tomic601, I believe which ever is recommended by Ayre for general play. There is an A or B switch on the back and I believe it's on A. I do know that the upgrade guts the entire insides of the QB9 and that upgraded filters are part of that. Unfortunately, I know nothing about the DAC chip or filters, etc...
Ayre QB9 Twenty Upgrade
Hi Folks,I have an Ayre QB9 DSD DAC and I'm wondering about the new upgrade that Ayre is offering. It's cost is about $1500.00 so I'm not about to jump on the band wagon until I get some input about its sonic improvements. Currently, my QB9 has a Wireworld Platinum Starlight USB cable, Herbie's Tenderfeet, an Akiko XLR tuning stick, a Synergistic Research Blue Fuse, an ISO Regen with LP1 linear power source and an ASR Magic power cord. It sounds very neutral and very natural and I expect that I would ad those tweaks to the upgraded version as well. Any input about the sound differences would be greatly appreciated.Thanks!
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Filter settings are "Listen" and "Measure". Ayre recommends Listen for listening, Measure if you are a reviewer testing the unit on the bench (the Listen filter has better time-domain performance but rolls off the highs). I'm pretty sure the filters are one of the few things *not* changed by this upgrade.https://www.ayre.com/2019/10/11/ayre-qb-9-twenty-update/ |
Ayre implements the filters in a Xilinx FPGA, which provides the necessary horsepower. In an e-mail, Hansen told me that, during the development of Ayre's digital products, "We have custom filters whereby we can load whatever coefficients we want into [the FPGA] . . . an external switch allows us to load different filter coefficients and hear the audible changes they make. This is a great test, as it allows for everything else to be held completely constant. I spent four solid months doing nothing but listen[ing] to the effects of various filters—corner frequency, stop-band response, minimum-phase vs linear-phase, apodizing, sharpness at the 'knee,' windowing functions, interpolation rates (eg, 2x vs 4x vs 8x vs 16x), dithering functions . . . every single factor I could think of. |
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