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Eastern Electric Tube DAC Plus Digital-to-Analog Converter

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Now they say that there is a subatomic particle which can travel faster than the speed of light. If confirmed the laws of Physics will have to be re-written. I find particular delight in such new scientific evidence, since humans have a tendency to pontificate when they think they know absolute truth. All it takes is a new experience, a new test, to administer a dose of humility and a re-evaluation.

Perhaps another “truth” of audio needs to be exploded – that 24bit 192kHz is as good as digital sound gets. As I first acclimatized myself to the Eastern Electric Tube DAC Plus, the update to the very popular and affordable 32 bit cruncher by designer Alex Yeung, I smiled widely. In one instant my artificial “ceiling” on my system’s potential had been obliterated, while simultaneously reinforcing my conviction that 24 bit DACs have seen better days – 32 bit is the hot new technology in DACs.

Eastern Electric Tube DAC Plus Digital-to-Analog Converter

It’s funny how we get trapped in our conceptions, such as the supposed limit of how good an audio system can sound. Whether we want to or not we tend to set ceilings, hypothetical limitations, on how good an audio system can get. So many times I have heard breakthroughs which blast right past those mental barriers (sort of an Audio Blast). I have tried to consciously resist setting them, and yet it happens to every audiophile.

When the affable Bill O’Connell of Morningstar Audio, the distributor for Eastern Electric in the U.S., sent the latest version of the Minimax DAC, now named Tube DAC Plus, I was privately concerned whether it would outperform the Opamp-enhanced original. A truly fair comparison would be to the stock unit, but a new and improved version besting the previous stock unit is not as much fun. But if it bests the hot-rodded original then it’s really worth talking about! If it was inferior or marginally better I would be forced to conclude that it was an upgrade with limited efficacy; perhaps even a debatable improvement.

The first few moments, about ten to fifteen seconds, of hearing the Tube DAC Plus I struggled to holistically comprehend its sound. I had expected performance near that of the original, but what I heard was so entirely different that I needed to reorganize my framework and reestablish my mental blueprint. The DAC, and consequently the entire system, was performing at a level above the mental ceiling I had constructed. Let it be known that this product is not merely an improvement but a reformulation, as is evidenced by a new circuit board and updates as delineated by Alex:

1. Async 24/192KHz USB OEM by M2Tech
2. Dual separate power transformers for digital and analog
3. Fine tune on the tube output stage
4. Fine tune on the power supply
5. High speed relays/resistors input signal module

You might be tempted to say, “It just looks like a bunch of ‘fine tuning’”, and you would be half-right. But if you thought that such tuning results in a marginal to average improvement you would be entirely wrong. After all, it looks virtually identical to the previous-generation production model in pictures. In actuality, the Plus unit is about 25% wider and deeper than the first, and it is roughly one third heavier. The layout on the front is similar and operation of the DAC is the same; LEDs indicate Power, OPERATE, PHASE (power phase inversion), TUBE (tube/solid-state) operation, and Signal (indicates lock on a digital source’s signal).

The backside similarly is uniform with the previous version, allowing for AES/EBU, BNC, Coaxial, Toslink, and USB inputs spaced out physically a bit more generously. The DAC is still only single-ended (RCA) cable compatible, but at the price point this can be forgiven as true balanced operation would add substantially to the unit’s cost. Affordability seems to be a priority in Alex’s designs, and the DAC Plus (MSRP $1,100) is consistent with that philosophy.

The Plus continues to be a tube DAC, supplied with one Shuguang 12AU7 output tube, the same one that came with the previous version. Tube rolling was efficacious with the previous model and was as well with this model. In the brief time of use of the Plus I rolled in a Siemens silver plate 12AU7 and heard a brightening and lightening of the sound palate. A slight smear and veil were removed from the music, but I felt that the bass, though cleaner had slightly less heft than with the Shuguang. With clinical sounding gear the stock tube might be preferred, but if one is seeking ultimate incisiveness, maximum detail especially in the treble without being slapped in the face, the Siemens is a lovely choice.

At the request of Bill I have eschewed discussion of Opamp rolling here; it seems that no matter how many times warnings are given there are some who will try to take a soldering iron to their unit – completely unnecessary as explained in my articles about this unit – to its detriment, then suggest that the distributor is somehow liable for righting the incompetent DIYer’s wrongs! Apart from my official opinion of this piece shared here I may Opamp-roll the Plus version later; if I do I may post my impressions on audiophile forums. My understanding is that one set of Opamps is now soldered, leaving only one set remaining as “socketed” for swapping.

