Prometheus DSD DAC: an owner’s first impressions

In 2024 an owner of a Demograf Audio CS4397 converter heard the designer’s newer DSD converter, Prometheus, and later ordered one. Below we summarise his first impressions: how it compared with his own CS4397 converter, with an SQtech Matrix DSC and with a Reimyo DAP-999, and why he describes its sound as analogue in the sense of tape rather than of softness.

These impressions are summarised and translated from owners’ posts on an audiophile forum. They are the subjective views of their authors, not measurements or claims of Demograf Audio.

Which units he heard

The owner calls it the designer’s “DSD DAC”: a converter that turns the incoming signal into DSD, as the SQtech Matrix DSC he had heard before also does. The first unit he heard was a demonstration sample with inexpensive capacitors; the second, in another system, was a base configuration with a solid-state output. He ordered his own with an EF14 tube output stage and better parts. Prometheus converts PCM to DSD on a programmable-logic chip and has a solid-state output stage as standard, with AL4, EL8, EF14 or ML6 tubes as an option.

His reference was his own CS4397 converter with switchable tube outputs, which he describes as the DAC with the most detailed treble he has heard. Our article Hyperion vs Krell Reference 64 follows how he came to it.

Compared with his CS4397 converter

• Bass: faster, more sculpted, more dynamic and easier to follow.
• Midrange: higher dynamics and sharper attacks, all on headphones.
• Treble: resolution only a touch below his CS4397 converter’s. He stresses that the treble is fully present: the analogue quality he hears does not come from a warm or subdued top.
• Stage: somewhat smaller.
• Timbre: the decisive difference. After the DSD converter, his own CS4397 converter sounded “digital” to him on every count, and he did not want to listen to it.

He notes that his CS4397 converter carries far more expensive parts, tubes and capacitors included, while the demonstration unit used inexpensive capacitors.

What he means by analogue

He separates two meanings of the word. One is the smooth, slightly blurred sound many people call analogue. The other, which he heard here, is the analogue of tape: bright, rich, shimmering timbres, a fluid and cohesive texture, instruments that play as whole objects, and attacks so fast and so unaccented that an inexperienced listener would not notice them. He says he did not expect to get those emotions from digital. To hear how fast the attacks were, he adds, he needed a direct comparison with another DAC.

vs SQtech Matrix DSC

Months earlier he had found the SQtech Matrix DSC to be the only DAC that technically surpassed his CS4397 converter, and he had nearly bought one. Comparing from memory, he places the DSD converter and the DSC close in technical ability: the DSC slightly firmer and more dynamic in the bass and with a larger stage. In timbre he heard no contest. The DSC had left him uninvolved on headphones: its timbres were not wrong, he writes, but they did not move him. The DSD converter’s did.

vs Reimyo DAP-999

Later he heard the Reimyo DAP-999, a long-coveted multibit DAC for him, in a showroom system. He found it excellent in every respect: musical, melodic, even in the good sense, with pleasant vocals, a fluid texture and good dynamics, and in sum the strongest multibit DAC he had heard; only the Krell Reference 64 rivals it, better in the bass but clearly behind in the midrange, timbre and naturalness. Then he switched to the DSD converter in its base configuration with a solid-state output, in the same system, and heard everything improve:

• far more overtones and decay in the midrange;
• much richer vocals and instruments, with more varied timbres;
• higher dynamics and technical ability;
• more information, both in the number of sounds and in the texture and timbre of each instrument.

He stresses that the Reimyo is in no way a poor DAC: when he first switched it on, he simply wanted to listen to music, and he had no complaint about any aspect of it.

Reported reservations

• A somewhat smaller stage than his CS4397 converter and the SQtech Matrix DSC.
• Treble resolution a touch below his CS4397 converter’s.
• Bass slightly less firm than the DSC’s, by his recollection.
• These are impressions of a demonstration unit and a base configuration; his own unit with an EF14 output was still on order at the time.

Summary

This owner heard the designer’s DSD converter take a step over his own CS4397 converter in bass, dynamics and, above all, timbre, with treble resolution almost as high and a slightly smaller stage. He placed it close to an SQtech Matrix DSC in technical ability and well ahead of it in timbre, and ahead of a Reimyo DAP-999 on every count he listed. The analogue quality he describes is that of tape: rich timbres and fast, unforced attacks.

Which Demograf Audio piece fits

• Prometheus is the current programmable-logic converter: PCM is converted to DSD on the chip and passed through a window filter, with native DSD1024 and PCM up to 32-bit / 768 kHz over I2S, and S/PDIF coaxial and USB (Amanero) inputs. The recommended output stage is solid-state; an AL4, EL8, EF14 or ML6 tube stage is available.
• Hyperion is the converter on the Cirrus Logic CS4397 that this owner used as his reference; see our Hyperion owners’ review.
• For a CD-centred system with a classic-chip presentation, the Reference Tube DAC is built on the TDA1540, TDA1541, TDA1547, PCM63 or PCM1704.

Every converter is made to order by Dmitriy Gubchenko, with a one-year warranty (extra warranty available: +1 or +2 years).