Toslink vs 75ohm Coaxial digital cable for Music

Damn.. I think I need to get this through mine mind. All the reference info that can be found in the web on this topic is close to 1 decade ago.. and ppl has seem forgotten Toslink is in fact something of a dark horse.

Exception: Dont talk about BNC, AES/EBU.. I think these 2 are of different league.

So any of you guys find toslink far more superior compare to similar price digital cable?

And anyone has compared the TCI cobra with the vDH Octocoupler?

Toslink is the worst digital interface because it involves conversion from electric pulses to light and then back again. As you would expect, the senders and receivers are usually very cheap devices. The jitter measurements are noticably higher than Coaxial. Avoid!

one of the reason why a lot of people find toslink not as good as 75ohm coaxial is that the Toslink optical transmitter/receiver used is usually of the low quality type. This contributes to jitter.

It looks something like this
http://my.element14.com/toshiba/totx147pl/transmitter-fibre-optic/dp/1225776

Maybe you could do some research and change the transmitter and receiver with a high quality one. Make sure to match a suitable one with the correct electrical characteristics though.

It would have the advantage of electrical isolation, no impedance mismatch of the 75ohms coaxial, RFI immunity.

I've never done this, so you need to do your own research.

Use "glass" toslink cable rather than plastic

Good article to read below
http://www.6moons.com/audioreviews/toslink/toslink_2.html

Hi Wong KK,
I see.. but that doesnt really happen at my case, the toslink still reign supreme over the coaxial... though I never try any RM1k plus punya digital cable. Toslink basically has more air and body, plus more details over the coaxial.

Have you done a simple A/B comparison between them?

Hi Carz,

the 6moon page... refer many times already.. basically it is a bit old, since digital age very quickly nowadays.

wongkk wrote:Toslink is the worst digital interface because it involves conversion from electric pulses to light and then back again. As you would expect, the senders and receivers are usually very cheap devices. The jitter measurements are noticably higher than Coaxial. Avoid!

toslink has received bad press for a long time cos the earlier versions used low-quality optical transmitter/receiver (like what carz said).
however, today's toslink connections have improved, otherwise why would respected companies like benchmark and weiss offer toslink?

carz wrote:

Use "glass" toslink cable rather than plastic

today's medical-grade plastic optical fibre sounds as good as glass ones.

i use a benchmark and i use a qed toslink cable to connect from cd transport to the dac. i find no difference between the toslink and the coax (using mit terminator 3).

Hi sflam,
That's assuring, Thanks. I was thinking of getting some good digital cable to try out this.. but I takut being disappointed.

Have you try other Toslink cable? vDH Octocoupler 2 doesnt inform anything that this is the glass version, although it was clearly stated in their previous version.

IMO, I suspect Coaxial 75 ohm cable injects more of their own character into the final music reproduction because of their weakness (Or should I consider strength as well?) to be influenced by EMI and all the electrical related problems. That's why this metal cable is surprisingly tweakable.

adrian4454 wrote:

Have you try other Toslink cable?

i hv tried a cheap thin plastic cable and the qed beat it. the qed is the new breed of toslink cables that use medical-grade plastic optical fibre.

i am not sure if vdh optocoupler 2 is glass, but i know that wireworld and audioquest still make glass toslink cables.

Hi adrian, I have to admit that I have not looked at TOSlink for a very long time since I upgraded to my current one box SACD player. I did use TOSLink to connect my DVD player to my receiver, but got rid of that in favour of HDMI.

after Carz had me linked to Farnell website on Toslink Optical transmitter, then I realized a potential "upgrade".. had my hand and ass itched for a while until I finally decided to do this:

Change theFiber Optic Transmitter of my CD player(Marantz CD63Ki). Reason why:
- This transmitter light on since day 1 until now, no matter u use or dont use it (Generally apply to my unit). So it basically remained on for 10~12 years. Itchy ass syndrome telling me.. the brigthness of light isnt as good as it was.
- There is replacement out there! of the same brand "Sharp". And it has improved spec. Data Transfer rate 8Mbps now has 13.2Mbps(well, it doesnt matter when this fellow only run 16bits of 44.4khz), Jitter max at 30ns now down to 15ns, Pulse width distortion 30ns now down to 15ns on the new one!

