Winfield Hill (co author of "The Art Of Electronics") published the schematics and PCB layout of his incredibly fast amplifier here on diyAudio
https://www.diyaudio.com/forums/solid-state/287023-winfields-100w-dc-10mhz-1000v-amplifier.html
Readers may be interested to know that his output stage is a conventional EF2. Not EF3, not CFP. It's EF2. He gets 1000 v/us from an EF2. Check out the schematics.
His VAS stage runs at higher bias current (80 mA) than the driver stage (60 mA), a seldom-seen design choice.
https://www.diyaudio.com/forums/solid-state/287023-winfields-100w-dc-10mhz-1000v-amplifier.html
Readers may be interested to know that his output stage is a conventional EF2. Not EF3, not CFP. It's EF2. He gets 1000 v/us from an EF2. Check out the schematics.
His VAS stage runs at higher bias current (80 mA) than the driver stage (60 mA), a seldom-seen design choice.
I often wonder why Mr. Self did not use these symmetrical designs to
elaborate/base the books on. From a hobbyist standpoint , they are just as easy and
have fewer issues. My CFA SP can match a blameless without TMC
,clamps or any other B$ to tweak the design.
I suppose he wanted to go down his path. perhaps Baxandall/Hawksford
were adversaries. Ha ha...
OS
elaborate/base the books on. From a hobbyist standpoint , they are just as easy and
have fewer issues. My CFA SP can match a blameless without TMC
,clamps or any other B$ to tweak the design.
I suppose he wanted to go down his path. perhaps Baxandall/Hawksford
were adversaries. Ha ha...
OS
That brings up the question , why did HE do it ?
Besides a "mine is longer" metric for his amp , what is the purpose ?
Showing off the expensive $$$ "academia" ?
PS - I backed down to <200v/uS for the final design. No ringing and
ultimate stability out weighed "mine is long". BTW - I had a near 1KV/uS
"infidel" H bridge design . It was just thermally unstable and picked up
Room RF when built. I scrapped it and went with my present CFA.
Who needs that much bandwidth ?
Designs must fit the goal.
OS
I'm certain Prof Hill's design fits his goalwinhill2 said:
Not sure Stochino's does.
YMMV
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Nevertheless you brag about 400 v/usec as recently as two hours ago, in post #62.
Brag is subjective. The 400V/uS was stated.
You turned it into "brag".
"troll" comes to mind.
OS
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I'm certain Prof Hill's design fits his goal
Not sure Stochino's does.
YMMV
Mine plays music and given it cost me nothing has been very good value. Any issues with it are due to the construction, not the core amplifier.
Can I hear the slew? Nope.
Hi Richard, nice to see you back.
At what distance did you listen?
And what size room?
Stochino's amp started out like Winfield Hill's, as an amp for instrumentation or lab use.
And both seem fit to demonstrate techniques to improve slew rate.
Best wishes
David
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About 3m with the speakers usually 3m apart. The room with the 1000W amp was 9x5.67x3.57m, large with high ceiling but furnished quite hard & bright. Not a plush Victorian cushion. This was the Listening Room for most of our DBLTs on speakers ... hence the 1000W amp.
I must admit this is mainly with my own recordings made with my mike and a Sony PCM-F1. There's only a literal handful of commercial recordings that will clip the 1000W amp in these conditions at realistic levels. Well recorded piano is good if you've ever experienced a real piano player playing Beethoven well on a real grand piano
Also small groups of very good unaccompanied singers which may be the music with greatest dynamic range at sensible but realistic levels of all.My much more limited experience this Millenium confirms this will more exotic instruments like Aboriginal clap sticks but these don't sound bad (or even different) when clipped .. unlike piano. Don't forget there's modern 'music' (??) where clipping 50% of the time is hardly detectable, let alone objectionable.
Clipping at 1000 watts even at 3m means you must have been playing it uncomfortably loudly and I just don't know what is achieved doing stuff like that assuming normal sensitivity speakers.
I had a business acquaintance a year or two back who carried the Vivid loudspeaker line for a while. Apparently they had quite a few cases on the big model where the speakers were blown.
It seems a peculiarly British thing to hammer speakers. I was doing a show 2 years ago and these four 40 something guys came into the listening room and asked to play a Pink Floyd CD.
I had to walk out. How my 703's survived unscathed I don't know and that was on a 240 watt per channel amp - probably 350 given the speaker load impedance.
I had a business acquaintance a year or two back who carried the Vivid loudspeaker line for a while. Apparently they had quite a few cases on the big model where the speakers were blown.
It seems a peculiarly British thing to hammer speakers. I was doing a show 2 years ago and these four 40 something guys came into the listening room and asked to play a Pink Floyd CD.
I had to walk out. How my 703's survived unscathed I don't know and that was on a 240 watt per channel amp - probably 350 given the speaker load impedance.
It could also mean you live on the forum?
Bonsai: It's nice to see you back! Your posts and the articles you used to have on your site are very enlightening. Hope you are having great success marketing the amp line.
Regarding D. Self and his not using symmetric circuits: he explains himself quite clearly in most of the editions of his book and pointedly in "The Push-pull Voltage Amplifier" chapter of the 6th ed. It always comes down to economics for him and as far as his experience goes, the "Lin" is cheaper and affords similar performance.
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Maybe because symmetric amps cancel even harmonic distortion that many people treasure, and odd harmonic distortion is not better that asymmetric circuits.
And if you have done any design and simulation, you will see that when both polarities are driven, it's hard to make the circuit bias stable and accurate.
It's amusing that DIYA features a lot of elaborate designs that rarely outperform a simple "blameless" amp. I think people add a lot of extra stuff that looks cool in the schematic, but actually does nothing to improve the performance. Been there like 1975, when there was no spice and transistors were expensive. Until I started using spice, I didn't know why certain things like cross coupling worked so well, and why other things like op-amp IPS so badly. 40 years later, people are still reinventing the wheel.
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