The Entech 203.2 D/A converter is an affordable audiophile product from the Entech division of Monster Cable (The Monster Group). Monster’s hardware division has assembled a blue-ribbon collection of consumer audio industry designers, including Peter Madnick (of Audio Alchemy fame) and Richard Marsh (of MIT cables and capacitors). The team is headed by Demian Martin (Spectral).
Product PointsApplications: Project, recording and mastering studios
Key Features: Accepts 32 kHz to 48 kHz sampled digital audio signals on optical or coax connectors; stereo analog outputs unbalanced on RCA connectors; 15 W external transformer
Contact: Entech at 805-493-0205
+ Power supply has separate grounding wall power cord; no wasted outlets
+ Good sound
+ Optical and coaxial digital inputs
+ Accepts 24-bit digital signals
– No power-on indicator
– Uses external power supply with nonlocking coaxial plug
– Fixed analog output levels
– Only has unbalanced (RCA) output jacks
The Score: An excellent, economical 24-bit-capable outboard D/A converter that can replace inferior D/As in DAT machines, CD players, digital consoles, DVDs, etc.
This DAC raises a few questions as to what sonic performance you can buy for less than $300. Advertised as a 20-bit unit, the Entech comes in a compact, brushed-aluminum package with black trim. It accepts 32 kHz to 48 kHz sampled digital audio signals on TOSlink (optical) or RCA (coax) connectors, with either consumer (S/PDIF) or professional (AES/EBU) channel status bits.
Stereo analog outputs are unbalanced on RCA connectors. A rear- panel switch selects between the coax and optical input. Power is supplied via a 15 W external transformer, with an attached grounded power cord.
The low-voltage output on a coax plug has a snug fit but, without a locking mechanism, it can be pulled out accidentally. I also miss a power indicator; with only a lock LED one can’t determine if the Entech is powered until a valid digital audio signal is connected. The designers made the right trade-offs to reach the very economical price.
Internal construction is clean and Spartan with five voltage regulators, metal film resistors throughout, and polypropylene and polystyrene coupling and filter caps. Active ICs are the Crystal Semiconductor 4329 DAC with integral digital filter, the Crystal 8412 digital audio receiver and a Burr-Brown op-amp as audio output driver and low-pass filter.
I was curious to see how a $300 D/A would stand up against my reference standard, a modified high-end audiophile Counterpoint model DA-10. The Counterpoint originally cost around $4,000. This multibit ladder DAC uses an UltraAnalog module and was also designed by Peter Madnick.
Soundwise, I’ve found most professional DACs unable to match the tonal balance of the analog source. Some are very harsh and bright; others are cold, or simply dry. These are inexact terms, but it’s difficult to map the world of measurements to the terminology of sound description.
The combination of my custom-built reference UltraAnalog A/D and Counterpoint D/A comes closer, tonally, to the analog source than any pro A/D-D/A combination I’ve auditioned in my studio.
Conversely, manufacturers of audiophile DACs have a lot to learn about jitter rejection from the pros. Audiophile DACs can sound great in a home with a high-quality CD transport, but the harsh studio environment of multiple clocks, high-jitter DAWs and digital consoles eats D/A converters for lunch.
Only two DACs I’ve auditioned, the dB Technologies and the Prism (both professional), have produced consistent sound in a high-jitter studio environment. To get great sound quality in my mastering studio, I’ve had to marry an external jitter reduction unit (either the Audio Alchemy DTI-Pro 32 or the Meridian 518) with my audiophile Counterpoint DAC. It shouldn’t have to be this way – a good D/A should have both good sound and perfect jitter rejection. This is the challenge designers should lick today.
The Entech DAC combines Crystal Semiconductor’s latest jitter-free technology with audiophile topology, but at a cost of less than a tenth of my reference DAC.
My first listening test was with test tones, not music. I was pleased that no harmonic distortion was evident whether I fed the Entech a dithered -60 dB FS 16-, 20- or 24-bit sine wave. This is good news. It means that even though it’s advertised as a 20-bit DAC, it isn’t necessary to redither digital sources to 20 bits to properly audition them; though the noise floor of a DAC may be 20 bits, it is possible to hear 24-bit tones through that noise floor. The bench tests confirm this.
I listened to the Entech 203.2 DAC with a variety of high-quality 16-, 20- and 24-bit music sources, including CDs, 30 IPS 1/2″ master tapes digitized through my UA A/D converter, and the 24-bit output of my Sonic Solutions workstation. The sound of the Entech is very good. It’s musical and pleasant to listen to, clean, with imaging and definition just a bit vaguer and less defined than that of my far more expensive reference DAC.
The Entech’s bass is a touch looser than the reference DAC’s and the high end is a little brighter (cymbals are a bit metallic), but not very hard, even when driven to full level.
For its pleasant sound and no serious faults, I give the sound of the Entech a solid B rating and it stands up very well against an A+ unit like the Counterpoint.
Putting that B grade into perspective, the Entech 203.2 is better-sounding and easier on the ears than many professional DACs. It may not be possible to build a Class A D/A converter for less than $4,000 because it requires an expensive power supply and analog electronics design.
One reason this little audiophile DAC beats the sound of pro DACs may be that most pro D/As have balanced outputs, which often compromise sound by going through additional stages of amplification. Designer Madnick has clearly followed a “less is more” philosophy and the single Burr-Brown op-amp he’s chosen is up to the challenge of driving my line-stage preamplifier. I’ll have to check out Entech’s $450 model 205.2.
Crystal Semiconductor’s new line of 1-bit DACs use switched-capacitor analog filters, which the company claims renders the DAC virtually immune to source jitter. My ears perked up when I heard that. I wanted to see if the sound of the Entech would improve by adding a Meridian model 518 jitter reduction unit (with dithering/gain bypassed).
The sound improved a bit, primarily in the high end, with the slightly over-bright cymbals becoming more natural sounding. The brightness I’d heard earlier must have been largely due to jitter. With the addition of a jitter reduction unit costing five times the price of the DAC, the 203.2’s sound quality moves toward the B+ range. Rather like souping up a Ford Taurus with a Jaguar V12 engine.
This does not negate Crystal’s claim of DAC resistance to jitter, because I find the Entech is far less sensitive to jitter differences than my reference DAC. Before the invention of the Crystal DACs with the integral switched-capacitor filter, 1-bit DACs have been highly susceptible to jitter. It might not take much additional internal circuitry to make the Entech unit audibly unaffected by jitter.
I’ve given the Entech the job of driving my Stax headphone amplifier, replacing an old 16-bit DAC that no longer met my needs. Incidentally, over the headphones, the differences between my reference DAC and the Entech were far less than I had heard through the speakers. The Entech 203.2 sounded warm, tight and clear through the headphones and I no longer had a preference. The virtues of a good D/A converter must be appreciated in a properly controlled acoustic environment with excellent loudspeakers.
The Entech 203.2 has very good sound. It will improve the sound of DAT machines, serve well as the main DAC for project or mainstream recording studios, replace the integral DACs in digital consoles, do well in surround-sound applications, or act as a second, or utility, DAC for high-end mastering studios.
(Thanks to Brian Carion for loan of his Audio Precision Portable One Test set and to Fred Forssell for much advice and for coinventing a really useful jitter measurement device.)