All transports are NOT the same

[E-Stat]

I'm afraid I lost you. Distortion is 'most certainly audible when playing musical content' on what specifically?

I am referring to the traditional tests supplied by virtually all audio manufacturers that are based upon test tones only. It has been the experience of many that such has little correlation to real world conditions. Much like running a car on a dynamometer.

Is this the preamp you referring to in the preceding statement?

Yes. BTW, it has less than 0.01 distortion at 2V RMS output (typically less than 0.005% in midband) and its high level stage frequency response is +- 0.5 db 5 hz to 50 khz with -3db points below 1 hz and above 200 khz. It should be perfect, right? Guess what?

What testing methodology? Measurements taken to find non linearities that may be audible?

I'm not a "read-the-graph-to-appreciate-music" kind of guy. Hearing content in recordings masked by the preamp.

At the immediate moment, I'm not aware of any dedicated preamps that use op-amps as the gain stage.

There is a very good reason why.

However, theoretically, you could use the vunerable NJM4556 to make an audibly transparent preamp according to known human thresholds of distortions.

You and the Robot could share beautiful theory together.

rw

[WmAx]

I am referring to the traditional tests supplied by virtually all audio manufacturers that are based upon test tones only.

As you know, manufacturer provided specifications are not reliable.

Yes. BTW, it has less than 0.01 distortion at 2V RMS output (typically less than 0.005% in midband) and its high level stage frequency response is +- 0.5 db 5 hz to 50 khz with -3db points below 1 hz and above 200 khz. It should be perfect, right? Guess what?

Well, this does not tell me anything about it's performance into a specific load, at a specific amplitude or at specific frequencies.

There is a very good reason why.

Well, that is debatable. I believe it's because the market for most component preamps is biased to believe the operational amplifiers are 'bad sounding' even though this is contrary to the actual technical performance, which can be excellent with modern devices. The opinions concerning op amps by the audiophile market are not based on proper double blind testing methods nor on correlative data that based on perceptual research, suggests an audible difference.

-Chris

[E-Stat]

As you know, manufacturer provided specifications are not reliable.

While I agree with your statement, that is not the case with Audio Research. According to your criteria, it should be transparent. I really wish it were. I use the preamp exclusively for use with my phono source.

Well, that is debatable. I believe it's because the market for most component preamps is biased to believe the operational amplifiers are 'bad sounding' even though this is contrary to the actual technical performance, which can be excellent with modern devices. The opinions concerning op amps by the audiophile market are not based on proper double blind testing methods nor on correlative data that based on perceptual research, suggests an audible difference.

I hear what you are saying but disagree. There have been many a preamp in the past, some actually pretty good like the Dayton-Wright SPA, that were IC based. The quality of receivers and integrated amps has improved such that I believe those who go the extra step to develop preamps want performance beyond that which is generally found in those components. Simply ask the engineers as I have.

rw

[WmAx]

[.

The quality of receivers and integrated amps has improved such that I believe those who go the extra step to develop preamps want performance beyond that which is generally found in those components. Simply ask the engineers as I have.

If the engineer has spseicifc data that coorelates with known human audibility thresholds or has organized and demonstrated a valid DBT that substantiates the claims of audible performance, then that is good. If he does not, then what he claims is a performance improvment is just that, a claim.

-Chris

[E-Stat]

[If the engineer has spseicifc data that coorelates with known human audibility thresholds or has organized and demonstrated a valid DBT that substantiates the claims of audible performance, then that is good. If he does not, then what he claims is a performance improvment is just that, a claim.

You will find dissenting opinions on that topic from a number of talented engineers such as Nelson Pass, William Johnson, Lou Johnson, Luke Manley, Jud Barber, Dan D'Agostino, etc.

I have already commented on why that is the case.

