Topic: Re: TASCAM DR-680 portable 8-track #5

[waltmon]

Any comments in regards to the Busman modded 680?    I'm told with no external pre definitely get it modded...just curious as others have said they see no tangible performance difference with the mod.

[Gutbucket]

Nah. It doesn't fall anywhere close to the 'definitely' category [edit- unless it's coloration you are looking for].  I've not heard the Busman mod, but feel no need to change the stock pres.  They are clean, quiet and do the job.  I'm not saying I don't hear any difference at all when I use the V3, but I have no hesitation in not using it, and haven't really set things up correctly to listen closely and critically enough to my own samples made both ways to be convinced I'm not just self-biased and imagining I hear a difference.  I pretty much use it for practical reasons, like when I need all 8 channels. [but the V3 is a 'clean' preamp, similar to what the built-in 680 preamps are designed to be anyway.  If you want the coloration of transformer saturation, the argument for using an external preamp that provides that becomes more compelling]

[obaaron]

I use my UA-5 digi out and it works great!

[waltmon]

About to snag a ua5 bmp2+ myself to use with 680...

What battery are you using with UA5?

[achalsey]

I personally have found the V2 to be more detailed/have more clarity than the 680 pres.  The 680 pres, to me, also have a much more pronounced low end (often overwhelming so compared to the V2). 

I've been running AKG CK 1X directly into the 680 and have found it does not sound as good as when I was running a V2 in between.  Originally I ran CK 1X > V2 > 680, but once I got a set of CK 63s I've been using them with the V2 and CK 1X > 680 as back up, and have never once preferred the 680 pres.  This obviously may have to do with the fact that the 63s should be a better mic in general, but still.

Just my opinion.  In the very few options I've tried, I definitely prefer the external pre to the stock 680 ones.

[waltmon]

About to get a UA5 but hope to find a v2 and an ad2k again...

[Gutbucket]

More detail and clarity is what I think I hear when I use the V3, but then I'm going digital in and using the V3's ADC as well.  I've never run the V3 in analog.  I suspect the difference may possibly be more evident in your case due to the characteristic AKG 'sound' which I think of as manifesting mostly in the upper midrange / treble region which is pretty much the detail and clarity region.

I need to go back and do some more critical listening now!

[Stagger]

Cross post from my resurrection of the battery thread but should be of interest to y'all
--
Also grabbed a http://www.amazon.com/gp/product/B00B7ID99I/ref=oh_details_o00_s00_i01?ie=UTF8&psc=1 for $15.00. Not bad for a 32gb class 10/UHS-1 card. Only issue is that I don't think that the 680 will take advantage of the UHS feature which slows down the card a bunch. Oh well, I know my Nikon D7000 will make use of the UHS so I'll just take one of my regular Class 10 cards for the 680. 

[lukpac]

Dredging this up from part 3:

Well nobody answered my question as to whether the Hi-gain setting is a boost or not. I posed the same question to Chris Johnson, the man who does the Busman mods on the DR-680. Here's what he had to say in case anyone is interested:

"Well the low gain is really a cut as it uses resistors like a pad but I feel that it should be left in low gain and only use high gain if needed. The noise floor in low gain is better. I look at it like this… If you need to turn the gain up past 20 in low gain then switch to high gain and use less gain to give the best noise floor and headroom.

I think that each person should do what makes them comfortable and gives them the best sound. I do not subscribe to the opinion of not running something through a couple extra resistors in because it “may give less circuit noise”, the difference is negligible in this case.

The stock unit has a much higher amount of noise in high gain than the low gain setting. The modified unit lowers the noise by -12db in high gain and -6db in low gain. The stock unit from my measurements has about 30db more noise in high gain at the 0 setting for gain.

Hopefully this clears the air a bit."

The other day I recorded an acoustic show in my living room. The vocal mic was an SM58 and was maybe a foot from the singer's mouth, so it wasn't getting hit very hard. I had the mic gain set to LOW and the trim up to about 20 or 25. Alas, the vocal track ended up with a fair amount of noise on it. Not terrible, but more than I was hoping for. But I was following the directions from the manual:

When adjusting the input level, at first, set the MIC
GAIN switch to LOW and adjust the input level on
the TRIM screen. If the input level is still too low even
when the trim is set to maximum, set the MIC GAIN
switch to HIGH

Tonight I decided to play around a bit with a mic splitter, first sending the second feed to a mixer and then to the 680 via line-in, and then directly to another channel with the gain set to HIGH. After adjusting the trim so the levels were the same, both of those resulted in *far* less noise than recording directly with the gain set to LOW.

