[ted_b]

Rob,
Given your comment about how much you prefer toslink (galvanic isolation, etc) does that input support DoP in the Hugo (realizing that if it did it would be DSD64 only)?  And do you prefer glass vs plastic (sounds like a grocery store decision)?  I'm not sure I've ever read a rave review on any value or even  hi-end toslink cables.  Thx
Ted

 

[Hifi Nutter]

I'm not Rob (or anything close to it ) but my take is that the Hugo will play both formats, so why ask the player (iPhone Onkyo player) to do conversion to PCM when you don't have to.  Leave DoP enabled and that way what is DSD stays DSD (actual recording provenance notwithstanding of course) into the Hugo.  The bigger issue is to be on the lookout for the best version of your recordings.  For example, if you like BIS's music, don't buy their SACDs and rip them to DSF (or DFF) but instead buy them at their native resolution on the eclassical site.  This native resolution may, in fact, be as low as 24/44.1k (for their early recordings that appeared on SACD) but it's the closest to the master, if not the master.  On Chord DACs (cuz they do PCM so well) it's a big enough improvement to care to go out and find this stuff.

My "tip" is mostly for stereo playback.  Since BIS (same example) doesn't sell their native PCM surround tracks you'll need the upsampled DSD 5.1 on the SACD for that..currently.

Net/net, if it was recorded/mastered in PCM, buy it and play it in PCM.  If it was recorded/mastered in DSD (or analog-to-DSD) then play it in DSD.  Sometimes one format is all we got for hirez, so even if the original material was PCM, if the higher rez PCM is not available to buy you may find that the kidd glove treatment to get it remastered on SACD may be enough to pick that format (over, say, the 80's redbook version).   It's a lot of work, sometimes, but in the end we get as close to the master tape as possible.  This work makes those faux upsamples that appear constantly on the hirez market even more frustrating to see. 

Ted so what is all my cds pcm or dsd or does it say on the case? I'll leave it on dop then,didn't realise pcm means the onkyo is converting it,thanks

 

[OK-Guy]

Ted so what is all my cds pcm or dsd or does it say on the case? I'll leave it on dop then,didn't realise pcm means the onkyo is converting it,thanks

 
WAV.

 

[holeout]

Rob the onkyo player lets me play high def music from my iPhone to the Hugo,all I've done is burn my cds to the player so still none the wiser whether I use pcm or dop settings

You are talking about the Onkyo player's DSD output format to either select PCM or DoP. Using the PCM output, the player convert DSD files to PCM for output. DoP encodes the DSD signal in the PCM stream and will be retrieved by the Hugo to native DSD. The PCM output is for DACs without DSD support, so for the Hugo I'll definitely use DoP.

 

[Rob Watts]

Hi,
 
Actually I do both - I am a design consultant for audio with custom silicon chips, and design for Chord, using my IP. Now silicon chip design means very high initial cost, so you go for big volume. But FPGA design means higher cost per device, but a great deal more flexibility.
 
Now FPGA's are gate arrays, kind of blank pieces of silicon, where the designer programs the part. Ignoring the design effort, the up front charges are nothing. So you can design silicon to suit a niche high-end market, where sales can be very small. For custom silicon devices, you have to sell millions to get your money back. There is no way the complexity that goes into Hugo would make it into a custom chip, the volumes are too small.
 
Now the down side to FPGA is that you are dependent on the FPGA performance. When I first started with FPGA's (mid 90's) you could do a DAC but no filter. Then in the late 90s, you could do a DAC and a filter, and the gate count started to exceed DAC's you could buy off the shelf. Today, the bottom end Spartan is 10 times more capable than an off the shelf DAC chip in terms of gate count, and the FPGA I am using for the QBD replacement has serious gate counts - well over 100 times more capable. So you have the flexibility to do much more interesting things, with the downside that the unit cost of each device is more expensive. but that does not matter for the high-end.
 
So the designers of spartan are just supplying a very complex blank canvas, I have to paint the picture. With Spartan 3 I had a small canvas, with Spartan 6 I have a much bigger one! 
 
