Topic: Tascam DR-70D 4-channel audio recorder (Part 2)

[willndmb]

60d users shouldn't dump their 60ds, IMO.

agreed
The pros for me are the camera/line/headphone all active at once and adjustable
The con is two xlr

[voltronic]

Maiden voyage of the 70D tonight at a high school small ensembles concert.  Also the first try at the 4-mic phased array I learned from Tony Faulkner and others over at GS.  With no external preamps, I am seriously impressed with how this recording came out.  Variety of ensembles, mostly very quiet stuff and I was recording on HIGH gain and so far the only significant noise I'm getting is the school auditorium HVAC.  Once I get a chance to export some samples I'll post them here, along with a request for feedback on how to balance the omnis and subcards.  I may do that in a separate thread though as Gutbucket suggested, but wanted to post here about the great results I got with this little guy right away.  If you're on the fence - do it!

[PH]

Bean, the output of the VMS 02 is likely the same as the newer VMS-5U, +18.
So you should be able to run it as hot as you want and not clip your converter.

That said, you can always dial back the VMS a bit (or any preamp) to prevent any possible overs into the converter.

[F.O.Bean]

Bean, the output of the VMS 02 is likely the same as the newer VMS-5U, +18.
So you should be able to run it as hot as you want and not clip your converter.

That said, you can always dial back the VMS a bit (or any preamp) to prevent any possible overs into the converter.

Thanks a lot PH +T! The vms02ib only has one gain knob though. Some have 20/30/40db gain knobs, but mine just has 20/40db settings[same for both channels, so no separate gain knobs for each channel], so I will only ever use the 20db for mostly what I do

Thanks for the info. I feel a lot safer now that the 70D wont clip! And my Littlebox has variable gain on both channels, so its no problem. I'm excited that I'll have a little control of each channel with regards to the vms02ib, since it only has the one gain knob That said, both channels have been almost dead even running two different mk41s[one from 1980 and the other from 1992]. Just goes to show Schoeps quality control Mine should be here Friday! Lets hope, because I'm hitting a show Friday night! Hopefully I get all of the settings right for the first show with it!

[F.O.Bean]

OK, been checking out external batteries for the 70D, and looks like I'm going with the RavPower Element 10,400mah!

http://www.amazon.com/gp/product/B009V5X1CE?ie=UTF8&ref_=de_a_smtd&showDetailTechData=1#technical-data

Just one question(yes I'm serious ) but how do you charge it? With just another USB like my computer? Or an adapter that I have that can plug USB cables into the wall? Or does it come with an AC adapter? Because there's no mention of one in the sales page for it! I've never owned a USB battery before, and I honestly have no clue how to charge the RavPower batteries But I'm guessing its just another USB port like my computer or the adapter I just mentioned!

Thanks,
Bean

[PH]

Bean, both ways you mentioned will work. Any USB outlet or USB Wall Wart should work fine. I've been using a 5000mA one for my iPhone for a while and I can get two full charges on that before the USB pack needs a recharge.
The 102000mA should be roughly twice that. I'm guessing it will power the 70D for 8-12 hours plus give your iPhone a charge. Ha!
My 70D arrives tomorrow, and the batteries and card next week.

[willndmb]

OK, been checking out external batteries for the 70D, and looks like I'm going with the RavPower Element 10,400mah!

http://www.amazon.com/gp/product/B009V5X1CE?ie=UTF8&ref_=de_a_smtd&showDetailTechData=1#technical-data

Just one question(yes I'm serious ) but how do you charge it? With just another USB like my computer? Or an adapter that I have that can plug USB cables into the wall? Or does it come with an AC adapter? Because there's no mention of one in the sales page for it! I've never owned a USB battery before, and I honestly have no clue how to charge the RavPower batteries But I'm guessing its just another USB port like my computer or the adapter I just mentioned!

Thanks,
Bean

FYI it takes 12+ hrs to charge so plan ahead
I use an iphone wall plug and the charge cables comes with it I believe

[2manyrocks]

^ yep. 

You'll like the Ravpower.

[PH]

How many hours of runtime (4ch) are you guys getting on a full charge with the 10200 or 12000?

[voltronic]

I have the slightly larger capacity RavPower battery listed on the FAQ page, and mine came fully charged, which was a pleasant surprise.

After running the 70D with 4 channels with 48V phantom for just over 2 hours, the indicator still shows full bars, whatever that means.

[vanark]

Full bars means 75-100% power remaining.

[stevetoney]

Full bars means 75-100% power remaining.

Very roughly yeah, but not really.  What you don't want to do is assume that, say, if there are four bars that each bar correlates to 1/4 of the battery energy.

