John Curl's Blowtorch preamplifier part III

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Are you sure you are sending a clean signal from your speakers. Something like attached. Are you sure you do not have an intermodulation between R channel and crosstalk from L channel, that would create audible 2kHz. Your PC card is OK, right? Have you measured electrical and acoustical output? I can "hear" something on a 20+22kHz twintone from notebook + headphones, because notebook sound chip creates some digital trash. After switching to a moderate external DAC there is nothin audible.

Tomorrow when the crew is all here I can try it with two oscillators directly driving a pair of tweeters.
 
OK, but to me the amount of (audible) improvement left to gain would seem to be small so the advance is very incremental vs say tape to digital transition?

Yes, it is small in absolute terms. However, it may be that people who say they don't like digital or don't like the Sabre dac sound will find the new dac to be a clear notch above any other chip dac we have today. The new dac is especially nice sounding when used for DSD, and with HQplayer type conversion of CD PCM.

OTOH, for people who do not listen closely to myriad little details quickly flowing past in well recorded music, a new and and better top of the line dac chip may not mean much.
 
I ended up with different states of tune that worked well with the particular music I like (mostly blues based) and found it suffered in others.....but when I’ve got it dialed in to this point where the music takes control I notice it crosses over to other genres much better.

Blues often require lower bass extension to sound at its best. The key point here is you need to have good phase behavior, little group delay between the sub and the main speaker (esp. the tweeter). This is almost an impossible task with ready made analogue sub crossover because around crossover frequency, your main speaker is not flat (so you have to deal with an 'uncertain' acoustic response).

The vocals are what I gauge my tuning by and again when this point is met the Vocals layer up and become enveloping.....

Vocal is tricky, especially with female voices. You might think the vocal is more entertaining when the system is actually wrong. The less bass you have, the vocal (which is HF) might appear 'clearer' or better.
 
Blues often require lower bass extension to sound at its best. The key point here is you need to have good phase behavior, little group delay between the sub and the main speaker (esp. the tweeter). This is almost an impossible task with ready made analogue sub crossover because around crossover frequency, your main speaker is not flat (so you have to deal with an 'uncertain' acoustic response).

Vocal is tricky, especially with female voices. You might think the vocal is more entertaining when the system is actually wrong. The less bass you have, the vocal (which is HF) might appear 'clearer' or better.

All of what you say jives with my experience......it’s quite difficult to get the delay timing right between the sub/mains, it involves inclusion of tweeter.(something I never would have guessed before digging deeper)

DSP is really an awesome tool that I never gave much thought to before last year but once understood it’s a definate ah-ha moment!

The bass is my weakest link......two 10” subs driven by a decent but nowhere powerful enough amp, so in this case it probably helps.

I’ve got two lab 15 eminence and a crown xls 2002 in the closet for the new build....new 10” mtm mains.

The main reason to figure this out (besides curiosity) was to be able to replicate it in my new setup.
 
Now, I wonder if Batman is going to chastise Robin for presuming to be a mind reader. Or maybe for trolling 😱

Quick, to the cave Batman 😀😎

Just telling it like it is, ScottW has asked the same question over & over - gets the same reply over & over - that sighted listening impressions & forum ABX listening impressions are both a bit of fun (something you already agreed to. AFAIR), no one impression is more reliable, truthful than the other.

Why does ScottW ask this same Q again & again and you don't - maybe ScottW would like to answer?
 
<snip>

Scott continually asks this same question & doesn't accept the answer he gets from you or me ....

Could be so, but iirc, I haven't noticed the question before .....
Can't say if he'll accept my answer but maybe he (now?) understands what it is about.

<snip>What he really wants to argue is that forum run ABX testing is superior to sighted listening & should be treated as such but he can't bring himself to admit this bias.

According to him, he is not fixated on ABX tests.
I would agree if someone states that a positive test result (including replication/repetition) from a controlled listening test (even blinded) carries more weight than a positive result from a "sighted" listening test.

Simply for the reason that one can't show validity for a sighted listening test....
 
Now I'm with amplifier design. Later on I will figure out what the fuss is about with DAC.
Why? What happened to the room acoustics?
OTOH, for people who do not listen closely to myriad little details quickly flowing past in well recorded music, a new and and better top of the line dac chip may not mean much.
Is that your opinion or citing of proof somewhere?
 
Could be so, but iirc, I haven't noticed the question before .....
Just the times he posed the same question to me

I'll ask again, why is testing such as Markw4's any different? I've also asked before why aren't all the sound of cable, op-amp rolling, sound of capacitor/resistor etc. threads on the various fora "just a bit of fun to be shared".

Quite so, when MM says markw4's DAC observations should stand unchallenged I asked why they don't need to pass any kind of protocol and get nothing in response except more studies to read.

You could have fooled me.


Can't say if he'll accept my answer but maybe he (now?) understands what it is about.

According to him, he is not fixated on ABX tests.
I would agree if someone states that a positive test result (including replication/repetition) from a controlled listening test (even blinded) carries more weight than a positive result from a "sighted" listening test.

Simply for the reason that one can't show validity for a sighted listening test....
Well, let's see?
 
You simply have to cite a proof that listeners miss out audible difference during level matched audio DBT due to the stress and when the stress is removed, they can hear it in level matched audio DBT. I asked you this before but you have yet to provide a proof. All you provided was more of your opinion.

As "proof" is not possible to get from this kind of experiments, the question for "proof" doesn't make sense.
If you ask for evidence then why should I be obliged to provide evidence for a claim that I've never made??

Further, you usually don't know, if someone _hears_ an audible difference, all you know are the results of the trials and your own criterion for success (to keep it simple and short for the moment,neglecting all the specifics).

