Topic: Tascam DR-70D 4-channel audio recorder for DSLR cameras

[dallman]

I highly recommend the Reference manual on tascams's site for some additonal reading as it has some info the manual that came boxed does not cover. It answered a few questions that I was having. Such as:

Meters...was wondering where the meters where since there are no number markings...there is a bolded down arrow thing and per the reference manual this is -16dB

Peak light...If i understand this correcly the peak lights (near the gain knobs) only light when using a mic input, not when using a line input...from pg 6:

1/L knob and PEAK indicator – Use this knob to adjust the input level from the 1/L connector on the left side of the unit. The 1/L PEAK indicator lights when the 1/L input level is about to cause distortion. This also lights if distortion occurs in the analog circuitry during mic input. This will not light, however, if distortion occurs in the analog circuitry during line input. (See “Adjusting the input level” on page 19.)

Do I have that right? Anyone tested the peak light with line in while recording, does it light up?

Also I wish they told us where exactly the point the peak light comes on instead of just "about to cause distortion".

What the manual is referring to is that if the signal is overloaded within the Tascam using your mics it will show as such, but if the signal is overloaded in the preamp or whatever is feeding the line in (because something would be boosting a line signal), that will not and cannot be detected. This is always the case, although I may not be explaining it exactly right.

[Chris K]

ok so if i'm brickwalling a preamp which is feeding line into the 70d, then peak lights on the 70d will not light. gotcha. unless the 70d is brickwalling too. Ha.

So my 4 x AA rechargeable test failed....it started a new file at the 2 gig mark when i was getting lunch. When I came back battery meter was just the tiniest sliver and over 1hr 30min into the next file so i just turned it off. Didn't want to fully discharge a brand new set of batts. Must have been at least 5 hours on the rechargeables with 16/44.1 and 24V phantom power.

[Cheesecadet]

I recorded a friends band the other night with my FP24 > XLR Out Interconnects > Tascam DR-70D XLR In on channels 3/4 and the peak lights were going off on the DR-70D.  Got home and listened to the recording and the recording was perfect with no distortion or brick walling, etc.

[Chris K]

Had my first outing with the 70D on Saturday night. Ran 24/44.1 for DtB. Ran JK Labs DVC line in to the 70D via rca>xlr cable. Like a dumbass I had all 4 tracks in record on mode, but only needed tracks 1&2. So tracks 3&4 recorded but nothing was there. I did have 3&4 set to line in input also.

It's gonna take me a bit to get the levels right. I was using the -16dB arrow as a guide and just barely going over it, but in the DAW it is obvious that is a bit too conservative. Next time I will try the dual record mode set at -3dB and try to get 1&2 levels closer to 0dB. Live and learn and nothing I can't fix in post.

Ran the Landreth Bros opening band for 45 min and Donna for almost 2 hours on the new 4xAA engergizer rechargeables and still had life left to listen in the car on the way home. Backup usb battery was available but not used for this gig.   

[2manyrocks]

I seem to recall the peak lights will flash on my 60d even though it isn't clipped. 

[hi and lo]

I seem to recall the peak lights will flash on my 60d even though it isn't clipped.

It would be helpful if Tascam had bothered to document the level at which the Peak Indicators light up. Unfortunately, they didn't (shocking!).

Peak indicators are often calibrated differently. Some recorders and A/D's will only indicate a true peak (i.e. the signal has reached and exceed 0 dBFS - dB full scale), but more commonly peak indicators are calibrated to activate anywhere from -1dB to -3dB. Even better, some units will even let you adjust the Peak indicators (like the 7xx series).  For folks that have used older units like the SBM-1, a good rule of thumb has always been that the peak indicators should "dance" a bit with occasional blinks, but never solidly illuminated.

My guess is that Tascam has calibrated it for the latter and that you've still got a small bit of headroom when the Peak indicators light up.

[tomuo]

The Peak level indicator point is different depending on whether the limiter is on or off.
With the limiter ON, the peak indicator can show a peak that the limiter brought into control, but there will be some transients that are so short that the limiter doesn't get them fully.
With the limiter OFF, it should show peaks  at -0.13dBFS.

The limiter settings are fixed.   0.08ms attack / 100ms release.   Threshold -1dB , ratio inf:1    Hybrid digital/analog (using analog headroom, which is why the peak indicator works differently when engaged).

[hi and lo]

The Peak level indicator point is different depending on whether the limiter is on or off.
With the limiter ON, the peak indicator can show a peak that the limiter brought into control, but there will be some transients that are so short that the limiter doesn't get them fully.
With the limiter OFF, it should show peaks  at -0.13dBFS.

