USB to Spdif Conversion or stick with Toslink

[Kato]

I hope this query hasn't been dealt with previously, but I am trying to determine the merits of using a usb to spdif converter.

 

For HD recordings (i.e., from HD Tracks), I'm currently using a MacBook (Amarra) --> mini Toslink plug --> Simaudio 300D.

 

I am quite impressed on some recordings, although I sometimes feel that it is missing some of the magic I experienced with the McIntosh SCD301 that I once had but sold as I wanted to move to a music server. I have read that the Toslink is subject to jitter (even though the DAC may deal well with this jitter I'd rather remove it altogether) and the USB section of the DAC is not worth dealing with (as indicated by Simaudio).

 

I'm wondering if the MacBook USB --> USB to Spdif converter --> DAC solution would provide any improvement in sound. I'm thinking of something like the Bel Canto or Musical Fidelity products (I'm sure that there are many others).

 

Any assistance (thoughts, cautionary tales, preferences, etc.) would be very much appreciated.

 

Many thanks in advance.

 

Kato

Vancouver

[esldude]

Yes, go USB/SPDIF converter route. MF is likely a better choice than Bel Canto. Want to make sure you get an asynchronous converter. The MF is not sure about the Bel Canto, but I don't think it is.

 

The Macbook does not have a low jitter toslink. You would benefit from going the USB route.

[got tinnitus]

+1.

 

I felt the optical from my MBP was painting everything with the same brush strokes: swapping to Halide's The Bridge bought back the magic.

 

The Bridge is limited to 96k but that's fine with me as most of my music is CD rips.

The big plus with The Bridge is it's all-in-one so no extra cables to buy.

[Raym87]

I went with the Stello U3.....way, way better than toslink.

[Maxxwire]

Kato- Not all optical Toslink cables are the same and neither do they have the same kind of filament. Common plastic fiber filament Toslink has a bandwidth of about 6 MHz and this is what has given Toslink such a bad reputation because it chokes out the harmonics of the 3.3 MHz fundamental which needs bandwidth out to 10X that of the fundamental on order to form a nice square wave.

 

Back in 2002 I bought an 30 MHz Bandwidth Audioquest Optilink 4 Glass Toslink cable which has the same Fused Silica Glass filament that they use in their ATT/ST Glass cables. Over the last 10 years I have compared it to many coax cables up to a price-point of $600 and I have yet to find one that has the absolute transparency that the Audioquest Optilink 4 Fused Silica Glass Toslink has in that it has a 30 MHz bandwidth which is sufficient to allow the full development of the Digital signal's harmonics which is essential for the best sounding digital music playback.

 

Most recently I used my old Musical Fidelity V-Link to compare my .99999 silver Illuminations D-60 coax to the Optilink 4 Fused Silica Glass Toslink and although the Illuminations D-60 sounds absolutely great on its own when compared to the Fused Silica Glass Toslink it immediately becomes apparent that a lot of low level detail is being completely glossed over by the Illuminations D-60 and a portions of the harmonic structure of the Music is not being fully fleshed out.

 

Those who have never used or heard a 30 MHz bandwidth Fused Silica Glass Toslink will continue to assume that Toslink is vastly inferior to coax and will never be bothered with what their Music might sound like using a 30 MHz bandwidth Fused Silica Glass Toslink cable like the one John Atkinson used to allow the V-Link add so much additional fidelity to the Benchmark DAC in his Stereophile Magazine Review of the V-Link...

 

"I then changed to the V-Link, had it feed the Benchmark via a 1m length of AudioQuest Optilink-5 glass TosLink cable, and did not touch the Benchmark's volume control. The violins in the Sibelius were now slightly less steely, the soundstage a tad wider and deeper. More important, the sounds of individual instruments, such as the horns at the start of the first movement, and the timpani and plucked double basses at the start of the second, were slightly more of a piece with the surrounding acoustic."

 

[Julf]

Not all optical Toslink cables are the same and neither do they have the same kind of filament. Common plastic fiber filament Toslink has a bandwidth of about 6 MHz and this is what has given Toslink such a bad reputation because it chokes out the harmonics of the 3.3 MHz fundamental which needs bandwidth out to 10X that of the fundamental on order to form a nice square wave.

 

But you don't need to transmit a square wave. A stable sine wave is fine. So no need to be able to transmit harmonics. All that matters is that there are enough level changes/transitions, the steepness doesn't matter as long as the frequency is stable.

