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--- audio:audio_by_van_alstine_work [2020/01/02 17:38] – [Transcendence Five] mithat
+++ audio:audio_by_van_alstine_work [2020/01/02 17:42] – [Transcendence Seven] mithat
@@ Line 23: / Line 23: @@
 **Contribution:** Concept origination, development, and implementation.
-**Discussion:** This was a continuation of the work I started with the Transcendence Five. Historically, AVA had demonstrated some success with two different hybrid approaches. In the first, high-voltage MOSFET buffers were placed inside the main feedback loop of vacuum tube gain stages. In the second, a low-cost opamp stage was used to provide high impedance buffering of a conventional closed-loop tube preamp design. My idea centered around placing a high-speed solid-state buffer IC stage //inside// the global feedback loop. This would allow AVA to offer a preamp with performance that exceeded their tube/MOSFET hybrid at a considerable cost savings. This design was so good that it obsoleted their tube/MOSFET hybrid preamp until I was able to complete work on the Transcendence Seven.
+**Discussion:** This was a continuation of the work I started with the Transcendence Five. Historically, AVA had demonstrated some success with two different hybrid approaches. In the first, high-voltage MOSFET buffers were placed inside the main feedback loop of vacuum tube gain stages. In the second, a low-cost opamp stage was used to provide high impedance buffering of a conventional closed-loop tube preamp design. My idea centered around placing a high-speed solid-state buffer IC stage //inside// the global feedback loop. This would allow AVA to offer a preamp with performance that exceeded their tube/MOSFET hybrid at a considerable cost savings. AVA considered the design so good that it obsoleted their tube/MOSFET hybrid preamp until I was able to complete work on the Transcendence Seven.
 ===== Transcendence Seven =====
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 **Contribution:** Development and implementation. This was a major rethink of the work covered by AVA's [[https://patentimages.storage.googleapis.com/3b/ca/c7/daa969bad4f092/US5017884.pdf|“Fet Valve” patent]] and embodied in their first-generation Fet Valve products.
-**Discussion:** One of the reasons my Transcendence Six design outperformed AVA’s more costly discrete MOSFET hybrid approach was that it used the optimized 12AT7A-based gain stage core initially developed for the Transcendence Five. So a natural progression was to see whether using that gain stage in one of the discrete MOSFET output buffer architectures covered in their patent provided an advantage over the IC-based buffer I designed into the Transcendence Six. In the process of designing the new MOSFET stage, I revisited a number of assumptions made in the original AVA implementation and produced a circuit optimized for this application that was vastly simpler than the one it replaced. AVA thought its performance warranted it being offering as a premium hybrid product.
+**Discussion:** One of the reasons my Transcendence Six design outperformed AVA’s more costly discrete MOSFET hybrid approach was that it used the optimized 12AT7A-based gain stage core initially developed for the Transcendence Five. So a natural progression was to see whether using that gain stage in one of their patented discrete MOSFET output buffer architectures provided an advantage over the IC-based buffer I designed into the Transcendence Six. In the process of designing the new MOSFET stage, I revisited a number of assumptions AVA made in the original implementation and produced an optimized circuit that was significantly simpler than the one it replaced. AVA thought its performance warranted it being offering as a premium hybrid product.
 ===== "T7 CF" =====