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In Reply to: RE: CH Precision DAC cheapest $36,000 to $127,000 (+!) posted by Jon L on June 17, 2024 at 08:57:37
:)
Spline filtering and PCM1704, CH Precision must be Wadia fans. Back then, probably, no one thought you could make a discrete R-2R but that is not the case these days so you need a really good story to differentiate yourself from all the other commercial DAC-chip-in-box companies. Sounds like they should work more on that story.I don't know the market price of new-old-stock PCM1704 chips but if that is $100 each and they are using four then that's adding ~ $1600 to the retail price.
Edits: 06/17/24Follow Ups:
You should check your history. Accuphase made a discrete 16bit and then later 20bit DAC back in the 1980s. Discrete DAC architecture is nothing new...probably making a resurgence due to lack of chip availability. I own an Ayon Skylla II, which uses the BB PCM1704 (4 of them) and Ayon switched to ESS and later AKM due to lack of availability of 1704s (seems CH has enough but how many $50K dacs get sold per year?).
https://audio-database.com/Accuphase-kensonic/etc/dc-81l.html
After that they switched to chips...the preferred one being the BB PCM63K (the DC91 DAC used like 16 per channel in their MMB configuration). At one time the BB PCM63 was about $70 per chip when Sigma/Deltas were like $2.
https://www.stereophile.com/content/accuphase-dp-90-cd-transport-dc-91-da-processor
The simple fact is this: A laser trimmed R2R IC like the BB PCM-1704 is MUCH higher precision than any discrete ladder DAC can possibly be with macro sized resistors. Same holds true for BB PCM63, AD 1865, TD1541 etc.
Now you mention it there was a company called UltraAnalog that made DAC modules, which contained discrete components. Maybe Accuphase used those? I think you are right that discrete DACs were made out of necessity before good monolithic DACs then faded away during the PCM63/1702/1074 era and are now back with us.The claim that a laser-trimmed PCM1704 is MUCH higher precision should be tempered. Here is the linearity plot from Stereophile's measurement of a CH Precision C1.2 ($43k as reviewed in Jan 2023). This uses four DAC chips per channel (two paralleled for each phase).
We can see the linearity error starts to grow below -60dBFS (JA is more generous in saying -80dB). Compare that to the holo May DAC with a discrete R-2R DAC.
Here there is no linearity error until down to -120dBFS. This is up there with delta-sigma DACs and I don't know how Holo does it. You might find plots for PCM63/1702/1704 that are much better than CH Precision's implementation but even the best will not exceed the Holo May.footnote for anyone who doesn't read graphs:
The blue lines represent the 'gain' of the DAC from input digital value along the bottom to the measured analog output voltage on the left axis. Both are scaled in dB with the top-right corner representing the max analog output voltage for the maximum input digital value. Ideally the blue line should be straight as it slopes down to the minimum values in the bottom left corner. The red line shows the slope of the blue line - the blue line should have a slope of 1 (= 0dB). The red line should be completely flat across the plot with a value of 0dB, where it is not 0dB indicates a linearity error in the DAC.
Edits: 06/18/24
The ultraanalog used a 12 bit BAC for the last 12 bits. It used discrete for the first 8 bits.
For whatever reason, the CH is not the best linearity measurement I have seen for the PCM1704. Not that this has any correlation with sound quality whatsoever.
Morricab - Are you stating that my Adcom GDA 600 will most likely outperform a Holo Audio May KTE (resistor ladder) when playing CD's? I have 2 Adcom's. Thank you.
Technically probably not...sonically with cds I wouldn't be surprised if you prefer it.
The May attains signal-to-noise figures at the threshold of electron noise and has an effective resolution of more than 22 bits, neither of which the PCM63 can match.
"...attains signal-to-noise figures at the threshold of electron noise"I'm not saying the May isn't special but come on....
"threshold of electron noise" matters not for HiFi but applicable to LNA for radio astronomy or medical instrumentation. Never seen Friis formulas applied to HiFi.
Edits: 06/21/24
to make a point. Its is a very, very, very quiet DAC, despite being a ladder DAC. I honestly don't think much about the specs, I just listen. But you are made aware when you do listen that the sound come out of inky blackness and the soundfield is incredibly coherent ans stable, both of which I would attribute to that S/N ratio.
nt
And neither of which will dictate if he prefers the sound of it or not.
the May to an Adcom would be deaf. The May is a bespoke product like Ferrari and highly biased into class-A in the discrete output stage. While the Adcoms sounded pretty good in their day and offered HDCD decoding in their digital filter chip, they are more akin to a Hyundai. I have never heard a better DAC than the May and at it's level, the differences between products in minimal technically and mostly flavors of tuning.
Well, a friend of mine had their level 2 DAC (not the May but same tech) and it was destroyed by my Ayon DAC and a Lampizator Atlantic TRP2 DAC. Wasn't really close in terms of actual listening...sorry to point out the obvious but the measurements themselves don't mean much for how somethign sounds.
"the measurements themselves don't mean much for how something sounds"
Owned a Tambaqui last year and still own the excellent measuring Benchmark DAC3 HGC. Sold the Tambaqui, and the Benchmark now sits in a box. I like the sound of my two Mojo Audio R2R DACs better. Those Mojo DACs use old AD-1862N (special Z version) chips and they only process up to 24/192 but to me they sound tonally rich and musically satisfying while the Tambaqui, which I characterized as sounding mostly perfect, just didn't provide the same level of enjoyment.
Exactly! I have a friend with a Tambaqui and it just detaches me from the music.
My Ayon Skylla II DAC with BB PCM1704s and tube output stage sounds resolved, full and engaging.
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