John Curl's Blowtorch preamplifier part II

Status
Not open for further replies.
It was regarding a sidebar / derailment ....

Pfunnie this was brought up, the response to a friend.
Strange that those so quick to judge find difficulty with pots
faders, attenuators and the like for example with links to
all manner of bouy.

It's obvious the point was lost on those
with a proclaimed wit much greater than
those would care to comment about, so
in ellipses they strike the keyboard
and cast their hooks to a bouy near.

The duality others observed.

The music maker,
the music taker,
and ne'er the twain shall meet.
 
...it can take some practice and careful listening to notice what to listen for. If any interest in giving it a try, here is a link: https://www.dropbox.com/sh/9r5kiiptr00seub/AAC5zEynkg-ZmriNSkQxFPaEa?dl=0

Mark, what should we listen for?

What ever happened to that little BBC speaker?

@ Richard, have fun and happy trails. That a nice days drive to vegas for you.
Well for the average guy, for you and your new ride, perhaps a half-day.

What did you do with your old ride? Next time please consider trade-in price
to one of us mere mortals, would ya?
 
Last edited:
Mark, what should we listen for?

I have only had the experience of coaching someone to listen in person, where there can be some back and forth conversation, and the student as it were could ask questions along the way.

Being together in-person, both of us would be listening to the same system, and I would know that system was producing detailed enough sound for a difference to be distinctly audible. And depending on the source material, I could describe which instruments and sounds seem to be most affected to me, and maybe think of some way to guide you towards focusing attention on what the differences sound like to me.

So, trying to respond to your question in some way that might be helpful under the present circumstances would, I think, require another approach.

I would suggest trying one of the freeware bit-crusher VST plugins, and run it in a VST host of your choosing. Reaper is the name of one pretty good host program. Bit-crushers can be found by google search.

Then I would suggest adding enough bit-crusher effect until you can hear it quite plainly, then start reducing it until you can hear bit-crushing to 16-bits when working from a high quality 24-bit source. If using Windows operating system, its important to use ASIO sound card drivers whenever possible. Otherwise, its necessary to make sure you fully understand how to manage Windows sound engine. It can do SRC (sample rate conversion) on you on the fly without any warning. In addition, Reaper can do the same thing if not correctly configured. These are among some of the reasons it's best to do this in person while working with someone who is familiar with all the necessary details and can confirm everything is working properly.

Anyway, once you can identify the presence of any bit-crushing at all, the next step would to add a dither-noise plugin prior to the bit crusher and repeat the exercise all over again. To do that correctly, the depth of the dither noise should be adjusted appropriately as the bit-crushing depth is changed. For simplicity, I will omit discussion of shaped noise dither.

Of course, if you get lucky, you could skip all that and simply get a high-rez 24-bit file and dither and bit-depth reduce it to 16-bits. Or you could have someone else provide the two files for you to work with.

Then hopefully your system would be able to clearly reproduce the subtle differences, and maybe you would be able hear the loss of subtle details of sound in the 16-bit version without needing any self-training sessions. (However, my guess would be that most systems are not able to provide clear enough reproduction.)

Regarding BBC speakers, I don't know anything about that. I do still have some of the old metal case Radio Shack speakers around here somewhere that people sometimes used for checking mixes on consumer grade gear. Don't know if it's possible to hear 24-bit verses 16-bit differences on them.
 
Last edited:
Disabled Account
Joined 2012
@ Richard, have fun and happy trails. That a nice days drive to vegas for you.
Well for the average guy, for you and your new ride, perhaps a half-day.

What did you do with your old ride? Next time please consider trade-in price
to one of us mere mortals, would ya?

I will be going south parallel to Calif hwy's but on hwy 95... Nevada.... can cruise at high speed on that road.... not patrolled... no people either.

I wish I knew.... was great also... springs and sway bars changed for lower stance and better cornering... stiffer springs. Supercharger spun up higher also with crank pulley changes and retuned A/F. Black on Black. larger heat exchanger for Water-Air supercharger inter-cooler etc. Larger exhaust (3 inch diam) system.


Leave in 2 days. a good 8 hour drive... non-stop at speed. My lady will drive also... she loves to go fast any way.

-Richard
 
Pfunnie this was brought up, the response to a friend.
Strange that those so quick to judge find difficulty with pots
faders, attenuators and the like for example with links to
all manner of bouy.

It's obvious the point was lost on those
with a proclaimed wit much greater than
those would care to comment about, so
in ellipses they strike the keyboard
and cast their hooks to a bouy near.

The duality others observed.

The music maker,
the music taker,
and ne'er the twain shall meet.
The poetry came together well at the end, all over the place though at the start, what's all that about? ;)
 
Last edited:
Don't know if it's possible to hear 24-bit verses 16-bit differences on them.

I listened for a while to SACD vs CD layer today, modified* Sony SCD-777ES same player same system for both. Brief and not definitive but I heard no difference that would excite me (no difference really). IMO any test that involves different equipment setups for one vs the other is a waste of time.


*AD712's removed among other things :D
 
Last edited:
IMO any test that involves different equipment setups for one vs the other is a waste of time.

Not clear why there would need to be different setups for one vs the other. Seems like one setup should be plenty, so long as it doesn't obscure any details.

Regarding the Radio Shack speakers, I was just wondering how much detail they where capable of, I never tried to find out.

Or, if you are sort of obliquely referring to what RNM described trying previously with different players, that may have been out of convenience, or the only way he happened to have available at the time. Hopefully, it will get down to one setup once new amps and other other updates are in place, at least that would be would be my guess.

