Jump to content

InstaSnake from ETS


Recommended Posts

I have always used 4-way snakes I built for doing insert car work with my CarCom system. I had several sections of multi-pair Mogami cable so that I could have a break at the hitch whether we were using a tow dolly or a process trailer. Each section of cable has of course 4 XLR connectors each end, so it meant disconnecting 4 connectors, re-connecting keeping the connections the same, and the Mogami cable was fairly large diameter making it difficult to run into the car interior.

The new snake using baluns CORRECTION: has no baluns from ETS works with a single shielded CAT5 cable. The cable is very thin and can be easily run into the car, the break at the hitch is now a single CAT5 coupler. I had to change out all the connectors with the units from ETS because they had really low quality Calrad-style XLR’s and no color coding. Now, with the new snake I can easily run 3 phantom powered microphones and the CarCom speaker and have an easy break at the trailer hitch.

post-1-130815086182_thumb.jpg

Link to post
Share on other sites
  • Replies 65
  • Created
  • Last Reply

Top Posters In This Topic

This sort of 4-way snake would be perfect for running the wireless quad box to the set or in those situations where the main cart is far from the set and you would like a 4-way Stage box on the set. This is a passive system, not to be confused with the big active CAT5 distribution systems that Richard Lightstone, Mark Ulano and others use.

Link to post
Share on other sites

Jeff,

I remember you posting the original link to ETS and the box that you show now. What is the model number or did you add the xlr cables yourself?

Answered my own question and here it is: http://www.ramelectronics.net/music-sound/cables-and-accessories/snakes/cat5-balunsnakes/pa202p/prodPA202P.html

ETS InstaSnake PA202P, Receive (4) Male XLR's with a 1.50 foot pigtail, to RJ45 jack, metal case. (About $145.00)

Thanks.

RL

Link to post
Share on other sites

Jeff,

I remember you posting the original link to ETS and the box that you show now. What is the model number or did you add the xlr cables yourself?

RL

They only had boxes without the pigtails when I first looked into ETS products. They later released a product with the pigtails which I thought would be much more useful. I did have to change out the connectors since they came with cheapie Calrad-style connectors. There was no real numbering or color coding either --- the boxes are labeled 1, 2, 3, 4 where the pigtails exit the box, but that's not sufficient. I also found out that the system does not work with the CAT5 cables I have already (made up by LSC with Neutricon connectors and flexible cable), cables that I use to feed video assist baluns. The InstaSnake requires shielded CAT5 cable if you want it to pass phantom power. ETS makes up cables also at half the cost of LSC so I ordered 3 x 25' cables to be used for car rigs. All in all the "system" is quite expensive, starting with the product from ETS, changing out the connectors, having proper shielded cables made and then adding in the Nuetricon couplers. At some point I will figure out what it all cost but I know already it is going to make the work a lot easier.

Link to post
Share on other sites

When you say shielded Cat 5, would that be Cat 5E (meaning enhanced) or Cat-6 which has 23 gauge copper wire versus 24 gauge for Cat 5E

Cat 5E Vs Cat 6

When comparing Cat 5E and Cat6, the main difference is in the transmission performance and extension of the available bandwidth; that is 100 MHz for Cat 5E and 200 MHz for Cat 6. This includes better insertion loss, near end crosstalk, return loss, and equal level far end crosstalk.

Due to its improved transmission performance and superior immunity from external noise, systems operating over Cat 6 cabling will have fewer errors when compared with systems operating over Cat 5E cabling. That is, systems using Cat 6 networks will have higher reliability than Cat 5E networks due to fewer re-transmissions of corrupted or lost data packets.

source: http://www.topbits.com/cat-6.html

RL

Link to post
Share on other sites

My first thought when seeing this is that Cat5/6 is okay for sending a courtesy signal to video village.  But... Doesn't sending a critical audio signal down a Cat5 cable defeat the purpose of having Star-Quad or any other balanced cable designed to reduce line noise?

Link to post
Share on other sites

When you say shielded Cat 5, would that be Cat 5E (meaning enhanced) or Cat-6 which has 23 gauge copper wire versus 24 gauge for Cat 5E

RL

I should know this, CAT5, CAT5e or CAT6 cable, but I'm not sure. From the information you have supplied it looks as if for this snake the cable should be the superior CAT6 and must of course be shielded cable. I will ask ETS what sort of cable they used.

Link to post
Share on other sites

My first thought when seeing this is that Cat5/6 is okay for sending a courtesy signal to video village.  But... Doesn't sending a critical audio signal down a Cat5 cable defeat the purpose of having Star-Quad or any other balanced cable designed to reduce line noise?

