John Curl's Blowtorch preamplifier part III

[chris719]

Don't know about speaker destruction, but being deafened when attempting near field critical listening could be an issue. I tend to listen at much lower levels than the system is capable of. Turn it up to impress visitors.

Yeah, hearing damage works too. I'd love to see someone demonstrate their ability to hear noise floor modulation on an AK4499 DAC in mono mode.

Of course the exercise of extracting the noise floor of a recording is not that difficult in most cases, but no one wants to see the answer. I suspect some recording where these supposed effects are audible are two orders of magnitude worse than -120dB.

Yep, I am always surprised by how many modern recordings have relatively high noise floors.

 

[scott wurcer]

What does annoy me is noise gates on pop recordings of a certain era and the fading out of noise between tracks. But that's just me.

I meant the hiss not pops and crackle, the things you mentioned even in small residual amounts are annoying.

 

[Max Headroom]

I have just done a subjective comparison test..... There were no audible differences between the Apple lightening DAC and the iPad headphone socket DAC. I expected this.

There was a slight improvement in resolution of very subtle sounds in the iPod shuffle headphone socket DAC, and is what I already use for most of my listening. I also expected this.

So, my question is:- for what is an exceptional performance from a £9 DAC, how much more can be reasonably expected from DACs that cost £100, or £250 or even £1000, and where is the price plateau of diminishing returns?.

Sighted test and expectations......according to the usuals in this thread your appraisal is totally worthless and/or product of your imagination, I am surprised that you so far have not been taken to task/attacked for your lack of scientific method !. However, yes it does beg the question of just how good does a DAC stage need to be ?. The tweaked $5.00 PCM2704 DAC I run directly from my laptop sounds good, really good and is essentially just a 2" extension of the headphone cable, so convenient.

Dan.

 

[scott wurcer]

I am surprised that you so far have not been taken to task/attacked for your lack of scientific method.

😱🙄

 

[mountainman bob]

Merrill,

I spent almost my entire career working in the media industries, and never once have I ever heard the expression, colloquial or otherwise, ‘Technicolor sound’. It shows that you just make things up as you go along because they sound good to you at the time, and when you get found out, you kick off.

ToS

Technicolor Sound Post-Production

 

[tapestryofsound]

Sighted test and expectations......according to the usuals in this thread your appraisal is totally worthless and/or product of your imagination, I am surprised that you so far have not been taken to task/attacked for your lack of scientific method !. However, yes it does beg the question of just how good does a DAC stage need to be ?. The tweaked $5.00 PCM2704 DAC I run directly from my laptop sounds good, really good and is essentially just a 2" extension of the headphone cable, so convenient.

Dan.

Dan,

Yeh, your right, a totally worthless review devoid of any scientific method. 😱

My expectations were based upon reading a number of reviews of all the DACs I compared today, and what I have been listening to over the past twelve months. I am talking about tiny little differences that I am able to disregard. Although the DAC in the G4 iPod shuffle is considered a cut above the onboard iPad headphone DAC. There are so many DACs out there between £100 to £250, I really don’t know where to begin.

I suppose that it could considered to be expectation/confirmation bias, coupled with all the vagaries of testing with blind/not so blind, short term/long term memory blackouts, subjectivist/objectivists and goodness knows what the heck else there is. Amazingly,if I care to listen, I can actually hear the minute differences, and you know what? I really don’t care anymore. 😛

It just seems to me the music matters more than anything else.

ToS

 

[tapestryofsound]

Technicolor Sound Post-Production

Er Bob, I was talking about 3 strip Technicolor as it was more than 60 years ago, and I am fully aware and cognisant about what the Technicolor company does presently in terms of sound production. Technicolor, as a film process was last used in the 1970’s by Serge Lione to make spaghetti westerns. ToS

 

[mountainman bob]

Er Bob, I was talking about 3 strip Technicolor as it was more than 60 years ago, and I am fully aware and cognisant about what the Technicolor company does presently in terms of sound production. Technicolor, as a film process was last used in the 1970’s by Serge Lione to make spaghetti westerns. ToS

I’m pretty sure the whole ‘technicolor sound’ reference was paradoxical in the sense of vivid, maybe even over the top sound?

 

[Max Headroom]

Merrill,I spent almost my entire career working in the media industries, and never once have I ever heard the expression, colloquial or otherwise, ‘Technicolor sound’. It shows that you just make things up as you go along because they sound good to you at the time, and when you get found out, you kick off.

