Originally Posted by germanium
The friend of mine who is the engineer I was talking of in the previous post was Jack Strayer. He worked for A&M records, Disney Studios & a number of others. He was a electronics engineer. Whenever he went into a studio that had transistor gear he & his crew working with the studio personel removed the transistor gear & install thier own tube gear for the recording sessions they were working on to get the best possible sound.
The amps in question that he was working on before he got sick & died was sold to Red Rock Audio. They modified his design with different lower quality parts & proceeded to sell them at an exstravagant price never invisioned by Jack strayer. Jack was going to sell them for $7,000. Red Rock audio was asking 40,000 last I seen.
In the review posted by 6 moons audio reviews they mentioned that jack was old school & didn't believe in certain parts selections. What they didn't realize was Jack was actually extremely meticulous with his parts selection & used parts that were top gradeoff the shelf or custum designed by people that were 1 in a million in thier understanding of the device they were designing & precious few others could actually design his particular output transformer for example. Jack had even approched the transformer company that makes Red Rocks transformers & they said they couldn't do the type of design. The disign that Jack specified was very difficult to wind or even calculate the reactances within it because of the complex windings but done right it could have flat response well beyond the audio spectrom with very little phase shift. Someting that is impossible with standard transformer design such as what was used in the Red Rock Renaissance amp. Even the speaker wire had to be custom ordered to the length required as the transformers characteristic output impedance matching was done inside the speaker wires amp end plug & was complex enough that it would have been impractical for most consumers & even for some recording engineers to do. By doing it this way though one could very quickly change to different impedance speakers as quickly as changing a plug.
The review of the Red Rock verion is here 6moons audio reviews: Red Rock Audio Renaissance
This is the high priced version that really meant for consumers, not the pro version made by Jack strayer my friend. I spent a fair amount of time with both Jack & his amp to know that it really did sound better than any of the high priced tranny amps or tube amps we compared it to.
All this is to say please don't think it bad that I say something has a tube like sound as it is indeed the highest compliment that I can give. Jacks amps sound was full of life & body without sounding harsh. Unlike the old design consummer tube amps these had had high frquency extention up the kazoo all the way up into AM radio land 500KHz + & full power bandwith that was truely flat 10Hz to 30KHz, a far cry from the 30Hz to 15KHz +or- 3db of the older consumer tube gear.
Here is a link to Jack Strayers original amp.http://www.nutshellhifi.com/VSAC98.html
It is second picture from bottom. This is the stereo model in powder coat black. The 50watt monoblocks looked just like this but had only 2 small signall tubes in the center position. There was also a brushed stailess steel top version. The stereo version had 2 chassis, one for power supply & one for the amp itself. The mon blocks were four chassis to get stereo set up the same way as the stereo version. The stereo version had 572-10 tubes & the monoblocks used 811 tubes both from Svetlana.
These amps weren't just Class A amps but Class A1 limited meaning they could not be driven out of Class A as as soon as you approached the Class A limit the small signal tubes were set up not to be able to drive any current so the amp would go into soft clipping at the class A1 limit.
Jack strayers amp is the top amp on the list of amps used at Opus 4 studios http://www.opus4studios.com/Opus4Studios/Equipment.html
. I also knew Dr. Mike Matesky from when I was a member of the Pacific Northwest Audio Society, Dr. Mike Owns Opus 4 & He was involved with building it at that time.