Differences

This shows you the differences between two versions of the page.

--- audio:audio_by_van_alstine_work [2019/05/22 04:24] – [DAC core for Vision and Vision Hybrid DACs] mithat
+++ audio:audio_by_van_alstine_work [2019/05/22 04:41] – [DAC MK5] mithat
@@ Line 103: / Line 103: @@
 **Contribution:** New reconstruction and output stage based on a discrete, class-A, solid-state gain stage I developed as an independent project.
-**Discussion:** I had been developing a discrete, class-A, solid-state gain stage as an independent project for a number of years. My goal was to create a design that was free of the issues I kept hearing in opamp ICs. Late in 2014 I thought I succeeded and built a single-stage differential-to-single-ended anti-imaging filter/output stage using the module for the Vision DAC board I had designed earlier for AVA. The results impressed AVA enough that it was immediately adopted for their Vision DAC offerings.
+**Discussion:** I had been developing a discrete, class-A, solid-state gain stage as an independent project for a number of years. My goal was to create a design that was free of the issues I kept hearing in opamp ICs. Late in 2014 I thought I succeeded, and so I built a single-stage differential-to-single-ended anti-imaging filter/output stage using the module for the [[#dac_core_for_vision_and_vision_hybrid_dacs|Vision DAC board]] I had designed earlier for AVA. The result impressed AVA enough that it was immediately adopted for their Vision DAC offerings.
 ===== Vision SL improved =====
@@ Line 121: / Line 121: @@
 **Discussion:** Phew! With the Vision DAC incapable of effectively supporting newer in-demand digital audio formats, AVA asked me to design for them a product that would. The original design brief specified support for up to 192kHz PCM sample rates and DSD64. I insisted on a design that provided support for DSD128 as well and that had the infrastructure to support DSD256 once that format matured. (AVA released official support for DSD256 in 2018.)
-Working closely with application engineers at AKM, I was able to develop support circuitry for the AK4490EQ that provided improved low-frequency reference voltage stability; this in turn reduced the low frequency nonlinearity appreciably over more conventional approaches.
+Working with application engineers at AKM, I developed support circuitry for the AK4490EQ whose low-frequency reference voltage stability was significantly greater than the circuits used in AK4490EQ reference designs. This in turn reduced the low frequency nonlinearity of the DAC appreciably over more conventional approaches.
-This would be the first time AVA would use in-house burned microcontrollers --- and it did so in a big way: I ended up using three independent microcontrollers in the final product, one for each of the DAC’s core functions: input selection and control, DAC control, and the user interface. Also notable in this design is the scale to which SMD technology was adopted and the high level of build integration. These required introducing significant changes to AVA’s manufacturing workflow, but this has brought AVA’s production methods more in line with modern approaches.
+This would be the first design that required AVA to use microcontrollers they would burn in-house --- and it did so in a big way: I ended up using three independent microcontrollers in the final product, one for each of the DAC’s core functions: input selection and control, DAC control, and the user interface. Also notable in this design is the scale to which SMD technology was adopted and the high level of build integration. These required introducing significant changes to AVA’s manufacturing workflow, which in turn has brought AVA’s production methods more in line with modern approaches.
 ===== Vision SLR, Fet Valve CFR =====