PMA said:
What is your criterium for 'better': having it reproduced correctly at the output (if it is part of the music) or having it NOT appear at the output (if it is interference)?
In the first case I would vote for the 811, in the second case, I'm not sure. Possibly the 4558 might do better here, but that's an educated guess.
Edit: Apologies, I didn't see the first couple of screen shots, only the last one. OK, so you proved:
That switching causes measureable 'clicks';
That shielding supresses the 'clicks' a lot.
I noticed that after the click passed it was as before, so no permanent change. I would think that the two first cases would cause an audible click. And even if the clicks were not audible, unless the switching between units would take place during a music signal zero crossing, the switching would be audible even with perfect switches.
If I may offer some additional experience: I have been working with IC attenuators a lot lately, in particular the CS3318 which is used in my DCX mod. This attenuator is basically a stepped attenuator in IC form, followed by a buffer stage. Switching is during zero crossing. I cannot hear the switching, not even with no signal and ear-in-the-speaker. So, it's a mixed world out there.
Jan Didden
salas said:
Hi Salas,
I don't agree that the target for DB testing is 'the human and soul pleasure'. The target is, for instance, to find out if two pieces of equipment sound differently. Or, if it is confirmed that they are different, which one is preferred. Or something else. So again, a reason to leave out all other inputs except the sound.
But you bring up an important issue of adaption and how long the periods should be between switching between equipment. It stands to reason that listening too short will not give you the processing time to perceive the difference. Knowing that our memories are limited in time and change in time, it also stands to reason that too long a period may also give wrong results.
I don't know what the 'correct' period is; and it could be dependent on the type of music and possibly on the listener's experience.
Jan Didden
janneman said:
Let me clarify. To get the better pleasure from better sound, which is the purpose and goal of high fidelity, you need to be sure that your final music replay tests are reliable. And excluding all those individual adaptation matters discussed about the human factor, is not really scientific IMHO. Because science has to include all factors rather than trying to neutralize them in my view. And psychology is an accepted science taught in universities. Or am I wrong about that?
Yes, psychology is taught at every major university. And when you take your first experimental psych course, you'll learn about the absolute necessity to do properly controlled blind testing for any sort of sensory research.
Coincidently, today I'm taking a sensory threshold test at work. Wine tasting. Double blind, as is the industry standard. Not ABX, but a triangle format (which is statistically more powerful).
Coincidently, today I'm taking a sensory threshold test at work. Wine tasting. Double blind, as is the industry standard. Not ABX, but a triangle format (which is statistically more powerful).
CFB clamp
Hi David,
Thank you. As a matter of fact, I'm reluctant to drop a schematic of the FB clamp on this forum, as it seems that nobody, except you, shows any interest in a better (and foolproof) clamp. Apparently, people are only interested in their own designs, even when these designs are outdated by more than a quarter of a century.
At the moment, I'm building another website, comprising not only the PGP amp, but also some background info and less complex alternatives, which will include the CFB clamp as well.
Cheers, Edmond.
lumanauw said:Hi, Edmond,
You are holding something very interesting (especially the concept behind it)
Hi David,
Thank you. As a matter of fact, I'm reluctant to drop a schematic of the FB clamp on this forum, as it seems that nobody, except you, shows any interest in a better (and foolproof) clamp. Apparently, people are only interested in their own designs, even when these designs are outdated by more than a quarter of a century.
At the moment, I'm building another website, comprising not only the PGP amp, but also some background info and less complex alternatives, which will include the CFB clamp as well.
Cheers, Edmond.
salas said:
I think the difference of viewpoint is that listening to music and DB tests have different goals. Of course we want to enjoy our music, and our hifi is a tool for that. And that means that we carefully dust off the LP, dim the lights, light a cigar, pour some wine, and then settle down to enjoy Wagner.
But if I want to find out if changing an electrolytic cap for a film cap makes an audible difference, I really have to exclude the light, the cigar and the wine: I need to concentrate on the sound, compare before-after, can I reliably, repeatable, discern a difference? That process is completely different from the normal mode of listening to music.
Jan Didden
salas said:
Salas, sorry, I don't understand the question. Really; I'm not being facetious or obstructive or something.
The way I see it, is that psychological influences would skew or bias your judgenment. Like in the famous test by Floyd O'Toole where the results in a sighted test of the same speakers, shifted judgement towards the larger, prettier speakers, compared with DB tests. Is that the kind of psycholgical filtering you mean?
Jan Didden