Look at the discharge curve of any battery and you'll understand why.  The curve shows how the voltage decreases over time.  The number of bars is actually an indication of the battery voltage.  Although I suppose a manufacturer might go to special lengths to put a chip into their batteries to correlate to the non-linear discharge curve, I really doubt any of them do.

So the battery discharge curve is typically steep at the start, flat in the middle and steep at the end.  What that means is that when the battey is fully charged, you see all the bars, but shortly after you start apply a load, the first bar goes out because the voltage curve is steep as the voltage drops fairly quickly.  Then for the majority of the time, the indicator stays on either three or two bars because the battery voltage settles out at a nominal voltage and drops really slowly.  Towards the end of the battery discharge cycle, the voltage might still be fairly close to the nominal voltage, but the battery is getting close to being spent.  At the end of the cycle, the curve drops off steeply, so that means that you'll go from say two bars to zero quickly.  Most of my devices go from two bars to zero in ten minutes or less.

So you shouldn't rely on those bars as anything but a really rough indicator.  It's best to do run time tests AND understand the above relationship between number of bars and the run-time so that you'll have a pretty good feeling of how much time you have left on your battery. 

[rockymtnryan]

So for my first 2 channel run with this deck I had the settings on stereo, instead of mono, resulting in one file that included both channels.  I also realized after that I had channels 3/4 set to record even though there were no mics plugged in. The result was an extra file for channel 3/4 that was the same size as the one for 1/2. Thought that was interesting.

My question is what would be the advantage, if any, to have it set for mono?  Seems like it would be just a lot of extra work to merge the L and R files in post.  Unless there is a sonic difference I'm not aware of.

Also noticed since I was running 24/96 the end result was more files than I used to have with the HD-P2 running 24/48.  I think it created 4-5 files for channels 1/2 on a 3 hr 15 min recording.

[voltronic]

Full bars means 75-100% power remaining.

Very roughly yeah, but not really.  What you don't want to do is assume that, say, if there are four bars that each bar correlates to 1/4 of the battery energy.

Look at the discharge curve of any battery and you'll understand why.  The curve shows how the voltage decreases over time.  The number of bars is actually an indication of the battery voltage.  Although I suppose a manufacturer might go to special lengths to put a chip into their batteries to correlate to the non-linear discharge curve, I really doubt any of them do.

So the battery discharge curve is typically steep at the start, flat in the middle and steep at the end.  What that means is that when the battey is fully charged, you see all the bars, but shortly after you start apply a load, the first bar goes out because the voltage curve is steep as the voltage drops fairly quickly.  Then for the majority of the time, the indicator stays on either three or two bars because the battery voltage settles out at a nominal voltage and drops really slowly.  Towards the end of the battery discharge cycle, the voltage might still be fairly close to the nominal voltage, but the battery is getting close to being spent.  At the end of the cycle, the curve drops off steeply, so that means that you'll go from say two bars to zero quickly.  Most of my devices go from two bars to zero in ten minutes or less.

So you shouldn't rely on those bars as anything but a really rough indicator.  It's best to do run time tests AND understand the above relationship between number of bars and the run-time so that you'll have a pretty good feeling of how much time you have left on your battery.

Yeah that's how cell phone batteries tend to behave also.  Totally agree that each user should do a runtime test with their own mics, etc. to really have a good idea.

[2manyrocks]

Buried in part 1, one of our members reported running over 10 hours on the 10400 Ravpower without phantom power.  I've lost track of how I came to think so, but my impression is runtimes of 6 hours with phantom power are no problem.  Somebody probably needs to confirm the expected runtime on full phantom power for all 4 channels and then add it to the FAQ to settle this recurring question. 

So for my first 2 channel run with this deck I had the settings on stereo, instead of mono, resulting in one file that included both channels.  I also realized after that I had channels 3/4 set to record even though there were no mics plugged in. The result was an extra file for channel 3/4 that was the same size as the one for 1/2. Thought that was interesting.

My question is what would be the advantage, if any, to have it set for mono?  Seems like it would be just a lot of extra work to merge the L and R files in post.  Unless there is a sonic difference I'm not aware of.  Shouldn't be any sonic difference.  If you have static or some problem in one channel, I find it easier to edit it out of the one channel if I am dealing with one channel instead of two stereo channels, but of course you can split a stereo file anyway.  Others are probably more knowledgeable of better answers. 

Also noticed since I was running 24/96 the end result was more files than I used to have with the HD-P2 running 24/48.  I think it created 4-5 files for channels 1/2 on a 3 hr 15 min recording.  24/96 should produce a larger file than 24/48. The recorder splits files at a certain file size.  So you'd get more files at 24/96 than 24/48 all other things being equal.  yes??