Topic: Tascam DR-70D 4-channel audio recorder (Part 3)

[Jamos]

Have to check this - I just fired mine up and set 3/4 to the built-in mics(MIC) in BASIC - gain LOW (and then again with HIGH same result)

Then in INPUT - I made Input Gain MIC on channel 3 - and LINE on Channel 4 - and I can't see a difference...at least when it comes to the built in mics.

The MIC / LINE option should only affect the TRS/XLR combo jack inputs.  When using the internal mics, it should make no difference. 

[stevetoney]

I dont think there are any real gain selections there  - other than the EXT switch from line to mic. Those are just source selectors.

The difference between Mic and Line on most recorders is ONLY that there's a gain differece.  Typically, the only thing that changes between the two settings is line setting is something like 20 db less sensitive than the mic setting. 

I know that it seems like every recorder that comes out, it's asked whether line bypasses the internal mic preamps, but it's rarely the case.  Even the SD7XX were confirmed by the SD designers that the line-in setting doesn't route differently than mic in and the only difference is that Line in is less sensitive to accomodate line in devices.  It's a pretty safe assumption that (for what we've paid for this recorder) that's not the case here, but at the very minimum there's a significant gain difference between the two settings.

[Life In Rewind]

I dont think there are any real gain selections there  - other than the EXT switch from line to mic. Those are just source selectors.

Wanna bet? 

What do you think is changing when you change the setting from mic to line?

There is no such setting in the BASIC menu...other than the acknowledged change in the EXT input level.

Under the INPUT menu > INPUT GAIN

you can choose "LINE" "MIC" or "MIC + PHANTOM" But two of those wont turn on your mics.

[stevetoney]

you can choose "LINE" "MIC" or "MIC + PHANTOM" But two of those wont turn on your mics.

Ah I understand our difference.

Many people...me included...use either external preamps or mics that are powered from something other than phantom on the recorder.  I have one pair of mics that have their own 12V power supply unit.  If I'm not getting mic power from the recorder, I can use either Line or Mic on the input screen to record to any channel.  Either one of them works and the only difference is the gain on Line is about 20db less sensitive than Mic.  (I can further tweek the gain ranges through use of low, high, and high + on the basic menu.)

Life In Rewind, I believe what you're saying is that you're using the DR70D to power your mics.  In your case, yes the only valid setting on the input menu is MIC+Phantom.  In your case, Line or Mic won't do you any good since your mics won't function.  Since they won't function in those settings, there's no gain difference between Line or Mic since you get nothing from those two settings anyway. 

[Life In Rewind]

you can choose "LINE" "MIC" or "MIC + PHANTOM" But two of those wont turn on your mics.

Ah I understand our difference.

Many people...me included...use either external preamps or mics that are powered from something other than phantom on the recorder.  I have one pair of mics that have their own 12V power supply unit.  If I'm not getting mic power from the recorder, I can use either Line or Mic on the input screen to record to any channel.  Either one of them works and the only difference is the gain on Line is about 20db less sensitive than Mic.  (I can further tweek the gain ranges through use of low, high, and high + on the basic menu.)

Life In Rewind, I believe what you're saying is that you're using the DR70D to power your mics.  In your case, yes the only valid setting on the input menu is MIC+Phantom.  In your case, Line or Mic won't do you any good since your mics won't function.  Since they won't function in those settings, there's no gain difference between Line or Mic since you get nothing from those two settings anyway.

In the YARN example - I ran both - phantom condensers and battery powered stereo mic (on MIC). But I can't see the benefit of going LINE when my level is already too low in MIC. Going LINE IN sounds like my gain would have been even lower.

[DecomposingCadaver]

There are reports about massive noise when trying to record from the DR-70D's 3.5mm OUT, making recording impossible:

http://www.dvxuser.com/V6/showthread.php?329630-Tascam-DR-70D-what-do-you-think/page19

"When recording the 1 kHz test-tone from my SD MixPre-D with the DR-70 the internal recorder shows a noise-floor of -80 dB RMS, but when I record the signal from the DR-70's 3.5mm OUT I'm seeing a noise-floor of -55 dB RMS which is too noisy to use for proper audio. ( it's fine for a sync track )

Who knows if Tascam can fix this with a firmware update, but for now I would forget about trying to use the 3.5mm OUT from the DR-70."

I wonder if this is true of all units or only something that's happening to a few units? Those who own the DR-70D, can you run some tests?

[chk]

does anyone know/or has anyone tested the voltage delivered via the DR70s' PIP (plug-in power) via the 1/8 input?
apologies if this has already been covered, but i haven't seen it anywhere...and i don't have a multi-meter.  thanks

[voltronic]

There are reports about massive noise when trying to record from the DR-70D's 3.5mm OUT, making recording impossible:

http://www.dvxuser.com/V6/showthread.php?329630-Tascam-DR-70D-what-do-you-think/page19

"When recording the 1 kHz test-tone from my SD MixPre-D with the DR-70 the internal recorder shows a noise-floor of -80 dB RMS, but when I record the signal from the DR-70's 3.5mm OUT I'm seeing a noise-floor of -55 dB RMS which is too noisy to use for proper audio. ( it's fine for a sync track )

Who knows if Tascam can fix this with a firmware update, but for now I would forget about trying to use the 3.5mm OUT from the DR-70."

I wonder if this is true of all units or only something that's happening to a few units? Those who own the DR-70D, can you run some tests?

