DAC chips compared by ear: TDA1540, TDA1541, TDA1547, PCM1704 and CS4397

Between 2010 and 2017 owners of Demograf Audio converters built on different chips wrote about how they sounded side by side, often after sessions in Dmitriy Gubchenko’s listening room. The chips were the Philips TDA1540, TDA1541 and TDA1547, the Burr-Brown PCM1704 and the Cirrus Logic CS4397, each with a tube output stage, plus a prototype on an AKM chip. Today these chips are the heart of the Reference Tube DAC versions Calliope (TDA1540), Persephone (TDA1541), Aphrodite (TDA1547) and Katerina (PCM1704), and of the Hyperion (CS4397). Below we summarise what owners heard. For how the chips work, see our guide to NOS multibit DAC chips.

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.

The converters described here were earlier, often one-off builds; today’s versions differ in detail. The TDA1547 is a 1-bit bitstream chip and the CS4397 a multibit delta-sigma chip, so this is a comparison of architectures as well as of chips.

The chips at a glance, as owners heard them

TDA1540 vs TDA1541

NIK preferred the TDA1540: better bass, nothing bright, excellent vocals and a larger stage than the TDA1541. Another owner, Alexander, describes how his TDA1541 DAC transformed his system with scale, natural timbre, resolution and emotion. He later tried two versions of the TDA1540 itself. The TDA1540D made classical and live music more vivid in dynamic nuance and natural in timbre, but electronic music lost the impact it had with the TDA1540P. “Nothing is universal,” he concludes; “everything depends on the genre, even two versions of the same chip.”

A third owner, vitta77, who heard the TDA1540, TDA1541 and TDA1547 builds, calls the TDA1540 the most comfortable of them, especially on headphones with a tube amplifier: a DAC to live with, unless you keep wondering what the double bass player is doing in the background.

TDA1541 vs TDA1547

One session, three DACs

andafan, a TDA1541 owner, heard the TDA1547, TDA1540 and TDA1541 side by side once. The TDA1547 produced a “wow” effect, bright and polished. The TDA1540 charmed him. Against both his TDA1541 felt like the outsider: behind the TDA1547 in impact, dynamics, sharpness and precision, and behind the TDA1540 in involvement. Back home the same evening, though, he found he could simply enjoy music on it. On reflection he felt the TDA1547 lacks the analogue quality of the TDA1541 and, even more, of the TDA1540. To him the TDA1541 is not a compromise between the other two but has a voice of its own, closer to the TDA1540. Starting from scratch, he would begin with the TDA1540; with one DAC only, he considers the TDA1541 a sensible choice that needs no replacing.

Cooler but more informative

vitta77 compared his TDA1547 DAC, with EL8 output, with a TDA1541 build. The TDA1547 seemed colder to him, with an occasional icy touch, while the TDA1541 was more comfortable and relaxing and easier to listen to on headphones. Switching quickly between them, though, he found the TDA1547 far more informative and interesting, with very high detail that never turned into a mere collection of small details. Its drawback, he says, is that it needs a system of matching quality. After a later rebuild with output transformers and an Amanero USB input feeding the chip over I2S, he heard tighter, better-defined bass and more detail, with natural timbre.

Against a Weiss and a Philips

In May 2012 only_a_lad heard TDA1541, TDA1547 and prototype AKM builds against a Weiss DAC202 and the Philips SAA7322/SAA7323 converter built into a Sennheiser HEV 90, through Sennheiser HE 90, Stax SR-009 and Beyerdynamic DT 911 headphones, with classical, jazz, rock and metal. He liked the TDA1547 most, for its musicality, juiciness and involvement with a well-balanced sound, a good stage and dynamics. The AKM prototype sounded powerful and loud and pushed the stage forward a little, but he found it less musical for now. He placed the HEV 90’s built-in converter between the TDA1541 and the TDA1547.

TDA1547 vs CS4397

borlebsin ordered a single DAC containing both a TDA1547 and a CS4397, with two tube headphone outputs, one of them balanced for the AKG K1000, and continuous output-level control. He heard the CS4397 as extraordinarily detailed with no harshness at all, softly analogue, very wide-band and very deep in its stage, on loudspeakers and on headphones alike. He found the TDA1547 less spacious and less extended, but captivating in its singing midrange and overall balance, with violins that sounded less broad but beautiful and refined.

He also compared them with a Berkeley Audio Design DAC and USB converter, though in a different system. It gave a wide stage too, but he heard the CS4397’s spaciousness extend into depth as well, and found the Berkeley’s sound drier.

Headphones straight from the tube output

Driving headphones directly from the DAC’s tube outputs, he found that low-impedance models gained a great deal, and that the Beyerdynamic DT 911 reproduced the organ’s lowest C, around 16 Hz, clearly. High-impedance headphones, the Sennheiser HD 800 and the DT 911 itself among them, still sounded better to him through a separate headphone amplifier.

