Coax to Optical Converters Anygood?

Hi Chris. Original sent to your email address as above. Just resent it. Check your spam filter.

Ginov,

I didn't get your pm.
Was it on Audio Circle? (rodge827)
email: rodge827 @ comcast . net (delete spaces)

Chris

Hi Chris, I sent you a pm. Let me know here if it went astray.

Ginov,

I found out about the Dual Core from US distributor Tim Ryan of Simplifi Audio. I had purchased a Dspeaker Antimode 8033s from him, and before the D/C came out he offered me one at a prerelease discount. The 8033s impressed me so much that I took the plunge on a D/C, and I'm very happy I did!

The Buffalo 32s Dac is a DIY kit from Twisted Pear Audio. I purchased mine from the original owner/builder about a year ago. The 32s was TPA's first dac board with the ESS Saber 9018 chip. They have since improved with the Buffalo 2 and now 3.

I have been listening to the Dual Core Dac more than the 32s, so as to get a better grasp of the sound quality it produces. The best that I can describe the differences is an apples to apples comparison. Both apples taste (sound) wonderful, but in the end only one will win me over. I'm leaning more and more towards the D/C dac with it's pure uncolored sound. Every dac I have had in the past "flavored" the sound a bit, the D/C dac is a whole new experience, and refreshing at that. :-)

Best,
Chris

Hi Rodge827

You're welcome. I'm glad to have been helpful. There isn't much commentary out there on the www on the dual core as it's such a new product. I was drawn to it through reading a guest editorial in TAS by Robert Greene. He comments about the need to address room interactions to get the best out of any system, regardless of cost. I tend to agree after hearing a friends DEQX-based DSP active system that is very impressive.

Good luck with the Behringer. I look forward to hearing what your thoughts are when you get the D/C settled in and will email you.

I'm not familiar with the Buffalo dac.

The dual core ADC is good and i' m sure you are already aware, but be mindful in your comparison that your other DAC is also undergoing an extra round of digital to analogue conversion compared to the D/C!

Have fun

Cheers
Ginov

Hi Ginov,

Thank you for the lead on the Behringer SRC 2496. I looked into buying one, but most dealers in the states are sold out. The new shipment should arrive sometime in the next couple of months, so maybe then. I received my Dual Core on July 27th. There were delays in the release and limited distribution.
I'm using a MSB Digital Director that is working as my coax to optical converter. I like the unit and it runs off a 12v supply same as my CD transport and Dual Core. I have only had the unit hooked up for a couple of days and I'm vey impressed with it too. My transport has dual coaxial outputs and this has made for a fun comparison to my Buffalo 32s dac. I can switch between the Analog and SPDIF inputs on the D/C to compare the two. No clear favorite yet, I want to give the D/C dac a chance to run in for a while. rodge827atcomcastdotnet If you want to compare notes. My info can also be found on the Audio Circle Forum.
Thanks again,

Chris

Just saw this and even though a bit late in the piece I thought I'd add my 2 bobs worth. I recently bought a dual core anti-mode. I love it and find it to be a very significant improvement as a DAC over a Musical Fidelity M1 and even my beloved CAL system 1. It is a very good DAC and the DSP room correction is brilliant (at least in my room). I overcame the limited digital input (single toslink) issue by using a Behringer SRC 2496 ultramatch pro (a real audio bargain although a bit ugly). It has three digital inputs (optical, RCA and aes/ebu). This works very well as an upsampler and I run my Teac VRDS 10 via an active digital RCA cable into it. In my opinion the upsampling improves the sound and the behringer allows me to plug my USB interface into the system via the optical input for HiRes computer audio (i don't use the usb input on the dspeaker). The dual core (with latest firmware) handles the 24 bit 96khz signal its optical input without any issues. One surprising thing (to me at least) is the quality of the ADC of the dual core. I am, at least for now, running my turntable via PS audio phono stage into the dual core too and it appears the benefit of the room correction outweighs the limited downside of the Analogue to digital conversion (I need to further evaluate this to see if this holds up in the long term). I wasn't expecting this when I bought the dual core as I was using the ps phono stage direct into my power amp (Leak St20) and loved the brilliant transparency this gave me.

Anyhow, after all this, my advice is use a behringer with the dual core and enjoy the improved sound from CD as well as providing extra inputs.

Al,

Your assumption is correct on the addition of jitter with a converter, no argument there. I was going to rely on the Dual Core to handle the jitter.

Assuming that bit errors do not occur, and I would expect that they would not occur with any decent converter

That is where my concern is. To find the best converter to do the job, so that all the 1's and 0's make it to the dac.

Best Regards,

Rodge

I wasn't all that concerned with jitter as such, more with the quality of the signal not being compromised. Understanding that the more in the signal path the better the possibility for the signal quality to go awry.

Assuming that bit errors do not occur, and I would expect that they would not occur with any decent converter, the only way I can envision that signal quality could be degraded (that would have sonic consequences) would be via the introduction of jitter. My comments were based on that assumption, which I believe is correct.

In any event, good luck with the upgrade, however you decide to proceed.