As I've cited already often the publications that showed the evidence for significantly different numbers of correct responses (when comparing different test protocols while presenting the same sensory difference) then it depends solely on the success criterion, if a participants "misses" the audible difference or (presumably) "hears it".

Up to now you refused to read the publications.....


I did cite evidence by quoting the title of the thread and some of your own replies on Hydrogenaudio. You will have to point out with quotes why that thread doesn't qualify as evidence.

I must have missed it.
Please post the link to your message where you brought up the evidence.

Your claim, your obligation to point out why something you might have posted should be considered as evidence.
 
I understand what is said, but I still see both sides saying "you are absolutely correct" rather than simply agreeing or not on an individual basis. I won't ask anymore.
Sorry, I missed your post before I posted the above reply to Jakob2

What you interpret as "you are absolutely correct" I view as a reply poster relating similar experience to the impressions posted by the poster. Just the same as posters agree with those who say all (qualifier of choice inserted here) DACs, amplifiers sound the same.

It's a sharing of opinions - I don't see where your problem lies?
 
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I understand what is said, but I still see both sides saying "you are absolutely correct" rather than simply agreeing or not on an individual basis. I won't ask anymore.

As I am still puzzled, but would like to understand, could you rephrase or explain your sentence above?

What do you mean by "on an individual basis" ? Is that related to the EUT (sighted or unsighted) or related to the member/individual that is reporting?

My impression on this matter simply is:

If a member posts a negative result from "sighted" listening on for example two DACs, you would not object and not demand a controlled listening test ("blinded").

If a member posts a positive result from "sighted" listening on for example two DACs, you're demanding results from a controlled listening test ("blinded")

That is the reason why I think it is a matter of double standard.
 
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Why? What happened to the room acoustics?

?

You seem hung up on room acoustics, I agree it is important but someone in a situation such as mine (and pretty sure many others) is not able to do much with acoustic treatment as the listening area is part of the home.....in my case the family room.

A thick Persian style rug on the tile floor is all I could muster....I might be able to finagle some heavy curtains for the widows but haven’t got that far yet.

So what does a person do in this situation? Well in my case I’m tuning the system to the LP......making it comply to the space.

First step is realizing a flat speaker fr is not going to work.....crossover must be tuned to the room.
Yes this is not ideal if you want to move your speakers but if you have a dedicated space it won’t be a issue unless you decide to sell them.
 
Now, I wonder if Batman is going to chastise Robin for presuming to be a mind reader. Or maybe for trolling 😱

Could be so, but iirc, I haven't noticed the question before .....
Can't say if he'll accept my answer but maybe he (now?) understands what it is about.



According to him, he is not fixated on ABX tests.
I would agree if someone states that a positive test result (including replication/repetition) from a controlled listening test (even blinded) carries more weight than a positive result from a "sighted" listening test.

Simply for the reason that one can't show validity for a sighted listening test....

Apparently not, double standards? Selective memory loss? Who knows, more to the point, who cares anymore? Answers on a postcard please
 
You seem hung up on room acoustics, I agree it is important but someone in a situation such as mine (and pretty sure many others) is not able to do much with acoustic treatment as the listening area is part of the home.....in my case the family room.
Study Linkwitz. He was of the opinion that a normal living-room comfortable for conversation should also be good for speakers and designed them accordingly.
 
As "proof" is not possible to get from this kind of experiments, the question for "proof" doesn't make sense.

How convenient :rofl:.

Of course, avoiding a response to a direct question is not proof that the statement is either true or false, and can be eventually chosen conveniently, depending on the conjuncture. Isn't this obfuscating, or what? :rofl:

tenor.gif
 
Opinion. Sorry if that wasn't clear.
Having opinion is fine. Just curious, which source / experiment is your opinion based on?
As "proof" is not possible to get from this kind of experiments, the question for "proof" doesn't make sense.
If you ask for evidence then why should I be obliged to provide evidence for a claim that I've never made??

Further, you usually don't know, if someone _hears_ an audible difference, all you know are the results of the trials and your own criterion for success (to keep it simple and short for the moment,neglecting all the specifics).

As I've cited already often the publications that showed the evidence for significantly different numbers of correct responses (when comparing different test protocols while presenting the same sensory difference) then it depends solely on the success criterion, if a participants "misses" the audible difference or (presumably) "hears it".

Up to now you refused to read the publications.....
Playing semantics game again. You've been trying to smear the value of audio DBT by saying it has "problem". All you've responded with was your opinion and conjecture regarding that "problem". Even you (one who's been going at it for a while) don't have a proof that audio DBT creates debilitating stress that causes listeners to miss out audible difference. I know what the problem is. It's loss of sales from high end audio business.
I must have missed it.
Please post the link to your message where you brought up the evidence.

Your claim, your obligation to point out why something you might have posted should be considered as evidence.
You are joking trolling stalling, right? Already forgot this in 5 days? 🙄

You seem hung up on room acoustics, I agree it is important but someone in a situation such as mine (and pretty sure many others) is not able to do much with acoustic treatment as the listening area is part of the home.....in my case the family room.

A thick Persian style rug on the tile floor is all I could muster....I might be able to finagle some heavy curtains for the widows but haven’t got that far yet.

So what does a person do in this situation? Well in my case I’m tuning the system to the LP......making it comply to the space.

First step is realizing a flat speaker fr is not going to work.....crossover must be tuned to the room.
Yes this is not ideal if you want to move your speakers but if you have a dedicated space it won’t be a issue unless you decide to sell them.
This tells me that you aren't familiar with room acoustics. Options are endless. Look up makeshift sound absorbers and diffusers. And don't give up.
 
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