TDA1541 vs PCM1704, and the Naim DAC

In March 2011 shag compared, in the designer’s room, a Naim DAC (on the PCM1704K) with Demograf Audio converters on the PCM1704, TDA1541 and TDA1540, on headphones and on loudspeakers with 30 cm full-range drivers. He found the PCM1704 and TDA1541 builds the most interesting. The PCM1704 was slightly brighter: on classical music everything “flew”, with beautiful decays and a dense sound. The TDA1541 was more balanced across the range, comfortable and calm. Both gave him remarkable detail. Next to them, the Naim DAC seemed slightly veiled and constrained at the top and bottom. He credits Naim with serious engineering work and suspects the op-amps, and believes that replacing an op-amp output with transformers and a tube stage brings detail and space without losing density, audible above all in full, low chest voices.

TDA1547 vs AKM, and vinyl

Later shag heard a DAC on the AKM AK4399 and the TDA1547 against vinyl, with identical CDs and records. The AK4399 gave very high resolution, the TDA1547 an analogue quality closer to vinyl. On a new jazz pressing they sounded almost identical; on an original-era classical record the vinyl sounded a little freer. He concluded that a well-mastered CD and the TDA1547 can complement a vinyl collection. The AKM converters in these sessions, including the prototype only_a_lad heard, have no equivalent in the current Demograf Audio catalogue.

TDA1547 vs Mytek

Rusmeloman, who moved from a TDA1541 DAC to a TDA1547 build with Sowter step-down output transformers, calls it a very natural DAC, with rich decays and timbres. He compared it with a Mytek Stereo192-DSD DAC, which he liked as a product. The Mytek played somewhat more dynamically and made more accents, which he thinks may lead a beginner to take it for the more detailed DAC. Over longer listening he heard this as a metallic colouring and insistence, without a live atmosphere. “I am not saying the Mytek is bad,” he writes, “I am saying the DAC7 is very good.”

PCM63: heard only in other makers’ DACs

No Demograf Audio converter on the PCM63 took part in these sessions. borlebsin, who had bought eight PCM63 chips for a DAC of his own, changed his plans after hearing the CS4397 against an expensive DAC on the PCM63; after the CS4397 and the TDA1547 he felt no wish to return to it, though he did not find it bad. Later he heard a two-box PCM63 DAC by another builder and was impressed by how well the chip was used: behind the TDA1547 in vocal harmonics for him, ahead of it in space and resolution, and close to the CS4397, which still went deeper in the bass.

The designer’s view

In 2017 Dmitriy Gubchenko summarised his own experience with the same output stage, tubes and transformers. He describes the TDA1547 as an early 1-bit design that, with careful filtering, gives high detail and dynamics in the bass and the euphony of the old Philips chips. The CS4397 with the same output stage gives him somewhat higher dynamics and detail. An AKM AK4497 sounded a little simpler and more distant to him, with less and slower deep bass. He made these comparisons mainly on large multi-amplified loudspeakers; with headphones, he notes, far more factors affect the result.

What the comparisons suggest

• Listeners divide along taste and music more than along chips: the TDA1540 for comfort and naturalness, the TDA1541 for balance, the TDA1547 for musical detail, the CS4397 for scale and extension.
• The same chip was heard differently in different systems: the TDA1547 was bright to one listener and cool to another, and analogue to a third.
• Several owners found that the output stage, cables and system mattered as much as the chip.

Which Demograf Audio piece fits

• The Reference Tube DAC is one chassis in five versions: Calliope (TDA1540), Persephone (TDA1541), Aphrodite (TDA1547), Artemis (PCM63) and Katerina (PCM1704). It takes 16-bit / 44.1 kHz PCM over S/PDIF coaxial with no upsampling. In Dmitriy Gubchenko’s voicing, Calliope is natural and organic, Persephone fast, Aphrodite dark and velvety, Artemis large-scale and Katerina strong in bass and attack. The stock output stage is solid-state; tube output stages, including EL8 and AL4, are optional. Owners’ fuller impressions of three of these versions are in our reviews of Calliope, Persephone and Aphrodite.
• Hyperion is the current Demograf Audio DAC on the Cirrus Logic CS4397. It takes USB (Amanero) up to 24-bit / 192 kHz and DSD256 as well as S/PDIF coaxial. The stock output stage is solid-state; a tube output stage, EL8 and AL4 among the options, can be fitted to order. More owners’ impressions are in our Hyperion owners’ reviews.
• Owners have also compared the CS4397 DAC with the Lampizator Golden Gate II, MSB Analog DAC, dCS Debussy and Rockna Wavedream.

Every Demograf Audio converter is made by Dmitriy Gubchenko. Each is made to order and covered by a one-year warranty (extra warranty available: +1 or +2 years). If you are unsure which chip suits your system, write to us with your amplifier, loudspeakers and the music you play most.