Electrocompaniet Classic ECD 2 D/A processor

Like many audiophiles of a certain age, I first became aware of the Norwegian company Electrocompaniet when I read a follow-up review of "The Two-Channel Audio Power Amplifier" in Vol.1 No.4 of The Audio Critic, cover-dated July/August/September 1977. "Okay, audio freaks, eat your hearts out. Here's what we think is the world's best-sounding power amplifier," Peter Aczel had written of this 25Wpc amplifier in his original review in 1976. Electrocompaniet was founded 40 years ago, in 1973, by Per Abrahamsen, initially to distribute cheap Bulgarian speakers in Norway and to manufacture public-address electronics. The design of its first hi-fi amplifier, introduced in the mid-1970s, was heavily influenced by the thinking of Finnish engineer Matti Otala, then an up-and-coming superstar in the world of audio engineers, and was described in a paper, "An Audio Amplifier for Ultimate Quality Requirements," that he gave in 1973, at the 44th Audio Engineering Society Convention.

That Electrocompaniet amplifier was impossible to find in the UK, where I then lived, and in the absence of actual experience, the reputation of its sound quality grew to mythic proportion. But when I did finally hear the Electrocompaniet amplifier at an audio show, I was not disappointed.

Which makes it all the more peculiar that, in more than 37 years of working at audio magazines, I have never reviewed an Electrocompaniet product. With this review of the company's ECD 2 digital/analog processor, which costs a dollar short of $3100, that streak of inattention has come to an end.

The ECD 2 . . .
. . . is a wider-than-usual (18.3") component, with a black-painted steel chassis and a thick acrylic front panel. Into the latter are set a blue fluorescent display on the left, a gold on/off button in the center, and, on the right, four gold buttons grouped in a diamond pattern and labeled Navigation. Of these four, the top and bottom buttons are for volume up and down (from "0" to "100" in 1dB steps), the middle two for selecting the input. The buttons are duplicated on the remote control, which also has a Standby button. When you select a source with valid data, the display shows the sample rate on its left and the volume on its right for about five seconds, after which it reverts to showing the input name.


On the left of the rear panel are the balanced and single-ended analog output jacks; and at its center, the five digital inputs: USB 2.0, and two each coaxial and optical S/PDIF. On the right are the AC inlet, trigger input and output jacks, and an RS232 port. The 18-lb ECD 2 stands on three compliant feet. Its USB input doesn't need a driver program when the ECD 2 is used with Macintosh computers; a Windows driver, and manuals for all current Electrocompaniet products, are provided on a CD-R.

The ECD 2's digital and analog circuitry are carried on a large, blue printed circuit board mounted behind the rear panel and running almost the entire width of the chassis. This board is stuffed with surface-mount parts. A large XMOS chip handles the USB input, and the digital data are fed to a Burr-Brown SRC43921, the same asynchronous upsampler chip used in the Bryston BDA-2 and Musical Fidelity V-DACII. This feeds two Cirrus 4398 multi-bit, delta-sigma DAC chips. Although the 4398 is a two-channel part, the ECD 2 has one per channel, presumably used in dual-differential mode to give a 3dB increase in dynamic range. This chip has an integral volume control, and a separate port for DSD data; perhaps an upgrade will be offered to enable the ECD 2 to decode DSD datastreams.


The analog circuitry appears to be based on discrete transistors, with local regulation for the power-supply rails and much decoupling in evidence. The power supply is based on a toroidal transformer mounted behind the front panel.

Although its volume control makes it possible for the ECD 2 to be used straight into the power amplifier, I stuck with the traditional arrangement of feeding it to a preamplifier, in this case the Pass Labs XP-30 that I reviewed in March. I left the Electrocompaniet's volume control at its maximum setting of "100." Although I occasionally used the Marantz NA-11S1 media server's or Ayre Acoustics C-5xeMP disc player's coaxial outputs to send audio data to the Electrocompaniet, I mostly used the ECD 2's asynchronous USB input with Pure Music running on my Mac mini.

The ECD 2 is specified as handling PCM files with sample rates of up to 192kHz. As the Electrocompaniet has a DAC chip capable of decoding DSD data, I tried playing some DSD files using Pure Music. However, while these files played, it looked as if Pure Music was converting them on the fly to 176.4kHz PCM to make them compatible with the ECD 2.

I've always been a bit suspicious of upsampling converters, concerned that the benefit of driving the DAC chip with higher-sample-rate data would be offset by the possibility of mathematical imprecision in the upsampling process. But the ECD 2 allayed any such fears I might have had. In Trevor Pinnock and the Royal Academy of Music Soloists Ensemble's excellent new recording of Erwin Stein's chamber-orchestra version of Mahler's Symphony 4 (24/192 ALAC files from Linn CKD438), the acoustic around the piano in the opening movements was deliciously apparent, while the images of the solo oboe, clarinet, violin, and cello were presented more forward in the soundstage, and were well defined and stable. The single double bass that carries the responsibility of providing the work's tonal foundation was weighty yet well defined. In the first part of the symphony's third movement, Ruhevoll, poco adagio—where, after several solo instruments serially intone a forlorn melody over a pizzicato bass riff, the harmony resolves on a low bass note—the ECD 2 made sure it was goose-bump time.

Company Info
Electrocompaniet AS
US distributor: Electrocompaniet Inc.
97 Linden Street
Oakland, CA 94607
(510) 291-1222
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SAAudio's picture
What firmware were you listening to

Several listeners have reported that different firmware versions have an influence on the sound of the M51. General consensus seems to be that v1.39 is the best sounding with v1.41 having less bass and is not quite as dynamic. It would be interesting to know what version firmware the latest sample runs. As a long term user of a NAD M51 I find your further thoughts on this remarkable device very interesting.

John Atkinson's picture
NAD M51 Firmware

SAAudio wrote:
Several listeners have reported that different firmware versions have an influence on the sound of the M51. General consensus seems to be that v1.39 is the best sounding with v1.41 having less bass and is not quite as dynamic. It would be interesting to know what version firmware the latest sample runs.

Turning on the M51 with the Input button pressed reveals that our new sample is running the v.1.41 firmware. I have no idea how to roll it back to v.1.39 or if that is even possible.

John Atkinson

Editor, Stereophile

SAAudio's picture
NADC M51 firmware

Thanks John. It is easy to change firmware versions. V1.39 can be found here: http://www.fileswap.com/dl/BlRT7tfhYl/ . V1.41 can be found on NAD's web page. It would be very interesting to know your thoughts on any differences.

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