Julf wrote: > Quantum effects matter in stuff like semiconductors and thermal noise, > but considering how ignorant of the functioning of even basic electrical > circuits the average audiophile is, we are pretty far from having to > look at quantum effects when *applying* the results of the research work > of semiconductor engineers and physicists.
Hi Julf, I would entirely agree with you that it is not obvious how any quantum effects would manifest. My point is that taking "objective" measurements inside the electronic processing chain may not be a completely reliable guide to determining what is happening when you actually leave the box alone to do its stuff. My loudspeakers only contain passive components (& not many of them!) in their crossover circuitry & the transducers are simply attempting to convert the complex analogue signal fed to them into sound waves. Sound is propagated through the air by pressure waves alone - there is no wave/particle duality at this stage to be concerned about. In other words when I listen to these sound waves I am not participating in any kind of observation/measurement that could cause any superposition process earlier in the audio chain to collapse. The ABX listening test is therefore the ultimate "objective" test of system performance, preferable to any measurements within the electronic part of the chain, especially the digital to analogue conversion stage - I think that Arny has made the case that the analogue amplification stages can be realised with vanishingly small non-linear artifacts being added to the input signal. Hope you get my drift. The chap who designed my DAC has written a short paper on his design philosophy & methodology. He stresses that he listens first to identify shortcomings, *-Then-* takes some measurements in the hope that they will assist in rectifying the perceived problems, makes his changes the electronics as appears necessary and then listens again. If there are still problems he either tries measuring something else or starts making incremental changes where possible to see if they make matters better or worse. It's all an iterative process for him. Since he's spent 20 years working in recording studios & has designed both ADCs & DACs used often by recording engineers, he has access to a lot of kit & recordings. For example, he could compare the purely analogue chain of processing from the amplified output of a professional high speed analogue tape machine (with very low analogue "jitter" of the kind that Arny finds objectionable, caused by wow & flutter) playing an analogue master tape with the output of the same device fed through an ADC-DAC chain prior to the same amplification which is almost an ABX test in itself (it's actually a sighted A-B test, but could easily be altered to a full ABX). I tend to trust the judgement of recording engineers (which is why my system doesn't have tone controls or user-adjustable balance), so I thought I'd take a punt on his box of tricks. Since it also contains a good fully-balanced headphone amplifier & a MM/MC phono preamplifier with equalisation, neither of which I had already although I do have some decent cans & a reasonable record deck with some legacy LP's. So I figured I wasn't risking that much dush if the DAC made no audible difference to my system. I still think it does - the ABX test is the real "proof of the pudding"... Dave :) ------------------------------------------------------------------------ Golden Earring's Profile: http://forums.slimdevices.com/member.php?userid=66646 View this thread: http://forums.slimdevices.com/showthread.php?t=106519 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
