Diy spdif cable.

[DragonMaster]

cable direction dependent.

There's diodes, or what? (Let's make you remember that wires are made out of a big stack of purified cooper, and there's no direction in that thing)

 

[fmak]

There's diodes, or what? (Let's make you remember that wires are made out of a big stack of purified cooper, and there's no direction in that thing)

---------------------------------------------------------------------------------
I have stopped postulating. Cable direction can be as important
and cable type. Purity of Cu does eem to come into it. The Japanese 8N stuff can sound ordinary.

Yes, the earth is flat.

 

[DragonMaster]

Try them with an Auto AB comparating switch. And what if you changed the direction of your mains wires to see if it sounds different?

 

[Jocko Homo]

You just had to mention directionality......

Yes, I have heard it, and it annoys me. I should be able to measure it, but all cables look like a bunch of squiggles on a TDR. Which squiggle dos what......I have no idea, but that must be it.

It better be it........!

Jocko

 

[pburke]

Who came up with 1.5 m??? The connectors are not the problem, and the worst sounding D/A box that I made had a 6" coax into it........

If they are in the same box...........there are ways around using a PLL to screw up the clock. That is the problem with SPDIF.

Jocko

Jocko - a followup on this because I just decided to add a USB interface to my DAC... and everything I can come up with is a USB to SPDIF chip or dongle type unit. Based on your comments it sounds like you wouldn't want to run SPDIF from one component to another without a nice long cable in between? But what if I kept the the lead length under something like 1 inch?

I'm talking using a PCM2902 or simlar chip to turn USB into SPDIF, then run a "cable" to the CS8412 in my DAC from that daughter card.

Am I looking at big problems here or is there a different logic between these chips than with real "cables"?


Peter

 

[Spoonfed]

Interesting thread.

I have also DIY my own Spiffy Diffy sorry SPDIF

Used RG6 quad shelded coax with full 'metal case' gold plated RCA's (the type with the sping bits... only sort that would fit RG6 that i could find )
The coax core has a very good contact in with the centre pin on the RCA..... solder was added only on the exposed side to keep in place.

I also have one of these http://www.eichmanncables.com/digital_cable/index.html
"proper" SPDIF cables i am trialing.

I "was" in the bits is bits camp with SPDIF..... i guess my previous receiver (as with seemgly many receivers) really do struggle in ablity to resolve such differences.

My new Panasonic XR45 on the other hand really does open ones eyes

The "home brew" vs "proper" SPDIF's do sound different. The thing is im not sure which is "right".... if that is even possible

The "proper"cable brings vocals a little bit more forward.... a little more full.... though perhaps a bit more "dry".
The "home brew" seems to have a bit more "air" with vocals staged a touch further back... and a little more "open" i think.
The "fall off" at the edge of vocals/etc seems to be a touch sharper with the "proper" cable.

i am really still quite suprised at the difference.... did not expect to hear such... esp as noticable as it can be on some tracks.

The thing is which is "right"????


The "proper" cable while having RCA's are "sort of" not RCA's with the outer "sheath" earth replaced by a "pin" extention of the cable..... this setup.. along with the "core" of the cable running full length inside the centre pin (even visable at the tip) perhaps goes as far as reducing the RCA's effects as discussed in this thread?
see http://www.eichmanncables.com/bullet_plug/index.html


But more importantly........ someone tell me if what im hearing from my "home brew" is better than the $120 AUD cable im near buying haha

 

[Geek]

Most lively and entertaining thread

Here, the ultimate digital cable/connector for you guys:
http://www.rfparts.com/coaxial/f4pnr.jpg



*runs away*

 

[pburke]

...
see http://www.eichmanncables.com/bullet_plug/index.html

[/B]

those bullets are great for analog signal cables (I use them exclusively in those positions) but comparing them with a standard Canare BNC connection on my DAC was a no-contest win for the BNC. The advantages of the low mass (unshielded) plugs/pings just don't seem to work very well in the 75-ohm digital cable position.

I think a nice long 5 foot+ Teflon Beldon coax cable (1694A) with BNCs on both ends, connecting to high-grade bnc jacks on both components is the reference to beat.

