dCS Elgar Plus DAC

The dCS Elgar Plus DAC

Elgar Plus was the upgraded form of the landmark dCS Elgar. dCS launched the original Elgar in 1996 as its first consumer product and the world’s first 24-bit-resolution DAC designed for home use. It was not the first 24-bit DAC overall: dCS gives that distinction to the professional dCS 950 from 1993.

The original Elgar initially accepted data up to 96kS/s; a later software and hardware revision added 176.4 and 192kS/s. Elgar Plus then combined PCM input up to 24-bit/192kS/s with DSD support, and dCS described it as the first 24/192-DSD audiophile D/A converter.

DSD support arrived in stages: Elgar Plus Mk1 accepted PCM and DSD through SDIF-2, while Elgar Plus Mk2 added DSD through IEEE 1394. The 1394 input carried encrypted DSD from compatible dCS components; it was not simply a generic consumer DSD connection.

High-end dCS Elgar Plus Digital to Analog Converter. In 2002 retail was $ 19,000.

The documented sequence is therefore: Elgar in 1996 with input up to 96kS/s; later Elgar support for 176.4 and 192kS/s; Elgar Plus Mk1 with DSD over SDIF-2; and Elgar Plus Mk2 with DSD over IEEE 1394.

From October 2001, dCS offered a pair of 200Mbit/s IEEE 1394 interfaces as standard on the Elgar Plus, with software version 4.10 or later. dCS used the link to carry encrypted stereo DSD between its compatible components and noted that separate word-clock synchronization was required for low-jitter conversion.

The Elgar Plus works in a dCS stack with the Verdi and Purcell. Verdi can send encrypted DSD from SACD over IEEE 1394, while a 1394-equipped Purcell can upsample CD PCM to DSD before the Elgar Plus converts it to analog.

Automatic input selection—dCS’s Easy Play behavior—was added from October 2002 on compatible systems, including Elgar Plus software version 4.20 or later.

The advanced technologies used in Elgar Plus provide the user with a number of additional features, besides those provided by the ordinary audiophile DAC. This opens up greater freedom of choice for configuration options and utilization in specific systems.

The patented dCS Ring DAC is the central conversion architecture in Elgar Plus. The unit oversamples and maps incoming data to a 5-bit stream at approximately 3MS/s. For the 44.1kHz and 48kHz sample-rate families, 64× corresponds to 2.8224MHz and 3.072MHz—not 2,822 or 3,072 million samples per second.

To understand the advantage, compare it with conventional ladder DACs. A ladder uses weighted resistor or current-source values, so component tolerances can create signal-correlated linearity errors. The Ring DAC instead uses equal-value current sources and changes which sources represent a given sample, averaging component-value errors over time.

Single-bit delta-sigma systems avoid weighted current sources but generate substantial out-of-band quantization noise and are sensitive to timing error. The dCS approach first oversamples PCM, modulates it to five bits and then distributes it through the Mapper. This is designed to reduce correlated distortion; it does not make the converter literally immune to clock, temperature or component errors.

A 24-bit input specification describes the word length the DAC accepts, not proof that the analog output resolves every one of 24 bits. dCS documents the Ring DAC’s low-level linearity benefits, but the article should not make the unsupported absolute claim that Elgar Plus “resolves all 24 bits.”

Other DAC Options And The dCS Elgar Plus DAC

The dCS Elgar Plus is a much better DAC than the Schiit Modi 3. However, the latter costs only a hundred dollars. We went through the Schiit Modi 3 when studying the architecture of a Schiit stack.

If you own a Devialet Gold or Silver Phantom, you should prefer using the Devialet DAC. They are located inside the mainboard.

The analog inputs just get converted through ADC to a digital signal and then converted back for output. As good as the ADC is in Devialet, fewer conversions are always better.