   

Rob excuse my ignorance or lack of knowledge on the subject but in layman's terms do you design your filters around the Spartan chip?Is someone else the brains behind the Spartan as in your interview you said you were building a 20 grand dac around the Spartan 3 then the Spartan 6 came out so you scraped the idea and used the technology in the Hugo,couldn't you design a better chip than the Spartan if this is the case so everything is in house for total quality and is to exact specification for audio
Regards paul

 

[Hifi Nutter]

WAV.:evil:

Thanks paul,so pcm or dop?lol thick as me

 

[Rob Watts]

  Rob,
Given your comment about how much you prefer toslink (galvanic isolation, etc) does that input support DoP in the Hugo (realizing that if it did it would be DSD64 only)?  And do you prefer glass vs plastic (sounds like a grocery store decision)?  I'm not sure I've ever read a rave review on any value or even  hi-end toslink cables.  Thx
Ted

Sure, any input will support DoP.
 
I have tried glass against plastic using red-book, I could not hear a difference.
 
I have had some reports that you need glass for DoP DSD as some optical transmitters are at the edge when trying to do 176.4k, so if it works reliably with DoP stick with plastic, and if it doesn't work go for a better cable.

 

[Hifi Nutter]

Hi,

Actually I do both - I am a design consultant for audio with custom silicon chips, and design for Chord, using my IP. Now silicon chip design means very high initial cost, so you go for big volume. But FPGA design means higher cost per device, but a great deal more flexibility.

Now FPGA's are gate arrays, kind of blank pieces of silicon, where the designer programs the part. Ignoring the design effort, the up front charges are nothing. So you can design silicon to suit a niche high-end market, where sales can be very small. For custom silicon devices, you have to sell millions to get your money back. There is no way the complexity that goes into Hugo would make it into a custom chip, the volumes are too small.

Now the down side to FPGA is that you are dependent on the FPGA performance. When I first started with FPGA's (mid 90's) you could do a DAC but no filter. Then in the late 90s, you could do a DAC and a filter, and the gate count started to exceed DAC's you could buy off the shelf. Today, the bottom end Spartan is 10 times more capable than an off the shelf DAC chip in terms of gate count, and the FPGA I am using for the QBD replacement has serious gate counts - well over 100 times more capable. So you have the flexibility to do much more interesting things, with the downside that the unit cost of each device is more expensive. but that does not matter for the high-end.

So the designers of spartan are just supplying a very complex blank canvas, I have to paint the picture. With Spartan 3 I had a small canvas, with Spartan 6 I have a much bigger one! 

   

Wow how interesting is that from the main man himself,really Am in awe of the knowledge you know and what is involved to make such products,i just buy and plug in and play which is what yourself wants it's a business after all and you have to pay for that knowledge but it's nice to know you actually care what ppl think of your product and that you use it for your own personal use,blows my mine,i just work in a factory,proud i've worked all my life but nothing that's gonna change the world

 

[Hifi Nutter]

You are talking about the Onkyo player's DSD output format to either select PCM or DoP. Using the PCM output, the player convert DSD files to PCM for output. DoP encodes the DSD signal in the PCM stream and will be retrieved by the Hugo to native DSD. The PCM output is for DACs without DSD support, so for the Hugo I'll definitely use DoP.

Hole out your a star nice one mate really appreciate it

 

[Clemmaster]

I really like that Chord is finally getting some exposure on Head-fi. I tried to talk about the QuteHD anywhere possible (and, I hope, relevant) but I didn't see much response. This DAC brought me joy (w/ TeddyPSU) almost as much as the much bigger NFB-27. A feat for such a small device!

The Hugo was / is on my radar but I don't have a real use for the built-in amp. I like that it is battery powered, though.
Any plans for an updated Cordette (EX plus?)?

 

[Stormfriend]

My preference has always been optical - it's much smoother, and more natural. Generally, optical is not liked as it has more jitter than coax, but all my DAC's have been able to remove incoming source jitter. The benefits optical has is that it reduces ground induced RF noise from the source, and this is responsible for the warmer sound as noise floor modulation is reduced in the analogue stages.   

Great, thanks. it means I feel comfortable going for an optical-only source and knowing its not just an afterthought on the Hugo.

 

[ted_b]

  Sure, any input will support DoP.
 
I have tried glass against plastic using red-book, I could not hear a difference.
 
