I've been doing some Escort research. I particularly enjoyed these two quotes from Wikipedia (about the Lotus 1.6L Twin Cam variant):
"...and a LHD Ford Anglia mule, which, fit with one of the first prototype engines, had overtaken a fast Jaguar at well over 100 mph in the hands of Jim Clark on his way back from Goodwood to Scotland."
And this:
"Harry Mundy, who designed Lotus TwinCam, was offered the choice of payment for his work of £1000 cash or a royalty of £1 per unit. Colin Chapman had signed a 1000 unit purchase agreement with Coventry Climax for the FWE engine used on Lotus Elite, and was on the last stretch of making 1000 Elites and accepting FWE deliveries in 1961. (The Elite's final factory production volume was 1030, with over 1200 registered with the Lotus Elite World Register currently.)
Mundy took the cash, and the TwinCam went on to be made 55,000 units and beyond."
Bugger!
There two main ways how to combine analog amp (Class A or B) with Class D (or switching power supply), parallel and series combination. It looks that Devialet uses parallel one.
I started thread with series combination of Class A and Class D here: www.diyaudio.com/forums/solid-state/304722-200w-class-amp-efficency.html
not finished yet but hope soon.
Last edited:
Current dumping, in principle, is OK. It is just when you try to get away with marginal design with it, like Quad did.
Aggressive, “intellectual” marketing. I hope there is substance behind this.
Company presentation - Devialet
Corporate investors - Devialet
Has anyone of you heard the Phantoms playing music, not hip hop?
Review: Devialet Phantom | WIRED
Technical:
US Patent Nos: 7545212, 8901998, 9190928, 9257949
George
Why does the language in those links automatically make me doubt them? Is this the kind of stuff that STILL turns people on?
Sadly not mine. Owned by Bill Gwynne rally school. Full cage, LSD, straight cut box, quick rack, fly off handbrake with a stage 1 1600 engine. Designed to go sideways. Turns out I can't turn off my natural reaction to give it a big handful of opposite lock.
Being a Northampton boy, the lotus Twincam is a very important point in UK engine history as its links to the genesis of Cosworth and the area being so important for motorsports.
Now back to Audio 🙂
I had a 2L four door Ghia.....I rebuilt the engine, had it balanced (hopelessly out of balance from factory), I rebuilt and ported the head, fitted extra leaf to rear springs and replaced rubber sandwich with steel plates, shorter stiffer front coils, front clip on extra sway bar, ex Capri rear sway bar and one piece tail shaft.
Once that was done I had the Weber dyno rejetted and advance curve adjusted.
Result was a seriously fun 2L go kart, went like hell, no axle tramp, traction and handling to the max.
Dan.
Yes, and this property is unusual, sad to say....the only other amp I have heard with this pleasing property was a Parasound.
Unless this degree of 'silence between the notes' is experienced, one can only conclude that all recorded and reinforced sound is 'hashy', 'shouty' and 'mashed'.
The other Friday night I ran my filters on a pub PA system and the result is dead quietness between notes with every guitar and bass string, note and nuance clearly discrete.
It took no mental effort to 'zone in' on every individual sound source in the mix, and when listening to the 'whole picture' the result was wonderfully pleasing musical pleasure, as it is intended.
Sine wave testing does not reveal excess noise as does music, a standard waveform/protocol that does would be very useful in distinguishing systems and confirming subjective findings.
Dan.
Does the degree of 'silence between the notes' can be tested with a multitone test signal (*) looking at the FFT baseline between the test tone peaks or with a repeating burst tone signal looking at the silence baseline between the repeating burst tones?
(*) like Scott’s file https://linearaudio.net/sites/linearaudio.net/files/30multitone_flat_96.wav
George
(*) like Scott’s file https://linearaudio.net/sites/linearaudio.net/files/30multitone_flat_96.wav
George
Good question George, I'm not sure.
It seems that sine impetus does not excite excess noise in the manner that music does.
It is noteworthy that 'noise' type music (eg Dead Kennedys, AC/DC, violin etc) in combination with typical NFB amplifiers causes 'tail' of junk directly after each impetus.
With continual/repeated excitement this excess noise does not quench/decay and builds to a continuous noise in the background causing masking, harshness and reduction in perceived HF and LF extension....we have all heard this in low-fi/mid-fi gear (and plenty of so called hi-fi gear).
My filters change/eliminate this excess noise decay characteristic for the better, and because they are easily and instantly applicable, on the fly AB comparisons are practical and educational.
In this case, pink noise changes quite dramatically and sounds 'matter of fact' and as it should....on most systems pink noise is reproduced 'unnaturally' and is 'bursty' in character.
Zero loop feedback amplifiers markedly reduce this dependency, and perhaps this is the 'secret sauce' of current feedback amplifiers.
Dan.
When it is time.....soon to be is to catch up with some Physics Phd's and demo what I have and formulate a plan to work out what is going on at the dare I say it 'quantum' level.
I have quoted here audio experimentation subjective experiences....there are many many other applications including LED lighting, WiFi transmission, AM/FM reception and transmission, altering wines etc etc.
Right now I don't have proper explanation but the subjective changes are proven.
Deep understanding I think will tie together a bunch of fields of concern including electrosensitivity and geopathic stress, explain dowsing and provide solution to upcoming problems like massive proliferation of 5G networks.
Dan.
Last edited:
Once, not long ago [about 2 months], I was in a place where (about) 50 people listened to this Devialet amplifier and 3 others. Most (way more than halve) decided that the best sound came from one of the amplifiers, and that amplifier was not the Devialet.
The music, loudspeaker, source, where the same for all presentations, the SPL was calibrated to be the same also.
The music, loudspeaker, source, where the same for all presentations, the SPL was calibrated to be the same also.
I am afraid not. It is again one of the purely subjective feelings that has nothing in common with any exact measuring method.
You can also use FFT techniques to put "holes" in real music tracks. There is NOTHING here that does not have a measurement technique that is well known. The build it, see how it sounds, and make up a story design technique won't go away, as I have measured (rather easily BTW) you often end up with an effects box and a rather strong one at that.
The failure of GNF amp to capture "inter-note darkness" goes right back to the feedback goes round and round and comes out later. Sigh! 😴
George - Those test files have two versions IIRC one for 64K FFT's and one for an FFT of exactly the sample rate. The later is only useful to those who use one of the comprehensive open source libraries like Octave, PYTHON, etc. The first gives right answers for ONLY 65536 length FFT's which are almost always available on the free tools I see folks use here.
This "silence between the notes" is something like "tight bass" or "rock solid bass". These terms are also not related to their simple meaning. Those "tight bass" are often frequencies somewhere between 60 - 100 Hz. Similarly, "clean sounding" amplifier has often horrible distortion and "silence between the tones" is attributed to the amp with very poor multitone distortion. These terms are simply NOT self-explanatory and usually are related to very different technical parameters.
- Status
- Not open for further replies.