If John where to say that there is sonic difference and it's not worth his time to find out why.
I would accept this answer.
I would accept this answer.
(Bandwidth [GHz])*(Rise Time [nS]) =0.35. Assuming the bandwidth is good enough for audio, the rise time doesn't mean ****. It is what it is, according to the corresponding bandwidth. You can rather say that the output inductor may lower the amplifier's closed loop bandwidth, but for all practical purposes this is irrelevant.
Damping factor could be an issue in extreme cases (large inductor, amortized for stability reason with a rather large resistor, and a difficult speaker load, that drops it's impedance to absurdly low values, like 1 ohm).
Don't worry, it's yet another fetish that Mr. Curl is using to differentiate his products from what he calls "mid-fi" (that's anything that amplifies the signal and costs less than an arm and a leg).
NVA's Richard Dunn also leaves out the inductor for sonic quality reasons but he insists customers use his own low capacitance speaker cables to maintain the warranty.
NVA Hi-Fi ? High quality British Hi-Fi | Monoblock / Stereo / Integrated Amplifiers | Phono | Cables
I removed them from an EL84 amp i built once and it sounded better for it. A chipamp LM3886 kit also sounded a bit better without an inductor, obviously not big differences but noticeable. I didn't fit them to my current power amps either. I don't want to guess at a scientific explanation so i'll leave that to others.
NVA Hi-Fi ? High quality British Hi-Fi | Monoblock / Stereo / Integrated Amplifiers | Phono | Cables
I removed them from an EL84 amp i built once and it sounded better for it. A chipamp LM3886 kit also sounded a bit better without an inductor, obviously not big differences but noticeable. I didn't fit them to my current power amps either. I don't want to guess at a scientific explanation so i'll leave that to others.
Is also the same bloke who proscribed playing Babylon Zoo as breaking his amplifier's warranty...
Interesting character, shall we say.
Special casework - NVA cases are bonded together with acrylic weld and the top plate with structural adhesives to avoid the magnetic contamination of steel screws.
Doesn't acrylic soften when heated?
We do have both copper and aluminum screws.
Doesn't acrylic soften when heated?
We do have both copper and aluminum screws.
Other than an OTL I am having trouble thinking of a tube amp design that would need this.
As an aside, does anyone know at what point people started calling the series L||R a Zobel rather than Thiele network?
I've not enjoyed an argument with Richard Dunn for a number of years now, interesting character right enough 😀
I have used a couple of his plastic amp's (A60's) in the past, not bad to be honest.
I have used a couple of his plastic amp's (A60's) in the past, not bad to be honest.
lol some self proclaimed guru advised me to fit one, i didn't know jack s**t back then but i made a decent amp, in the end.
It's an imperfect nomenclature across the board. A number of other folks (ST Micro for one) call the series L||R a Boucherot cell. For what little it's worth, I'll be sure to call whatever HF-loading stability circuits by their topology rather than Thiele, Zobel, or Boucherot for clarity purposes. 🙂
As to whether or not such circuitry is audible or not, I don't know and would be definitely reluctant to state in any sort of general catch-all language, as that need be assessed on a case-by-case basis. My "design conservatively" mindset likes them though. Especially in light that many DIY designs will be poorly characterized, especially in terms of board and chassis layout. Magic smoke is not fun.
I can only recommend, not PROVE that an output coil is audible to people who don't really listen seriously anyway.
I first heard the idea about not using an output coil from Nelson Pass, back in the 1970's. Then I heard the Julian V. of NAIM took it out of his amps. Later, when I started with Parasound, the engineers in Taiwan were already leaving out the output coil, and I have kept the tradition. However, I do believe that it is audible with the best listening playback equipment. Perhaps some of you should try and find out for yourself, rather than heckle me.
I first heard the idea about not using an output coil from Nelson Pass, back in the 1970's. Then I heard the Julian V. of NAIM took it out of his amps. Later, when I started with Parasound, the engineers in Taiwan were already leaving out the output coil, and I have kept the tradition. However, I do believe that it is audible with the best listening playback equipment. Perhaps some of you should try and find out for yourself, rather than heckle me.
I could not hear sound from "pure resistive load".
This zone of amplifier behaviors is out of (my)interest.
This is DIY forum, not consumers, first "law"is to attune audio components, not simply connecting random amp with random speakers(using random or fashion cable) and listening "results".
This zone of amplifier behaviors is out of (my)interest.
This is DIY forum, not consumers, first "law"is to attune audio components, not simply connecting random amp with random speakers(using random or fashion cable) and listening "results".
If output inductor is not in your toolbox then there should be other means. And I like amplifiers that can get away without Miller caps.
A marketing masterstroke. You cannot fault Julian for his ability to keep em coming back for all the add ons. Even now the clan of NAIM do it.
Bill, I thnk there's more to it than just good marketing.
When I heard their small integrated amp in the mid 80-ies for the first time, I was very pleasantlxy surprised by how clean and clear the sound was. That was no marketing, that was some excellent design concept at work. At that time, few could keep up that level of sound quality without an astronomical price tag attached.
When I heard their small integrated amp in the mid 80-ies for the first time, I was very pleasantlxy surprised by how clean and clear the sound was. That was no marketing, that was some excellent design concept at work. At that time, few could keep up that level of sound quality without an astronomical price tag attached.
Making people buy your speaker cable to get around a design decision is good marketing! As for the power supply upgrade path its pure genius.
Capacitive load, step it from some 1nF to 1uF in steps 1-2-5-10. You may find some area of instability, e.g. for loads like 15nF - 100nF, though with 1uF load the amp may remain stable.
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