Aqua La Scala Mk II Optologic R2R Tube Hybrid DAC

Aqua La Scala Mk II Optologic R2R Tube Hybrid DAC

When two of the main design objectives for a DAC in the high-end audio market are avoiding obsolescence and making a digital product sound like analog, we think that’s doing it right.

Hailing from Milan, Italy, Aqua (Acoustic Quality) takes a very technologically advanced path to realizing both of these important factors with the release of the Mk II revision of their La Scala DAC. The La Scala Mk II features FPGA decoding, R2R (resistor ladder) filtering and conversion, a tube/MOSFET hybrid output stage, and the innovative “Optologic” technology that was originally introduced in their flagship digital converter, the Formula xHD.

Formula xHD broke the mold on DAC architecture, eschewing any of the easy, well-worn traditional paths to conversion (i.e. the Sigma Delta, “DAC on a chip” approach, for one) and all of the compromises and sonic problems that come with them.

It’s the sound of a properly implemented R2R DAC that keeps listeners coming back to that well, and it’s the profoundly high-tech implementation that makes Aqua’s resistor-ladder DACs highly sought after throughout the audiophile world. Just try to find a bad review of Aqua’s DACs… Don’t worry, we’ve got time. Let us know if you find one.

While the Formula xHD pushes the envelope on R2R performance to absolute state of the art, La Scala Mk II offers something of a different perspective with the addition of tubes into the output circuit. Besides the ability to tube roll and try NOS or boutique options, owners of the La Scala Mk II benefit greatly from their influence on the sound.

Now also featuring Formula’s innovative “Optologic” ground isolation scheme, the La Scala Mk II registers better timing, coherence, micro dynamics and timbre, without losing that atmosphere magic for which La Scala is widely renowned.

Previous owners of the La Scala DAC can purchase upgrade boards to reach the Mk II level.

The Music Room's tester and reviewer Duncan Taylor recently spent some quality time with the La Scala Mk II DAC in his system at home, and penned a 4-part review. Part 1 Part 2 Part 3 Part 4 / Conclusion

Features

• Designed and handmade in Italy

• MODULAR DESIGN with upgradeable multi-board system

• Proprietary FPGA-based digital decoding without a digital filter

• Discrete R2R resistor ladders using low noise, metal foil ultra-precise resistors for filtering and converting the digital signal

• Galvanic and magnetic isolations between the FPGA and R2R ladder converter

• Jitter-free digital interface AQlink (I2S protocol), offering an uncompromising digital connection to Aqua La Diva cd transport

• etherCON RJ45 (AQlink) input jack, allowing both standard RJ45 and professional etherCON RJ45

• Zero jitter S/PDIF digital receiver stage, using PLL (phase locked loop) technology

• Upgradeable asynchronous USB module, with resolution up to 384KHz/24bits and DSD64/DSD128 via the DoP protocol. No drivers required for Apple and Linux

• Operates with Apple computers running OSX 10.7 and above, and PC computers running Windows 7 through 10 and XP (ASIO - WASAPI bit perfect high-speed)

• Digital phase selector on front panel

• Two separate low-noise power transformers, one for the analog and one for the digital section

• High-performance discreet regulators (MOSFET, J-FET, BJT) throughout both power supplies

• Tube/MOSFET direct-coupling analog output stage operating in pure class-A, with ZERO negative feedback

• Fully discrete analog stage -- ZERO Op-Amps used in the entire DAC circuit

• MOSFET-based, low-noise "virtual battery" circuit for the tubes' anode supply

• High-quality parts selected for sound quality:

- 105° long life capacitors
- low noise Metal Foil ultra-precision resistors
- double metallized film pulse capacitor
- ultra-fast diodes
- halogen-free cables

• Aluminum anti-resonant cabinet with Nextel finish

Specifications

Digital inputs
- AQlink / RJ45 (I2S serial bus) - PCM 24 bit / 384kHz – DSD64, DSD128 via DoP
- BNC coax (S/PDIF) 75 ohm - PCM 24 bit / 192kHz – DSD64 via DoP
- RCA coax (S/PDIF) 75 ohm - PCM 24 bit / 192kHz – DSD64 via DoP
- AES/EBU balanced 110 ohm - PCM 24 bit / 192kHz – DSD64 via DoP
- USB port - PCM 24 bit / 384kHz – DSD64, DSD128 via DoP

Supported Native Sample Rates
Up to 384KHz/24bits PCM (USB and AQLink inputs), up to 192KHz/24bit (S/PDIF), and DSD64 & DSD128 (via DoP) on all inputs

Asynchronous USB (High Speed)
USB Audio Class 2 with Type B connector

Digital Receiver
PLL (phase locked loop) technology at 128 or 256 FS (internally selectable)

AQlink (I2S bus)
CMOS level

Oversampling factor
1x

Analogue Output Voltage
Unbalanced RCA Output: 2.2 V RMS
Balanced (transformer balanced) XLR Output : 2.2V RMS

Output Impedance
RCA: 100 Ohms
XLR: 600 Ohms

Frequency Response
20Hz to 22kHz +0.5dB/-0.5dB

Phase Response
Linear phase

THD + N
<0.1% at 1KHz

Power Consumption
115V - 58VA
230V - 58VA

Dimensions
( W x D x H ) 450 x 370 x 100 mm

Weight
20lbs