CHORD ELECTRONICS DAVE

[lovethatsound]

I now face running in my second Dave. Mine finally arrived today after living with a loan Dave for six weeks. I can't remember with the loan (which only had about five hours use before I got it) how long it took to reach the point when it stopped improving but I'm sure it was over 200 hours.

well it's a very pleasant experience running a Dave in,so you get to enjoy it all over again . congratulations on getting your own Dave,enjoy your music.

 

[Crgreen]

Well, for the first time I'm actually going to enjoy burn-in.

Possibly to state the obvious, I now understand how Robb Watts and Chord have worked this. The Huho was (is) an outstanding product, its faithful rendition of timbre being its most obvious feature. The Mojo is a trickle-down bargain, but with the Dave Rob just went for it, given the opportunity to see how far he could take things. Without wishing to sound too hyperbolic, we're not talking musical reproduction here, more recreation.

I had to wait five weeks for my Dave, but I'm betting that once Stereophile, the Absolute Sound and Hi-Fi Plus publish their reviews (surley forthcoming?) it's going to take considerably longer than that.

Listening to Jeff Beck tearing it up at Ronnie Scott's at the moment. I quite liked the album before - it now sounds like a masterclass in electric guitar.

 

[JaZZ]

Listening to Jeff Beck tearing it up at Ronnie Scott's at the moment. I quite liked the album before - it now sounds like a masterclass in electric guitar.

 
Usually not a reference for high fidelity, but I also fell in love with DAVE's reproduction of electric guitars.

 

[bigfatpaulie]

Out of interest, my understanding of the DAVE is that is basically uses software (lots and lots of lines of code) to define its output characteristics.  If that's true, then I suppose potentially DAVE could get different 'software' versions to change its signature, correct?
 
I suppose also the code could be refined further as well?

 

[tkteo]

  Out of interest, my understanding of the DAVE is that is basically uses software (lots and lots of lines of code) to define its output characteristics.  If that's true, then I suppose potentially DAVE could get different 'software' versions to change its signature, correct?
 
I suppose also the code could be refined further as well?

 
I *think* I recall Mr Watts mentioning that DAVE can be sent in when there is a major update to the code.
 
But best to hear from Mr Watts himself.

 

[x RELIC x]

Out of interest, my understanding of the DAVE is that is basically uses software (lots and lots of lines of code) to define its output characteristics.  If that's true, then I suppose potentially DAVE could get different 'software' versions to change its signature, correct?

I suppose also the code could be refined further as well?

More than just the WTA filter. There's also the Pulse Array DACs and the way it handles the analogue output that's very transparent. From what I've been reading of Rob's posts (highly recommended) he basically stuffed the FPGA full with all the code he could. He's repeatedly said (Hugo, 2Qute, TT, Mojo) that if there is a significant improvement to the sound he would provide the update of the code, but it would need to go back to Chord for the update.

I see it like this... Nobody asks for updates to the filters in a ESS Sabre, BurrBrown, CS, TI, etc., DAC. Rob just uses FPGA chips for his filter because they allow so much more flexibility (and capability) from the get go to implement his code.

 

[rkt31]

there are some YouTube videos of dave playing. as said by Rob what is instantly noticeable is the timing and starting/ stopping of notes. this is evident even in the video. it sounds as if recorded live.

 

[miketlse]

  Out of interest, my understanding of the DAVE is that is basically uses software (lots and lots of lines of code) to define its output characteristics.  If that's true, then I suppose potentially DAVE could get different 'software' versions to change its signature, correct?
 
I suppose also the code could be refined further as well?

 
See post #7429 http://www.head-fi.org/t/784602/chord-mojo-the-official-thread-please-read-the-3rd-post/7425
 
Rob Watts has said in other posts that the main code for the DAC processing is mature, and was essentially identical for the Hugo, Hugo TT, Mojo, 2Qute and DAVE, which helps to explain the similarities in their sound reproduction.
The main technical changes in all these models seem to be related to the power supplies, reducing RF interference, the size and capability of the FPGA chip itself, and handling the input signals to the DAC (and i think that this is the area where most, if not all code updates will have taken place). 
The FPGA chip seems to be obeying Moores Law, in just the same way that the CPU in your desktop/laptop/phone does - ie every 18 months the capability doubles, and the power use halves. This translates into Robs DAC code stays the same, but each successive generation of FPGA can simultaneously run the code on a greater number of cores.
 