[Maxxwire]

But you don't need to transmit a square wave. A stable sine wave is fine. So no need to be able to transmit harmonics. All that matters is that there are enough level changes/transitions, the steepness doesn't matter as long as the frequency is stable.

 

Julf- There must have been a misunderstanding and I wanted to point out that I just wanted to point out that I never said anything about the 'need to transmit a square wave'. What I did say was a quote from Audio Asylum co-founder Jon Risch when he said "Now the digital audio signal is transmitted at about a 3 MHz fundamental rate, with harmonics up to at least ten times that frequency, in order to acheive a nice square wave shape." Please note that Jon specifically said 'nice square wave shape' and nothing about transmitting a square wave.

 

As far as the integral importance of transmitting digital signal harmonics in another case go according to Jon Risch went on the record as saying...

 

"The basic fundamental frequency component is taken to be the base frequency, which is about 2.8 Mhz for 44K/16 bit audio. However, they do attempt to square up the wavefrom as much as possible, less transistion time equals less possibility for jitter, so the harmonics are probably significant up to 10-20 Mhz."

 

The 'nice square wave shape' which Jon Risch was referring to where transmitting the harmonics of the digital music signal are so important to achieving a lower transition time which subsequently lowers the possibility of jitter shows how the transmission of harmonics are very important to the accurate transmission of the digital music signal. The reason I sought out this information in the first place was to try to figure out how the 30 MHz Bandwidth Audioquest Optilink 4 Fused Silica Glass Toslink was able to sound so much better than my $150 XLO Reference 4 digital coax, $350 MIT Digital Reference coax, $500 Synergistic Research Digital Corridor, $200 Illuminations D-60 digital coax and even a $600 Marigo Apparition Mk 2 Reference digital coax that I borrowed from the local audio shop specifically for the purposes of comparison.

 

When I found out from Jon Risch that the bandwidth of the digital interconnect has a profound effect on its ability to transmit a more complete set of harmonics which results in lowering the possibility for jitter of the digital signal it went a long way towards explaining how it was that the 30MHz bandwidth Audioquest Optilink 4 Fused Silica Glass Toslink cable was able to bring a much greater level of micro and macro level detailing and a truer tonal character along with a more startlingly transparent presentation of the music to my audio system than any of the Digital coax cables I have ever owned or auditioned.

 

As I said before the Digital coax cables that I've owned sounded great when I was using them in my digital front end, but compared to the 30MHz bandwidth Audioquest Optilink 4 Fused Silica Glass Toslink cable none of them could achieve the same excellent levels of playback quality.

 

[sandyk]

Maxxwire

Are you suggesting that the additional conversion to optical and back again, using a typical bandwidth challenged Optical receiver has no effect on Jitter ? It seems to me that a proper coax SPDIF interface using high quality SPDIF transformers and a good quality coax cable, will still be better than going through an additional stage, with perhaps less than optimum PSUs, although I do agree that a Telecommunications grade optical cable would be better than using a cheap plastic based Toslink cable.

Alex

[esldude]

I agree a higher bandwidth Toslink is potentially better. But like Alex points out, lots of optical receivers aren't that good with the extra bandwidth anyway.

 

Then RG59 of good quality has like 1,000 mhz (1 ghz) bandwidth while something like RG6 has more than that. All without getting into exotic or expensive cable. The only remaining advantage of Toslink is electrical isolation.

 

So you are saying your 30 mhz Toslink is better than coax. While that might be so, it isn't just on a basis of bandwidth as the coax has much more.

[Maxxwire]

sandyk- I have known perfectly well about the additional conversion from electrical to IR Optical all along and I am in no way inferring that it does not induce some amount of degradation, but rather that there must be more areas of concern that are being overlooked because over the last 10 years as the 30 MHz Bandwidth Audioquest Optilink 4 Fused Silica Glass Toslink has time after time proven that it sounds much better than any other digital cable that it has been compared with whether they be digital electrical coax or lower bandwidth Toslink cables.

 

I have even A/B tested it with both the Dayton GOC 65 strand Filament Glass Toslink and the 12 MHz bandwidth 280 strand SonicWave Glass Toslink and in each case the low bandwidth Glass Toslink cables make a very poor showing against the 30 MHz Bandwidth Glass Toslink.

