Mola Mola DAC Upgrade for Makua/Kula

Mola Mola DAC

FUTURE-PROOF BY BEING FAR AHEAD

We decided to design, from the ground up, a discrete DAC whose unbeatable staying power results simply from being more than 10 years ahead of the performance curve. To put it in perspective: today's best DAC chip available claims no better than 22 bits of dynamic range and only 20 bits of linearity. High-resolution music deserves better than that. To accommodate this, Mola Mola's DAC is designed using circuits and digital algorithms developed entirely in-house.

The converter is a two-board stack that fits into one of the preamp's option slots. On the first board, all incoming digital audio is upsampled to 3.125MHz/32 bits and converted to noise-shaped PWM. On the other board are two mono DACs: a discrete 32-stage FIR DAC and a single-stage 4th-order I/V converter with 4th-order filtering, which converts the PWM into analogue with a breathtaking 130dB SNR.

This is near the theoretical limit for 24-bit files and far beyond that of even quad-speed DSD. Uniquely, distortion remains below the noise floor even for full-scale signals. A quick look at current and historic trends of high-end ICs indicates that for the foreseeable future, this kind of performance will remain unavailable to manufacturers forced to rely on the same 'chip du jour” that also powers their competitors' products.

Even by today's exacting standards, extraordinary care has been taken to deal with jitter. Mola Mola's DAC uses a home-grown asynchronous upsampling algorithm whose input frequency measurement slows down rapidly until, after a few seconds of lock, the frequency ratio measurement is frozen. Frequency stability is then wholly determined by the internal clock, a laboratory-grade 100MHz SC-cut oscillator. This is effectively an atomic clock sans the physics package (which contributes nothing to spectral purity but quite a lot to cost).

Key features

Inputs and Outputs

AES/EBU (XLR)
Optical (Toslink)
USB type B
Bluetooth (SBC, AAC, APTX, LDAC)
Ethernet (Roon Ready)

SUPPORTED FORMATS

PCM up to 384kHz/32 bits (>192kHz and >24 bits via USB and Roon only)
DoP and Native DSD up to quad speed (USB and Roon only)

PERFORMANCE

Full-Scale Output Level: 20dBu

Signal to Noise Ratio: 130dB

THD, IMD: not measurable (estimated -140 dB)

Bandwidth: Up to 80 kHz (apodizing response)

Integrated jitter: <1ps from 10Hz upwards, <300fs from 1kHz upwards

Jitter rejection: >80dB at 1Hz after 20 seconds of lock