[Slaphead]

I don't know much about that, but wouldn't it mean having to disclose the proprietary (and currently-encrypte-against-reverse-engineering) code structure to the silicon fabricator?

You may very well have a very definite argument against it, but bear in mind that the most secretive company outside of Lockheed's Skunkworks, Apple, does just that.

 

[Mython]

 

I don't know much about that, but wouldn't it mean having to disclose the proprietary (and currently-encrypte-against-reverse-engineering) code structure to the silicon fabricator?

You may very well have a very definite argument against it, but bear in mind that the most secretive company outside of Lockheed's Skunkworks, Apple, does just that.

 
 
Perhaps, but, aside from Samsung, who would dare to cross swords with Apple, on one or more of their core technologies?
 
Apple can rain-down legal pain & ruin upon anyone foolish enough to do such a thing, China notwithstanding, and because of the sheer scale of their production, they can handle the financial losses of someone (temporarily! LOL) trying to rip-off their technology.
 
 
Overall, the same cannot be said for a small specialist company like Chord (or, indeed, Rob himself, since the technology is fundamentally his intellectual property, and not Chord's, if I'm not mistaken).

 

[Slaphead]

Perhaps, but, aside from Samsung, who would dare to cross swords with Apple, on one or more of their core technologies?

Apple can rain-down legal pain & ruin upon anyone foolish enough to do such a thing, China notwithstanding, and because of the sheer scale of their production, they can handle the financial losses of someone (temporarily! LOL) trying to rip-off their technology.


Overall, the same cannot be said for a small specialist company like Chord (or, indeed, Rob himself, since the technology is fundamentally his intellectual property, and not Chord's, if I'm not mistaken).

I totally 100% agree wih you, Mython, but I'm just bloody curious to hear Rob's or John's answer on this.

 

[miketlse]

You may very well have a very definite argument against it, but bear in mind that the most secretive company outside of Lockheed's Skunkworks, Apple, does just that.

 
I think that Rob has explained the benefits of using FPGAs in some of his other posts (but they may be on one of the other dac threads) - i think they do mention that trying to put everything in an ASIC leads to easy paths for noise and jitter to pass through the whole processing chain, and this noise and jitter then has to be removed somehow in conventional dac designs. Using FPGAs eliminates these issues, so allowing better dac performance to be realised.

 

[miketlse]

I totally 100% agree wih you, Mython, but I'm just bloody curious to hear Rob's or John's answer on this.

 
The disadvantages of solid silicon do get a mention in the paragraph that starts "The second major disadvantage of ASIC silicon DAC's"
http://www.head-fi.org/t/702787/chord-hugo/5925#post_10679015
 
I will try and find the post that i was thinking of.

 

[Mython]

Cheers, miketise,
 
I just went and did a search and there are, indeed, a couple of interesting posts in the Hugo forum, from Rob. The Hugo thread is one I don't keep track of, so I hadn't seen those posts.

 

[QRomo]

   
The disadvantages of solid silicon do get a mention in the paragraph that starts "The second major disadvantage of ASIC silicon DAC's"
http://www.head-fi.org/t/702787/chord-hugo/5925#post_10679015
 
I will try and find the post that i was thinking of.

Those disadvantages apply to off-the-shelf DACs that incorporate analog conversion on chip. What Slaphead is asking about is implementing just the FPGA digital logic as an ASIC, where those disadvantages don't apply. In fact, my understanding is that an ASIC implementation will usually run faster and/or use less power than the equivalent FPGA implementation and that the downside is mainly just cost, both in terms of design time and complexity as well as initial set up for manufacturing. That's why ASICs are usually only an option in high volume or high price-per-unit products. 

 

[GreenBow]

   
 
 
yes, it means a cable with one of these ferrite bands around it:
 
https://www.amazon.com/eBoot-Pieces-Ferrite-Suppressor-Diameter/dp/B01E5E5IY4
 

 
Some cables already have one fitted, others can very easily be fitted with one, manually, as they just clip-on

 
I have got a few of those kicking around somewhere. I have been wondering for ages what they were.
 
Please would they make any difference on the USB cable to the Mojo? (I realise you were talking about coaxial.)

 

[Mython]

   

Spoiler: Warning: Spoiler!

   
 
 
yes, it means a cable with one of these ferrite bands around it:
 
https://www.amazon.com/eBoot-Pieces-Ferrite-Suppressor-Diameter/dp/B01E5E5IY4
 

 
Some cables already have one fitted, others can very easily be fitted with one, manually, as they just clip-on

 

 
I have got a few of those kicking around somewhere. I have been wondering for ages what they were.
 
Please would they make any difference on the USB cable to the Mojo? (I realise you were talking about coaxial.)

 
 
Yes, they are viable for USB cables, as well as co-axial cables.

 

[sanakimpro]

Hi! Does it matter which type of cable you use for Mojo's Coax In - DX90's Coax Out? I'm pairing it via Coax to DX90, but using a 3.5mm TRS cable.
It plays fine, I think? Not sure if it's the best configuration, though? I'm worried that there might be some crosstalk happening?
 