 

I do not want to cause any contention here its just that I've been thoroughly enjoying this 30MHz Glass Toslink cable for 10 years now and it is so radically different than the common place 6 MHz plastic fiber filament Toslinks which I heartily agree with you literally choke the life out of the music. I did not share this with you to 'one-up' digital coax, but rather to let you know that the 30 MHz Bandwidth Audioquest Optilink 4 Fused Silica Glass Toslink exists because there some folks with digital front ends that perform on a much higher level than mine does and I think that this Glass Toslink cable could lift the sound quality of their audio system to a spectacular new level.

 

It is rare that I see this high quality high bandwidth Fused Silica Glass Toslink in use. About the only name you might recognize who knows its advanced level of capability and uses it is John Atkison at Stereophile who used his Audioquest Optilink 5 Fused Silica Glass Toslink cable to get a $169 24/96 Musical Fidelity V-Link to improve the sound quality of a Benchmark DAC and they are supposed to be pretty much immune to jitter. I consider the Computer Audiophile site very much up to those high standards of professionalism and expert knowledge of digital audio and so I wanted to let the membership know about the capabilities of this rarely seen 30 MHz Fused Silica Glass Toslink cable which is a rare gem that few in the world of digital audio have knowledge of.

 

 

[Maxxwire]

It isn't just on a basis of bandwidth as the coax has much more.

 

esldude- I agree with you about bandwidth alone not being the secret to good performance in a digital cable! That Synergistic Research digital coax I had had a 1 Mhz bandwidth and because if it the cable sounded so highly detailed that it sounded spitty! I have a huge appreciation for detail, but hearing the singer's mouth open just before they sang was just too much detail.

 

Thank you very much for your comment about the electrical isolation that Toslink offers as being a benefit. Please don't get me wrong. I am not trying to prove that Fused Silica Glass Toslink is better than digital electrical coax I'm just sating that in the 3 digital front ends I have used in my audio system the Fused Silica Glass Toslink has out performed all of my other Toslink and digital coax cables. Again, I'm not challenging the performance capabilities of digital coax but rather telling you about an amazingly obscure alternative that has proven to be a highly effective alternative in my audio system over the last decade that a few members might possibly be interested in.

 

 

[Julf]

The 'nice square wave shape' which Jon Risch was referring to where transmitting the harmonics of the digital music signal are so important to achieving a lower transition time which subsequently lowers the possibility of jitter shows how the transmission of harmonics are very important to the accurate transmission of the digital music signal.

 

And my point is that the transmission of harmonics isn't that important to the accurate transmission of digital music. A sharper transition might lower the amount of bit-to-bit random jitter, but as the receiving device usually either regenerates the bit clock independently, or recovers it with a phase-locked loop with a low-pass / smoothing function, it doesn't matter.

 

In one of my previous lives/careers, I was responsible for the architectural design of long-distance fiber optic data networks. Believe me, the issues of transmitting a few megabit/s of data a couple of feet is rather trivial compared to transmitting gigabits for hundreds of miles, but the principles are the same.

[Maxxwire]

Julf- We could argue for days about whether your or Audio Asylum co-founder Jon Risch's theories of digital signal transmission are correct, but the fact remains that when I replaced a 6 MHz bandwidth Monster Lightspeed Toslink with the 30 MHz Audioquest Optilink 4 Fused Silica Glass Toslink that there was such an improvement in sound quality that it was like listening to a much better recording of the same Music and that elevated sound quality has continued through each and every application I have used this unique Fused Silica Glass Toslink in over the last 10 years.

 

I am just trying to raise awareness of the improved sound quality that both I and John Atkinson who continues to use the Audioquest Fused Silica Glass Toslink as his preferred reference S/PDIF cable in his digital equipment reviews for Stereophile Magazine have achieved through the use of this unique Fused Silica Glass Toslink cable which is the same Fused Silica Glass conductor that Audioquest also uses in their ATT/ST Glass cables and has 6X more bandwidth than the common 6 MHz bandwith Toslink cable that most people are familiar with the horrible sound of.

 

 

[Audio_ELF]

Julf- We could argue for days about whether your or Audio Asylum co-founder Jon Risch's theories of digital signal transmission are correct, but the fact remains that when I replaced a 6 MHz bandwidth Monster Lightspeed Toslink with the 30 MHz Audioquest Optilink 4 Fused Silica Glass Toslink that there was such an improvement in sound quality that it was like listening to a much better recording of the same Music and that elevated sound quality has continued through each and every application I have used this unique Fused Silica Glass Toslink in over the last 10 years.