So spec wise it is indeed an improvement. Generally the end result I will consider as psychoacoustic. Reason is I havent been listening my system quite some time and been swapping external DAC punya chip; and was doing at midnight... can't really test the system until next morning. So you need to take my audible improvement with a pitch of salt. Micro details seem to improve and seems to hear more recording distortion~~

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adrian4454,
Nice to see that you have experimented. I suggest that you research around and try to find the BEST toslink transmitter and receiver there is, and use it.

You need to also change the "receiver side" TOSLINK too to get the best jitter reduction.

Use a good glass or medical grade plastic optical cable to get the optimum results.

>>>>> And it has improved spec. Data Transfer rate 8Mbps now has 13.2Mbps(well, it doesnt matter when this fellow only run 16bits of 44.4khz), <<<<

YES, the speed does matter and a lot !!!

Which model of Sharp Toslink are you using ?

The SONY SCD-1 (circa 1999) uses Sharp GP1F32T

Make sure when swapping out the Toslink Transmitter/Receiver, that the electrical characteristics are compatible.

Low grade Toslink transmitter/receiver introduces a lot of jitter

Haha Carz, Thanks for the encouragement. If it weren't u I would not have thought of this.

Frankly, it is the only matching kind I can find. I dont see any other better quality one in Farnell; although Toshiba did offer higher cost one, but the spec is does not tell about jitter reading, and the pin layout is totally different.

Marantz CD63Ki use Sharp GP1F32T(Obviously cannot buy the same anymore, it is obsolete). I change it to Sharp GP1FAV50TK0F.

The receiver end is quite current, so I just leave it... I suspect it is a Toshiba unit. As I dont have the Service manual to find out. DAC is Audio GD DAC19 Mk3.

Which brand of Toslink cable is glass? I only know the Wireworld Super Nova 6 is... the rest.. dont dare to write in their brochure..

I believe plastic optic, no matter how good they are, will deteriorate when time goes by. Anyway, I am using the TCI Coral now.. cheap cheap one. But still outshine any Coaxial version I tried.

>>>>Marantz CD63Ki use Sharp GP1F32T(Obviously cannot buy the same anymore, it is obsolete). I change it to Sharp GP1FAV50TK0F <<<

So the SONY SCD-1 toslink transmitter is not the best now, judging by the specs.

>>>>The receiver end is quite current, so I just leave it... I suspect it is a Toshiba unit. As I dont have the Service manual to find out. DAC is Audio GD DAC19 Mk3

It is not a matter of being current. There are still current Toslink receivers that are poor in specs, and it will not do you much good to just change one side. You will still suffer slow rise time and jitter on receiver end. I suggest you research and change the one on the Audio GD DAC19 Mk3

Hi Carz.. dont mind recommend other brands of the transmitter/receiver or where to find them? Thanks.

Try researching what SONY SCD-XA5400ES is using. This is the latest/current model and reputedly one of the best Sony SACD/CD player

adrian,
Toshiba TORX147LF RECEIVER. Reputed to be good

http://my.element14.com/jsp/search/browse.jsp;jsessionid=E34M5CZQJPIEACWNBBSRFWI?N=0&Ntk=gensearch_001&Ntt=Torx147&Ntx=mode+matchallpartial&suggestions=false&ref=globalsearch&_requestid=409682

It is offered as an option on Buffalo DAC
http://www.twistedpearaudio.com/digital/torx.aspx

Have you researched SHARP and TOSHIBA complete catalogue, and find out what is the BEST they have ? Maybe their websites ?

Hi Carz,
Do not have the catalogue, more like the spec sheet. Ya I've done the comparison before. The only thing that show Toshiba better is the higher data rate. 15Mbps compare to Sharp 13.2Mbps. Other than that, it is very close. And Toshiba one doesnt have much of distortion and jitter data.