I still don't know what to do with short runs - coiling up a long wire inside the component doesn't seem to be a proper approach when you need a 1" spdif connection between two chips, but I can't find much of an answer on this. I suppose I just have to build it and try it...

Peter

 

[Dr.H]

My 2c

Tried 1695a as well as some other belden cable and must say that for SPDIF, 1695a is rellay good.

Comparisons were made against the following:

Monster M1000: Monster sounded bright, edgy, digital

Mark Levinson MDC 1: This was compared with 1695a on the following system: ML Reference DAC, Reference Transport, Reference pre-amp and some big ML monoblocks (not reference) with the B&W Nautilus Signature.

The MDC-1 was marginally better in that system than the FREE (got samples) 1695a. Even the hifi sales guy had to admit to this.

Worth trying.

 

[Dr.H]

A comparison with the Illuminati D-60

http://www.audioasylum.com/audio/cables/messages/28380.html

 

[Calamaro]

All that said, which factors affect SPDIF digital cable quality?

1. impedance?
2. connectors?
3. lenght?
4. conductor material?
5. ???

I've read that copper clad steel -now frequently used in coaxial cables- is affected by skin effect as signal travel on copper wire surface avoiding steel center wire. Is skin effect a problem also for digital transmission?

Found elsewhere on the net someone talking about unshielded digital cables based on same old cat5 (wrong impedance, I know, but he looks so happy that I wonder if...). He's quoting a 'less is more' approch by 47 Lab (Ota cables).

 

[Guido Tent]

There's diodes, or what? (Let's make you remember that wires are made out of a big stack of purified cooper, and there's no direction in that thing)

since you are transferring energy from source to DAC, there IS a direction

best

 

[Crankshaft]

When we get zero-loss cables and interfaces there will be no directionality to debate.

 

[Speedskater]

Most of this thread is thirteen years old!

 

[MINUX75]

1) a minimum lenght
2) a minimum picoFarad between the two wires
3) a minimum contact. Beware contacts hiden, Inside connectors.
4) a minimum noise aroud the cable. (smps)

to reduce capacity between the two wires i prefer unshield câble.

 

[Gusser]

SPDIF is the same bandwidth as an NTSC analog video signal. Therefore the engineers who developed the SPDIF standard utilized the same electrical interface. Up to 1 volt at 75ohms.

So just use a 75ohm video cable. It's really that simple. For short distances under 6 feet, even a cheap audio cable will work most times.

People without technical backgrounds seem to get all worked up over SPDIF cables. It's very simple. Just use what was intended and skip the audiophile magazine dribble.

 

[DF96]

1) a minimum lenght
2) a minimum picoFarad between the two wires
3) a minimum contact. Beware contacts hiden, Inside connectors.
4) a minimum noise aroud the cable. (smps)

to reduce capacity between the two wires i prefer unshield câble.

Five items of advice; all unhelpful, some seriously so.

1) length does not matter, if the right cable is used
2) it is vital that the capacitance is not minimised, as the cable must be 75 ohm characteristic impedance
3) any reasonable contact material will do
4) if reasonably good cable is used then external interference will not be a problem, as SPDIF is quite robust

Unshielded cable is not 75 ohm coax so is definitely the wrong cable which in the worst case will lead to data errors, but even in better cases will increase jitter.

People without technical backgrounds seem to get all worked up over SPDIF cables.

People feel the need to 'improve' their systems. For those who don't understand circuits and can't solder, swapping cables is about the only thing they can do so they convince each other that this is a worthwhile way to pass the time.

 

[cteleake]

I built Thorsten Loesch's X-1.5 interconnects, a trust me, they sound lean and 'right'.

 

[DF96]

That cable (intended as an analogue interconnect) happens to have about the right characteristic impedance for SPDIF, but it appears to be an unshielded twisted pair so quite unsuitable for any unbalanced connection whether analogue or digital. You may be lucky and not seriously degrade the signal, or you may suffer interference (or radiate it).

The fact that bad cables (no matter how expensive or carefully DIYed) can work for SPDIF shows how well-engineered SPDIF is, and also shows how unnecessary it is to use expensive or DIY cables.