 

I am just trying to raise awareness of the improved sound quality that both I and John Atkinson who continues to use the Audioquest Fused Silica Glass Toslink as his preferred reference S/PDIF cable in his digital equipment reviews for Stereophile Magazine have achieved through the use of this unique Fused Silica Glass Toslink cable which is the same Fused Silica Glass conductor that Audioquest also uses in their ATT/ST Glass cables and has 6X more bandwidth than the common 6 MHz bandwith Toslink cable that most people are familiar with the horrible sound of.

Do you get commission each time you type "Fused Silica Glass"? :-)

 

Please don't take offence - but are you a business?

 

Eloise

[Julf]

We could argue for days about whether your or Audio Asylum co-founder Jon Risch's theories of digital signal transmission are correct

 

We could, but I'd rather not. For me the choice of believing in some theory by a web forum co-founder versus believing the decades of practical and theoretical expertise and experience of the engineers that make the text you type (and this whole forum) appear on my screen, over hundreds of miles of fibre optic cables deep down under the Atlantic is a fairly easy choice. Your choice might be different.

 

the fact remains that when I replaced a 6 MHz bandwidth Monster Lightspeed Toslink with the 30 MHz Audioquest Optilink 4 Fused Silica Glass Toslink that there was such an improvement in sound quality that it was like listening to a much better recording of the same Music and that elevated sound quality has continued through each and every application I have used this unique Fused Silica Glass Toslink in over the last 10 years.

 

OK, so the fact is that you prefer the sound of Fused Silica Glass Toslink^TM. Fair enough. That is one subjective opinion, and of course just as valuable as anybody else's subjective opinion.

[Maxxwire]

believing the decades of practical and theoretical expertise and experience of the engineers that make the text you type (and this whole forum) appear on my screen, over hundreds of miles of fibre optic cables deep down under the Atlantic is a fairly easy choice. Your choice might be different.

 

Julf- Yes I agree with you that data only digital transmission can go for long distances without corruption, but digital music in S/PDIF travels with not only the digital data but also the master clock, word clock, and bit clock that are native to S/PDIF which as we all know can be very easily corrupted making the transmission of digital music in S/PDIF even just a few feet over either electrical coax or optical toslink the potential for being a sonically degrading journey.

 

[joveral]

Tried Toslink for a few months and I swapped it out for Wavelink...I realized I have missed out big time in music quality! Since then I have sold off my VDH OPTOCOUPLER Mk II and upgraded SPDIF. Give it a try and listen for yourself...cheers!

[Julf]

Julf- Yes I agree with you that data only digital transmission can go for long distances without corruption, but digital music in S/PDIF travels with not only the digital data but also the master clock, word clock, and bit clock that are native to S/PDIF which as we all know can be very easily corrupted making the transmission of digital music in S/PDIF even just a few feet over either electrical coax or optical toslink the potential for being a sonically degrading journey.

 

In most fiber optic communication systems, the clock is likewise carried in the data stream, but yes, the clock oscillators tend to be of a much higher precision than in audio.

[Maxxwire]

I hope that you are not inferring that digital transmission using S/PDIF isn't completely riddled with the possibility of data/timing corruption because I was reading on another thread here at CA which instructs people to completely avoid S/PDIF because even going through just a few feet of either electrical coax or optical toslink can be treacherous in terms of the degrading jitter incurred making the quality of the S/PDIF interconnect of great importance.

 

 

[Maxxwire]

Do you get commission each time you type "Fused Silica Glass"? :-)

 

Please don't take offence - but are you a business?

 

Eloise

 

Eloise- I understand why you are asking and I am not offended in the least. I have no affiliation with nor am I a representative of any business. The reason I mentioned the the composition of the optical conductor material so many times in the post is to call attention to the fact that it is not the common place molded plastic fiber material that is used for the conductor in the very poor sounding and virtually ubiquitous toslink cables that most people are familiar with.

 

I am just a fellow audio hobbyist and music lover who is hoping to be able to share my greatest discovery in digital audio since I bought my first outboard dac 12 years ago. The day I bought my Theta DAC back in 2000 they very clearly instructed me to use its electrical coax input and not its optical toslink input. Unfortunately the cd player I had at the time had only a digital optical output I needed to find a toslink optical cable that was more on par with the many great digital coax cables which were readily available.

 

In 2002 after many months of searching on the internet I found the glass toslink for 1/2 price that I am still using today. As I said earlier I removed the 6 MHz bandwidth plastic fiber optical toslink that I was using and replaced it with the 30 MHz bandwidth glass toslink and for the first time I was able to hear my favorite music clearer than I ever had before without its harmonic structure being muddled by the low 6MHz bandwidth of the molded plastic conductor that I had just replaced which up until that time I thought was the only kind that was available.