I suspect what is inside my Audio GD is a Toshiba unit. Base on the external shape. So I will let this rest. Thanks.

It is a waste if you mod the transmitter side without modding the receiver side as well. will not be optimizing it.

Toshiba TORX147LF RECEIVER Pulse width distortion is 15ns. The jitter specs will not be far behind. These specs are more important than the data rate.

Toshiba has many model of toslink receiver, some are not so good. specs will depend on what is use on Audio GD DAC19 Mk3. you could write to manufacturer to ask

I think a decent Toslink connection could possibly outdo a RCA based coaxial connection. I don't have much regard for RCA based coaxial digital connections and don't even think a RCA based coaxial connection can be called 75ohms anyway. Why? Because the RCA connectors and sockets are not true 75ohms and this causes signal reflections which results in jitter. Sure there are indeed manufacturers like WBT who make 75ohm RCA connectors such as their NexGen series but these are very expensive and cheaper BNC connectors perform better. Like why spend RM80K to make your mother's station wagon perform like a sports car when you can buy a sports car for RM60K.

Adrian, I know you would prefer not to discuss BNC but personally i'd go for the coaxial connection but i'll change the RCA jacks on the equipment to BNC and go for a pure 75Ohm BNC connection from source to processor. This should be much cheaper than modifying your Toslink sender/receiver and should sound superior to Toslink I think.

Just my 2 cents ya

Hi Carz,
Thanks. But I do make peace with this now~

Hi Bimmerman,
You are right on the 75Ohm impedance thing.. BNC not only solve this problem, it reduce the "different material" contact further, which also make the signal "purer".

The RCA and Optical digital out is fed on the same signal path from the Chipset from the Player (At least in the Service manual I can see from the Marantz CD63ki). The RCA Digital out has a pulse transformer in place. suspect it is to reduce distortion or eliminate other unnecessary voltage signal leaking out.

If you ask me, Optical is the best bang for buck in term of pure data transmission over all the voltage signal version. It virtually has no EMI distortion to speak of in its transmission process. This alone has made the RCA, BNC, and even the AES/EBU trying very hard keep up.

Maybe you should give it another try, this time with a new Toslink cable you can get hold of; if your DAC is very current. ~~

I can't make a fair comparison on this as I dont own any expensive or decent Digital Coaxial cable... So you can be my eye and ear on this~

Adrian,

You sure do offer up some valid points on Toslink but while its free from RFI/EMI, it has its own set of problems too. Just for your info, a good digital coaxial cable is a lot cheaper than you think. Withdraw RM500, go for a meal with steak, soup and salad and you can still buy that coaxial cable with the change. That Chris Sommovigo cable is one of them bargains. Just FYI.

Having said that, I was happily and blisfully married to Toslink for like almost 2 decades from the 1980s.

Back then I had a Pioneer Laserdisk player feeding my Audio Alchemy DAC via Toslink and it made good good music daily and nightly. Not only that, when moviephile folks brought their LDs over to my place for movie night, they were just dumbfounded as to how my conceptually inferior 2 channel movie soundtrack was just so much more engaging and pleasing to the ear compared to their then state of the art Dolby ProLogic multichannel systems. After that I had a hard time trying to get rid of a bunch of burly men hogging my living room on weekends and dropping popcorn everywhere.

Today I own a Swiss Army Knife of a DAC which accepts almost all types of digital connections (except I2S) and it allows me the small luxury of auditioning many types of connections. I even tried glass optical via AT&T ST optical and it was simply astounding! Then I tried AES/EBU and it was just as amazing. In the end I settled for BNC. But not because BNC was superior to the former two mind you. They all painted beautiful soundscapes and none was superior to the other. I chose BNC because it suited my tastes better.

Now back to RCA coaxial. DHLabs sells in spools a budget price/giant killing cable called the D-75. I doubt my own soldering skills so I hired a local soldermeister using expensive Siltech exotic metallurgy solder and a pair of expensive WBT RCA connectors which they claim are true 75 ohms. And how did it sound? Short answer...Truly bad! So I chopped them off and crimped on a pair of cheap Neutrik BNC connectors in place (same cable) and the difference was night and day!!! I kid you not!!!

