SD USBPre2 spdif into Tascam DR100mk2
Old 3rd January 2014
  #1
Gear nut
 

Thread Starter
SD USBPre2 spdif into Tascam DR100mk2

Very dull at the office today, so I was reading through several pages of Gearslutz topics

I came across a very interesting idea that might be just what I am looking for. Something I had never thought of: running an external preamp + A/D converter through S/PDIF into my Tascam DR100mk2 with the USBPre2 being powered by an external USB battery.

So basically this uses the DR100mk2 only as a "digital file dump", with most of the important stuff going on in the USBPre2.

What I couldn't find though is much discussion on the details of this setup. Any drawbacks to this combination? Bugs in the the USBPre2 or the DR100mk2? Things to be aware of? For example, I assume that you would have to record at something like 96/24 or 48/24 because that is what the DR100mk2 supports, and not at 88/24.

How long can a USB external battery pack last powering the USBPre2 with two mics running phantom power (such as my Rode NT5's)? Assuming something along the lines of a 20,000 mAH battery. I suspect the answer is: A lot longer than the DR100mk2's batteries will last.

Regards, Christine
Old 3rd January 2014
  #2
Lives for gear
 

Hello Christine-
I use 1 DR-100 and 1 DR-100 II. Both 100's will loaf for 2.5 hours while supplying 2xphantom power on NiMH AA's alone ( will do 3 hrs, really), and the supplied Li battery runs considerably longer. So my guess is 6+ hours comfortably with phantom power and AA's and supplied Li installed, and probably far more w/o phantom power.

Have you made recordings with the DR-100 and top shelf mic's? It doesn't leave one wanting for much when run at sensible recording levels.

I have synch'd the MK II with a few devices just to see if it works, and it does-but I haven't tried the USB Pre. And don't know how, if at all, that might affect battery run time.

BTW, you do have to have the 100's in HD Mode to access higher sample rates. However, I don't know if that's required for a synch. Unless you work with mp3's, there isn't a reason not to leave the unit in HD mode.
Old 3rd January 2014
  #3
Gear nut
 

Thread Starter
Using run of the mill grocery store (GP brand) NIMH batteries my DR100 mk2 switches to the LION battery the moment I turn on phantom power to my two Rode NT5's. If I use a fresh pair of Duracell AA's, they list about 2 or 3 minutes on phantom power. The LION battery goes for about 2.5 hours or so.

Funny thing with the NIMH batteries is that if I switch everything off and turn it back on again the batteries will still show 2 bars of power. I think I read somewhere that some DR100's have faulty circuits for figuring out how much power is left, or something to that effect?

I don't know if these NT5's are particularly hungry (they give nice recordings though), bad batteries or a problem with my DR100. I have little to compare to. I do like equipment with LION batteries. I recently bought a second LION battery for my DR100 so I have enough power available for long recordings, just to be on the safe side.

As for the external preamp and A/D's of the USBPre2.... I am probably suffering from GAS Forget I mentioned it...

I have also been thinking about the DR680 (for the extra tracks and XLR inputs), although I understand these eat batteries. And you can't always use the power adapter. Unless someone knows how to hook up one of those external LION batteries to a DR680?

*EDIT* Just found this thread: Suggestions on powering Tascam DR-680?
Post #15 seems very useful, links to this youtube review: http://www.youtube.com/watch?v=AbqzmkkmqJ4 *EDIT*


Regards, Christine

Last edited by connloyalist; 4th January 2014 at 12:06 AM.. Reason: Found relevant thread
Old 4th January 2014
  #4
Lives for gear
 

Everyone keeps going around the same circles with these Tascam products-mostly the DR-680 but also the DR-100. Both pieces of gear have excellent battery life.

The problem, it seems to me, as that very few understand the technology of NiMH batteries, and that their capacities need to be actually measured by devices capable of applying specific loads and/or performing industry standard practices of measurement. Those same devices are capable of charging batteries to their maximum capacities. Therefore, users are 1) buying terrible batteries and/or 2) believing any capacity that is stamped on the battery, 3) not being able to determine what the capacity of the battery really is, and 4) not having any idea of how to fully charge a NiMH battery.

Battery brands are not all the same at all, and confusion reigns when batteries with the best brand names, such as Maha (Maha having one of the best and most accessible charger/analyzers) having the absolute worst battery performance and lifespan. The last GP (that you mention) batteries I tested (at least a year ago) were junk.