 

Just 1 year ago I got a USB-S/PDIF Converter for the first time and that was when I first became familiar with Computer Audiophile. It didn't take long to find out that the members here have a high appreciation for the very best sounding digital music. After registering back in July it took another couple of months to work up the courage to post about the glass toslink which I found works as amazingly well with both of my USB-S/PDIF converters as it did with the audio alchemy i2s Bus processors and Theta DAC in my conventional conrad-johnson powered vacuum tube audio system.

 

My only purpose on this thread is to positively respond to Kato's statement that "I have read that the Toslink is subject to jitter (even though the DAC may deal well with this jitter I'd rather remove it altogether) and the USB section of the DAC is not worth dealing with (as indicated by Simaudio)" with my own decade long experience with a very obscure kind of optical glass toslink that improved the sound of my music playback in a way that no other S/PDIF has been able to.

 

 

[Julf]

I hope that you are not inferring that digital transmission using S/PDIF isn't completely riddled with the possibility of data/timing corruption because I was reading on another thread here at CA which instructs people to completely avoid S/PDIF because even going through just a few feet of either electrical coax or optical toslink can be treacherous in terms of the degrading jitter incurred making the quality of the S/PDIF interconnect of great importance.

 

Opinions and mileages vary. What I stated earlier is that fibre optic cable bandwidth (and thus the steepness of the transition) can affect bit clock jitter. With a properly buffering DAC that uses a PLL to recover the master clock, the random nature of the bit jitter makes the master clock fairly independent of bit clock jitter.

[Maxxwire]

Even though I am now suspecting that Kato from Vancouver who still only has 1 post on the forum may have been troling when he brought up the subject of jitter and toslink cables here is an example of how a highly respected usb dac like the Benchmark can have its sound quality improved enhanced using an optical toslink cable.

 

John Atkinson who has been a professional audio equipment reviewer both in England and the United States for over 30 years reported that he was able to not in theory or opinion, but in actual demonstration elicit these significant sonic improvements when he used his go-to reference S/PDIF cable to enable the $169 Musical Fidelity V-Link to improve the sound of the Benchmark DAC over the optical toslink connection

 

"I then changed to the V-Link, had it feed the Benchmark via a 1m length of AudioQuest Optilink-5 glass TosLink cable, and did not touch the Benchmark's volume control. The violins in the Sibelius were now slightly less steely, the soundstage a tad wider and deeper. More important, the sounds of individual instruments, such as the horns at the start of the first movement, and the timpani and plucked double basses at the start of the second, were slightly more of a piece with the surrounding acoustic."

 

 

 

[Julf]

Even though I am now suspecting that Kato from Vancouver who still only has 1 post on the forum may have been troling

 

Possible. But out of your 11 postings, 6 specifically mention "Audioquest Optilink 4" and "Fused Silica Glass Toslink", one additional one mentions just "Fused Silica Glass Toslink" without mentioning "Audioquest Optilink 4", and 3 others are direct responses in treads following from your mentions of those phrases. I guess that leaves 1 posting from you that isn't promoting the Audioquest Optilink 4 Fused Silica Glass Toslink cable. Trolls come in many shapes and sizes.

[The Computer Audiophile]

I think the original post is completely valid.

 

Dont turn this thread into a debate.

[Maxxwire]

Chris- Thank you very much for your opinion about Kato's original post as it helps me to feel that he may have read my responses concerning my positive personal experiences with optical toslink. I just wanted to thank you for Computer Audiophile and finally having a chance to share my first few posts after participating as a read only viewer for a year.

 

Julf- I must say that you have a very creative mind. If your not active in politics you should be because you could run one heck of an effective campaign with your ability to spin anything in any in any way you want it to go!

 

I have been posting on audio related websites on the internet for many years and I realize when I'm in a spiraling conversation that has no possible chance of resolution. So I have decided to let the readership consider the actual real world experiences which I have already posted in the thread demonstrating that both I and the publisher in chief of the original audio equipment evaluation magazine have had with his chosen reference S/PDIF cable that he uses to evaluate digital audio equipment with for the readership to consider as I will no longer feel the need for me to be posting to this thread.

 

I want to thank you for being such a gentleman and according me such a warm welcome as a brand new member making his very first few posts here at Computer Audiophile.