Now, I don't have an expensive Toslink cable in hand but after searching through my storeroom, I found my old Toslink from my Laserdisk player days. Still looks like new more than 25 years on... Anyway, I tried it last night and how did it sound......

Roll the drums.....

Better than the RCA in areas, inferior in other areas but it has nothing on my current BNC configuration.

As BNC connections used to be mostly used in industrial/commercial applications (display/terminals in mainframes used to use BNC connections), it could be you are simply benefiting from down-to-earth, straight-forward, true industrial grade connection components. I.e the components and implementations are consistent in quality and there are no inconsistency matches, something that can be frustratingly common in the consumer environment.

BNC connectors are true 75 ohms (as oppose RCA) so it reduces signal reflection. Signal reflection occurs in areas where there is a difference in impedance.

But be careful, BNC connector are available in 75 ohms and 50 ohms type. Most Pasar Road vendor will tell you the wrong thing when you ask.

Wah Bimmerman, Respect! I didnt know you are this "in" on the digital cable tweak"ary".

hmm a 20 years old Toslink... If it is glass version it woulod still be ok provided the terminated end is capped away from dust or scratch; but if it is plastic type.. hmm I believe it does degrade a bit even if it is well maintained.

The terminated end of the toslink truly worth paying attention to because dust or finger print can easily tainted it. Furthermore, the newer generation pay more attention on the terminated end to ensure the transmitted light is not smeared due to less perfect dome shaping.

Anyway, I never tried before a set meal of RM500... my toslink cable only cost me RM200++ only So the so called decent Digital cable still consider as a premium for me.

Anyway, Thanks for sharing guys!

Uncle Wong, the WBT RCA connectors are so well made I don't think there is much quality variance in each unit or from batch to batch. Every piece is even serial numbered and I got 2 pieces with serial numbers just one digit apart. Furthermore, these are so finely made, you could wear them as a fashion statement at the KL fashion week and not look out of place.

Carz, Bingo! My feeling is that using 75 Ohm BNC connectors reduce if not eradicate signal reflection as i've said earlier and this I believe is why BNC sounds better than RCA digital coaxial connections.

adrian4454 wrote:Wah Bimmerman, Respect! I didnt know you are this "in" on the digital cable tweak"ary".

hmm a 20 years old Toslink... If it is glass version it woulod still be ok provided the terminated end is capped away from dust or scratch; but if it is plastic type.. hmm I believe it does degrade a bit even if it is well maintained.

The terminated end of the toslink truly worth paying attention to because dust or finger print can easily tainted it. Furthermore, the newer generation pay more attention on the terminated end to ensure the transmitted light is not smeared due to less perfect dome shaping.

Anyway, I never tried before a set meal of RM500... my toslink cable only cost me RM200++ only So the so called decent Digital cable still consider as a premium for me.

Anyway, Thanks for sharing guys!

No lah Adrian, i'm just learning as I go along lah.

I've also never had a RM500 meal before but RM25 set meal, yes, at the Bavarian Beerhaus. The balance RM475 buys you one heckova digital coaxial cable. The meal will leave you quite satisfied and the cable... more so!

The DHLabs D-75 on the other hand will afford you a 8 course chinese dinner for 4 with the change going to the cable. A pair of true 75 Ohm BNC connectors and 1.2 meters of D-75 for aroundRM200++.

If your source and DAC supports AT&T ST Optical, I think it's even cheaper and you get to polish both ends of the glass optic cable yourself, as meticulously as you wish for less than RM200 per pair. But problem is you'll have to buy 1 pair so find a buddy who wants to try ST glass optical and split the cost.

bimmerman,
how much was the cost the the DHLabs D-75 cable per meters ? Where did you buy it ?

Have anyone tried Audioquest HS6-A 75 ohm coaxial cables (avalable loose for DIY), triple shield, good to 3GHz. RM20/m

You know how to terminate and polish AT&T ST Optical

Well implement 75 ohms SPDIF transmission can be better than optical, provided the impedance match from transmitting pcb way up to the receiving pcb and spdif receiver chip (on the DAC side) is well implemented.