You should be getting an easy 3 1/2 hours from the supplied Lithium battery with mic's that draw 2.8 to around 4 mA. I've found that the Li battery chargers more fully when charged from something other than the optional and grossly over priced Tascam charger. A computer USB port or phone charger works nicely.

I can tell you that one week ago a Mark II was used with 2 AA batteries that measure right at 1750 mAh (specified 2000 mAh) and ran for a little over 2 1/2 hours with mic's drawing 2.8 mA, and there was plenty of juice left, and the Lion battery never even engaged.

Make sure the battery indicator is set in the NiMH position, and not the Alk position.

*It's not at all unusual for the battery in use to toggle back and forth, especially when the unit is started or stopped, but this is not the place to explain that.*

In all likelihood, you will now hear from a bevvy of people claiming terrible battery life when using any batteries, including batteries which have some impossible capacity specifications (like 2600-2900 mAh) printed on them (Maha?).

The talent, the space, the microphones, and their placement are going to determine what your recording sounds like. The USB Pre 2 is a long way below all of that on priorities for quality sound. I say this from using SD products along side of with these much less well built Tascam units. (Not that I wouldn't like a SD multi-track!) If you really want to spend money, buy better mic's. That will take you further than your other options.

Good luck in your decisions.

Edited later to correct battery capacity for 1 1/2 hour recording.
Old 4th January 2014
  #5
Lives for gear
 

Quote:
Originally Posted by connloyalist View Post

I have also been thinking about the DR680 (for the extra tracks and XLR inputs), although I understand these eat batteries.
No, they do not eat **good** NiMH batteries. Even ones with pretty low **measured** capacities.

Quote:
Originally Posted by connloyalist View Post
And you can't always use the power adapter. Unless someone knows how to hook up one of those external LION batteries to a DR680?
Buy an 8 NiMH cell battery back from Radio Shack and plug it in. Or buy a Li and plug it in. Or just switch NiMH batteries.
Old 4th January 2014
  #6
Gear nut
 

Thread Starter
Points well taken, thank you.

I live in Europe, so not anywhere near a Radio Shack. Can you suggest a list of good NIMH batteries, or where I can find such a list? Unfortunately those GP batteries appear to be ubiquitous around here.

What kind of performance would you expect to get out of something like a set of Duracell Procell batteries compared to the standard Duracell AA's? (Because I know where to find those).

Yes, I do switch my DR100 between Alkaline and NIMH setting when I change battery type. I always charge the internal Lithium battery using my computer's USB port (resulting in the about 2,5 hours on P48 I spoke of). Is there a way to test the power draw of a microphone? Just so I know....

Regards, Christine
Old 4th January 2014
  #7
Lives for gear
 
amfortas2006's Avatar
 

Check out Sistech.com (swissbatteries). I use them since 7 years, they make hq rechargeables in europe
Old 4th January 2014
  #8
Lives for gear
 
John Willett's Avatar
 

Quote:
Originally Posted by connloyalist View Post
Very dull at the office today, so I was reading through several pages of Gearslutz topics

I came across a very interesting idea that might be just what I am looking for. Something I had never thought of: running an external preamp + A/D converter through S/PDIF into my Tascam DR100mk2 with the USBPre2 being powered by an external USB battery.

So basically this uses the DR100mk2 only as a "digital file dump", with most of the important stuff going on in the USBPre2.

What I couldn't find though is much discussion on the details of this setup. Any drawbacks to this combination? Bugs in the the USBPre2 or the DR100mk2? Things to be aware of? For example, I assume that you would have to record at something like 96/24 or 48/24 because that is what the DR100mk2 supports, and not at 88/24.

How long can a USB external battery pack last powering the USBPre2 with two mics running phantom power (such as my Rode NT5's)? Assuming something along the lines of a 20,000 mAH battery. I suspect the answer is: A lot longer than the DR100mk2's batteries will last.

Regards, Christine
It seems that a lot of the replies have, unfortunately, missed the point and have been totally ignoring the OP's question.

Firstly - the DR100-II will have a longer battery life than normal as the phantom will be switched off and all analogue controls set to zero - you are only using it as a "bit bucket".

