R2R DACs - En liste

[Claus-DK]

can i sir ?

Can what my friend ??

[kvik]

@Alvin: Your soekris based dac is on the list now. I am not sure about the Denafrips ones. First time I looked at denafrips website all three were there with pictures and text, now only Ares is left. Also, pictures showed Dac-8Pro2 and Dac-1Pro as double-units (separate psu), however pictures on your site now shows them as single units (taller, as if psu is integrated now). If you have any info about changes in design or specs, feel free to share them here (or in your dealer section, if you have extensive information).

[kvik]

Fordi det er rart at have noget at se på også, er her billeder af nogle af enhederne på listen..

dac1.jpg (1.05 MiB) Vist 23686 gange

dac2.jpg (1.05 MiB) Vist 23686 gange

dac3.jpg (1 MiB) Vist 23686 gange

dac4.jpg (1.37 MiB) Vist 23686 gange

dac5.jpg (698.84 KiB) Vist 23686 gange

[LarsHP]

Endnu en R2R DAC: Audio-gd R2R 7

At dømme efter prisen, skal dette være en high end DAC og sandsynligvis være efterfølgeren til Master 7 Singularity, der er baseret på PCM1704 chip'en.
Hvordan den støtter DXD og DSD "natively" ved jeg ikke ...

http://audio-gd.com/R2R/R2R7/R2R7EN.htm

[kvik]

Jeg så den faktisk hos Audiophonics i dag under nyheder, reflekterede ikke nærmere over det, tænkte de mente NOS 7.

[Ostebaronen]

Endnu en R2R DAC: Audio-gd R2R 7
(...)
Hvordan den støtter DXD og DSD "natively" ved jeg ikke ...

De skriver selv at det er en Amanero dims som tager imod signal fra USB/RJ45/HDMI, den spiser DXD og DSD råt!

[LarsHP]

Endnu en R2R DAC: Audio-gd R2R 7
(...)
Hvordan den støtter DXD og DSD "natively" ved jeg ikke ...

De skriver selv at det er en Amanero dims som tager imod signal fra USB/RJ45/HDMI, den spiser DXD og DSD råt!

Ja, men det jeg ikke forstår er, hvordan en ladder DAC læser et DSD-signal "natively"? Den skal jo kun kunne læse 16 eller (max) 24 bit samples ... eller er det netop det, det handler om MAX 24 bit: at den så bare tar 1 bit ad gangen (og glemmer alle de fine modstande den har og kun læser én værdi, foruden nul, ad gangen), men i rasende hastighed?

[Ostebaronen]

Det gør det heller ikke. Der er jo en FPGA foran som re-clocker og tilføjer filtre til signalet. Ergo det bliver konverteret til noget R2R ladderen kan "forstå".

[LarsHP]

OK. SÃ¥ det er sludder, at den kan afspille DSD "natively"... Uanset er det ikke noget der betyder noget for mig. Jeg ejer ikke en eneste DSD-fil og regner ikke med at komme til det heller.

[LarsHP]

Kingwa ligger ikke på den lade side:
Ny NOS DAC med diskret opbygget(!) R2R konverter med (single ended) hovedtelefonudgang og pre out:

http://www.audio-gd.com/R2R/R2R15/R2R15CH.htm (kun på kinesisk)
http://www.magnahifi.com/en/webshop/product/r2r15-nos €325 (€268,60 excl VAT)

[LarsHP]

Forøvrig interessante oplysninger på Audio-gd R2R 7 siden:
http://www.audio-gd.com/R2R/R2R7/R2R7EN.htm

"Pros and cons of R-2R DAC:

Advantages:
1. R-2R will not convert the clock signal into the output signal.
2. R-2R is not sensitive to jitter while Delta-Sigma DA is much more sensitive to jitter.
3. The output signal is much more precise compared to Delta-Sigma DA.
Weaknesses:
1.THD today is extremely good with Sigma Delta chips; R2R ladders are good too but not as good.
2. Glitches and accuracy of the ladder resistors are very difficult to avoid and require complex technology to resolve it.

R-2R basic design in the market:
The R-2R DAC is very popular nowadays and available from DIY kits and completely up to of the shelf high-end products. In the low range DIY market, the R-2R design is often based on old technology designed a long time ago by MSB and only includes basic R2R ladder design and do not include the wonderful correction design of the original MSB technology. This design uses data shift registers logic chips in series mode to convert the data to an analog signal. The structural R2R technology issues cannot be avoided, and performance is solely depending on the accuracy of the ladder resistors.

In the High-End of the shelf (finished products) market, the R2R design is much more complex only to reach best performance. A basic R2R ladder is simply not sufficient enough to achieve good performance and sound quality! Some manufacturers are using shift registers design. A less complex and less performing design based on traditional logic chips working in serial mode to correct the ladder.

A far better design switches resistors in parallel mode. An ultra-fast FPGA controls and corrects the R2R ladder. The parallel design mode controls every bit respectively and therefore achieve unprecedented performance. (In parallel mode only 1 clock cycle is needed to output all data; serial design mode needs at minimum 8 up to 24 clock cycles) The parallel design is much more complicated. Once designed properly it can correct every bit of the ladder. Photo below shows a design with such FPGA, can correct the unavoidable imperfections of the R2R ladder caused by tolerance of resistors, glitches to achieve best performance.

