is the case, the battery may only provide 2167mah at 12v, or about 5 hours of use.

[drewloo]

7200 milliampere-hour divided by 400 milliampere-hour (dr-680 current draw) = 18 hours of run time in theory.  In reality you'd want to multiply that number by .85 since you don't want to run the battery down to empty so you're still looking at at least 15 hours from it.

I'd be a little wary of these numbers.  You're math is right (I'm willing to concede anyway, but isn't the 680 more like a 750ma draw?), but I'm afraid there might be some marketing hype in their reported specs.  One part says 26 watt-hours and 12volts, the other just says 7200mah.

400ma seemed low to me, actually, but that's what was previously mentioned so I went with it.  750ma seems more realistic.  Thx for the correction. 

[tgakidis]

There is also the phantom power consideration, right?  6 Channels of mics with phantom uses up more power then 6 channels of line in.

[NOLAfishwater]

There is also the phantom power consideration, right?  6 Channels of mics with phantom uses up more power then 6 channels of line in.

that should be a good question to email Tascam. how much power does each pair of channels consume when sending 48V phantom power.

[Chadfish]

It's all greek to me. I'm a simple man. I just need to be pointed to a simple battery and cable to use for the 680. Something tested and proved worthy by the tapers, and reasonably priced.

As for the backlight staying on... I've read a lot of threads and can't remember the specifics, but I thought I read that you can turn it off, but the menu item for that was named in a way that was somewhat misleading.

[NOLAfishwater]

It's all greek to me. I'm a simple man. I just need to be pointed to a simple battery and cable to use for the 680. Something tested and proved worthy by the tapers, and reasonably priced.

I think that is what people are trying to figure out

[Todd R]

There is also the phantom power consideration, right?  6 Channels of mics with phantom uses up more power then 6 channels of line in.

that should be a good question to email Tascam. how much power does each pair of channels consume when sending 48V phantom power.

Agreed, tascam's input would be good.  But as a guess:

My 680 operates off of a 9v battery, so that voltage needs to be stepped up to 48v.  Phantom spec is up to 10ma per mic, though many are in the 2-6ma range (usu lower).  Assume 6ma/mic to be somewhat conservative, and assume the 9v>48v step up is 80% efficient, that leads to ~80ma phantom draw per mic pair, or ~250ma phantom draw for 6 mic inputs. Half that if you're mics are only drawing 3ma per mic.

[johnmuge]

http://www.bhphotovideo.com/c/product/503090-REG/Tekkeon_MP3450_MP3450_myPower_ALL_Universal.html/

        I've been using this Tekkeon MP3450 with great results.  I recorded for 2 1/2 hours with 6 mics all with phantom power on and it only went down 2 notches.  I recorded another 2 hours with 4 mics with phantom on and it went down another 2 notches.  At that point, I recharged it.  It went down in price to $99 at B&H. 

[Chadfish]

It's all greek to me. I'm a simple man. I just need to be pointed to a simple battery and cable to use for the 680. Something tested and proved worthy by the tapers, and reasonably priced.

I think that is what people are trying to figure out

And I'm so grateful for that! I know a lot of stuff, but electricity and the numbers and math etc. just triggers my dyslexia and I go "Duhhhh..."

I wonder about connection cables too. I was researching the R-44 for a long time before I saw the light, and there was a reversed polarity issue you had to watch for when battery powering that machine. With these DVD batteries and the 680, does the battery just come with a power cable to run from the battery to the 680? Do I need to buy a specific cable?

[rastasean]

It seems most portable devices have reverse polarity. Doesn't the dr680?
The instruction manual for the tekkeon 3450 states NOT to use the battery with reverse polarity devices (like the r44) but to email support. When you do, they just advise to rotate the plug 180 degrees which will reverse the polarity.

[Chadfish]

It seems most portable devices have reverse polarity. Doesn't the dr680?
The instruction manual for the tekkeon 3450 states NOT to use the battery with reverse polarity devices (like the r44) but to email support. When you do, they just advise to rotate the plug 180 degrees which will reverse the polarity.

So rastasean, you do have to reverse the way you plug in any adapter to use with external batteries?

I have read of people frying their R-44s, but never the DR-680. But I think people were having to cut their power wires and rewire them so as not to fry the recorder. I'm looking for something that just works, and is not easy to confuse by plugging in something wrong like a tip to a power cable, and potentially fry my recorder.

Johnmuge: The Tekkeon MP3450 looks pretty cool, though the reviews have some quality control issues mentioned. If I could get a solid 6 hours with (6 mics phantom) out of the battery I would be happy, even more happy with 10hrs. Do you have to plug in the tip attachment a special way (reversed) for it to work?

[johnmuge]

I didn't want to deal with all of those tips so I had Ted (tgakidis)  make me up a custom power cable with the correct ends.

[Chadfish]

Good to know!