Oh, I have optical and USB cables, etc, but this is for my portable setup which only has Coax output.
 
Thanks!

 

[Rob Watts]

Rob, I've got a question regarding the use of FPGAs in Chord devices, especially relating to the Mojo.

I don't really know the cost to volume ratio of FPGAs compared to ASICs, but I'm led to believe that an ASIC is possibly a more economical solution in terms of high volume production and in terms of power consumption (at least with small enough manufacturing processes)

I totally understand that an FPGA is an advantage when it comes to "time to market", and it makes significant economical sense with the majority of Chord products in that they are relatively low volume and high end. However given that the Mojo appears to be the big thing these days, selling by the bucket load, would it not make sense to order bulk ASICs based on your design, given that your design is pretty much set in stone now.

If the truth be told I don't know how transferable your FPGA design is to an ASIC, but as it's logic gates in both I'm guessing it's achievable.

When you are talking about an ASIC it depends what you are trying to achieve as there are many ways of doing this with costs ranging from fractions of million $'s to tens of millions.
 
Its not something I have plans to do at the moment - I have much more interesting things to do!
 
Rob 

 

[Mojo ideas]

When you are talking about an ASIC it depends what you are trying to achieve as there are many ways of doing this with costs ranging from fractions of million $'s to tens of millions.

Its not something I have plans to do at the moment - I have much more interesting things to do!

Rob 

In reply to Slapheads comment I'd just like to say Time to market? I think you may have not understood that our Dacs are Rob's life work! That's more than thirty years. Therefore each design feeds into the next with all the gained knowledge. It would simply not be possible for another designer to rustle up a comparable Dac design. I've said to him a few times now that he's giving too much information away and he points to one of his block diagrams and says " good luck to any engineer that tries as that particular section took him six years of practical experimental research has to get right. Other blocks took even longer and some are still considered a work in progress. I can assure you all Rob is totally, absolutely obsessed with pushing the boundaries of sound reproduction and we share, follow and translate his vision so far it's worked out pretty well for us all.

 

[GreenBow]

Please everyone,
I just came across a potentially reasonable mid range phone which might pair with the Mojo. It's hold SD up to 128GB. (Reviews well on Which?.)http://consumer.huawei.com/uk/mobile-phones/tech-specs/p9lite-uk.htm
 
I don't know if it will output bitperfect, or digital, because I don't know enough about phones.

Connectivity

Content start Wi-Fi 2.4GHz 802.11b/g/n, Wi-Fi direct Wi-Fi hotspot, Micro-USB NFC(only for VNS L31&L21)

 
 
---------------------
 
 

In reply to Slapheads comment I'd just like to say Time to market? I think you may have not understood that our Dacs are Rob's life work! That's more than thirty years. Therefore each design feeds into the next with all the gained knowledge. It would simply not be possible for another designer to Russel up a comparable Dac design. I've said to him a few times now that he's giving too much information away and he points to one of his block diagrams and says " good luck to any engineer that try's. As that section took him six years of practical experimental research has to get right. Other blocks took even longer and some are still considered a work in progress. I can assure you all Rob is totally, absolutely obsessed with pushing the boundaries of sound reproduction and we share, follow and translate his vision so far it's worked out pretty well for us all.

 
That's meant to be:
"rustle"
"anyone that tries".
 
(Sorry, oops, haha.)

 

[miketlse]

  Please everyone,
I just came across a potentially reasonable mid range phone which might pair with the Mojo. It's hold SD up to 128GB. (Reviews well on Which?.)http://consumer.huawei.com/uk/mobile-phones/tech-specs/p9lite-uk.htm
 
I don't know if it will output bitperfect, or digital, because I don't know enough about phones.

Connectivity

Content start Wi-Fi 2.4GHz 802.11b/g/n, Wi-Fi direct Wi-Fi hotspot, Micro-USB NFC(only for VNS L31&L21)

 

It says on the link you provide that the phone has micro USB (but not optical). That version of android should allow OTG (but it is not mentioned on the page!).
 
However it does offer dual-sim which could make it interesting for some users.
http://www.darty.com/nav/achat/gps_communication/telephone_mobile/telephone_portable/huawei_p9_lite_white.html
 
For me, I would be taking the risk of buying a phone, that may or may not perform better (RFI wise) than my current phone, just to gain the extra SD capacity for a few months, until the mojo add - on module is released. I would rather struggle on with my current phone, for a few months.

 

[jmills8]

It says on the link you provide that the phone has micro USB (but not optical). That version of android should allow OTG (but it is not mentioned on the page!).

However it does offer dual-sim which could make it interesting for some users.
http://www.darty.com/nav/achat/gps_communication/telephone_mobile/telephone_portable/huawei_p9_lite_white.html

For me, I would be taking the risk of buying a phone, that may or may not perform better (RFI wise) than my current phone, just to gain the extra SD capacity for a few months, until the mojo add - on module is released. I would rather struggle on with my current phone, for a few months.

my Huawei holds 64 gigs internal and 128 gigs sd. Has 4 gigs of ram.