Anyway, I wonder why you heard no difference. If there were differences in noise, maybe you would have heard it better than most of us, or at least me. But, not so sure about differences in some subtle details or small amounts of distortion.
 
Last edited:
Anyway, I wonder why you heard no difference. If there were differences in noise, maybe you would have heard it better than most of us, or at least me. But, not so sure about differences in some subtle details or small amounts of distortion.

Yes my point is the signal path must be as identical as possible to eliminate confounders. I don't see that there is a distortion making process inherently involved in creating the two files, change in subtle details maybe. The noise floor was not audible on either and the volume was constant. I can easily see why this is a don't care to many people and anyway the LP's sounded much better :D.

As for higher BW source material (i.e. CD vs 96k) speaker IM has been proven to be a problem, I don't see a road to any definitive tests.
 
Last edited:
Daniel, using RME converters already has me worried. Which model? Also, what amplifiers and speakers? How far were listeners from the speakers, in the very near field? And I don't know what "Meridian's own equipment" means. Also, did they have someone on the research team who could hear the difference and verify the test setup? These are not silly questions.

So this is EXACTLY what I meant by "no true Scotsman" arguments about "good" equipment, as much as you're now trying to backpedal away from this argument. Which is it? Only the specially deemed equipment will deliver the goods?

Look, the thing is this: Some reputable mastering engineers claim to be able to hear the difference, I make the same claim. However, in my experience not all equipment and listening environments work for this type of testing despite specs that would make it seem like they should.

This has nothing to do with logical fallacies. There is no fallacy to say that doing the testing properly is trickier than some engineers are likely to expect. Actually, exactly what equipment and environment is used may not matter to me at all, so long as someone who can reliably hear can verify the test setup. That means someone who can hear needs to be identified and recruited. I would start looking with reputable people, not audiophiles, who can reliably identify test files on the experimenters equipment or their own equipment. The experimenters can provide the files and operate the equipment to make sure the recruitment test is honest.

What would William Ockham say? If things require these nearly-ridiculous "off spec" values in order to achieve some sort of performance only a selective group of individuals can hear, and that's only in story, then what are we led to believe? Either the effect is mythical, or its effect size is so small as to be meaningless.

There's nothing to say that you (a generic you) have proved this is audible. Prior plausibility is slipping. The ball is in your court.

By the way, I just had some recent communication with someone who claimed to manage 6 recording studios and a mastering room. He indicated they couldn't hear the difference between properly dithered 16-bit and 24-bit, without looking. The only thing that seemed make sense to me is that I suspect they didn't recruit people with listening tests. Or maybe they didn't choose the right equipment out of what they had on hand. On the other hand, I understand Bob Ludwig does use listening tests for employee recruiting. And I believe the people he hires can hear the difference. Such people exist, so I say let's get one or more of them on the research team.

No this is special pleading.
 
Daniel,
1. I know what you meant, and you are wrong.
2. You are trying to address what is essentially a scientific issue by trying to make it into a cheap, theatrical political debate. Shame on you.
3. You have made my ignore list.

Hooray to me! It's always great to be ignored by someone who wants to do "science" on terms convenient for his agenda.

For what it's worth, I found the argument that Mark was making pretty vacuous and just pretty words wrapped around a concept that says "me and my equipment are better than yours. You must be this tall to ride this ride".
 
Member
Joined 2014
Paid Member
Can someone humour me, as I am confused as to what we are supposed to be hearing with 24 bit vs 16 dithered. With dithered 16 bit and a regular DS DAC the noise floor is -130dB which puts it well below even Ed's room noise floor and audibility limits in presence of program material.

So assuming people can hear the difference, what are they hearing? I might be missing something but I can't work out what gets thrown away in the conversion that can be detected. (note I still agree that 24 bit is very useful for recording).

Extending this and given the best converters are 20-bit ENOB has anyone tried 24 vs 20 vs dithered 20bit as you could argue the dithered 20-bit should be better?
 
Can someone humour me, as I am confused as to what we are supposed to be hearing with 24 bit vs 16 dithered.

The only situation when I heard the difference that I could support by a positive ABX result was listening with headphones, very low level part of especially recorded (= extremely low noise recording chain) music sample and this part was listened at very high volume level. Then, it was possible to find clear distinction in the background noise. However, far from "standard" listening conditions.
 
William of Ockham (1285–1347/49) that pluralitas non est ponenda sine necessitate, “plurality should not be posited without necessity.” The principle gives precedence to simplicity: of two competing theories, the simpler explanation of an entity is to be preferred. The principle is also expressed as “Entities are not to be multiplied beyond necessity.”

For those who were unfamiliar with the best known of his work. Seems dead on for this thread!

But I like the modern version, "Lots of hand waving and talking hides the truth."
 
The most interesting tests I've seen, were sighted A/B tests with experts who knew unit A was best, and could hear it. And in the tests, 80-90% could hear A was better. No surprise.
Except, when they thought they were listening to A, they were listening to B...

Maybe more of a cognitive dissonance test than a hearing test? System 2 can sometimes overrule system 1, if system 1 doesn't strongly object.

Also, there are long lists of experiments showing there are all kinds of ways of fooling people into producing wrong answers. And nobody here is immune to such effects, despite perhaps a smug feeling when seeing someone else succumb that one is above such foolishness one's self.
 
Status
Not open for further replies.