Fas42’s Stereo ‘Magic’

[opus101]

I went to a private demo of Wilson's most recent flagship offering which I think they called 'Master Chronosonic', last year. Price tag well into six figures I think. They sounded worse than my mid-three figures Taobao speakers without any doubt whatsoever.

[opus101]

9 hours ago, fas42 said:

 

Because the load to the driving electronics is ridiculously low, a conventional headphone amplifier is a non-starter - what is required is a full blown speaker amplifier, which then effectively becomes a current amplifier; its outputs are essentially short circuited by the extremely low impedance of the ribbons.

 

Based on my reading of the review of these on 6moons, I think this is in error. Yes the speaker amp becomes a current source in effect but via some series resistance which is supplied with the headphones. Its those series resistors that turn the speaker amp (voltage output) into a current amp. But the voltage amp still sees a typical speaker load (I forget the value of those resistors, maybe 6ohms?).

 

It therefore follows that subsequent comments about the amp always being  'in classA' don't logically follow. Nor does your suggested way to 'ruin' the sound - ironically that series R is already in circuit in the standard configuration. I understand Schiit have figured out a different way to drive these Raals with some custom electronics, obviating the need for the series Rs.

[opus101]

25 minutes ago, gmgraves said:

I know what’s possible and what isn’t. That’s for sure Frank.

 

Often mistaken but never in doubt 

[opus101]

11 minutes ago, gmgraves said:

Telarc’s Jack Renner and Robert Woods were admirers of Mercury’s C.R. Fine, and used his spaced omni mikes. 

 

MLP recordings to me sound in general too bright, the tonal balance sounds 'tipped up'. How might this happen? Or is it just my ears which aren't correct? I don't hear this with the very few Telarc recordings I have though.

[opus101]

1 hour ago, gmgraves said:

Then how come, on most systems, it doesn’t show-up on an oscilloscope, even when that scope is set to it’s highest sensitivity? On most wide-band ‘scopes, the highest sensitivity is equal to a signal that is more than 130 dB down from the DUT’s maximum signal output, and for most people this “RF interference” still doesn’t show itself. 

 

A bit of back-of-envelope work. A typical mainstream 'scope will have 1mV/div max sensitivity and have an 8bit ADC. This gives 39uV as the lowest level signal it will resolve. 130dB relative to this is 123V - which DUT gives that much output?

[opus101]

1 minute ago, gmgraves said:

My point exactly!

 

Tell us the answer to my question - which DUT gives 123V output?

[opus101]

2 minutes ago, sandyk said:

 

 A USA mains supply !  😉

 

Ah so the DUT must be a mains supply conditioner, right?

 

But that doesn't fit because @gmgraves clearly called its output a 'signal' and mains supply conditioners only output power, not signal.

[opus101]

Just now, gmgraves said:

You are correct. I am referring to the output signal found on the RCA or XLR output jacks of any audio component (except for power amps, then it’s the speaker terminals on the amp.).

 

So which DUT did you use to base your 130dB claim on? This enquiring mind wishes to know.

[opus101]

5 minutes ago, Rexp said:

Doesn't sound like a maistream scope would pick up much? 

 

That's one way to look at it. Another is it'll pick up everything within its bandwidth - then how to tell which part is the signal you're looking for? There's a very good reason why much RF work is done with a spectrum analyser not a 'scope.

[opus101]

1 minute ago, gmgraves said:

You’re dreaming. 

 

So are you with your 130dB claim. Apparently.

[opus101]

Just now, gmgraves said:

While you are right, RF interference with enough amplitude to be a problem would be easy to see on a ‘scope (with no audio signal). Most of the time there is none.

 

How high an amplitude in your experience becomes a problem? Unfortunately there's no way to see 'none' with a 'scope so how would you know there was indeed none?

[opus101]

Well I've heard some 'golden eared' claims before but yours is the first claim I've met to be able to hear RF. Dogs and bats, eat your hearts out.

[opus101]

10 hours ago, gmgraves said:

Well, if one can’t “hear” the effects of RF interference in one’s system’s presentation, what difference would it make if the interference were present or not? You aren’t making a lot of sense here.

