Topic: TASCAM DR-680 portable 8-track #6

[hi and lo]

The 680 has alerts for going over zero and for overloading the mic inputs.  See page 16 of the owner's manual for what they look like, but if you're overloading the input stage it shows it underneath the level meter of the channel that's overloading by putting a box around the circle at the bottom.  It's pretty easy to miss if you're not looking for it.

http://tascam.com/content/downloads/products/43/E_DR-680_OM_vA.pdf

^ This.

The reference line for the meters is at -18 dB and although the metering isn't as elegant as a traditional LED meter, it's definitely has features to indicate both 0 dB clipping and input stage overload.

Were you running line in? It's damn near impossible to clip the input stage of the 680's line in, so I imagine you were running mic-in with the gain all the way down (like -20)?

[lukpac]

Also, experiment. Run some tests in your living room with your stereo cranked or something.

If there's some combination of things that would result in overload without any sort of indication, it would be interesting to know, but as above, I certainly haven't run into it myself.

[carlbeck]

I was running line in from my Aerco, there were no indicators at all to indicate it was clipping or brick walled or whatever. It was really weird, I know to look for the indicator under each channel & there was nothing which is why I was frustrated when I heard the recording. Without a doubt the Aerco was too hot, it was running about 45 on the gain, my fault for not checking it because I assumed it was still at 25db. Just a disappointing experience with the 680 overall based on the meters. I just don't understand how they can go from great meters on all the old decks to this new garbage but I guess that's what happens when you take five years off from taping, new technology right? 

[Carlos E. Martinez]

The only unresolvable problem in the DR680, also shared by the DR60 and all other lower priced Tascam recorders, is that the limiter is not in the first stage, as it should be. A poor decision from Tascam.

I wonder how they did that on their top recorder P82, as it is supposed to compete with Sound Devices, and they do put their limiters where they should be.

It's strange that nobody seems to complaint or even mention this (not minor) thing in this or other Tascam forums. Perhaps complaining over this might make Tascam correct that, at least on some of their models.

[hi and lo]

I was running line in from my Aerco, there were no indicators at all to indicate it was clipping or brick walled or whatever. It was really weird, I know to look for the indicator under each channel & there was nothing which is why I was frustrated when I heard the recording. Without a doubt the Aerco was too hot, it was running about 45 on the gain, my fault for not checking it because I assumed it was still at 25db. Just a disappointing experience with the 680 overall based on the meters. I just don't understand how they can go from great meters on all the old decks to this new garbage but I guess that's what happens when you take five years off from taping, new technology right? 

Gotcha. My guess is you were clipping the input of the Aerco in which case the 680 (or any recorder for that matter) isn't going to give you any indication that the signal is distorted. The closest thing you'll get to a warning is if the levels look 'sluggish,' but they're going to be well below 0 dB and not necessarily clipping the 680s inputs.

[Chuck]

It's strange that nobody seems to complaint or even mention this (not minor) thing in this or other Tascam forums. Perhaps complaining over this might make Tascam correct that, at least on some of their models.

I don't use the limiter, so it doesn't mean that much to me how it's implemented.

[fobstl]

This is what I was thinking also. I have never had an issue with overloading or the meters on the 680.

Gotcha. My guess is you were clipping the input of the Aerco in which case the 680 (or any recorder for that matter) isn't going to give you any indication that the signal is distorted. The closest thing you'll get to a warning is if the levels look 'sluggish,' but they're going to be well below 0 dB and not necessarily clipping the 680s inputs.

[Carlos E. Martinez]

I don't use the limiter, so it doesn't mean that much to me how it's implemented.

Limiters are a must in location film/video recording, particularly on documentaries where you may have unexpected peaks.

In any case they are effective when they adjust the first stage, before distortion or clipping occurs.

[JimmieC]

I didn't even know the DR-680 can determine the input signal from the preamp is overloading.  I'll have to check that display out on the DR-680 because I allows get nervous when the Lunatec V2 red LED lights turn on.  Then, I get home and it sounds just fine.

[hi and lo]

I didn't even know the DR-680 can determine the input signal from the preamp is overloading.

Just to be clear, it will only tell you when the input of the 680 (mic or line) is being overloaded. It won't tell you when upstream equipment (i.e. the aerco, in this case) is the cause of signal distortion.

[JimmieC]

I thought I was reading and understanding those comments wrong.

[lukpac]

I was running line in from my Aerco, there were no indicators at all to indicate it was clipping or brick walled or whatever. It was really weird, I know to look for the indicator under each channel & there was nothing which is why I was frustrated when I heard the recording. Without a doubt the Aerco was too hot, it was running about 45 on the gain, my fault for not checking it because I assumed it was still at 25db. Just a disappointing experience with the 680 overall based on the meters. I just don't understand how they can go from great meters on all the old decks to this new garbage but I guess that's what happens when you take five years off from taping, new technology right? 

As others have asked/pointed out, are you sure the signal wasn't distorted at the output of the Aerco? It's possible that there was nothing wrong with the meters on the 680, and that any distortion was present before the signal hit the input stage.

[achalsey]

I didn't even know the DR-680 can determine the input signal from the preamp is overloading.  I'll have to check that display out on the DR-680 because I allows get nervous when the Lunatec V2 red LED lights turn on. Then, I get home and it sounds just fine.

Don't worry too much about the red peak indicator light.  From the manual:

PEAK INDICATOR The LED peak indicator, which monitors the signal between the input
and output amplifiers, illuminates the green LED at -14dBu and illuminates the red LED at
+16dB (10dB before clipping).

Anything less than constantly on, or close to it, you should be fine.

Someone was actually kind enough to mock this up for me a while ago.  Forgot about it, but thought it was appropriate (though off topic) here.

http://i.imgur.com/ygUdQBv.jpg

[carlbeck]

I was running line in from my Aerco, there were no indicators at all to indicate it was clipping or brick walled or whatever. It was really weird, I know to look for the indicator under each channel & there was nothing which is why I was frustrated when I heard the recording. Without a doubt the Aerco was too hot, it was running about 45 on the gain, my fault for not checking it because I assumed it was still at 25db. Just a disappointing experience with the 680 overall based on the meters. I just don't understand how they can go from great meters on all the old decks to this new garbage but I guess that's what happens when you take five years off from taping, new technology right? 

As others have asked/pointed out, are you sure the signal wasn't distorted at the output of the Aerco? It's possible that there was nothing wrong with the meters on the 680, and that any distortion was present before the signal hit the input stage.

You are correct, I have no way to verify whether the signal was distorted or not, my assumption was that the Aerco wouldn't have been overloaded at the gain it was set on but obviously something wasn't right in the chain. I'm glad I posted the question here because as always you guys bring another perspective to the situation. While overall I'm still not pleased with the level meters I at least learned through the experience!

[Gutbucket]

The only time I ran an Aerco (borrowed) into the DR-680 (mine), the Aerco had problems and distorted.  The DR-680 faithfully recorded that distortion without overloading.  The Areco was subsequenty repaired and apparently works fine now, although I've not borrowed it again.  There are no level or clipping indicators on the Aerco (at least the one I used) so there was no way to know it was distorting at the time other than listening to the output.