Sighted is a-okay for training oneself to hear something. But, by whatever process you please, rigorous blinding is needed to actually confirm.
Sadly, when speaking about John's listening tests the words "rigorous" nor "blinding" tend to show up without some sort of negation thereof. Sorry, that spells heresay in this corner of the world.
Yes it is! US Patent number 4,107,619 issued on 15 August 1978. I made the assumption that it has expired by now.
@Vishnu (BTW I think you win the award for one of the longest lurks ever). You clearly haven't seen what Burson charge these days. But Ed Simon likes em.
Burson? Wrong Bay Area.
1980's - San Francisco Bay Area
...oh...never mind. I was just filling time, anyway, while a simulation compiled....
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You guys certainly carry on! Of course I have nothing against TIM or IIM or PIM (for that matter) but strictly relative to an OUTPUT STAGE, what Richard and I are looking for is static linearity.
Richard and I have been working on making a power amp together. I first thought that direct drive to the output stage would be adequate, but Richard convinced me that we should put some type of driver stage in to lower the open loop distortion of the output stage due to nonlinear input capacitance. Richard suggested this relatively complex output driver, and I went along with it. What we needed was how well this sort of output stage, (even if it was composed completely of bipolar devices) worked for other manufacturers. Nakamichi provided some significant information.
Of course, an entire design will require a number of requirements met, including TIM, IIM, THD, etc.
Richard and I have been working on making a power amp together. I first thought that direct drive to the output stage would be adequate, but Richard convinced me that we should put some type of driver stage in to lower the open loop distortion of the output stage due to nonlinear input capacitance. Richard suggested this relatively complex output driver, and I went along with it. What we needed was how well this sort of output stage, (even if it was composed completely of bipolar devices) worked for other manufacturers. Nakamichi provided some significant information.
Of course, an entire design will require a number of requirements met, including TIM, IIM, THD, etc.
Et tu? The Q word is hardly needed in this context.
BTW did you know the guy who lived in a trailer and sold foil beanies for RF shielding and also sued the entire IC industry because the PTO missed the fact that the current feedback amplifier was more than 15yr. old and granted him a patent.
Seemed rather prosaic to me, another op-amp on steroids that occasionally lets the blue smoke out. Even Stereophile has that problem with "commercial" products. Why revisit these 40yr. old designs, folks struggled to get decent performance out of the fairly low speed power devices of the day?
It actually is unbelievable, I was in charge of gathering prior art (for ADI) of which there was plenty but invalidating a patent is at least $4M in fees so he got a nuisance payoff that was not chump change, I can say no more.
I like to do a lot of blind double checking. I prefer sighted training and blind checking actually, it's more reliable. But, I have also noticed that on those occasions when I have fooled myself, there is a bias to how I do it, and it appears to be possible to compensate somewhat by being aware of the bias.
Also, in the case of PMA's listening test, there was confirmation after the fact that I did pretty well.
But, if you are asking how do I know if I heard some very small sound artifact correctly when there is no way to double check, I would say there is only some probability of being correct, not certainty.
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@Vishnu (BTW I think you win the award for one of the longest lurks ever). You clearly haven't seen what Burson charge these days. But Ed Simon likes em.
Yes Bill,
They had low measurable distortion and using two of the same model CD player they distinctly sounded better than the stock unit.
No magic involved. They used FET inputs and were less disturbed by all the stray EMI in the unit. Also there were the critics from the ninnys that discrete units that had lower rated THD must be better. How low is low enough?
In my testing the Burson was low enough that it didn't matter.
In my current project, the op-amp I know from experience, measurement and data sheets is a poor performer, shows up that way. Sort of a test to see if the listener is not deaf.
Mark: Once again you forget that you waxed on about the difference between two identical files and also you could not tell the difference listening to more than a tiny snippet on repeat (so listening to music they were transparent). I'm with Daniel that this is close to turning up the volume to listen for noise in quiet passages. Nothing you posted suggests that you could A/B the samples with any usual protocol. You couldn't even repeat it with headphones, which are usually better for this.
There may be a new protocol based on what you have found, but that needs 3rd party investigation, or possibly a new test setting up for people to try.
Edit: Ed, you did write 'this is truly a great DIY piece of gear', so assumed you were very enthused?
There may be a new protocol based on what you have found, but that needs 3rd party investigation, or possibly a new test setting up for people to try.
Edit: Ed, you did write 'this is truly a great DIY piece of gear', so assumed you were very enthused?
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And to bring some balance back I note was announced today that, following the August LIGO/VIRGO triangulation astronomers detected the source of the wave and have proved a theory on how heavier elements are formed.
Einstein’s waves detected in star smash - BBC News
Still amazes and humbles me.
Einstein’s waves detected in star smash - BBC News
Still amazes and humbles me.
I don't remember it exactly the same way as you. I think I said, "I never directly compared the two files until Pavel said they were the same, and I noted that there was a failure to directly compare them." That was way back here: http://www.diyaudio.com/forums/ever...-24-listening-test-opamps-53.html#post5128682
But, probably boring to most people if we start to re-litigate that whole thread all over again here. I'm sure I'm not the best listener around, that would be very unlikely.
What I would say is that I would like to see more research focusing especially on the top 5% of listeners. I would agree with Earl Geddes that new tests would have to be developed, and that it would be an expensive endeavor. Unfortunately, I think Geddes is right that most people just don't care so it probably won't happen anytime in the foreseeable future. Also, there is probably nothing to be gained by arguing about it. It's a time waster.
Ed: I fully believe in playing around. Heck I spend nearly £3 on an op-amp recently, but it was a dual . I'm finally at the stage to have fall backs for when my latest project crashes and burns either audibly or literally
Mark: You by your own admission can only hear half the audible spectrum. So you are way out that top group, so why worry. And no one on here has even close to the topsy turvy setup that is your preference, so you are a unique case for here and your experiences as such are hard for any of us to understand or replicate.
. I'm finally at the stage to have fall backs for when my latest project crashes and burns either audibly or literally Mark: You by your own admission can only hear half the audible spectrum. So you are way out that top group, so why worry. And no one on here has even close to the topsy turvy setup that is your preference, so you are a unique case for here and your experiences as such are hard for any of us to understand or replicate.
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