Digital Processor Reviews

Editor: Thank you, Messrs. Dudley and Atkinson, for your listening review and test measurements of the Allnic Audio D-5000 direct-heated-triode digital-to-analog converter in the December 2014 issue (p.93).

While Art was very positive about the D-5000 DAC's performance, though questioning the value of the flexibility provided by upsampling and DSD conversion (about which we all know many audiophiles are rather ambivalent), the measurement results John obtained shocked him—and us!! John wondered if the results could have been due to something that happened to the unit in transport to his residence, since Art's listening results did not square up with the measurements. We wondered the same thing. John's test results absolutely did not align with our own—not only of the review unit, but of every D-5000 produced.

Once the review DAC was returned to Allnic and Waversa Systems, their respective principals, Kang Su Park and Colin Shin, found that three of its four new old stock 3A5 DHT tubes were bad. Nothing else was amiss. The 3A5s are more than half a century old, and, like all DHTs, are also inherently delicate. They can indeed be damaged by rough handling, despite best efforts to provide "bombproof" packaging.

A pair of malfunctioning output tubes in one channel and one of the pair in the other could certainly have caused the measurements John obtained, including the performance differences between the left and right channels. In fact, once the 3A5 tube set was replaced, the review D-5000 DAC performed to factory specifications. Further testing in Korea has confirmed that no D-5000 DAC with tubes intact measures like the unit John tested.

Every Allnic Audio product, including all its tubes prior to installation and after, is thoroughly tested and burned in for days before shipment. We have a very high degree of confidence that all tubes are performing to specifications at the time they leave the Allnic production facility. However, one can never predict with absolute accuracy the treatment a device will receive in transit, nor the lifespan of a specific tube, let alone a 50-year-old and delicate DHT.

Fortunately, Allnic has thousands of 3A5 tubes, and where something has caused one or more 3A5s to fail, Allnic will replace them at no cost to the user. In addition, Allnic has set up a new facility for even more rigorous testing and burn-in of several types of NOS tubes used in Allnic products—including the 3A5—even though the measurements obtained from Stereophile's review sample of the D-5000 were, in our view, likely a result of tube damage incurred during transport.

Based on the rapidly growing number of purchasers and their exceedingly enthusiastic feedback, we are confident that the D-5000 is truly exceptional in sonic performance and build quality, and one of the most flexible DACs on the market—at any price.— David Beetles, Hammertone Audio

Distributor, Allnic Audio

Allnic is returning the review sample of the D-5000, fitted with known good tubes, to me. I will be publishing a Follow-Up review in a spring 2015 issue.–John Atkinson

I wrote that response to David Beetles's comment in good faith. However, after his comment and my response had been published, I was informed that that review sample had been sold. Allnic has offered to submit a new sample for a follow-up review, but that would not allow me to investigate whether or not the original sample's measured problems were indeed due to one or more of the tubes having become faulty, as he claims.–John Atkinson