BNC Word Clock cables

[snicka]

I am looking for some BNC cables for Word Clock connections. I have seen BNC Broadcast cables, BNC Digital Coax cables and BNC video cables.

Will any of them work, or do I need to look for a specific kind of BNC cable?

Thanks.

[m2]

The BNC broadcast cables and the video cables are probably the same deal. needs to be anything that will properly carry a 75ohm signal. Not sure what a 'Digital Coax' cable with a BNC is supposed to be.[?] But it sounds expensive enough to get the job done! I'd go with that! See this link from Apogee:

http://www.apogeedigital.com/products/bigben.php

Then click on cables and connectors and then click on the BNC connector to see a description of their cable for the job.

Good luck !

[snicka]

Thanks for the reply.

I did look at the Apogee cables at Sweetwater and they are pricey.

I'm not sure what makes them better than other ones I have seen by Hosa & Canare for about a third of the cost.

[PhireAlly]

Radio Shack has low loss 75 ohm BNC for $7.99, thats what I use without any clocking issues.
Good Luck

PhireAlly

[BradLyons]

There is a difference between a Video BNC cable and one designed for Word Clock, there is certainly a difference in price too. I do advanced clocking and I can assure you from experience, you can experience diverse issues with using cheap cable. To better understand why you should only buy quality cable, you need to really understand what jitter is. In the analog domain, talking cable, there is also going to be interference or "noise" that is introduced to the cable. This is why we use balanced runs, where there is a positive and a negative and at the end of that cable noise is cancelled out. The question becomes "how much noise do you wish to keep out", which is why you buy high-grade cable for better sound. But in the digital world, noise is "jitter" which causes audio glitches which can be so severe you're getting drop out and loss of audio clock. There is a myth that digital is digital, and that's not true.

I'll walk you through my setup to help further explain.... My home studio is configured as follows:

(1) Sweetwater Creation Station Rack PC running a Digidesign ProToolsHD Accel system.

(1) PC Tower running GigaStudio feeding 8-channels of TDIF from a Tascam PCI-822 card into the TDIF port of a Digidesign 192 I/O interface (this is going to be upgraded to a 2408mk3).

(1) Focusrite ISA428 w/ADC card feeding ADAT Optical into a Digidesign 192 Digital I/O.

(3) Focusrite Liquid Channels feeding AES/EBU into a Digidesign 192 Digital I/O

Sooooo I have the following all connected digitally

(1) Digidesign 192 I/O
(1) Digidesign 192 Digital I/O
(1) Tascam PCI-822 (about to be a 2408mk3)
(1) Focusrite ISA428 w/ADC Card
(3) Focusrite Liquid Channels
(1) Apogee Big Ben feeding a direct clock to everything (with a catch...I'll explain later)

The problem here is you can only have one master clock, but there are many devices to be connected as a slave. None of these products provide a stable, complex master clock that can be dependable over time. If you chain the clock, you're degrading the validity of the digital source and therefore introducing jitter or drop-out...BAD! I have everything locked to an Apogee Big Ben, I tried using cheap BNC cable and over the course of a few days I would have an error on ProTools that clock has lost its source. I just click okay and it's fine, but that's going to cause a problem in a session. With my expensive Apogee Cable, I've yet to get as much as a single drop-out and in fact...my audio quality is better. A GREAT MASTER CLOCK will improve the audio quality of nearly every product, because nearly every product doesn't have the same level of internal clock as something like a BigBen therefore allowing the product to function to the level it was intended to do so. BUT...a cheap cable can take away this quality, too.

Now the problem I have is I just added a Third Focusrite Liquid Channel, I'm connecting this digitally into AES/EBU but I have a problem.... I'm out of clock sends from the BigBen. So I tried a T-connector, it's okay... Apogee says this is fine, I'd like to know why because I have gotten drop-out once in a great while. To me if there is a single drop-out, it's not ideal. SO I'm having to go analog into the A/D of the 192 I/O at this point which is perfectly fine...but I will need a clock distribution I/O to clock this third Liquid. I have plans of getting a fourth unit and some additional digital gear to which I'll need more clock sends, so this is an important consideration. I've tried clock distributors with various success. THE BIG PROBLEM WITH CLOCK DISTRIBUTION is you're re-amplifying the source, that can be just as bad as using cheap cable and in some cases worse! In other words, I'm going to need a second Big Ben I've even tried using other cheaper clocks to re-distribute clock out of my ISA428 and got drop-out.

In a smaller setup, you may not experience the real problems... but when you push that envelope the slightest little issue because the biggest problem. I'm monitoring everything through a pair of ADAM AUDIO P33A 3-way active monitors, these things are BRUTALLY accurate....their frequency response is 35Hz to 35kHz. My room is highly-tuned, I can hear the slightest thing. In fact I once was tracking a Taylor 914 guitar through a pair of Earthworks QTC1's in stereo and was getting some nasty phase--my right channel sounded dark and not nearly as clean as the left channel. I discovered that, in taking some gear out to record a live concert I mis-wired the outputs of one of my pres with an XLR Female to TRS male (out of pre to a patchbay) with a cheap cable I used in my live-sound system. So I decided to try a test....to make sure it wasn't just a bad cable, I bought (2) of the same cables and experienced the same results. I patched in my Monster cable and the probem went away. That was a significant eye-opener for me, I've spent a great deal of energy and expense into my studio wiring from the recording rooms to the patchbays to the pres to the converters and back out to the monitors that something that small can be detected. Unfortunately, this means that I can NOT cut a single corner in my audio cables either digital or analog.

