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While costlier previous challengers had done certain things better, it wasn't significant enough to be a clear next level up that would appreciably upgrade my review/pleasure system. In fact most such challengers took away while they gave. The only one which offered worthwhile new features—remote volume control, SD card playback of AIFF files and a monitor GUI via HDMI for the latter—was the $3.995 Canadian Invicta. Its golden pre production sample simply didn't yet include the full feature set. That moved my wallet back into the trousers, never mind that said sample wasn't for sale. Whether a final production Invicta would trigger those reflexes again would depend also on how it fared against the DA-160. This by way of poking some lighthearted fun at misconceptions in this sector.


The digital things people tend to talk about matter less if at all whilst what isn't talked about matters very much. Nobody in their right mind would expect Burson's new affordable DA-160 to trounce the costly exotic brigade. Those leagues are too rich for my blood. The new DA-160 simply promised to win some ground over the HA-160D.
By the end of May I learnt that Burson delayed the release of the DA-160 "due to a last-minute design change." On whether the revision impacted any features or specifications, "nothing important changed. We had to refine the input selection control board. Then our case factory messed up our first order and finally we went through an intermittent crisis of not being able to source one of the transistors, a Toshiba SCJ74."

This might disappoint those who'd hoped that the last-minute redesign would net 24/192 async USB. Due to a misunderstanding between Burson and their USB transceiver's supplier, the HA160D had originally been advertised as running asynchronous USB. This went on well past my review. Eventually John Delmo informed me with embarrassment that their unit in fact did not. He asked that I amend the review accordingly. The DA-160 is adaptive too. With async's widespread superiority propaganda, CEntrance has some interesting anti propaganda [click on Design Philosophy once at that link] from designer Michael Goodman:
"The USB argument comes down to jitter management. It goes as follows. In asynchronous mode the device is clock master. In adaptive mode the computer is. Either works fine if correct design principles are followed. Here is the tricky part that often gets omitted. No matter which side is clock source (PC or DAC), both devices are still connected via USB cable. The digital data on that cable is always irregular because the computer is involved. Computers do many things at once. They end up sending data over USB in irregular intervals no matter who is the clock master on the bus. This irregularity causes jitter.


"So there is no jitter-free solution just like there is no dust-free house. Irregularity always creeps in and needs to be actively managed. Here is where the asynchronous vs. adaptive argument breaks down. In either of the two clocking schemes, jitter is present during transmission. It's inevitable and also okay if properly cleaned up prior to the D/A conversion where it matters most. Neither clocking scheme is superior. Both are capable of performing well if you know how to reassemble the bits prior to the DAC. How do you actually do that? There are many ways, the oldest and simplest being buffering. Irregular data comes in, regular data goes out. The most important part is to make sure that samples leaving the buffer on the way to the DAC are clocked accurately. We employ a proprietary two-stage clock management system that does just that. It cleans up the jitter on the USB bus so that samples are virtually jitter-free at the D/A conversion point."*

What CEntrance calls JitterGuard™ and AdaptiWave™ are an anti-jitter circuit and firmware respectively, the latter custom-coded to a TAS1020B USB controller chip which has been licensed to Empirical, Lavry, Benchmark Media and Bel Canto. If you look at the last two firms' propaganda, you'll find references to a "proprietary UltraLock™ clock system" and "Master Reference Ultra Clock" respectively. Either company's DACs as well as CEntrance converters enjoy measurement confirmation for excellent jitter rejection. There's clearly more to good USB audio than buzzword compliance.
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* Needless to say the CEntrance statement is a lightning rod for disagreement. My point for including it isn't endorsement. It's a strategic reminder that good results can come from a variety of solutions.


USB DAC board with Tenor transceiver chip, <10ps clock and variable buffer stage
Once again Burson doesn't offer descriptions on their adaptive USB implementation. Those who want the details must dismount the double-decker CS8416/PCM1793 board with its three multi-pin connections on stilts. I had Burson supply the above photo to avoid kinking the spider leg connections myself. In exchange for such silence we're not bombarded by—cough—proprietary marketing trademarks of the MegaClockLocker™ variety. Those who must have 24/192 async USB might reach for Simon Lee's $495 April Music U3. (That self-contained bus-powered unit runs the same XMOS processor which Ayre adopted for their 24/96 QB-9 converter when it came due for its 192K update. The U3 runs two high-quality clocks for the 44.1kHz and 48kHz upsampling frequency families.) After all, BurrBrown's PCM1793 handling Burson's actual D/A conversion is fully 24/192 compliant. Simply enter on a coaxial or optical input to decode native (or software player-upsampled) 24-bit 176.4/192kHz data.

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