The one concert I've recorded with the 70D I used the line out to the M10 as a backup.  Just listened to the M10 track and it sounds great in all of the quiet sections, showing the same noisefloor as the tracks recorded on the 70D.  The HVAC noise was sitting around -55dB though.  I'll try a test tonight with my FP24 > 70D > M10.

[voltronic]

OK, I just did some testing.  I'm uploading a dropbox link of all of the test files since I really don't know how to analyze background noise, so hopefully those of you with the knowledge and tools can do this properly.  I loaded all 4 files in RX4 which has the best spectrogram view of any of my software and zoomed far in to show the first 0.090 seconds of each file.  The spectrograms clearly show more background noise on the M10 files, but that's to be expected since there's another device before it in the chain.  Is it 25dB worse as is claimed in the dvxuser post?  Hopefully someone here will be able to tell for sure. 

The visual difference you will notice in the beginning of the screenshots is probably due to the fact that I was manually trying to start both recorders at the same time, but in both tests it looks like the 70D went first.

https://www.dropbox.com/sh/zx3g53ofi9fzaz8/AACyfwf9i9UsXHEVrNEiIeSGa?dl=0

Here's a description of what I did:

FP24 Tape Out (1/8") > 70D EXT 1/2 IN (1/8") > 70D Line Out (1/8") > M10 Line In

FP24 sending 1kHz tone for both tests.

TEST 1:
01_70D_150427_0010S12.wav
01_M10_150427_10.wav

70D and M10 levels set so both read -21dB while being sent the tone from the FP24.  The 70D could not be set to -20, it was either -19 or -21 after many attempts.

TEST 2:
02_70D_150427_0012S12.wav
02_M10_150427_11.wav

70D Slate Tone set to -18dB in SLATE menu, and that tone sent to the M10.  M10 level set to -18dB to match. 
Sending 1kHz from FP24 > 70D > M10 then read -28dB on M10 (still -21dB on 70D whose input levels were not touched from previous test).

After performing this test, connected FP24 directly to M10 with input level left the same from TEST 2.  M10 showed -25dB.

EDIT: It just occurred to me that it might also be useful to repeat the same steps with the FP24's tone turned off while recording, so the 70D and M10 are only recording silence / background noise.  I just packed everything away for the night though and won't have time to do any more testing until Thursday.

[dogmusic]

Not sure if this has already been tried...

I inserted an SD card with some 4-track DR70D recordings (@24/96) into a DR680.

The DR680 asked me to make a system file, which I did, but then it would not see the DR70D files. When I looked in "BROWSE", it only showed an empty folder.

So unless I've done something wrong, a DR680 will not play DR70D tracks.

[jmerin]

Did any one figure out the difference between line 1 +2 stereo and 1+2 external power? Those are two choices if you are using a mini plug source.
Thanks

I'm not real sure what you mean, but I think you're asking about the last setting on the Basic menu.  I was also initially confused by that, but figured it out.

Under Input 1/2, there are three choices;

- XLR/TRS, this is the choice most of us will use most of the time...that's means your inputs are from XLR 1 and 2 jacks
- EXT_STEREO, this means inputs 1 and 2 will record the signal from the 1/8 ext jack.  This is the default because, remember that the DR70D is designed to be used with a digital camera.  Use this setting the same as you would 'Line In' jack on the typical handheld recorder.
- EXT_POWER, this is the same as EXT_STEREO only with PIP turned on.  Use this setting the same as 'Mic In' jack on the typical handheld recorder.

When you move through the menu to inputs 3/4, the choices are different than they were for inputs 1/2;

- XLR/TRS, again most of us will use this choice...this is to record the mics connected to XLR 3 and 4.
- MIC, this is the default and it records the internal mic onto Channels 3 and 4 instead of the XLRs.

Thanks, what is PIP again? I will use Line in stereo.

[dogmusic]

PIP = Plug-In Power

[Cheesecadet]

Not sure if this has already been tried...

I inserted an SD card with some 4-track DR70D recordings (@24/96) into a DR680.

The DR680 asked me to make a system file, which I did, but then it would not see the DR70D files. When I looked in "BROWSE", it only showed an empty folder.

So unless I've done something wrong, a DR680 will not play DR70D tracks.

When you made the system file is that formatting the card? If so that could account for the missing files. I dunno

[voltronic]

Not sure if this has already been tried...

I inserted an SD card with some 4-track DR70D recordings (@24/96) into a DR680.

The DR680 asked me to make a system file, which I did, but then it would not see the DR70D files. When I looked in "BROWSE", it only showed an empty folder.

So unless I've done something wrong, a DR680 will not play DR70D tracks.

 

When you made the system file is that formatting the card? If so that could account for the missing files. I dunno

Either that or the system file created by the 680 expects a different file / folder structure than the 70D uses.  If the tracks are still there then the card obviously wasn't formatted by the 680.  Does the card with the 680 system file read in the 70D?

[dogmusic]

Not sure if this has already been tried...

I inserted an SD card with some 4-track DR70D recordings (@24/96) into a DR680.

The DR680 asked me to make a system file, which I did, but then it would not see the DR70D files. When I looked in "BROWSE", it only showed an empty folder.

So unless I've done something wrong, a DR680 will not play DR70D tracks.

When you made the system file is that formatting the card? If so that could account for the missing files. I dunno

No, it did not format the card. It just added to it. When I viewed the card in my computer, there were two system files: one for the DR70D and the new one for the DR680. The audio files from my DR70D were still there and intact.

No files were missing. But the DR680 simply did not "see" the DR70D audio files.