There are two issues that have concerned me regarding CAT5 system vs. standard mic cable (Canare StarQuad, etc.). One is the vulnerability to induced noise on the line, the problem we have when standard cable balanced lines run across high AC fields like HMI feeders, etc., and I have not yet tested this with the new snake. I have heard from others that the CAT5 cable used in this manner with the baluns at both ends, the six twisted pairs of conductors and a shield, offer as much immunity to induced noise as regular mic cable. The other issue is that of frequency response and cross talk. I have contacted several studios (mostly music) that have used the ETS gear to run stage boxes out to the floor from the control room and after making many critical measurements it is the conclusion that there is no penalty in frequency response. Cross talk has also been measured to be at least in the neighborhood of 102db down at the frequencies we are working at. I will also add that to my ear, there is absolutely no difference in sound quality from the microphone.

Link to post
Share on other sites

While we are on the topic of digital snakes, I just received a sample of a new Roland product that fits right in between the Aviom system and this ETS snake. It is the Roland S0808 digital snake. 8 in and 8 out, Phantom power, and external 12 v DC powering with either a 4pin for your battery or v-lock / NP1 battery.

Here is the link:

http://www.roland.com/products/en/S-0808/

Give me a call if you are local to LA and want to give it a spin.

(818) 980-9891 x302

Link to post
Share on other sites

That is a very slick labor-saving rig, and I agree, not just for trailer rigs.  When this topic came up here awhile back I thought there was some concern that the trafos in these things were not up to hifi movie audio standards--I thought that the Venerable Wolf objected to this setup on those grounds.  Are the trafos in these boxes ok, or was that found to not be an issue....?

Philip Perkins

Link to post
Share on other sites

Silly question but. How is phantom power getting through the ballen?

I open up a system that had the same specs as the InstraSnake and found nothing in it. I've modeled my snake on this and its worked great. Really good if your flying with it and need to keep your weight down.

Adam

Link to post
Share on other sites

Silly question but. How is phantom power getting through the ballen?

I open up a system that had the same specs as the InstraSnake and found nothing in it. I've modeled my snake on this and its worked great. Really good if your flying with it and need to keep your weight down.

Adam

As I have begun my testing of the ETS parts I started by opening up one of the steel boxes. There is definitely a transformer in there, mounted to a circuit board where all the connection have been made. There is quite a liberal quantity of silicone sealant covering the wiring and most of the transformer so I am not able to get any more info on the guts of this thing. I mentioned before that phantom power did not pass through the original CAT5 cable I had, cable which I have been using for video assist audio and video through Muxlab baluns. When I used shielded CAT5 (I don't know if that is CAT5e or CAT6) phantom power worked fine.

Link to post
Share on other sites

I ran some tests at Location Sound with help from Mike Paul on the ETS InstaSnake system. We ran frequency response test using a straight through XLR mic cable to the Audio Precision analyzer using the calibrated white noise and generating a frequency chart. We then ran the same test but this time running signal through the  InstaSnake. Comparing the two charts, there was no difference. So, my conclusion is that there is no degradation of the signal or frequency response penalty using the InstaSnake. I still need to do one more bit of testing on the vulnerability to induced noise on the CAT5e cable. So far, I have just done a very unscientific test by wrapping the CAT5e cable up in a bunch and wrapping a 50 foot 115 v AC stinger around the whole mess and listening for any hums. No problem with that test but I would like to test it up against an HMI feeder cable being powered from a generator. I may have to wait until I have a job.

Link to post
Share on other sites

I ran some tests at Location Sound with help from Mike Paul on the ETS InstaSnake system. We ran frequency response test using a straight through XLR mic cable to the Audio Precision analyzer using the calibrated white noise and generating a frequency chart. We then ran the same test but this time running signal through the  InstaSnake. Comparing the two charts, there was no difference. So, my conclusion is that there is no degradation of the signal or frequency response penalty using the InstaSnake. I still need to do one more bit of testing on the vulnerability to induced noise on the CAT5e cable. So far, I have just done a very unscientific test by wrapping the CAT5e cable up in a bunch and wrapping a 50 foot 115 v AC stinger around the whole mess and listening for any hums. No problem with that test but I would like to test it up against an HMI feeder cable being powered from a generator. I may have to wait until I have a job.

THANKS.  Real testing, at last!

Philip Perkins

Link to post
Share on other sites

...So far, I have just done a very unscientific test by wrapping the CAT5e cable up in a bunch and wrapping a 50 foot 115 v AC stinger around the whole mess and listening for any hums. No problem with that test but I would like to test it up against an HMI feeder cable being powered from a generator. I may have to wait until I have a job.

