Topic: Difficulties to connect Mk41 - actives - PFA to Tascam DR-70D

[swordfish]

I am not sure if a new topic is the right thing or if this need to be within the ongoing Tascam DR-70 Thread.

Nevertheless, in Feb. I started to get my lighter summer open taping rig together, Mk41 - actives straight out - PFA into Tascam DR-70D and tested it last Saturday.

I think the test fried my actives...but I am not sure why...I did a very good audience recording a few days earlier with some of the same equipment in the lineage MK41- actives straight out - TB - Sony M10.

I modified the Tascam with the latest firmware and connected Caps/Actives/PFA plugged it into the Tascam. 
The Tascam was set to 48 volts and the test recording showed the peaks of the recording but I had to fully crank the level and ended up in results about -20db. 

That told something must be wrong since the stereo was cranked.  I copied the files to the HDD of PC but you hardly could hear anything.

In the end I used my Shure FS 24 in the lineage with the same results, but I had the 48 Volts switched off in the Tascam before I connected the FS 24.

In the end I tested the MK41caps with my side out actives - TB - Sony M10, it revealed that the caps are fine, but testing the caps with the straight out actives - TB - Sony revealed that the straight out active cables is not working anymore.

Any Ideas what happened!  I am pretty sure this post is a mess but I tried to explain as good as I can.

Swordfish

[swordfish]

I am not sure what it is, all I can say that the actives worked flawless the last time I used them. 
As mentioned before the second active cable I own works well with MK41-TB-M10.

So it will be riddle for a while, IMO the equipment has to be tested piece by piece, I will start with the active cable....since I need that the most..

I am not sure what caused the surge current...switching from 48 to 24 Volt on the Tascam...switching from line + mic....Maybe the Tascam is the matter

Maybe it will make sense to have the PFA and the actives both checked simultaneously....will save time.. phhhhhh


Almost ditched the hobby last Saturday....but taping the Sunday eve "Kummerbuben" show helped all lot ....

SF

[2manyrocks]

A surge current could have damaged the PFA, or there could be a cable failure.

It's practically impossible to damage capsules with small-signal electricity.  From an electrical point of view they are very small value air-gap capacitors with a voltage tolerance that I imagine well exceeds 100V.

Is there a way for Swordfish to test the 70d to see if there is a surge current that would have done this?  Since phantom power is controlled by the menu on the 70d instead of a physical switch, other 70d users might very well want to know if there's a surge that would damage their active cables or know how to test to be sure there isn't a problem.     

[swordfish]

Not really.  It's not likely that a surge current large enough to damage a PFA would occur with phantom switching or even with hotpatching (it is designed to tolerate that).  Surge damage is more likely to occur at the PFA input if the polarization wire gets crossed with another lead.  And we don't even know that a surge was the cause of the failure, or even if the PFA has failed.

2nd that...

Since I have two active cables I will test the active cable once more to assure it is not working

MK41 - active cable straight out - TB - Sony M10 --> I had no levels at all

Mk41 - active cable side out - I had not matter at all and taped a show on Sunday...

I will report back.

SF

[swordfish]

Okay, checked the actives andsurprise they seem to be fine...can't tell...the conccetion between the TB and the plug is real tight and I damaged the plug once when I disconnected the cable from the TB...

Maybe the plug wasn't in all the way...after all that fiddling with the PA...can't say...

So everybody please relax, I am sorry and feel a bit ashamed.

I will do some field testing coming Monday and open tape the Alabama Shakes....after that show I will know more..give it some time and I will test the PFA in the lineage with the DR70 again and report back...

SF

[2manyrocks]

Are PFAs or active cable setups more susceptible to surge damage than microphone bodies? 

[F.O.Bean]

Glad everything got worked out I have run my mk4>kcy>pfa>70D for over 40 sets, and the only time I had anything happen, was a card the 70D doesn't like after running out of space. My fault though. I forgot to test that card with the 70D and just assumed it would work. I'm about to order a larger card right now that I KNOW will work so I have enough space for 4 channels at a festie, without having to swap cards!

But I must admit, I am really liking my mk4>pfa>70d sound. For a $200 deck that has FOUR great sounding preamps and a recorder built in, and the size it is, well, its a damn steal!!! Even if I was only running 2 channels, Id get one just for its preamps for an all-in-one I know I fluff the hell out of stuff I run, but this deck is a no brainer IMO! And you get SF11 with it. Icing on the cake lol

[swordfish]

I would test the PFAs at home again before field use.  It also helps to have a multimeter so you can check voltages on the input pins - be careful doing that however as I mentioned you don't want to short a polarization lead to a signal input lead.

For sure I will test the setup before field use, but I am not in the mood to do so at the moment...give it a weekend or two...but I will report back...let the nerves calm down..

I will use the acitve Naiant AKG/PFA setup....with the test...

SF

[it-goes-to-eleven]

Glad things seemed to have magically healed themselves. For those who don't know, swordfish is in Europe so the logistics are more complicated.

Nothing quite like that sinking feeling immediately before a gig when you realize you don't have levels at the recorder and you have no idea why.

[F.O.Bean]

Nothing quite like that sinking feeling immediately before a gig when you realize you don't have levels at the recorder and you have no idea why.

Worst. Feeling. Ever.

[it-goes-to-eleven]

I was once walking to a Tom Waits show with the 722. I had a great seat, the weather was great, it was sunny out. I was all geared up and really excited. Tom Waits! I was recording a lot of gigs at that time, so there wasn't much thought required. As I neared the venue and did my final check I realized I didn't have any levels on the 722. Given the simplicty of my rig - KC5's > cmc6 > 722, and the two independent signal paths (with no front end preamp), there wasn't much that could go wrong.  The cables involved were XLR's and they were well-seated. So, panic!

After a couple minutes that seemed like an hour, I realized the problem. On the gig prior I had experimented with a low gain external preamp. That required more gain on the 722 than was available in line-in mode. So I had run in mic-in mode to supplement the gain. That meant I had used the menu to disable phantom power, a workflow I just don't do. So, enable phantom, confirm levels, and calm down. The 722 does have a phantom indicating LED, but I always had those taped over.