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Old 27th November 2007, 06:09 PM   #62
puff
Gear Head
 
Join Date: Oct 2003
Location: chicago
Posts: 53
Quote:
why was the BLA guitar sample louder than the Benchmark ?
The BLA and the Benchmark were calibrated to the same level during tracking. Technically speaking, the Benchmark's 0dBFS should be slightly hotter than our converter's 0dBFS because ADC-1 uses a 123dB dynamic range A/D chip, and ours is only 120dB. Published dynamic range/bit depth is often much greater than what's actually achieved in the real world, though. I've come up with a method of converter configuration that differs significantly from what's typically done. I've found that it greatly reduces current noise and increases actual dynamic range, that is to say, the dynamic range that's actually achieved in real world practice.

Here's where it gets a little crazy: the BLA prototype used in this test is, from a technical perspective, severely handicapped. It's powered from an AC wall wart adapter and a switched-capacitor supply (a complete no-no for A/D's as it introduces noise into the power supply line). It's a two-layer PCB, whereas four-layer PCB's are typically used in these applications because of their greater noise immunity. addendum: an additional issue with the BLA prototype used in this recording is that the reset function was incorrectly implemented, causing our A/D to have difficulty calibrating itself for the proper amount of DC offset.

I want everyone to understand, though, that this was not intended to be a full-on scientific test, but rather a quick and dirty A/B to give a taste of we could achieve at a $600-ish price point.

Quote:
Send me one of your converters and I'll do this for you !!
Thanks for the offer. We have a couple of beta testers who are going to be doing this for us. One tester is going to be doing A/B tests and samples with a Mytek. The other will be using Prism, PMI, and Genex.

Matt
Black Lion Audio

Last edited by puff; 27th November 2007 at 07:56 PM. Reason: add item of interest
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