I would guess, though I'm not absolutely certain, that you can use any sample frequency you want as you are not using the ADC in the DR100-II.

Everything important is done by the USBPre2-D.

I don't know how long the batteries last on this.

An alternative is the AETA MIXY - this has 3 mic/line inputs plus a stereo line in and outputs all digital formats as well as consumer and pro analogue. This will work nicely with the DR100-2 and the internal rechargeable batteries of the MIXY will last about 9 hours I think. The MIXY comes with a mains unit and there is an option for a cable that attaches to a car DC socket for charging in the move.

I hope this helps.

And - yes - your idea to use the DR100-II as a "bit bucket" is an excellent one and will be vastly better than using the analogue circuits in the DR100-II.
Old 5th January 2014
  #9
Lives for gear
 
Lotus 7's Avatar
Quote:
Originally Posted by connloyalist View Post
....How long can a USB external battery pack last powering the USBPre2 with two mics running phantom power (such as my Rode NT5's)? Assuming something along the lines of a 20,000 mAH battery. I suspect the answer is: A lot longer than the DR100mk2's batteries will last.

Regards, Christine
To add some actual data about powering a USBPre2 from an external battery pack: I did occasionally use exactly such a setup a few times about a year ago. A USBPre2 connected to the S/PDIF input of a DR-100 Mk2. It worked fine, but I no longer have the Tascam.

Anyway, I powered the USBPre2 from an ANKER Astro-3 (now sold as the Astro Pro 10,000 mAh battery pack). I also use the Astro -3 as a back-up battery on my SD 788T for the times when the internal battery can't run long enough. The Astro-3 can provide 5 Volts to a USB port or 12 Volts to power a SD 788T. So can work with either SD device.

I did write a more detailed review of the Astro-3 battery supply on Gearslutz last year.

Before using the Astro-3 to power the USBPe2, I made a few current measurements on the USBPre2 using a metered USB power supply.
Test Conditions:
-->The actual voltage at the USBPre2 USB cable was 4.977 VDC for all measurements.
-->USBPre2 set for 44.1kHz/24 bits
-->Shure SRH-940 headphones connected to USBPre2 HP jack, volume set fairly low.
-->S/PDIF output connected to DR-100 Mk-2 2.5 mm jack w/Tascam cable.

Measured Results:

USB Pre2 Phantom Power OFF on both mic inputs, no mics connected
Display: No LEDs on
Current = 262 mA

USB Pre2 Phantom Power ON both mic inputs, no mics connected
Display: No LEDs on
Current = 283 mA

USB Pre2 Phantom Power on both mic inputs, (2) Line Audio CM3 mics connected, gain down, no sound.
Display: No LEDs on
Current = 364 mA

USB Pre2 Phantom Power on both mic inputs, (2) Line Audio CM3 mics* connected, gain up
Display: sound driving LED meters to -20 dB reading (both channels)
Current = 420 mA

USB Pre2 Phantom Power on both mic inputs, (2) Line Audio CM3 mics* connected, gain up- louder sound
Display: sound driving LED meters to -2 dB reading (3-red LEDs on in both channels)
Current = 450 mA

The LED display seems to be the "power-hog" on the USBPre2!

I posted a review of the ANKER Astro-3 battery which mainly deals with its performance when powering the 788T, however I confirmed that the Astro 3 can produce 16.32 watt-hours of power at either output voltage.

Based on an average USBPre2 current drain of 400 mA (2.00 watts) the "10,000mAh" rated Astro-3 should be able to power it for 8.16 hours.

Since it can provide up to 2 Amperes of current, it could also be used as an auxiliary power source (with an appropriate USB "Y" cable) for a USBPre2 AND a DR-100 Mk2 if the internal LiI and AA cells don't have enough power storage for a long job.

*The Line Audio CM3 mics draw a fairly typical 3.5 mA each from the +48 phantom powered mic inputs

Rode does not specify the current requirement for the NT5, but I'd suspect that it's comparable or less than a CM3.
Old 5th January 2014
  #10
Gear nut
 

Thread Starter
Thanks for the info Lotus. Interesting device, this Anker. I read on Amazon that the Astro Pro 2 now comes in a version all the way up to 20000mAH, and includes this in the description:

Equipped with two outputs for greater versatility: 1 DC 12V / 4A, 16V / 3.5A or 19V / 3A port and 1 USB 5V / 2.1A port.