Have you ever seen a DBT claim?

rw

[WmAx]

You will find dissenting opinions on that topic from a number of talented engineers such as Nelson Pass, William Johnson, Lou Johnson, Luke Manley, Jud Barber, Dan D'Agostino, etc.

Opinons on what, specifically? Are you somewhow implying that some of these engineers have dismissed correlating measurement with known human thresholds or dismissed DBT? Certainly, they could. Certainly, that would be unscientific and a good reason to dismiss any claims of audiblity such person may make.

I have already commented on why that is the case.

Have you ever seen a DBT claim?

The feasibility of proper evaluations is another matter from the one here. Here, the matter is reliable determination of audibility. Sighted listening is not reliable. THe signficant effort required to perform a valid DBT or ABX test in no way makes sighted listening reliable.

-Chris

[E-Stat]

Are you somewhow implying that some of these engineers have dismissed correlating measurement with known human thresholds or dismissed DBT?

Dismissed DBT.

rw

[WmAx]

Dismissed DBT.

rw

Ah. Then this text from my prior post is directly applicable:

That would be unscientific and a good reason to dismiss any claims of audiblity such person may make.

-Chris

[E-Stat]

Ah. Then this text from my prior post is directly applicable:

That would be unscientific and a good reason to dismiss any claims of audiblity such person may make.

Tell me of an amp or preamp (either/both) that you know was developed in such a manner for which you have a high regard.

rw

[WmAx]

Tell me of an amp or preamp (either/both) that you know was developed in such a manner for which you have a high regard.

rw

Well, regard in what manner? I won't make claims of audibility in this regard. But as far as technical achievement in regards to measurements, the best measuring unit I am aware is the Halcro dm10. It reminas remarkably linear at extrmely high output voltage into frequencies well beyong the audible range. Both IMD and THD are of extraordinary low levels.



Stereophile text: Fig.5 Halcro dm10 line stage, THD+N (%) vs frequency at (from bottom to top): 10V balanced into 100k ohms and 600 ohms, 7V unbalanced into 100k ohms and 600 ohms


IMD Products


The complimenting power amp by Halcro is the of the same stature. Indeed, if I was a rich man with excess money --- I would be tempted to purchase this equipment just for show. :-)

-Chris

[E-Stat]

Well, regard in what manner?

Admiring specs is ok, but I was really curious as to your sonic preferences. My favorite preamp thus far (have not seriously auditioned the VTL 7.5) - and waaay out of my budget is the C-J ART II. While I haven't heard the Halcro preamp, I am told by a trusted ear who has that it is wonderfully detailed, but a touch sterile.

You chose a $15k preamp. Are there any less expensive models that fit your "inaudible distortion" criteria ?

rw

[DMK]

Admiring specs is ok, but I was really curious as to your sonic preferences. My favorite preamp thus far (have not seriously auditioned the VTL 7.5) - and waaay out of my budget is the C-J ART II. While I haven't heard the Halcro preamp, I am told by a trusted ear who has that it is wonderfully detailed, but a touch sterile.

You chose a $15k preamp. Are there any less expensive models that fit your "inaudible distortion" criteria ?

rw

I agree with your "trusted ear". Sterile is exactly how I would describe the sound of the Halcro, although I didn't spend all that much time with it. And just to be contrary, I found the Wyetech Labs Opal preamp to be a touch more to my preference than the CJ ART II. HP and yourself disagree. Alas, it's unlikely I'll ever be able to afford either one. However, I could afford the Wyetech before the CJ at roughly half the scratch!

[E-Stat]

I agree with your "trusted ear". Sterile is exactly how I would describe the sound of the Halcro, although I didn't spend all that much time with it. And just to be contrary, I found the Wyetech Labs Opal preamp to be a touch more to my preference than the CJ ART II. HP and yourself disagree. Alas, it's unlikely I'll ever be able to afford either one. However, I could afford the Wyetech before the CJ at roughly half the scratch!

