Been in the Army. Many years later got PTSD, too. Been there done that, too. You are never the same once you are in a real death situation. But it can be character building to. Why else would I go into a civil war zone to help a family who cant get out with my friend/adventurer, Lisa, who was chased by Moist insurgents in the mountains at 12,000 feet. The whole escape and route is a story for the movies. You just cant make this s**t up... better adrenaline rush than anything in a movie.
[And, there are no such thing as hero's. Brave? No fear?]
Thx-RNMarsh
Back to the other, on-going high 'drama' here. But, how real is it?
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If the points are grounded you will see a bit more noise and depending on matching also distortion. The way Johns power supplies are made (stable quiet) it is probably not an issue at all. These are minor differences that take decent equipment to measure. Or these days a good sound card and maybe a nice preamp.
My father did 50, I have a great caricature of him and his buddies "The 50 Mission Kids" , they joked about it which is amazing.
Jacco brilliant, you captured John's comment that I am permanently double blind, was that intentional? Sorry to disappoint you, I simply consider myself capable of thinking through the technical issues, gurus usually exist in the eyes of others.
When they blitzed the town of Clydebank they almost killed my father and all my family, his house was destroyed and so was his grandfathers. I hate war, it is insanity pushed to it's furthest limits. Anyway, I too think this is a good thread but at times I think the name should be rearranged, something like Blowtorch John's Curls might be a better description. I am impressed by his temper control at times though, I doubt I would bother continuing with it if I took the amount of flack he does.
You really need to do time here, maybe two to three years of reading posts before becoming one with this thread.
Probably Scott, but it is a huge thread among many other such threads and life is short. I have been in the side lines here for some years now but I was too active on other hifi forums to join in with the fun here, mainly it was time wasted IMO. It was the fact that I could not see build pictures etc that made me join in the end. BTW my missis got quite into diy speakers about 7 years ago which I encouraged, she has been a member here ever since but has not been actively posting for ages now. She got quite friendly with Tubby (Tubby Tones) and Moray James (MJ Cables). I hope MJ was not too badly hit when the Bow burst it's banks recently.
More fun :
Peculiarly, despite J. Gordon Holt stating back in 1988 that the SCP-2 inverts polarity, I found the Stereophile-owned sample to be non-inverting. The Vendetta's output impedance was very low at 16 ohms at 20Hz, though it did rise smoothly with increasing frequency to a still low 95 ohms at 20kHz. The measured overload margins (ref. 0.5mV at 1kHz) were among the best I have ever measured, at 32.75dB at 20Hz, 31.6dB at 1kHz, and 29.4dB at 20kHz. The output level at the 1% clipping point was more than 15V! To sum up, this superbly uncompromised measured performance is a tribute to the Vendetta's designer.—John Atkinson.
Peculiarly, despite J. Gordon Holt stating back in 1988 that the SCP-2 inverts polarity, I found the Stereophile-owned sample to be non-inverting. The Vendetta's output impedance was very low at 16 ohms at 20Hz, though it did rise smoothly with increasing frequency to a still low 95 ohms at 20kHz. The measured overload margins (ref. 0.5mV at 1kHz) were among the best I have ever measured, at 32.75dB at 20Hz, 31.6dB at 1kHz, and 29.4dB at 20kHz. The output level at the 1% clipping point was more than 15V! To sum up, this superbly uncompromised measured performance is a tribute to the Vendetta's designer.—John Atkinson.
More :
Few people in the audio business would deny that John Curl is an audio design genius—arguably the greatest one of our generation.
He designed and built the electronics for Mobile Fidelity's SuperMaster and David Wilson's (of Wilson Audio) UltraMaster tape recorders, two of the three best analog recorders in the world. (The other is Keith Johnson's home-brew unit.) He designed the JC-1 head amp and JC-2 preamplifier sold under the Mark Levinson name some years ago. He designed head amps for SOTA, Michaelson & Austin (TVA), and has done consulting work for more high-end companies than you can shake a stick at.
Yet, for all his acknowledged design brilliance, fame has not brought John Curl fortune—like so many geniuses, he has earned a reputation for being hard to deal with. It's not that he drives a hard business bargain; quite the opposite, in fact. He has been cheated, defrauded, and ripped off by some of the best-known names in audio. His "problem," as seen by his clients, is that he an idealist of the first order, with strongly held ideas of how things should be done: ie, as well as possible and hang the cost. In the pursuit of audio perfection, Curl little comprehends the meaning of "compromise." His designs tend to be truly no-holds-barred, using the best components money can buy to produce the best sound and highest reliability the state of the art allows.
Bring it on John ....
I have spent some time with Richard Clark. He can be really abrasive but he is thorough and would follow the rules pretty obsessively for such a demo. He had a staff then of recently graduated engineers who were also very "by the book".
I myself have not been able to prove or disprove to my own satisfaction the assertions that an amp scaled and used properly is not audibly distinguishable from another similarly qualified amp. Whether in typical home use by audiophiles matches the "qualified" qualifier is a separate issue.
Tell us how. If the serious researchers are having trouble with this and you think its so easy perhaps a Nobel awaits you.
Actually, experimental design for testing like this is much more difficult than it seems. There are many places where bias can sneak in.
Here is a new solution to the crossover problem in class AB amplifiers: AHB2 - Power Amplifier | Benchmark Media And here is the patent United States Patent: 8421531 I'm not entirely sure that multiple amplifiers can cleanly trade off in a way that eliminates crossover distortion without bringing some other issue to light. Seems pretty similar to current dumping.
Ahh , a Noble is highly overrated after seeing how they give them away and anyone telling me there is no sonic difference between amplifiers are either deaf or dead ..
Two amplfiers from the same designer and manufacturer can sound different much less , it really makes me wonder the intent of those involved in such "scientific" endeavors. Poor program material and speakers can mask the difference , so if you wanted to skew things anything is possible , not so in the real world .
This reminds me of an incident years ago with an associate who sold Bose wave radios , he had a demo disc from Bose which was part of his presentation, anyway he would pop this disc in after careful placement of the radio and damn it , if it wasnt impressive. He did give me a copy and lol , its was , well , artistic and carefully EQ'ed for the bose radio, raised level and squashed dynamics to boot.
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Yes it seems a variation on Current Dumping. The inductor (Z1) in the CD bridge was always a difficult component as accuracy is concerned. They appear to circumvent that by replacing it with a resistor and then add capacitors to the other elements (Z3, Z4) to maintain bridge balance over frequency.
BTW I wonder why I need an amp with 120dB dynamic range when my listening room, at the quietest moments, has 90dB tops...
Jan
BTW I wonder why I need an amp with 120dB dynamic range when my listening room, at the quietest moments, has 90dB tops...
Jan
You want it , because its there and available ...
how are you getting 90db, whats your measured noise floor ..?- Status
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