John Curl's Blowtorch preamplifier part II

[Kindhornman]

Sy,
Agreed that a great cd mastered at 16/44.1 can sound great. I have Chesky cd's that sound excellent. But that is different than what we were saying that the cd does not sound exactly like the final mastered tape. As far as cd being obsolete that is another question. As Steve Eddy says the problem is that you can't easily get high quality digital from most sources that isn't of MP3 quality and that is the rub. When most music is released in a better quality format digitally that can be saved to hard drive things will change, until then we are stuck with cd's. With Wave or Flak files things are possible that aren't worth the time with MP3.

 

[a.wayne]

I'm not a fan of chesky recordings , prefering Reference recordings , Telarc ....

Chesky's stuff is way too bland , no life , no music , like food without the good spices and yes i do have most of his stuff ...

Now, arn't most recordings done at 24/192 and not at MP3 ....

 

[wayne]

The Harman system moves a stereo pair into the same position as a preceding system in a matter of a few seconds. I forget what the maximum mass is that can be handled, but it's an impressive machine. I think there are pictures and a description in Toole's book Sound Reproduction.

It sure makes fun sounds when it switches them around. Pneumatic?

 

[john curl]

I REALLY LIKE CHESKY, but primarily for the FIDELITY of the recordings. I have a number of DVD's, SACD's from them, and would 'kill' for a few vinyl recordings that they ran out of. I need REFERENCES, and the music can be pretty good too! Reference Recordings can be pretty good as well!

 

[bcarso]

It sure makes fun sounds when it switches them around. Pneumatic?

I believe so. In tests I think they also make a masking noise so the slightly different sounds based on stow-to-present differences don't give cues.

 

[jneutron]

I believe so. In tests I think they also make a masking noise so the slightly different sounds based on stow-to-present differences don't give cues.

It's so easy to just use linear motors and rails with rubber wheels. Why in the name of sam hill would noise be there??? It wouldn't matter what the speaker mass was either, the PID parameters can easily be softened to accommodate widely varying loads. Lower the gain, put in more integral and FF...sheesh.

jn

 

[a.wayne]

I REALLY LIKE CHESKY, but primarily for the FIDELITY of the recordings. I have a number of DVD's, SACD's from them, and would 'kill' for a few vinyl recordings that they ran out of. I need REFERENCES, and the music can be pretty good too! Reference Recordings can be pretty good as well!

Well heres one , DSD ....

World's Greatest Audiophile Vocal Recordings:Amazon:Music

 

[PMA]

I does make a big difference and is important. Discount it at your peril.

Important, not All Explaining, as tried.

 

[SY]

The phrase you're looking for is "sine qua non."

 

[jacco vermeulen]

It's so easy to just use linear motors and rails with rubber wheels.

Doesn't appear pneumatic to me.

(maybe a rat making noises behind the curtain, to make it a DD-BT ?)

 

[Pano]

Human ears just don't perceive small level changes as level changes, that's just how we're wired.

Eyes may be better at it - at least trained ones. I spent the morning doing A/B evaluation 2 very expensive DLP projectors. I was not able to level match exactly, but close. It was not too hard to see they were practically identical, with one just a little brighter than the other. The added lumens made it look better. Not hard to adjust to.

But it's easier with video than with audio. I could run the 2 projectors side by side on the same screen with the same signal. That would be kinda confusing with audio.

 

[jacco vermeulen]

Eyes may be better at it - at least trained ones.

Can you explain that , oh ye mighty banana warrior ?

(I'm thinking eye check-up at the optometrist)

 

[bcarso]

Doesn't appear pneumatic to me.

(maybe a rat making noises behind the curtain, to make it a DD-BT ?)

I don't know, just thought I had heard that. I wasn't involved in that part of the design, and I don't know the firm that contracted for it.

I'll ask Toole or Olive at some point how it is done.

 

[Triodethom]

Well, if you don't do something that basic and well-established as significant, how can anything else you do be taken seriously?

I would urge everyone to try this experiment: create two tracks that are identical except for a 0.2dB level, then tell someone that you want to compare the outputs of two amps, and let them ABX it. If they have sharp ears, you will get comments that the louder track is "cleaner," "more open," "better detail." Human ears just don't perceive small level changes as level changes, that's just how we're wired.

Not arguing with the result just surprised that .2db is all it takes for that result.

 

[fas42]

Nah, not a problem. The seal gap along the edge of the door is a 1/4 wavelength long waveguide/stripline. It appears like a short circuit within the oven because the other end of the waveguide is terminated by an open circuit. So it is designed with a specific frequency in mind.

Cellphones are not the same frequency.

Thanks. As Jacco mentioned, very helpful to have people around who live and breathe this stuff - saves a bit of Googling time, .

 

[Kindhornman]

Frank,
Now if you turned that microwave on and left it on and the phone range I think I might be interested in that model!

 

[WithTarragon]

Not arguing with the result just surprised that .2db is all it takes for that result.

Won't happen.
0.2 dB difference is below detectability.

 

[bcarso]

Won't happen.
0.2 dB difference is below detectability.

Note that SY is not stating that the listener detects a level change, but has a tendency to prefer the slightly louder presentation. For level changes about 1dB is stated to be the jnd for loudness, and is somewhat context dependent. See Just-noticeable difference - Wikipedia, the free encyclopedia

(For perceiving a balance shift I suspect the jnd for a stereo presentation is a good deal less than 1dB, but of course that's not what we're discussing here. What I found interesting is the level difference in the absence of any time delay effects for perceiving the signal to be coming entirely from L or R is 13dB in the frequency range of highest aural acuity.)

 

[SY]

Won't happen.
0.2 dB difference is below detectability.

Experimental results in the literature disagree with you.

 

[WithTarragon]

Note that SY is not stating that the listener detects a level change, but has a tendency to prefer the slightly louder presentation. For level changes about 1dB is stated to be the jnd for loudness, and is somewhat context dependent. See Just-noticeable difference - Wikipedia, the free encyclopedia

(For perceiving a balance shift I suspect the jnd for a stereo presentation is a good deal less than 1dB, but of course that's not what we're discussing here. What I found interesting is the level difference in the absence of any time delay effects for perceiving the signal to be coming entirely from L or R is 13dB in the frequency range of highest aural acuity.)

Both statements are incorrect.

Detectability does not require that the percept be "loudness", just that it is "different". Detecting a level difference is about 0.75 to 1 dB. This is true over a wide variety of conditions (there is an exception at lower overall levels with certain bandwidth - but for our purposes that is a rare occurence). For the "balance shift" the jnd is still about the same (0.75 to 1 dB).

This is a robust finding, in spite of what someone may have written in a wiki contribution.