It would be nice to think that future upgrades to DAVE could be performed in a similar manner to vacuum tube rolling, ie every two years you send your DAVE back to Chord, and they unplug the FPGA from its socket, and replace it with the newest generation of FPGA. No updates to the code needed. I suspect I am being rather optimistic, because I would expect that in reality, the FPGA is soldered into the circuit board.

 

[Samuel Snoopy]

At least I know number of taps, filter levels, DSD filter and number of pulse array Dac elements are different amongst these brother Dacs.

 

[iDesign]

Originally Posted by miketlse /img/forum/go_quote.gif
 
It would be nice to think that future upgrades to DAVE could be performed in a similar manner to vacuum tube rolling, ie every two years you send your DAVE back to Chord, and they unplug the FPGA from its socket, and replace it with the newest generation of FPGA. No updates to the code needed. I suspect I am being rather optimistic, because I would expect that in reality, the FPGA is soldered into the circuit board.

 
I agree and feel this is the right strategy for high-end digital audio companies to address issues of obsolescence and customer loyalty. If I were to purchase a $13,300 product, I would prefer that it is a longterm investment into a platform that could be updated for a small fee. A manufacturer like Chord also benefits because they retain the customer for a longer period of time and the product updates become a stable revenue source. I'm personally not interested in any companies that attempt to carry sales with the iPhone 5, 5S, 6, 6S, 7 approach-- and for the manufacturer, this approach has the effect of creating a secondhand market and a steep depreciation curve of their own products. So while Chord may or may not have specifically designed the DAVE to be upgraded over time, I hope this is the path they will take for the future products with Rob Watts' designs.    

 

[Rob Watts]

Ok, a few points.
 
Break-in - about 10 minutes.
 
Well yes that was to get your attention, and my honest answer is I do not know for sure, except that brain break-in is by far the biggest factor. In October I did an update to the code, getting ready for final production. This update had a SQ change, and it was not small.
 
I did the change on a unit that had at least 10,000 hours on it, so it was well and truly broken in. But the SQ change from the code took several months for the feeling that SQ was improving to stop, so brain break-in (getting used to the sound and I suspect the brain learning new ways to process the SQ) is very real - at least to me.
 
I actually have a brand new unit coming next week, so I can test for how much is down to hardware changes.
 
FPGA - yes its soldered in - and I have to do this. FPGA sockets creates too much inductance, and so decoupling becomes a major issue. At best using sockets it will just sound and measure badly, at worse it will simply not function. But Moore's law is definitely running out of steam. The 7 series FPGA's were "launched" in Sep 2011, and the devices were only really available last year. The ultrascale parts are not suitable for audio, so there are no better FPGA's on the horizon. But lets say Xilinx have a wonder FPGA available tomorrow in quantity, then I can't just drop what I am doing and re-design Dave. It is not a simple process of dropping a new chip in - a replacement to Dave (assuming new display too) would be a one man year of work for me, and with all the other projects happening, this will be many years away.
 
Code updates - my background in chip design forces you to make hardware that is right first time, which means lots and lots of testing before tape-out. And I treat FPGA design as hardware, not software. But you are limited by two things - knowledge and the FPGA. With the vast resources available in Dave's FPGA, its knowledge that is the limiter. I suspect I will learn a lot from the Davina project, so if this relates to a SQ improvement for a DAC I will put it in Dave. I will only do a code update if we are talking about a significant and worthwhile change in SQ.
 
Chord's Korean distributor asked for a simple block diagram for Dave so here goes:
 

 
And the different code for DSD+ :
 

 
Rob

 

[DaveRedRef-III]

Revelatory stuff Rob. As always, thank you for sharing.

Here's a question regarding the plan to launch amplifiers where the digital code runs on from Dave and is converted to analogue at the speaker O/P:

To the layperson this implies a measure of obsolescence in the Dave feature set as it will no longer be used as a Dac. So will the amplifier act as an enhancement to the Dave process or merely an alternative?

Being a business investor I am always looking at how companies monetise their tech and it seems to me if you can add to the processing capability of Dave in terms of SQ with the new amps in a serial processing strategy then owning a Dave as well as the amp would be a very desirable and effective selling strategy for Chord in that it both sells more units and further excludes the competition from any part of the audio path. Edit: (if the buyer wishes to achieve the very best SQ possible)

 

[DaveRedRef-III]

To take that strategy further, it would probably be of even greater potential for the less powerful Dac's in Chord's lineup.

 

[Crgreen]

Thanks Rob. I'm not sure my brain has ever really broken in, so it will be an interesting exercise

 

[miketlse]

Thanks Rob. Your posts about the design of DACs as an engineering system (and how different designs affect the sound quality), are always interesting.