Obviously there's going to be a greater chance of overload with the gain set to HIGH, but I certainly question the HIGH setting being noisier. Yes, when you're switching back and forth, there's clearly more noise with HIGH, but that's because the overall gain is much higher. Adjust the trim so the levels are the same and it sure seems like HIGH results in less noise.

Anyone else have thoughts when using dynamic (or ribbon) mics? Presumably with condenser mics the input is usually going to be too high for the HIGH setting.

[Gutbucket]

Tonight I decided to play around a bit with a mic splitter, first sending the second feed to a mixer and then to the 680 via line-in, and then directly to another channel with the gain set to HIGH. After adjusting the trim so the levels were the same, both of those resulted in *far* less noise than recording directly with the gain set to LOW.

Did you measure how much gain was added by the mixer?  That's the uncontrolled variable I see in the test scenario.

[lukpac]

Did you measure how much gain was added by the mixer?  That's the uncontrolled variable I see in the test scenario.

No measurements. Just had the direct LOW input panned left and either the direct HIGH input or the line input via the mixer panned right, and adjusted the levels until the source was centered. The difference in noise was not subtle. And of course when not using the mixer that variable was eliminated entirely.

I suppose I could make some test clips to analyze, but like I said, the difference wasn't subtle.

[Stagger]

Those of you that are running the Anker battery with the 680... Are you using just the DC->DC cable that comes with it or are you bothering with the "Adapter C" which appears to be 5.50 x 2.10mm. I cant find anything that states what the size is of the plug on the regular cable that comes with it but it seems to fit on the 680 just as securely. I don't have a volt meter to test polarity but they both seem to be Positive inner. If anything I'm guessing the adapter has a slightly smaller inner diameter but the difference is tiny if at all. Y'all bothering with sticking the adapter on the end or just using the supplied cable as is?

[dogmusic]

Those of you that are running the Anker battery with the 680... Are you using just the DC->DC cable that comes with it or are you bothering with the "Adapter C" which appears to be 5.50 x 2.10mm. I cant find anything that states what the size is of the plug on the regular cable that comes with it but it seems to fit on the 680 just as securely. I don't have a volt meter to test polarity but they both seem to be Positive inner. If anything I'm guessing the adapter has a slightly smaller inner diameter but the difference is tiny if at all. Y'all bothering with sticking the adapter on the end or just using the supplied cable as is?

I started off adding the adapter, but ended up using just the plain supplied DC->DC cable as is. It actually seemed like a better fit and less fiddly.

[lukpac]

Tonight I decided to play around a bit with a mic splitter, first sending the second feed to a mixer and then to the 680 via line-in, and then directly to another channel with the gain set to HIGH. After adjusting the trim so the levels were the same, both of those resulted in *far* less noise than recording directly with the gain set to LOW.

Did you measure how much gain was added by the mixer?  That's the uncontrolled variable I see in the test scenario.

Here are a couple of clips for examples:

SM57:

http://lukpac.org/mp3/samples/SM57_st.flac

AT853:

http://lukpac.org/mp3/samples/AT853_st.flac

Other than normalization, there was no post-processing of the files.

The output of the AT is higher and the difference doesn't seem as pronounced. Probably not a big deal if you're using high output condensers and/or recording loud groups, but it was definitely an issue for me recording quiet acoustic music.

[Stagger]

Those of you that are running the Anker battery with the 680... Are you using just the DC->DC cable that comes with it or are you bothering with the "Adapter C" which appears to be 5.50 x 2.10mm.Y'all bothering with sticking the adapter on the end or just using the supplied cable as is?

I started off adding the adapter, but ended up using just the plain supplied DC->DC cable as is. It actually seemed like a better fit and less fiddly.

Thanks for the reply and info dogmusic! Thats pretty much what I figured I was going to do but I am grateful for the confirmation that it will be secure in the long run. At some point I'll have to build myself a right-angle connector so it puts less force on the plug when the unit is in my bag in real life conditions but it seems to work fine for now. I also went ahead and picked up a set of the new 2500 mAh AA Eneloops to act as my internal backup both for recording time or hot swapping if I get another external. I have been using the normal 2000 mAh AA in my photo gear for about a year now and love the things but that is a whole other discussion.