Though I have not had the unit a long time I have used it with two systems, one comprising the King Sound The King speakers driven by a pair of Pathos Classic One MkIII integrated amplifiers in mono configuration, the other guided by the VAC Signature Preamplifier MkII running into the Pass Labs XA160.5 monoblocks (currently under review), and the King speakers. The transport has been a respectable Denon 2910 and cabling has been Clarity Cable’s Organic series and Vortex power cords. The digital cable was also Clarity Cable’s Organic Digital .5M.

I typically take a longer period of time to write about a component, but it takes only a short time to render an initial assessment on a striking product such as this. I will state unequivocally that I have had the Pathos amps and King speakers in no less than 10 discrete systems ranging from $20 – $70K, and they have never sounded anywhere near as compelling as with the Tube DAC Plus. I told one acquaintance on the phone, “This DAC can perceptually lift a rig’s sound $50k,” and I mean it. Those who have not put too many systems together will scoff at a statement like that, but those who know system building inside and out will not laugh. They will try it for themselves and find out I’m not exaggerating. I know because I built those other approximately $70K systems and with the Tube DAC Plus the $20K rig sounds holistically better. As a formality it needs to be said that the reliability of this unit is unknown. The previous version had a few units displaying problems with signal lock, which was immediately addressed by Eastern Electric. However, this new one has been without fault operationally. Its characteristic sound and inherent performance capability is immediately obvious.

Audio Blast: Eastern Electric Tube DAC Plus Digital-to-Analog Converter Rear Panel

4 Responses to Eastern Electric Tube DAC Plus Digital-to-Analog Converter

  1. Devlon says:

    Does the EE Dac Plus decode DSD now?

  2. Devlon,
    God’s Peace to you,
    I am not aware of DSD capability in the EE DAC line as of now. However, you may wish to discuss directly with Bill O’Connell, the distributor of EE in North America. He can be found at the Morningstar Audio site.

    Douglas Schroeder

  3. Aaron says:

    Mr. Schroeder,
    Would you please compare/contrast the Eastern Electric Tube DAC Plus vs. Benchmark DAC2?

    I currently have a Benchmark DAC1 (modded with Dexa discrete opamps by Parts Connexion) which is use directly with a rebuilt PS Audio 200c amp and Thiel CS7 speakers. My music source is primarily an external hard drive accessed by SONOS. Prior to opamp mod, the sound was too shrill in the treble to enjoy at moderately high volumes. The DEXA discrete opamp mod has dramatically smoothed the top end and improved the imaging.
    QUESTION: In theory at least, or in actuality if you know from experience, would the sound through my modded Benchmark DAC1 be improved further if I input an upsampled (e.g. 176.4 or 192kHz) signal from a dCS Purcell? Yes, I’m aware that the Purcell only outputs those rates (mono) through each of its XLR outputs which would necessitate the use of two Benchmark DAC1′s to reproduce full stereo. I read that the sample rate converter in the Benchmark DAC1 resamples all signals to 110kHz, so it seems like feeding the DAC1 anything higher than 88.2 or 96kHz would result in downsampling and as a result maybe degrading of the sound.

    Thank you.


  4. Aaron,
    God’s Peace to you,

    I am afraid I cannot definitively comment on a direct comparison between the Benchmark DAC2 and the EE Minimax DAC Plus as I Have never compared them side by side. I spent time reviewing the original Benchmark DAC but have not had a follow up to date. I have no doubt that you were able to improve the performance by replacing the opamps in the DAC1 with DEXA discrete opamps.

    Although it is impossible for me to say whether the upsampled signals would be of little or no improvement when fed to the DAC1, I do recall that when I had the Cambridge Audio Azur 84C I conducted a somewhat similar test. I fed the non-upsampled 16 bit 44.1kHz feed in comparison to the 24bit 192kHz to the EE Minimax DAC Plus and heard very little to no difference. So, in theory the samples with much higher upsampling may be ‘downgraded’ but whether this will cause it to sound worse or better to your ear you would have to experiment to find out.

    You certainly are creative in thinking up the “dual DAC” idea for the Purcell! I had thought of a similar setup over time, but I have not tried it yet. My guess is that you would be better served to seek a DAC which can handle such upsampled signals up to 192kHz rather than cobble together two of the questionable DAC1 units.

    I would think that Benchmark Audio would be happy to discuss the idea further.

    Douglas Schroeder

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