Regards,
-- Al

In any event, I think we're both agreed that the choice of a converter is less critical than what the OP appears to have been envisioning. And that reports of experiences with particular converters need to be considered in the context of the jitter rejection capability, if any, of the particular DAC that was being used.

Al,
I wasn't all that concerned with jitter as such, more with the quality of the signal not being compromised. Understanding that the more in the signal path the better the possibility for the signal quality to go awry.

What I was hoping to find, was if someone has used a converter(s) and could shed a little light on the experience, and perfomance to note.

The techs at DSPeaker are a pretty smart group. The Anti-Mode 8033s did a world of good for my subs, and to now be able to clean up any nodes to 500HZ, is very intriguing to me. I'm sure that they considered a coaxial input, but possibly due to cost and building constrictions felt that optical was the way to go? Dunno?....They are right about the ground issue.

Perhaps I'll purchase a converter and report back on the quality.

Thanks for your input,

Rodge

Yes, Kbark, based on the claimed insensitivity to jitter I'd assume that the D/A conversion process is performed by this unit asynchronously to the clock on the incoming signal. Which will greatly reduce the importance of the quality of the converter. However, respecting Steve's experience in these matters, I would not necessarily conclude that the resulting sonics will be COMPLETELY insensitive to jitter on the incoming signal.

I wouldn't rule out the possibility that there could be some subtle effects that occur in the circuitry, or that are inherent in the processing algorithms, that would result in a theoretically complete insensitivity to jitter being less than perfect.

In any event, I think we're both agreed that the choice of a converter is less critical than what the OP appears to have been envisioning. And that reports of experiences with particular converters need to be considered in the context of the jitter rejection capability, if any, of the particular DAC that was being used.

Regards,
-- Al

Good points, Al. However, perhaps the DAC/unit in question has a sort of asynch function built in. Possibly a Pace Car, if you will, built in?

I don't know the unit, nor have I looked it up. Just theorizing.

If the unit is truly insensitive to jitter, then I'd assume any converter that outs bit perfectly will work.

If in fact the unit's DAC function is insensitive to jitter on the incoming signal, then it should also have minimal, if any, sensitivity to the quality of the converter (assuming the converter is at least good enough to function reliably).

On the other hand, this comment by Steve Nugent of Empirical Audio, in this thread, would seem to be relevant:

It's strictly marketing that says that all jitter is eliminated. Never happens. I have yet to find a DAC that is not improved by a low-jitter source.

So the bottom line would seem to be that the DAC will have considerably less sensitivity to converter quality than DACs that don't use comparable asynchronous technology, but exactly how much sensitivity would remain is speculative.

Regards,
-- Al

The Dual Core is designed to work with analog, computer, and digital input.
Here is DSPeaker's reason for using optical rather than coax as taken from the FAQs page:

Q: Coax s/pdif (RCA) sounds better than optical tosink in our ears and due to the listening tests we have done in the past. So why use optical?

A: Our system does not derive its analog to digital converter (DAC) clock from the digital input(s), so jitter in the input is not a problem. Ant jitter in the input gets removed in the process, so there is no difference between the quality of coaxial and optical input in this respect.
The huge advantage of using optical is that there is no ground connection between devices.

Thanks for the encouagement :-). If I can't find a good converter I may stay with my trans/dac combo and use the line level input.

Rodge-- Milk toast diatribe? Good one. Well at least it was short.

But seriously, and in deference to your 25+ years of experience, without further qualification, your original question frankly made it seem like you didn't have much experience with digital audio. Hence my simple question to you.

Now that we know the unit you are looking at is actually considerably more than just a DAC, things make more sense. The Dual Core 2.0 indeed sounds intriguing, but given its lack of coax input, the company clearly is focusing on computer audio.

Best of luck finding a coax to optical converter to complement your transport.

Dg1968, The question that I asked was if anyone has any experience using a converter. I didn't expect another question and a milk toast diatribe on Dac purchasing or system implementation. Have you used a Coax to optical converter? If not then move on!

FWIW I'm considering to buy the DSPeaker Anti-Mode Dual Core 2.0. The digital input is optical, hence the need for a converter. It also has line level input, USB input, and can be used as a preamp.. The point in purchasing the Dual Core 2.0 is to simplify my system, and make it easier to move to computer audio in the future. Do a search and read the Dual Core's features. The little unit looks impressive, WOWed them at CES, and I'm sure sounds impressive as well. I'm using the DSPeaker Anti-Mode 8033s on my subs now which happens to help produce the best bass that I have ever had in my 25+ years in this hobby. The Dual Core 2.0 will do DSP corrections to all room nodes up to 500hz, be a dac and preamp as well.
So now you know why I'm considering the need for a coaxial to optical converter.

With so many DACs available across all price ranges, why are you looking to purchase one that lacks the functionality you require? No matter how well implemented, adding another conversion to your signal does not seem like a good idea.

Trucker, Thanks for the response. My transport is a 47 Labs Flatfish that has been upgraded with a super clock and BG caps. My hope is to find a converter that will compliment it and not loose the magic that it produces.
Thanks again.

I bought a cheap optical to coaxial from monoprice and it does convert, but definitely not hi-fi grade.