audio:audio_by_van_alstine_work
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audio:audio_by_van_alstine_work [2019/05/22 04:44] – [Vision SLR, Fet Valve CFR] mithat | audio:audio_by_van_alstine_work [2021/03/21 02:05] – ["T7 CF"] mithat | ||
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====== Audio by Van Alstine work ====== | ====== Audio by Van Alstine work ====== | ||
- | I have done quite a bit of consulting work for [[https:// | + | I have done quite a bit of consulting work for [[https:// |
- | The focus of my work with AVA has always been to bring the highest standards of audio engineering to the company while fostering | + | The focus of my work with AVA has always been to bring the highest standards of audio engineering to the company while helping to foster |
===== Transcendence Five ===== | ===== Transcendence Five ===== | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | New vacuum tube line stage to replace AVA’s existing design originally derived from the Dyna PAS 3. |
- | **Discussion: | + | **Contribution: |
+ | |||
+ | **Discussion: | ||
===== Transcendence Six ===== | ===== Transcendence Six ===== | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | Low-cost hybrid line stage using a computer-optimized 12AT7A gain stage and IC buffer output |
- | **Discussion: | + | **Contribution: |
+ | |||
+ | **Discussion: | ||
===== Transcendence Seven ===== | ===== Transcendence Seven ===== | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | 12AT7A-based premium hybrid line stage using a computer-optimized 12AT7A gain stage and optimized power-MOSFET buffer output stage. |
+ | |||
+ | **Contribution: | ||
- | **Discussion: | + | **Discussion: |
===== "T7 CF" ===== | ===== "T7 CF" ===== | ||
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c. 2002 | c. 2002 | ||
- | **Contribution: | + | All-tube buffered line stage using a computer-optimized 12AT7A gain stage and 12AU7 buffer stage. |
- | **Discussion:** While working on the Transcendence Seven, I was able to take a deep dive into the tube/MOSFET architecture covered in the AVA Fet Valve patent. One result of this is that I could not find a convincing reason why a power-MOSFET was better suited to buffering the gain stages than a cathode follower, but I was able to come up some reasons a MOSFET might be worse. So I developed an iteration of the Transcendence Seven design using a 12AU7A-based circuit to replace the power-MOSFET stage. | + | **Contribution:** Concept origination and development. |
- | At the time I wasn’t given the go-ahead to prototype and test this design. My understanding is the AVA wanted to maintain a commitment to their patented architecture as they felt this gave them marketing distinction. However, this circuit | + | **Discussion: |
+ | |||
+ | At the time I wasn’t given the go-ahead to prototype and test this design. My understanding is that AVA wanted to maintain a commitment to their patented | ||
===== Active power supplies for tube and hybrid electronics ===== | ===== Active power supplies for tube and hybrid electronics ===== | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | All-new power high-voltage supply regulation circuits for use with all AVA tube and hybrid products. |
+ | |||
+ | **Contribution: | ||
**Discussion: | **Discussion: | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | Remote |
- | **Discussion:** I was aware that AVA was losing preamplifier sales because they didn’t support any kind of remote control | + | **Contribution:** Concept origination, |
- | My original | + | **Discussion: |
+ | |||
+ | My expectation was that AVA would offer the remote as standard equipment on all “big body” preamplifiers. Instead it was offered as a relatively costly option, which they justified because the remote control transmitters were costly, which they were because of the small quantities they ordered them in, which was the case because remote control was offered only as an option. | ||
===== Ultimate 70 and Ultravalve power amplifiers ===== | ===== Ultimate 70 and Ultravalve power amplifiers ===== | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | Revision of AVA’s low-power tube amplifier circuits for the Dyna ST70 chassis. |
- | **Discussion: | + | **Contribution: |
+ | |||
+ | **Discussion: | ||
===== DAC core for Vision and Vision Hybrid DACs ===== | ===== DAC core for Vision and Vision Hybrid DACs ===== | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | Next-generation S/PDIF decoder and DAC board |
+ | |||
+ | **Contribution: | ||
- | **Discussion: | + | **Discussion: |
- | AVA originally wanted to support only 44.1kHz PCM formats | + | AVA originally wanted to support only 44.1kHz PCM formats |
- | This would be the first time AVA would use predominantly SMD parts in a PCB design. The previous generation DAC had used a single hand-soldered | + | This would be the first time AVA would use predominantly SMD parts in a PCB design. The previous generation DAC had used a single hand-soldered |
I was not involved in the development of the analog stages for the first DAC products using this board. However, I was responsible for the analog circuits found in the [[# | I was not involved in the development of the analog stages for the first DAC products using this board. However, I was responsible for the analog circuits found in the [[# | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | All-tube, next-generation premium preamp line stage. |
+ | |||
+ | **Contribution: | ||
**Discussion: | **Discussion: | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | Component value selection for best RIAA conformance. |
- | **Discussion: | + | **Contribution: |
+ | |||
+ | **Discussion: | ||
===== Vision DAC improved ===== | ===== Vision DAC improved ===== | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | New reconstruction and output stage based on a discrete, class-A, solid-state gain stage I developed as an independent project. |
+ | |||
+ | **Contribution: | ||
**Discussion: | **Discussion: | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | New line stage based on a discrete, class-A, solid-state gain stage I developed as an independent project. |
+ | |||
+ | **Contribution: | ||
**Discussion: | **Discussion: | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | All-new DAC product with USB and S/PDIF inputs supporting high-rate PCM and DSD formats. |
- | **Discussion: | + | **Contribution: |
+ | |||
+ | **Discussion: | ||
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. | 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. | ||
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[[https:// | [[https:// | ||
- | **Contribution: | + | Fully remote-controllable chassis and supporting circuitry. |
- | **Discussion: | + | **Contribution: |
+ | |||
+ | **Discussion: | ||
===== RB-RC ===== | ===== RB-RC ===== | ||
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c. 2018 | c. 2018 | ||
- | **Contribution: | + | Low-cost remote controlled volume circuit adaptable to AVA' |
- | **Discussion:** With the availability of a less costly remote control transmitter option that I established for the SLR and CFR chassis as well as the newly founded ability for AVA to burn custom microcontrollers in house, it was natural to apply these toward stripped-down remote control functionality for their RB (Real Basic) preamplifer chassis. The new design replaced the previous volume-only remote control | + | **Contribution:** Concept origination, |
- | ===== The future ===== | + | **Discussion: |
- | I continue to provide consulting services to Audio by Van Alstine, particularly in the areas of digital audio, small-signal analog audio, low-power power amplifier design, and user interface design. | + | ===== DVA Digital Preamplifier ===== |
+ | 2018--2021 | ||
+ | |||
+ | Coming soon | ||
+ | |||
+ | ===== The present ===== | ||
+ | |||
+ | I continue to provide consulting services to Audio by Van Alstine, particularly in the areas of digital audio, small-signal analog audio, low-power amplifier design, and user interface design. | ||
+ | |||
+ | ===== The future ===== | ||
+ | Within audio, my work focuses on developing solutions that represent meaningful audio progress rather than chasing coloration signatures that happen to be fashionable. On a more general level, my design interests include a desire to bring greater equity to technological realms and to improve user experiences in every stage of product use. I try to bring all this to bear as much as possible in my work for AVA. | ||
audio/audio_by_van_alstine_work.txt · Last modified: 2024/07/02 21:32 by mithat