Technicolour yawn is a standard Aus expression, where have you been ?.

I’m pretty sure the whole ‘technicolor sound’ reference was paradoxical in the sense of vivid, maybe even over the top sound?

Yes, standard expression.

 

[Evenharmonics]

Which brings me back to the perennial question:- just exactly what do you do as a day job besides hugging a keyboard?

Promoting what he sells through any means possible.

At what levels, though, and how much?

Just thinking about the noise floor of your average recording compared to the noise floor of a well-done DAC that has 120 dB+ SNR... I have serious doubts about the audibility of this phenomenon.

But he's heard it in subjective listening sessions.

 

[tapestryofsound]

I’m pretty sure the whole ‘technicolor sound’ reference was paradoxical in the sense of vivid, maybe even over the top sound?

Yes, absolutely right!

You might want to watch the restored version of ‘My Fair Lady’ someday.

Technicolour yawn is a standard Aus expression, where have you been ?.

Obviously under a rock - Ayers Rock, maybe even Brighton Rock.

 

[mountainman bob]

Merrill,

I spent almost my entire career working in the media industries, and never once have I ever heard the expression, colloquial or otherwise, ‘Technicolor sound’. It shows that you just make things up as you go along because they sound good to you at the time, and when you get found out, you kick off.


ToS

I’m pretty sure the whole ‘technicolor sound’ reference was paradoxical in the sense of vivid, maybe even over the top sound?

Yes, absolutely right!

🙄

 

[Terry Demol]

Yeah, hearing damage works too. I'd love to see someone demonstrate their ability to hear noise floor modulation on an AK4499 DAC in mono mode.

No one has suggested that it's an issue with AK4499.

Yep, I am always surprised by how many modern recordings have relatively high noise floors.

That's called compression and vintage outboard gear. 😎 Every time you compress, there is gain make up involved = noise floor rise. Lot's of vintage mics being used and the same goes for mic pre's. There's your noise. Plenty of great classic recordings were compressed to hell (and back) Here's a good example YouTube Great song, very compressed but done well. Sounds good to me. 🙂

PS, I love the wood block (or whatever it is) in chorus etc T

 

[chris719]

Then what is it a problem with? Almost every good part has better than 120 dB SNR. Of course you come to just obfuscate and cast doubt without offering anything.

I offered an example, what's your example of the problem?

 

[Joe Rasmussen]

I find it interesting when somebody says they know how design speakers, do it textbook, i.e. do a good engineering job and yet candidly admit it does sound all that great, like most textbook speakers (2-way in particular). Rather than say there is some kind of black art involved, could it be that we are overlooking something and that some have semi-blindly found/stumbled across 'ingredients' that deals with the still unknown? I have for some time really wondered about that. Am I alone?

 

[picowallspeaker]

One final subject for the night is that although the electronics and transducers used for audio reproduction are, for the most part, time invariant, our body’s auditory systems are clearly not so.

A pressure at an instant cant be a sound unless its changing at that instant. Calculus. A polnt on a sine wave has a derivitive, which is its rate of change, at that instant. And fourier tells us that even a pulse with zero width (an instant) has frequency. If you want to expand your knowledge, learn the math.

And of course it is always an approximation to use the term LTI as the systems we are talking about are usually in the category of "weakly non-linear" and "mainly time invariant" (sometimes even more than weakly non-linear)

 

[scottjoplin]

I find it interesting when somebody says they know how design speakers, do it textbook, i.e. do a good engineering job and yet candidly admit it does sound all that great, like most textbook speakers (2-way in particular). Rather than say there is some kind of black art involved, could it be that we are overlooking something and that some have semi-blindly found/stumbled across 'ingredients' that deals with the still unknown? I have for some time really wondered about that. Am I alone?

For anyone to say something like that is very naive, do you have any examples?

 

[Joe Rasmussen]

Why did you just say that? Makes no sense? I don't even know by what you mean as examples?

 

[scottjoplin]

An example of someone saying they know how design speakers, do it textbook, i.e. do a good engineering job and yet candidly admit it does sound all that great

 

[Joe Rasmussen]

OK, I understand. It was said here by one of the regular contributors a little while back and it stuck in my head. I paraphrased what he said. So I raised it because it intrigued me that many say that designing speakers is some kind of 'black art' and I don't think that is a satisfying answer.