And it comes with 10 different connectors. Now that sounds like a really useful piece of gear.

Regards, Christine
Old 6th January 2014
  #11
Lives for gear
 
Lotus 7's Avatar
Anker seems to be a reputable company. The battery/power supply I received has held up well, and the DC/DC converter has low enough noise that it does not cause any problems with sensitive audio gear. I contacted them to get a replacement output cable because I needed an extra one to modify with a Hirose connector to fit the 788T and I had one within 48 hours. My limited experience with Anker has been excellent so far. The 20,000 mAh looks like a real monster: 1.2 lbs of Li-Poly battery.

One thing to remember: These do fall into the US TSA regulations for "Larger Lithium Batteries" (8-25 g of Lithium). If you fly in the US, you can only travel with a maximum of (3) batteries of that size. I used to carry (4) LiI 7.2 Volt (internal) batteries for the 788T and would have liked to add the Anker Astro-3 as my back-up. That's no longer possible unless I'm traveling with a friend who can share the battery ration. Now I'm restricted to (3) LiI batteries in total, no matter what their capacity.
Old 6th January 2014
  #12
Lives for gear
 
rmx16's Avatar
 

Quote:
Originally Posted by Lotus 7 View Post
To add some actual data about powering a USBPre2 from an external battery pack: I did occasionally use exactly such a setup a few times about a year ago. A USBPre2 connected to the S/PDIF input of a DR-100 Mk2. It worked fine, but I no longer have the Tascam.

Anyway, I powered the USBPre2 from an ANKER Astro-3 (now sold as the Astro Pro 10,000 mAh battery pack). I also use the Astro -3 as a back-up battery on my SD 788T for the times when the internal battery can't run long enough. The Astro-3 can provide 5 Volts to a USB port or 12 Volts to power a SD 788T. So can work with either SD device.

I did write a more detailed review of the Astro-3 battery supply on Gearslutz last year.

Before using the Astro-3 to power the USBPe2, I made a few current measurements on the USBPre2 using a metered USB power supply.
Test Conditions:
-->The actual voltage at the USBPre2 USB cable was 4.977 VDC for all measurements.
-->USBPre2 set for 44.1kHz/24 bits
-->Shure SRH-940 headphones connected to USBPre2 HP jack, volume set fairly low.
-->S/PDIF output connected to DR-100 Mk-2 2.5 mm jack w/Tascam cable.

Measured Results:

USB Pre2 Phantom Power OFF on both mic inputs, no mics connected
Display: No LEDs on
Current = 262 mA

USB Pre2 Phantom Power ON both mic inputs, no mics connected
Display: No LEDs on
Current = 283 mA

USB Pre2 Phantom Power on both mic inputs, (2) Line Audio CM3 mics connected, gain down, no sound.
Display: No LEDs on
Current = 364 mA

USB Pre2 Phantom Power on both mic inputs, (2) Line Audio CM3 mics* connected, gain up
Display: sound driving LED meters to -20 dB reading (both channels)
Current = 420 mA

USB Pre2 Phantom Power on both mic inputs, (2) Line Audio CM3 mics* connected, gain up- louder sound
Display: sound driving LED meters to -2 dB reading (3-red LEDs on in both channels)
Current = 450 mA

The LED display seems to be the "power-hog" on the USBPre2!

I posted a review of the ANKER Astro-3 battery which mainly deals with its performance when powering the 788T, however I confirmed that the Astro 3 can produce 16.32 watt-hours of power at either output voltage.

Based on an average USBPre2 current drain of 400 mA (2.00 watts) the "10,000mAh" rated Astro-3 should be able to power it for 8.16 hours.

Since it can provide up to 2 Amperes of current, it could also be used as an auxiliary power source (with an appropriate USB "Y" cable) for a USBPre2 AND a DR-100 Mk2 if the internal LiI and AA cells don't have enough power storage for a long job.

*The Line Audio CM3 mics draw a fairly typical 3.5 mA each from the +48 phantom powered mic inputs

Rode does not specify the current requirement for the NT5, but I'd suspect that it's comparable or less than a CM3.
Thx for the info!
Topic:
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
 
Register FAQ Search Today's Posts Mark Forums Read

SEO by vBSEO ©2011, Crawlability, Inc.