The Devialet converts everything analog input into it to digital and then back to analog so the DAC itself cannot be ‘bypassed’ so it sounds most logical that the USB input isn’t well implemented or that it isn’t playing nice with the Antipodes. Reviewers state that they got better sound WiFi streaming to it (vs Macbook pro via USB or similar), but that they had dropouts,

Placement Of The Elgar Plus In A dCS Stack 

The dCS stack I refer here is composed by the dCS Elgar Plus + dCS Verdi + dCS Purcell. The price of the stack is around 32,000 dollars. Sitting atop an equipment rack, the triple dCS stack casts an impressive visual spell. The pieces can also be set on separate shelves, of course. It is much better than the Schiit stack we have already reviewed in this article, but also much more expensive.

When you’re listening to CDs, you can bypass the Purcell DDC and send the Verdi’s 16-bit/44.1kHz output directly to the Elgar Plus DAC, or you can customize the Purcell and choose your upsampling rate. Without getting hyper-specific about what I heard, the Verdi-Elgar Plus’s rendering of 16/44.1 was as good as I’ve heard the format, with close to the same level of transparency, focus, and spatiality as I heard upsampling through the Purcell. What the Purcell seemed to improve—especially in 176.4kHz or DSD mode—was image delicacy, dimensionality, and subtlety.

Despite their almost infinite possibilities of connection and playback, I recommend you to start with the most general settings.  Otherwise, you might never get to listen to an entire piece of music as you experiment with various digital filters and upsampling options

So instead of playing around, start by placing a CD in the drawer mechanism and operate the device as you would with any CD player. When you hit “Play”, the Purcell’s (Purcell is part of the dCS stack) display shows “441-DSD” and the Elgar Plus’s display shows “Purcell.” This lets you know that the transport’s signal is feeding the Purcell, which is upsampling to DSD and feeding the Elgar Plus via the IEEE1394 connection.

Improvements From The Original Elgar

The Elgar Plus improves on the Elgar’s performance and operation by adding DSD decoding via FireWire or SDIF-2 interfaces and by allowing it to slave to a word clock or to act as a master clock. It also adds a digital output and an improved and extended menu system.

Because the Plus accepts 24-bit PCM at 96 and 192kS/s, you can connect a compatible DVD-V player’s 24-bit/96kS/s linear-PCM output—some players may downsample it—and decode DAD discs. This is PCM data, not the encoded “bitstream” discussed in TV audio menus. Like other dCS DACs of the period, Elgar Plus uses the proprietary Ring DAC architecture for conversion.

Many DAC manufacturers use third-party converter chips, while dCS developed its own Ring DAC and software-driven processing platform. dCS’s early signal-conversion work included aerospace and defense projects, but it is too strong to claim that military contracts alone made this research possible. Elgar Plus software could be updated from a dCS CD or by a service agent through the rear software-update port.

Cons: Volume controls

The volume control is in 0.5db increments. I would have liked 0.1db increments to gain precision. This is the only thing I can think of that is negative about this equipment. It costs a small fortune but delivers leading-edge performance for what you pay.

Specifications

• PCM up to 24-bit/192kS/s and DSD D/A conversion
• Sample rates: 32, 44.1, 48, 88.2, 96, 176.4 & 192kS / s
• Accepts PCM input words up to 24 bits
• 8 digital inputs
• dCS-encrypted DSD input via the IEEE 1394 interface
• weight: 12kg (26.5 lbs)

Conclusions

Nothing can help awfully recorded and/or digitized productions, so if you’re expecting the dCS combo to work miracles on DDD discs ca 1984, you’ll be disappointed.

This box produces the most lifelike sound I have ever heard from a stereo system. The “blat” of the horns, the ringing of a triangle, the crisp thump of a bass, it’s all there. I found the overall sound unbelievably detailed and transparent throughout the entire frequency range.

I’ve been through laserdisc transports, glass-fiber optics, oversampling, and upsampling, and I’ve heard enough digital playback systems at audio shows to feel comfortable saying that these components from dCS comprised the best digital playback system I’ve ever heard for decoding standard CDs.

As far as what sets the dCS system apart sonically, I guess it starts with the proprietary Ring DAC, continues with the math encoded on the DSP chips, and ends with the structural rigidity and quality of the parts. Whatever dCS has done here, their computational, electronic, and mechanical brilliance adds up to what must be the state of the art of getting the most from digitally encoded music.