Tascam DR-70D - what do you think?

Richard Crowley said:
Every time I Google it, I see a display ad and photo on the right side of the window showing a camera claiming to be AG-DVX100 for $499
But you are probably right. I am not familiar with that model (or most Panasonic video gear in general).
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Of course the irony here is that that camera is the one this forum is named after. 8~)

http://www.bhphotovideo.com/c/produ...ic_AGDVX100B_AG_DVX100B_3CCD_24p_Mini_DV.html

I would love to see one new for $499, used yes - they are down in that range. Mostly because they are a Mini DV camera and only did SD so nobody wants them now. But they kicked butt when they came out and were really the first semi affordable camcorder that had decent sound.
 
jaypass said:
The recording I'm getting from the DR-70d is pristine, sounds phenomenal. But the signal coming out of the unit's 3.5mm jack into my GH4 is nosey as heck.
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I just ran a bunch of tests on my DR-70 unit and the problem is the 3.5mm OUT from the DR-70. 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.

As always, you get what you pay for. :-)
 
TheDingo said:
I just ran a bunch of tests on my DR-70 unit and the problem is the 3.5mm OUT from the DR-70. 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.

As always, you get what you pay for. :-)
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what were your settings in the Monitor section of the menu? there are several options for the 3.5mm out
 
Darren Levine said:
what were your settings in the Monitor section of the menu? there are several options for the 3.5mm out
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I tried the full gamut ( CAM and LINE from +12 dB down to -50 dB ) to see if a stronger or weaker signal would make a difference, which it didn't. The noise seems to be part of the OUT circuitry, so I'm dubious that this can be fixed without a hardware change.
 
you know what, im having a recall of some testing it did back when i got the 70d in which i experienced a significant noise out of the 3.5mm, but if i recall correctly i attributed it to some factor. might have been a dirty AC line/poor usb power supply. i'll see if i can figure that out agian
 
Darren Levine said:
you know what, im having a recall of some testing it did back when i got the 70d in which i experienced a significant noise out of the 3.5mm, but if i recall correctly i attributed it to some factor. might have been a dirty AC line/poor usb power supply. i'll see if i can figure that out agian
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I was running from 4 AA alkalines, so I don't think it's a power issue. I also tested the 3.5 mm OUT with my Tascam DR-07 Mk2 recorder and saw the same results. I was using a heavy duty 3.5 mm professional grade cable with custom soldered metal plugs.
 
Is this a problem with all DR-70D or just some units? i.e. is it a structural/design issue or is it a QC issue on some units?
 
I just plugged mine in and sounds pretty crystal out of the cam out jack. and unless i'm nutz, i definitely recall some noise issue with that when i first got it, but for the life of me don't remember what i figured it out to be.
 
OldCorpse said:
Is this a problem with all DR-70D or just some units? i.e. is it a structural/design issue or is it a QC issue on some units?
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My guess is that Tascam didn't put much thought to the design of the 3.5 mm OUT circuitry, expecting that most users were going to focus on the performance of the internal recorder.
 
Darren Levine said:
I just plugged mine in and sounds pretty crystal out of the cam out jack. and unless i'm nutz, i definitely recall some noise issue with that when i first got it, but for the life of me don't remember what i figured it out to be.
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You won't notice the noise from casual listening, but when you bring your recording into your audio editor you can see where the noise-floor sits when recording "silence". I consider -60 dB RMS to be the dividing line between an in-audible noise-floor under normal listening conditions, but when recording you need better than this to compensate for a weak signal or if you accidentally record with levels too low. Most of the better low cost recorders can reach a noise-floor of -70 dB RMS when recording a proper LINE level signal, which gives you 10 dB of leeway when making corrections in post.
 
Darren Levine said:
I just plugged mine in and sounds pretty crystal out of the cam out jack. and unless i'm nutz, i definitely recall some noise issue with that when i first got it, but for the life of me don't remember what i figured it out to be.
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What do we want?
A cure for Alzheimer's
When do we want it?
Want what?