Optical has the disadvantage of having to convert the electical signal to light and then changing that back.

If you DIY your 75 ohms SPDIF cable, make sure it is about 1.5 meters to minimise the detrimental effects if reflections.
http://www.positive-feedback.com/Issue14/spdif.htm

It is of course best to change the connectors on the CD-Player and DAC to true 75 ohms BNC. Use branded good quality ones like neutrik or similar, it won't be very expensive.

Interesting topic, I have a similar small project not too long ago. I tried 3 players; Philips cd160, Philips cd473 and Sony 338esd. Using different coax cable give different result. Than I saw this article http://www.jacquesstompboxes.com/oscillo.htm

I direct tap pin14 from Philips 7220 chip, it give me great result. I do the same to Sony with dotx signal and great result too. Than I change different coax cable, it is less influence the sound as compare to previous test. The finding is same as above article. Investing in good cable is good but if you can direct tap the spdif signal it will give you better result.

Many years ago, I managed to beg my colleague, a hardware engineer, to pass me a short piece of connector from the core of a RM30million mainframe machine that was being repaired. These type of connectors are used to transmit a lot of data at extremely high speed and at extreme reliability (you can't have hardware failure or transmission errors in a bank). I had my friend from 'that' shop terminate it into RCA/SPDIF for me using high quality WBT plugs. It gave very good results when used in my California Audio Labs transport/DAC last time. So I can understand how the things you guys did and are discussing can easily deliver the exceptional results that have been reported.

adrian4454 wrote:I am using the TCI Coral now.. cheap cheap one. But still outshine any Coaxial version I tried.

Out of curiosity I got one for myself also (TCI Coral optical) and really surprised how good the sound is compared to my other coaxial cable. Detail and transparent. The feeling reminds me the first time I tried Kimber Interconnect. I always thought coaxial sounded better than optical but no longer

A little bit off topic, I tried a plastic (Sony Brand) minitoslink - toslink cable connecting my MacBook to Benchmark DAC1 (non USB). To my surprise, the DAC did not acknowledge the connection. It is as if the toslink is not connected at all. The cable is very old abd given to me free by my dealer when I asked him about the minitoslink adapter. My SB3 died this week, that's why I am experimenting different ways to connect my MB to my rig.

A quick check at the DAC of the toslink does show a dim red light. Is it bcos of the deteriorating plastic in the cable, that the DAC does not recognise it as a source?

My experiment ended in dissapointment. I would now need to try out the adapter with a new toslink or just get a usb-spdif converter.

Regards,

Chee Lun

I think you need USB connection for your Mac to detect the DAC. I connect my HTPC via optical to a DAC and the PC never detect it but I got sound when I bitstream thru SPDIF.

When I connect via USB immediately PC detect the DAC and business as usual but the sound via optical is way superior compared thru USB.

Yes Cheelun, you are right. If the light at the receiving end is opaque or not bright; it will not function at all.

Yes Arremie, I have the same gain too. Now been having dream of a better glass optic version.. hai.. when will this ever end?

adrian,
GLASS cable, polished to a 1 micron optical finish
http://www.lifatec.com/toslink2.html

Our fibers are manufactured at our State of the Art modern facility in Germany
http://www.lifatec.de/produkte.php

Wah... very tempted. Thanks for the recommendation Carz..

U mention our fibers... hmm do you mean it is your company?

no not my company, it is cut and paste from lifatec website

see review below

http://www.computeraudiophile.com/content/Wireworld-Supernova-6-Glass-Toslink-Digital-Cable

Lifatec's Silflex 'v' Wireworld's Supernova 6

"I've done a home back to back of these in my system and found them to be both excellent cables. Before the ATV, which requires TOS>TOS i was using VDH optocoupler II in a 3.5mm MiniJack>TOS config.

All in all I'd put the cables in this order for sound quality:
1. Silflex Glass
2. Supernova 6
3. VDH Optocoupler II