I'm sure you know (but just to double-check), you need to have current flowing through the A.C. cable for it to generate an electromagnetic field.  The more current through the coil, the stronger the field.

Fire up a couple of 10K HMIs and you'll be in business.

John B.

Link to post
Share on other sites

this is all I know:

  • http://wolfvid.com/datasheets/faq_cat5_cabeling_specs.pdf

    Its hard for me to comprehend this contradiction:

    the input transformers we have in  Coopers and SoundDevices are highly engineered $ 80-150 pieces of eclectic metals with sophisticated shields and extended low ends, and we use fancy twisted quad shielded cable, and now we are putting not one butr 2  pieces of  $ 5.00 Chinese junk in front of them....  .. ( is the world changing this fast??)
    Yuk  wolf

Link to post
Share on other sites

Wolf, I don't understand it either, but the test (and my ears) do not lie. I can't explain but I am confident enough in my real world conclusions to put this thing into service (as soon as I have a job where I will be able to use it).

-  Jeff Wexler

Link to post
Share on other sites

Wolf, I don't understand it either, but the test (and my ears) do not lie. I can't explain but I am confident enough in my real world conclusions to put this thing into service (as soon as I have a job where I will be able to use it).

-  Jeff Wexler

I do have a concern about the transformers saturating at low freqs--that would be harder to test for than freq sweeps....

Philip Perkins

Link to post
Share on other sites

I think CAT5 and baluns boxes are a cool trick, and I use them myself for video assist hookups (up to two video and two audio lines per single CAT5 cable). However, I am skeptical that such a system can be noise free with mic level signals, particularly around the electrics often found in insert car rigs. It is my understanding that data signals can tolerate more line noise than we would consider acceptable for analog audio signals. Granted, I am not fully familiar with baluns transformer design, but like Wolfe, I am also skeptical about audio fidelity. For balanced audio cables for mic level signals, most of us would only choose starquad cable, which dramatically reduces induced cable noise, and I don't think CAT5 cable (shielded or unshielded) has the same amount of noise cancelation properties as the starquad scheme.

When used for video assist connection (where using shielded CAT5 cable or unshielded), I've sometimes seen a bit of noise in the video and heard a bit in the audio that is perfectly acceptable for video monitoring, but would not be acceptable for a master recording. When that noise becomes an issue, it is usually solved by using good ol' 75 ohm coax.

Jeff, I hope it works with mic level signals in the real world. The system has sure been handy for video assist. Let us know.

Glen Trew

Link to post
Share on other sites

I think CAT5 and baluns boxes are a cool trick, and I use them myself for video assist hookups (up to two video and two audio lines per single CAT5 cable). However, I am skeptical that such a system can be noise free with mic level signals, particularly around the electrics often found in insert car rigs.

Glen Trew

I am just as skeptical and concerned as you are and will be quite surprised (pleasantly) if it all does work out. I am fairly confident now that there is no frequency response penalty with the InstaSnake. The big question is the susceptibility to induced noise on the cable --- this is of special concern specifically for my intended use of this snake for insert car work. As we all know, with insert car/camera car work, we are constantly trying to find all the annoying noises we discover, wondering whether it is a fan running in the car, dirty AC from the Camera car generator, induced noise on one of the mic cables that just got buried under a last minute light balast, etc. I will have to be completely sure that the CAT5e cable is at least as immune to these sorts of induced noises before I will use it on a movie.

Link to post
Share on other sites

from a purely technical standpoint, induced electromagnetic noise is hardly an issue in sending digital information, unless it rises to a level that obliterates the digital pulses. thus the wide successful implementation of cat5 (etc) for inexpensive, reliable digital signal transmission.

As these data cables are made up of multiple "twisted pairs", they also naturally (physics) reject induced common mode noises, and frequency response is so flat as to also be a non-issue.  remember that analog telephone systems have been successfully operating over miles of unshielded twisted pairs for decades! For many years I had great success moving audio around throughout a stadium (for radio broadcasts ) over unshielded twisted pairs, although I preferred to use line level signals. Just as we use RF preamplifiers to counteract coax loss, broadcasters routinely use line driver preamps (RTS was popular, before SD) in these applications.  BTW fibre optic is now replacing this all!

the physics of "star quad" type cables is to improve on the "twisted pair" by twisting together two separate "twisted pairs", and it works quite well.  shielding is a separate, measure to prevent interference from getting into the signal carrying wires, and drain off interferences to "ground".  various forms of shielding provide varying effectiveness.

Both shielding and twisting are involved in data transmission lines, but the interference is analog, and the effectiveness need only be enough to protect the data signals from being masked out, as the interfering signals are analog and not digital.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...