I have had some reports that you need glass for DoP DSD as some optical transmitters are at the edge when trying to do 176.4k, so if it works reliably with DoP stick with plastic, and if it doesn't work go for a better cable.

Thanks Rob.  So a follow up:
* many of us who have reviewed/evaluated the Qute DACs (HD and EX) have found that we enjoy the sound from a USB/SPDIF converter better than direct through the USB receiver on the Qute (especially true on HD where a UK Hifi magazine measure the USB output has having significantly more measured jitter than the SPDIF..although still within reasonable spec).  Do these reports make any sense to you?  If so, would the same hold true for the Hugo (one dealer/user, Richard/Aumamp has already reported he thinks the Hugo goes to another level using an Audiophileo AP2 and a good linear ps for said converter)?  As another data point, I have recently been able to send the EX unpowered USB and subsequently found the differences between it and the SPDIF not a real issue anymore (which tells me maybe we were hearing rf noise, not jitter).  FYI.

 

[Stormfriend]

Two questions for Rob:

What's the best battery powered source you've used with the Hugo?
What's the best source you've ever used with the Hugo?

I'd expect the latter to be a Chord product of course, but I'm curious about the first.

 

[Ross]

  Hmm. Not an easy question to answer. Firstly an explanation of the pros/cons of the formats:
 
1. PCM Pro: excellent resolution of small signals, very small signals do not disappear into the dithered noise floor.
    Cons: Timing. Ear/brain can resolve 4uS, CD innately is at 22uS.
2. DSD Pro: Samples at 0.34 uS, albeit at not very good resolution, so has much better timing innately
    Cons: resolution. Noise shaper noise is not the same as dithered noise, any signal below noise shaper noise floor is lost.
 
Now the timing issue can be resolved by the DAC interpolation filter, and with an infinite tap length filter, timing is completely reconstructed. So red-book is capable of very much better performance, if you improve the interpolation filter. But with DSD, the encoding means that low-level details are lost in the noise shaper noise floor, and they are lost forever. So DSD has a compression in depth and instrument separation, due to poor resolution, but does not innately have timing problems. Check out 2L website, and compare the DXD recording to the DSD64 or DSD128 - to my ears, the loss in transparency of DSD is not small.
 
Getting back to design of the DAC. Now I run my DAC's with a very simple single stage active analogue section, with only 2 caps and 2 resistors in the direct signal path - and I do this for transparency. But this means the digital RF noise in the 100k to 1M band must be very low, so the digital source must be filtered - and DSD is at -20dBFS at 100kHz. So I can't put raw DSD into the DAC, or it will sound very hard. So the DSD is filtered, which converts it to regular PCM.
 
If I were doing a DAC for only DSD would I do it this way? Yes, I think I would, as simple analogue is always the best.
 
Incidentally, the DSD filters on Hugo has been improved - they are much smoother than with Qute.

 
Rob, a question on your answer above.
 
You say that redbook is capable of better timing, possibly exceeding DSD. Doesn't this depend on whether the information is in the initial recording? If a recording has been made at 16/44 for example, is the timing information still present in the original recording able to be reconstructed below 22uS? Surely the smallest interval recorded is 22us and therefore transients smaller than this will be lost and cannot be reconstructed ...?

 

[Clemmaster]

   
Rob, a question on your answer above.
 
You say that redbook is capable of better timing, possibly exceeding DSD. Doesn't this depend on whether the information is in the initial recording? If a recording has been made at 16/44 for example, is the timing information still present in the original recording able to be reconstructed below 22uS? Surely the smallest interval recorded is 22us and therefore transients smaller than this will be lost and cannot be reconstructed ...?

 
Everything can be reconstructed, provided your interpolation filter has enough taps to provide the necessary approximation of the sinc function (Nyquist-Shannon sampling theorem).
That's where the new Spartan 6 FPGA are like a breakthrough for audio processing: the advances in lithography made it possible to dramatically increase the number of gates while reducing the power consumption -> welcome Hugo!
 
Cost is of course a factor: the Spartan 6 tray costs < $100.
The Virtex 7 (flagship) features 13 times more gates but cost > $4,000...
 
We can just hope Xilinx and Altera will continue developing their process and offer better FPGA for cheaper in the future...