Well, hopefully mine will finally get here this week and I'll put it through the same tests.
Either I'll get the same results or it's a QC issue.

Darren - still love to kow what your fix was....if you can locate the rogue brain cells that took off with that info!
 
Still no luck on my end. There's a setting on the GH4 called "SPECIAL MIC" that's always locked on my camera. Could that have anything to do with it?

Hopefully we make some progress on this soon, if it is a QC issue I'd like to know if I happen to have one of the bad units floating around so I can get it repaired.
 
jaypass said:
if it is a QC issue I'd like to know if I happen to have one of the bad units floating around so I can get it repaired.
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I honestly think that Tascam put little thought into the quality of the 3.5mm out. It's comparable to the audio that my old Canon 60D camera recorded internally when fed a good signal, which is not usable for professional work. On the other hand the internal DR-70 recording is great, so why not stick with that.

If internal camera audio was a big deal to me I would have bought a JuicedLink Riggy box, which is a good match for pretty much any mirrorless or DSLR camera.
 
Has anyone come up with a solution for this audio hiss on the camera output?? I also am experiencing the same thing on my GH4.
 
OK, my DR70 JUST showed up from UPS five minutes ago.

I also got word from Jared McKenna that a -25db attenuating cable may be the fix.

I have seen this be "it" before.

We have several gain stages to deal with in this chain that all need to be taken into account and maximized:

1. The gain of the signal coming in to the DR70.
2. The gain of the output amplifier coming out of the DR70.
3. The relative level of the signal being amplified through the DR70's output.
4. The input gain of the camera's external audio input.

The extra 15db of hiss that has been measured can very easily be caused by less than optimal gain staging at any of these 4 points.

If the output amp on the DR70 is hot - then the attenuating cable will lower its noise floor by 25db.
If the signal the DR70 is capturing is still hot enough to hit the camera's inputs strongly then this issue is SOLVED.
If not, the question becomes; can one raise the audio gain on THE CAMERA enough to get a strong signal without giving back the 25db of noise reduction we just gained with the cable.

If this does it - at least it's a cheap and easy fix. It also means that the output amps on the DR70 is not noisy - it just means it's LOUD.


I'll have to procure an attenuating cable before I can test this, but I will do it along with the other standard tests.
I'll need a couple days - but I'll post the results here.
 
If you set the dr70 to its internal mikes you get loud hiss but normal level on the mics. I,m going to test outputting the dr70 to my field mixer and seeing if the problem is still there. This could be a GH4 only problem. Which would be ufortunate as I bought specifically to use for this in this way. I wish the gentleman who said he solved this trouble could remember what he did. Maybe he could do a little research for us.
 
I fed a LINE level 1 kHz test tone from my SD MixPre-D to the DR-70 adjusted the gain until the DR-70 was recording this signal at -12 dB, and then recorded the cam OUT from the DR-70 with an Olympus LS-12 recorder that is also adjusted to record at -12 dB. My LS-12 has a measured noise-floor of -75 dB RMS when fed a clean MIC level signal, but when checking the recording of the DR-70 cam OUT I see a noise-floor of -55 dB RMS. ( the DR-70 internal recording shows a noise-floor of -80 dB RMS ) So it appears that the DR-70 cam OUT is 25 dB noisier than the internal recorder.
 
I also repeated the test with a Tascam DR-07 Mk2 recorder instead of the Olympus LS-12 recorder and got the exact same results. The DR-07 Mk2 has a MIC level noise floor of -80 dB RMS when fed a proper signal. To me this looks like it has nothing to do with the GH4 and everything to do with the DR-70 putting out a noisy cam OUT signal.
 
OldCorpse said:
Thank you DPStewart for getting to the bottom of this, much appreciated!
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Well, Dingo's testing methodology is correct, so I may very well get the exact same results.

There are a whole lot of "IF"s in the analysis to come.

I have seen really tiny and cheap op-amps have bad quality control, resulting in a significant variance from one copy of a unit to another. That could explain some people getting better results than others.
 
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