The limiter settings are fixed.   0.08ms attack / 100ms release.   Threshold -1dB , ratio inf:1    Hybrid digital/analog (using analog headroom, which is why the peak indicator works differently when engaged).

Where did you find this information? I reviewed the manual and didn't see anything similar.

[Chris K]

Where did you find this information? I reviewed the manual and didn't see anything similar.

I believe Tom works for Tascam.

[Ozpeter]

Personally I'd be glad to see participation by other companies too in this forum, particularly when clarifications on technical matters are needed.  We've spent pages in back and forward arguments about how some aspects of other devices work, when a couple of lines from a company rep would lay the matter to rest right away (though perhaps that might spoil the fun?!).  As long as companies don't try to set the agenda here, (for instance by starting threads pushing products), as far as I am concerned they are more than welcome.  Tom's contributions have already been extremely helpful.

[hi and lo]

Personally I'd be glad to see participation by other companies too in this forum, particularly when clarifications on technical matters are needed...  Tom's contributions have already been extremely helpful.

I agree, especially when the information is as specific and helpful as what Tom provided. My apologies as I don't follow these threads closely enough to know tomuo's affiliations. Peak indicator functionality is quite important and I'm obviously dismayed that this  information isn't published in the manually, but it's certainly nice to be able to answer those kinds of knowledge gaps directly on this forum.

[Life In Rewind]

Toms comment mirrors my experience so far.

I've seen the peak light light up - but no "over" on the LCD.

It's close - but the LED lights first.

[F.O.Bean]

ok so if i'm brickwalling a preamp which is feeding line into the 70d, then peak lights on the 70d will not light. gotcha. unless the 70d is brickwalling too. Ha.

So my 4 x AA rechargeable test failed....it started a new file at the 2 gig mark when i was getting lunch. When I came back battery meter was just the tiniest sliver and over 1hr 30min into the next file so i just turned it off. Didn't want to fully discharge a brand new set of batts. Must have been at least 5 hours on the rechargeables with 16/44.1 and 24V phantom power.

Did you do a "break in" on the new AAs before using them? If I/you don't do a proper "break in" on my kickass Maha Powerex charger, then the batts don't get anywhere near their max capacity!!! You could also cycle them 5-6 times to do the break in too! Once you do the break in (which takes a few days for every [4] batteries it does at once), then it'll start to give you consistent results I couldn't praise my $50-$60 charger anymore. It does the break in, a refresh/analyze function, and charging functions, so basically, it does everything you'd ever need a AA/AAA charger to do My AAs are 5 years old, and they still hold an 80% charge, which is amazing IMO

[Life In Rewind]

How much run time did you get with

http://www.newegg.com/Product/Product.aspx?Item=N82E16875620002

Battery is only 8 dollars not bad at all!

I just ordered that one today - so we'll see!

The SCUD "Hobbit" arrived - nice aluminum case - basically a cell phone battery in a case.

I topped off the charge - (seemed partially charged, didnt take long.)

I ran 4 channels @ 44/24 w/2 phantom on - well over 3 hours...but made the mistake of starting this test too late - and fell asleep!

So - I'll check the last file length - my internals were about half - so it couldn't have run too long on those.

Recharging now - I'll repeat the runtime experiment with this, more proper, charge cycle.

The one drawback on this battery is it has a power button. - So you'd have to be careful digging around in your bag.
That said - the button is stiff and requires a solid poke - and its somewhat protected by the USB output cable.
(but something to look out for when shopping for these batteries)

[Life In Rewind]

How much run time did you get with

http://www.newegg.com/Product/Product.aspx?Item=N82E16875620002

Battery is only 8 dollars not bad at all!

I just ordered that one today - so we'll see!

The SCUD "Hobbit" arrived - nice aluminum case - basically a cell phone battery in a case.

I topped off the charge - (seemed partially charged, didnt take long.)

I ran 4 channels @ 44/24 w/2 phantom on - well over 3 hours...but made the mistake of starting this test too late - and fell asleep!

So - I'll check the last file length - my internals were about half - so it couldn't have run too long on those.

Recharging now - I'll repeat the runtime experiment with this, more proper, charge cycle.

The one drawback on this battery is it has a power button. - So you'd have to be careful digging around in your bag.
That said - the button is stiff and requires a solid poke - and its somewhat protected by the USB output cable.
(but something to look out for when shopping for these batteries)

Re-running my runtime test with a a fresh charge.

I hit something like 4 hours and 20 minutes before the blue light on the battery began to fade.

4 channels @ 44/24 w 2 channels of phantom running my APEX 435 LDs.