 

You were talking about using a 'scope, now you've shifted to using ears. Could we please return to using instrumentation and may I have an answer on the 'scope question? Pretty please.

[opus101]

5 hours ago, fas42 said:

 

Ummm, 30years ago there wasn't Internet, cordless phones, smart phones, etc - 

 

Errr - Wikipedia not to be trusted on cordless phones then?

 

Inter alia, in their subsection on Frequencies :

 

43–50 MHz (Base: 43.72–46.97 MHz, Handset: 48.76–49.99 MHz, FM) Allocated in December 1983, and approved for use in mid-1984 for 10 channels. 15 additional channels allocated April 5, 1995.^[6]

[opus101]

1 minute ago, gmgraves said:

Well, Mr Pedantic, that type of interference usually shows itself (depending upon the amplitude, of course) as a thickened baseline trace when connected to the component’s output under the “no signal” condition. Disconnect the scope and the line goes back to the normal no signal thin trace.

 

Did you try not connecting the scope probe at all and only connect the grounds between the 'scope and DUT? When you connect/disconnect the grounds notice any thickening of the trace?

[opus101]

I've just had a soundstage response memory holed by said 'even handed member'. And @One and a half's 'adios' post was scratched within about a minute of posting. So I take it detailed investigation of soundstage is verboten.

[opus101]

I've an email copy of your deleted post, if you'd like it back for posterity I can forward it on receipt of your email.

[opus101]

Have the knowledge but lack the inclination.

[opus101]

31 minutes ago, Archimago said:

Don't just say these parameters "barely give a sense of what the subjective experience is like"... That's what irresponsible audiophile magazines do and then audiophiles start thinking they make no difference! That is simply not true if you spend time with test results and listen closely. Some characteristics will be more audible than others.

 

Guilt by association? Actually what he's saying is true based on subjective experience - small FR deviations make less subjective impression than additive noise - sibilance for example. Sibilance gives an uncomfortable experience in listening longer term but an HF boost/dip of a dB or two can be borne, subjectively.

 

Harping on about sibilance for a while longer - for me its the first and most obvious sign a system is under-performing subjectively but to date I've not seen any objectivist attempt to make a measurement of it or even talk about it much. Must be a lacuna.

[opus101]

7 hours ago, Archimago said:

 

Wondering @opus101 if you can give me an example of a musical track that you use to evaluate for sibilance?

 

Good topic and I think it'd be much more useful to have some specifics to test out the assertion that there's any kind of lacuna. Sibilance is something I've generally found to be a function of the recording itself rather than DAC or separate from the frequency response of one's other hardware like speakers...

 

 

Generally sibilance issues are an artifact of the playback system, IME. But I do have one or two recordings that exhibit a sibilant flavour and one (that I have no idea of the whereabouts right now) that does demonstrate it on female voice, not just subjectively but in Audacity FFT too. I will look out these examples.

[opus101]

Here you go, I chopped the track to under 30s hoping its within 'fair use'. This is the female voice example which I managed to dig out off an old SDcard.

 

Listening to this on my current system its not objectionable in the way a sub-optimal replay system generates sibilance, just easily noticeable.

ALS-Rebecca Pidgeon_sample.flac

[opus101]

Apropos interfering signals, last night I watched a couple of episodes of 'Pints with Ayre' and in this one they mention (without too many details) the 'Ayre conditioner' which they developed as an upgrade from ferrite in that it doesn't need degaussing. They even use it on DC power rails  : 

https://www.youtube.com/watch?v=ecK4SBEvJEo

[opus101]

1 hour ago, Jaydon said:

Such as your belief that awful 100 year old cylinder recordings are made to sound realistic by your tweaks. 

 

I played the Nellie Melba track on my system. It was surprisingly listenable as the noise (sounded rather like static) stayed localized at the speaker positions while the singing floated in space between. I haven't done any of Franks tweaks btw.

[opus101]

2 minutes ago, kumakuma said:

 

You forgot to put the #troll hashtag on your post

 

 

Nope. As you're a keen supporter of @March Audio you'd view all my posts as trolling so it would be redundant.

[opus101]

I've known Frank long enough to understand he's relatively impervious (compared to the majority here) to being trolled. I was just reporting my experience since you piqued my curiosity by saying there's 'way too much noise'.