Accuracy of the ladder resistors (tolerance):
Many people believe the tolerance of the resistors in the ladder is most important to reach best performance. Nowadays 24 bit resolution is standard. What tolerance is needed to achieve 24 bit resolution?
When we look at 16 bit the tolerance of 1/66536, 0.1% (1/1000) is far not enough, even a tolerance of 0.01% (1/10000), the best tolerance available in the world today, still cannot handle 16 bit request correctly; we are not even calculating 24 bit here!
The tolerance of the resistor will never solve Imperfections of a ladder. This would require resistors with a tolerance of 0.00001% and can handle 24 bit resolution. This is only in theory because the discreteness of the switch logic chips have already too much internal impedance and will destroy the impossible tolerance of a resistor.
The solution is to correct the ladder and not only depend on the tolerance of resistors. It’s a combination of both: Ultra-low tolerance resistors controlled by a correction technology using very high speed FPGA are applicable in in our design.
Importunacy of the FPGA in the R2R 7: FPGA stands for Programmable Array Logic.
Nowadays the FPGA is applied in a lot high end grade DACs; like the popular ROCKNA WAVEDREAM DAC.
The internal hardware design is fully controlled by complex software. A huge advantage is the fact the software in the FPGA can easily be upgraded offering new features or improve the performance. Such design is much flexible and future proof!

FPGA tasks in the R2R 7

The FPGA in the R2R 7 is responsible for:
1. High performance SPDIF interface, replacing traditional less good performing SPDIF interface chips like DIR9001, WM8805 or AK411X,etc.
2. Full re-clocking process with FIFO design applicable on all inputs. This way the output data keeps fully synchronized with the clock signal to reject any jitter.
3. Built in 2X, 4X and 8X oversampling and digital filters and on top of this 4 different true NOS (only analog 6dB filtering) modes. To completely configure it to your liking!

Fully discrete output stages
The signal last stage is the analog output stages, they can much effect the whole DAC sound quality. After d/a conversion by the R2R D/A modules the analogue signal is transported by fully discrete matched-transistor output stages.
DC-coupled design with first class through-hole components. No SMD components are applied. The high speed special ACSS output stages are non-feedback and current driven design.
Special because almost all other designs need to convert the signal multiple times from and to current or voltage, resulting in less detail and less good staging.
The output buffers are single ended FET. Two stages in parallel to reach very low output impedance. All output stages are in pure class A design without any (negative) feedback to achieve purest and a real live sound reproduction.
The 4 OPA opamp’s are functioning as DC servo, this way no coupling-capacitors are needed and DC output is automatically biased! Resulting in a perfectly neutral sound.
There are no relays or other switches in the signal path after DA modules to perform the best and purest sound quality."

[LarsHP]

Endnu en DAC med diskret ladder DAC sektion:

Rockna Wavedream DAC

http://www.rockna-audio.com/products/wavedream-dac

... men den koster penge: Single ended - £3,950, balanced - £5,250

[LarsHP]

Audio-gd R2R 11
Single Ended Discrete Ladder Headphone amp

NOS design with R-2R resistor ladders DAC+Headamp
Built in 2 groups DA-8 R-2R modules
Unique noise reject technology remove the artifacts
DSD , DXD support from USB
Amanero Combo 384 USB interface
All parts soldering with silver tin All resistors are the KOA / Vishay, no upgrade options

Price: USD350 (Exclude shipping cost)

http://audio-gd.com/R2R/R2R11/R2R11EN.htm

[LarsHP]

Jeg bliver næsten forpustet ved det tempo Kingwa præsenterer R2R DAC'er for tiden: Nu kommer der en R2R 7HE også, som er en R2R 7 med indbygget "strøm-regenerator", hvis det hedder sådan på dansk. Beskrivelse:

The regenerative power supply like a proprietary electric generator built in the unit.
It can block most disturb from the power line , supply the ultra clean power supply for the audio amps , reproduce the most neutral and analog sound like audio signal for the system and the users.
In the regenerative power supply design, the AC power through the regenerative input transformer , conversion to DC power ,through the class A PSUs power supply for the regenerative wave generator and driver stages .
A balance regenerative regular wave generator produce the ultra low distortion 50Hz wave ,through the balance gain amps and the strong output stages , drive the regenerative transformers produce the clean AC power supply feed to the separate class A PSUs power supply for the L and R channel preamps .
The class A parallel connection PSU has very high input impedance to avoid disturb through the PSU from affecting the signal parts and low output impedance with very fast speed and high linear, it is a very clean power supply.

Pris: USD3480 + forsendelse og moms

http://www.audio-gd.com/HE/R2R7HE/R2R7HEEN.htm

[kvik]

R2R 7HE kabinettet er 50 cm dybt!
https://www.head-fi.org/threads/new-aud ... t-13663419

[kvik]

Abbasaudio, Aries Cerat, Arkhipov's, BorderPatrol og Etalon tilføjet.

[kvik]

Her en (meget positiv) brugererfaring med Audio-GD R2R 11. Hollandske MagnaHIFI har både R2R 11 (€325) og R2R 15 (€379), siden prisen er forskellig, må man antage enhederne også er det. Beskrivelsen på Audio-GDs hjemmeside af R2R 11 matcher dog beskrivelsen af R2R 15 hos MagnaHIFI, så jeg ved ikke, hvad forskellen evt måtte være. Dette med reference til listen i første indlæg, hvor jeg antyder de to er ens.

[kvik]

SW1X og MyST opdateret

[kvik]

Acuhorn, LampizatOr, Vertex AQ og Tidal Audio tilføjet, samt Audio Note opdateret.

[kvik]

Audio-Optimum og Trinity tilføjet