I hope that it is not too off-topic for me to enquire about it within this thread, but I am curious about the price of the Bartók being raised. Why did that occur?
The Chord DAC bandwagon
- Thread starter beammeup
- Start date
Amber Audio
This is the Day
dCS Dealer had this on their site last year:
Due to the current value of the pound sterling, dCS are having to introduce a 10% price increase to a number of their products, Including the Bartok range. This will take place from 15th Of September.
Thank you for the very quick answer.
DimitryZ
pfm Member
I am curious to have professional explain it to us. An FPGA is a programmable digital device. As such, it can do all the digital aspects of the DAC chip - filtering, segmentation, etc. But it can't produce an analog output - at the end of the day, there has to be a transition circuit that actually produces the "music." The only exception to this I know of is the DSD decoding, where the nature of the digital format makes the transition to analog very simple - this is what PS Audio does.
My understanding of the Chord "magic" is the very high pole number reconstruction filter that is claimed to combine best aspects of the "stock" filters that are commonly available. As the processing power of the FPGAs increased, Chord made their filters more complex and ostensibly better.
FPGA processing of digital input data is actually quite common in the DAC world. My understanding is that Chord takes to a much more complex level.
Modern monolithic DACs are actually VERY complex devices that use very sophisticated techniques to achieve their very high S/N and bit depth. It is actually VERY difficult to make a discrete DAC that has similar performance.
Musicraft
Trade: Musicraft
Fwiw, we recently took on Ed Meitner - EMM Labs/Meitner Audio and at a similar price their new MA3 @ RRP £9750 has an excellent VC.
EMM Labs know a thing or two and then some about designing DAC's
https://www.emmlabs.com/about.html
JezmondTutu
pfm Member
Just a knob rather than buttons but I think my question my question has been answered.
Amber Audio
This is the Day
Most DACs I’ve had recently seem to have gone with an old style proper rotary knob - RME, SONCOZ, Vega G, dCS. Current D90 has up/down buttons, prefer the knob
JezmondTutu
pfm Member
Most DACs I’ve had recently seem to have gone with an old style proper rotary knob - RME, SONCOZ, Vega G, dCS. Current D90 has up/down buttons, prefer the knob
Thanks. Most of the Chord dacs I’ve seen didn’t seem to have a rotary knob.
First up, i'm a professional DSP engineer, not a chip designer, or FPGA programmer, so I can cover some of this, but not all of it.
The FPGA can be used as a DAC simply because it can produce a bitstream, a fast switching digital output which by varying the amount of high and low bits can represent voltages by the bit density (PDM - see here https://en.wikipedia.org/wiki/Pulse-density_modulation)
For 16 bit audio at 44.1Khz, without clever noise shaping, you need to basically double the sample rate for each bit, so 15 bit @ 88.2Khz can represent the same voltages as 16bit @ 44.1Khz, so at a basic level, you can get 16/44.1Khz quality with a 1/1.4Ghz signal (44.1 * 2^15). Basically, 32768 * oversampling. This will have a flat noise floor across the audio spectrum below the level of the 16 bit data. Now we can improve on this by shaping the noise, which is the delta/sigma approach (feeding back the error to change the output bit) and by doing this we can shift the noise up about the original 22.05Khz nyquist frequency, and by doing this, achieve the same results without needing such a massive oversampling factor. There's lots of strategies, with different computational costs, and other tradeoffs, but the philips bitstream setup achieved the same quality with 64* oversampling, which is a much more manageable 1/2.8Mhz).
Now for higher bit depths, and higher sampling rates you need to increase the frequency, but you get the idea.
The FPGAs operate in the 200Mhz or so range (the larger ones are slower, the smaller ones faster). So, flipping an output bit at 200Mhz gives us plenty of wiggle room to generate high sample rate and high bit depth audio using the same philips delta/sigma approach that has been well explored. I imagine the chord box is performing high order noise shaping, and obviously it's long length FIR filtering too, but this is all easy stuff for an FPGA, actually, it's easy stuff for any computer.
The overall output quality will then be determined by the clock source for the FPGA, so a high quality stable clock will be needed to avoid modulation type errors creeping into the output.
When you read/see the prices mentioned earlier, do these units justify that price? Not everybody can/willing spend that amount on one unit, let's face it many PFM members complete sytems probably don't cost anywhere near 10 grand! Also is a 10 grand Chord unit/DCS Bartok unit 10 times better than a 1 grand RME DAC for example, probably not, therefore some value for money input must surely be applied to any final decision to buy!
John Phillips
pfm Member
This is correct AIUI. The approach taken in the Hugo is set out on this presentation from Rob Watts. The block diagram on slide 15 will mean little to many readers but confirms how the Hugo operates and which functions are on the FPGA.
The higher-end Chord DACs I have heard (only short demonstrations rather than auditions) have all sounded excellent to me, although expensive.
I imagine that the reviewer perceives a difference, and is scrabbling around to give some sort of word to describe the difference. Words aren't adequate to describe these subtle differences in perception, and I think it's unhelpful to try and find an engineering difference to support the perceived difference.
gavreid
Pretty Words...
They say the difference isn't subtle, same everything presumably, just different dac...
Well if you're job is to review DACs, you aren't going to say they all sound the same are you?
Amber Audio
This is the Day
I found the differences between the Qutest and RME very small, decision which to keep (RME) was more based on feature set than absolute sound quality/perceived differences - caveat - I’m old and not a HiFi Pro reviewer, I so have 2 ears that work though even after years of SLF and Skids.
gavreid
Pretty Words...
I have 2qute and the RME but they're in very different setups so I can't easily compare. I'm guessing but if the system doesn't major in soundstage then it wouldn't show up. But the question is a general one (I did say for example) would it be a scrambling of phase? Is that what a wide vs narrow soundstage is?
beammeup
pfm Member
Lots of further interesting responses regarding Chord. Those than can't tell the difference do you have a system transparent enough (usually the need for excellent loudspeakers) to hear any changes from the digital front end?
Chord does have a good following - it can only mean Chord is very good or ....
I got this response from an email after asking for advice on a DAC after mentioning Chord as a manufacturer for comparison (I won't say who)...
"if you want to hear what the musician intended go with R-2R…if you want an algorithm’s take on your music then go with the many Delta-Sigma, single-bit, closest approximation DACs on the market"
"Chord is only so popular because it is so popular…most people who own them and rave about them have only compared them to the mediocrity on the market"
Interesting response - but there you go...
Chord does have a good following - it can only mean Chord is very good or ....
I got this response from an email after asking for advice on a DAC after mentioning Chord as a manufacturer for comparison (I won't say who)...
"if you want to hear what the musician intended go with R-2R…if you want an algorithm’s take on your music then go with the many Delta-Sigma, single-bit, closest approximation DACs on the market"
"Chord is only so popular because it is so popular…most people who own them and rave about them have only compared them to the mediocrity on the market"
Interesting response - but there you go...
