Topic: TASCAM DR-680 portable 8-track #3

[tgakidis]

Yeah.  When I first noticed it I was running analog from the v3.  The v3 meters were spot on running my 414s but the 680 meters were off.  I switched to channels 3-4 on the 680 and bingo, no issue.  There is definitely something going on with analog input 2 on my 680.

[hi and lo]

I've experienced similar behavior on my 680... and iirc it was on channels 3 and 4. Huge differences in the metering.

It went away after powering down, unplugging everything, and then booting back up. It seems like the order in which you plugs things in and turn on phantom, mic/line settings, etc. seem to affect operation. Sorry I can't really be anymore specific, but if we experience it again we'll take better notes.

[Myco]

When I had my deck modded by Chris Johnson from Busman Audio, I believe he told me that the XLR inputs that Tascam uses are pretty much meh. I've loved my mod, I'd highly recommend it.

[tgakidis]

It's been a ongoing issue for atleast the last month.

[Chuck]

It's been a ongoing issue for atleast the last month.

Damn, I'm sorry to hear that Ted.
I hope it's a simple fix.

Please let us know how this issue resolves.

[Gutbucket]

Yeah sorry to hear that Ted, on-going intermittant problems really suck.  Does the problem seem to correct itself with a power cycle like hi and lo reports?

Myco, does Chris change out the XLR jacks as part of his mod? 
What else can you tell us about it?  Sensitivity change, reduced noise floor, sonic flavor direction?
At some point I'd love to hear a good comp of a stock vs Busman modded deck.

[Todd R]

This discussion makes me wonder.  I've had several instances in the field of one channel being lower, but I haven't been able to figure out what the cause was.

When I've had the instances of a low channel volume, it always has been at shows, and my only motivation at that point was to get things working.  After trying different things to narrow it down (switching cables/mics, taking outboard preamps out of the chain, whatever), I've always gotten it working so I could record the concert.

After the concert, I'd go home and try to figure out the cause, and never was finding the problem.  Since I could never replicate the problem at home, I've been assuming it is an intermittent problem, and have been presuming a cable issue.  I've got several pairs of cables I've been treating as suspect, and have taken to bringing extra sets of XLR ICs with me to shows for backup.

Bummer to think it is the 680, but from this thread I'm not sure if an instance of low volume in one channel has something to do with how everything is set up with the 680 (order of wiring up, menu selections, whatever) or if it indicates a problem with the 680, or whether it can even be traced to the 680.

For now, I'll continue to use my Sony D50 as a back-up recorder.  Bummer to feel this way, esp since it may not be the 680 at fault, but the experiences people are having do make you wonder. Too bad, a great piece of gear in all other respects.

[phil_er_up]

I've experienced similar behavior on my 680... and iirc it was on channels 3 and 4. Huge differences in the metering.

It went away after powering down, unplugging everything, and then booting back up. It seems like the order in which you plugs things in and turn on phantom, mic/line settings, etc. seem to affect operation. Sorry I can't really be anymore specific, but if we experience it again we'll take better notes.

I had a similar problem recently. Channel one was overloading on the Dr680 with huge spikes and the V3 meters was normal. I did a complete dismantle of every cord and found the SPIDF was not screwed in properly. Then it worked with no overloading of channel one.

I do agree with the statement above about booting up. I was running 4 mics and SBD feed at the time. Every time I made a change on the DR680 I powered off the big box preamp (one set of mics) and the V3 (other set of mics). I would take the XLR's out of the V3 digital and put it in the analog and retry the whole sequence again. Also swapping out channel 1 and 2 with the digital channel 5&6 on the DR680. Then I found if I did not do a certain order the DR680 did not seem to respond correctly.

That was the last time I recorded and wanted to do more tests before I brought this subject up. I thought it appropriate here. I think the order to power up machines that worked was BB, V3, then DR-680. I had to change the Digital channel each time on the Dr-680 from analog to digital to see if the spidf was working properly.  I tried this many times before I got it to work.

This was with 10 minutes to go before the band starting...but finally got it all working correctly. No overload in channel one due to either SPIDF connection or powering sequence is what I determined so far. First I thought something happened to one of my mics and sure glad that was not the case....so many times it can be so many different possibilities with all the preamps, recorders, cables etc that we hook up.

I still not sure if it is a DR680 problem or not...this thread makes me want to lean one way thou. Will have to do more tests to be sure for myself.

PS: I always thought the XLR connections were not very good on the DR680. I have many audio pieces at home with XLR's inputs/outputs and they are built so much better. They just snap right in and fit seems really good on my home audio gear the DR680 XLR connections DO NOT FEEL THAT WAY TO ME.

[Chadfish]

I have the Busman mod on my DR-680.  I don’t think the mod affects the color of the pres at all it just opens them up for better soundstage and detail while bringing the noise floor down. If anything on the tone, the mod makes the response more flat therefore more transparent.

I don't have a before/after mod comparison, but I did do a little test comparing mics going into the 680 straight vs. through a MixPre. I think I liked the sound going in straight better.
Here's my test: http://www.vimeo.com/16681934

[tgakidis]

I have totally narrowed it down to channel 2 of the 680 and it is constant.

[Chuck]

I have totally narrowed it down to channel 2 of the 680 and it is constant.

Damn. Really sorry to hear that.

[Myco]

Yeah sorry to hear that Ted, on-going intermittant problems really suck.  Does the problem seem to correct itself with a power cycle like hi and lo reports?

Myco, does Chris change out the XLR jacks as part of his mod? 
What else can you tell us about it?  Sensitivity change, reduced noise floor, sonic flavor direction?
At some point I'd love to hear a good comp of a stock vs Busman modded deck.

Sorry, my bad, it was not the XLR jacks. Here is what Chris modded for me, "The mod is a change of all the input op amps and all of the input capacitors.  I change the values of the input caps and use elna silmic II caps which have a nice detailed but warm tone not to be confused with a warm type mod." So maybe it's related to faulty input op amps? That would make more sense that the XLR jack itself, correct? I would think that an XLR problem would be exibited more by static or a not working at all, rather than a drop in gain. Since the op-amps provide gain, a faulty one would drop, or cause a spike in, the gain I would think. I'm nowhere near an expert on any of this, but logic would point this way.

[kirk97132]

I can tell you that the internal circuit boards including the one that houses the XLR/TRS inputs connect to each other via a flat plastic strip connector that makes it's connections via pressure by a hold down tab.  it is not even ribbon cable but a plastic film with metal contacts on it.  Maybe the internal connection is not "great" ?  BUT to check or reseat the connections would require you to basically dismantle your 680.  Unless you are comfortable doing open heart surgery on your deck I would not recommend trying it.

[NOLAfishwater]

I had a dropout on channel one on Wed night. It only happened in the second set. kind of weird. it is the first time that has ever happened. I wonder what the deal is.

[Teen Wolf Blitzer]

Man, reading this thread is not good publicity for Tascam.    Just confirms why I will never part with my 744.