[qo]

I'm gonna have to disagree with Brad on a couple things.

First, coloration due to audio cables, especially under 30 feet or so is simply a myth. As long as you have decent cable, that's not damaged, you're not going to hear a difference. The difference in impedance, and in shield quality, between, say, Monster cable, and e.g. Belden, of the same grade is nadda when measuring 30 feet. If you have longer runs then, sure, this starts to matter. At that point, go with a company that doesn't instigate lawsuits at the drop of a hat against mom and pop shops that have nothing to do with the cable business. Take Dave Derr's (Empirical Labs founder) advice and don't believe cable hype. The cables that run from my mixer to my near fields are 3 feet long. I challenge ANYONE to A/B Monster against Belden, Mogami, Canere, or any other cable using any monitors they chose. If they can guess correctly 10 out of 10 times, I'll be converted into a believer. Frankly, I don't think anyone would pass this test with 30 foot runs. And, even if they can, they represent a very small percentage of the population, so why worry about it? FUD is very easy to accomplish in the audio industry.

I encourage you to read THIS for more info. A quote from this link (if you read the link, you see that "audio scams" is in the context of discussing cable):

Some audio scams are so blatant you wonder how anyone could fall for them, like a replacement volume control knob that sells for $485. The ad copy proclaims, "The new knobs are custom made with beech wood and bronze ••¦ How can this make a difference??? Well, hearing is believing as we always say. The sound becomes much more open and free flowing with a nice improvement in resolution. Dynamics are better and overall naturalness is improved." Yes, I bet that's just what they always say.

Second, daisy-chaining Word Clock, if done right (i.e. don't terminate things in the middle of the chain, properly terminate at the end, and use solid connectors) works just fine. Countless studios do this with no problems at all. Word clock was engineered with daisy chaining in mind since there where no multi-out word clocks like Big Ben when word clock was developed.

But in the digital world, noise is "jitter"

Maybe I'm just reading this wrong, but noise is not jitter. Jitter is variance in the timing of the pulses that represent the word clock signal. As long as noise in the cable is lower than the receiver's sensitivity, it won't be misinterpreted as a clock pulse.

[qo]

Hey, for $30,000 you can have these speaker cables!

http://www.aurant.com/signaturefeature.php

And, here's that volume knob.

C'mon, pony up boys!

[epidot68]

Okay, I am a year late on this post but if I am reading for the first time, perhaps you are too.

I have used 75 ohm coax from Radio Shack - on clearance for $0.06 a foot!- with solderless BNC connectors to make custom length WC cables. (Never longer than 15 ft. in my case) I run these from my Big Ben to all my digital units and have never had drop out. The engineer who taught me to do this has 36 years experience in the recording industry and has some pretty good ears. We've heard no audio issues nor had "lock" issues.

Apogee recommends using 75 ohm terminating plugs where necessary, and it's a good idea to have some on hand when needed. Go to www.markertek.com to buy them at $4 per. You do need the "T" connector to use these, so have a few of those as well.

As for cables in general, the only difference I have seen is with microphone cables but the "mid-grade" Monster 500, or equivalent, works as well as the 1000 series. Of course this goes for the TRS cables coming out of a mic pre as well. It's all part of the mic signal chain. But, this is true for Microtech's, AKG's, etc. - not for a 57 - IMHO.

[PhireAlly]

I don't mean to prolong this thread anymore but I'm with "qo" on this.
I used to record a lot of my early stuff at Dave Derr's studio in NJ, at that time he was an Engineer/Designer at Eventide .... if menory serves me right , he was one of the designers of the H3000 Ultra Harmonizer, and so, given the success of his Distressor and Fatso .... it stands to reason that if Dave says "Don't believe the hype" then don't.

As Always
Good Luck.
PhireAlly

[qo]

One other thing to think about. Back in the 80's, before ethernet ran over twisted-pair, 10Mbit/sec ethernet ran over 50ohm coax cable (10base2, max length, 185 meters). And, you could string many hosts over the length of this cable (max 30, but I'd seen up to 150 in some of the LANs our department managed). Maintaining these sorts of LANs was no easy task, but they were built in compliance with existing ethernet specifications.

Ethernet back then used Manchester encoding which you can read about here. Bottom line is that the bit transitions on the wire ranged from 5 to 10Mb/s (usable bandwidth is still constant at 10Mb/s, if collisions are ignored).

So, now let's look at word clock. It's, what, 96Kbit/sec, max, in the real world (192Kb/s on Venus). In other words, it's over an order of magnitude less demanding than ethernet. Ethernet coax cable was (and is) dirt cheap. Granted, ethernet has built-in collision detection/avoidance with retransmissions possible, whereas the real-time nature of word-clock wouldn't allow this. But, just think about the HUGE difference in bit rates here. Then ask yourselves if you really need that high-priced word clock cable.