I heard the Wyetech at Seacliff some time ago. The ART II is simply amazing in its wonderfully spacious rendering of the soundstage and ultra sweet highs. While the Wyetech is very well built and quite gorgeous in person, I didn't find it to be as satisfying. Nor so with the Aesthetix Callisto, the Burmester, or the Edge. I will be the first to admit that it could be a question of system synergy. HP's system uses a pretty long run from pre to power amp. The output impedance of the C-J may be better able to drive the longer cables (albeit they are low cap Valhallas throughout). Here is the system as of May of this year:



On one of his visits, Harry Weisfeld suggested Harry try the Scoutmaster with the TNT's motor drive, SDS controller, and disk clamp. The result was quite good for significantly less money than the TNT-HRX. The Burmester 969/970 CDP remains in a class by itself sonically.

rw

[DMK]

Well, system synergy is what it's all about as well as the "different strokes" theory. I'd have the Wyetech Opal/Topaz combo if I were made of money but have to settle for the less refined Wyetech Jade and a non-Wyetech tubed power monoblocks. Life ain't perfect.
I'm always relieved to learn that we don't have to worry about preamps anyway since they all sound the same unless they're broken or purposefully euphonic! Someone on A/R once posted that it was simple to design a perfectly transparent preamp, presumably an active one. I asked when this magical and magically simple preamp would first hit the market as the world is waiting! Still waiting....

Anybody with three turntables is ok in my book!

[WmAx]

I regard the Halcro only for the measurments, which are outstanding. I make no claims of audiblity of this or any other preamplifier. My perceptions are as flawed as anyone elses without proper DBT evaluation, thus they are simply not important. Their are plenty(most) preamps that fit my inaudible distortion criteria, as defined by known JNDs from research.

-Chris

Admiring specs is ok, but I was really curious as to your sonic preferences. My favorite preamp thus far (have not seriously auditioned the VTL 7.5) - and waaay out of my budget is the C-J ART II. While I haven't heard the Halcro preamp, I am told by a trusted ear who has that it is wonderfully detailed, but a touch sterile.

You chose a $15k preamp. Are there any less expensive models that fit your "inaudible distortion" criteria ?

rw

[E-Stat]

Their are plenty(most) preamps that fit my inaudible distortion criteria, as defined by known JNDs from research.

Does that include SS models from the 70s like Skep's Citation (had one myself in '74) or Marantz? Ever bypassed one altogether using a high output, low impedance source such as a CDP?

rw

[WmAx]

Does that include SS models from the 70s like Skep's Citation (had one myself in '74) or Marantz? Ever bypassed one altogether using a high output, low impedance source such as a CDP?

rw

I meant to refer to 'most modern' preamplifiers(late 80's on up). I don't like to assume anything about old equipment that I have not seen a full set of measurement data. It might be fine. It might not. Modern equipment typically measures very well in respect to known JNDs in all practical conditions, though.

-Chris

[E-Stat]

Modern equipment typically measures very well in respect to known JNDs in all practical conditions, though.

What preamps are found in your "known JND" studies?

rw

[WmAx]

What preamps are found in your "known JND" studies?

rw

I don't mean to sound rude(so don't take it that way): this conversation is no longer interesting too me -- I just don't find discussion of equipment on a brand/model basis important unless certain unique circumstances are relvant(like the TIM condition of the IC-150).

Have a good one.

-Chris

[E-Stat]

I don't mean to sound rude(so don't take it that way): this conversation is no longer interesting too me

No offense taken.

I'm not at all surprised since every request for specifics of DBT or JND tests quoted here using the best gear alway results in silence.

rw

[mtrycraft]

No offense taken.

I'm not at all surprised since every request for specifics of DBT or JND tests quoted here using the best gear alway results in silence.

rw

JNDs are conducted in sound booth and headphones, usually, as they are after threshold detection.
You need numbers? Check out the citations.
Where are any of your citations supporting your claims?

[E-Stat]

JNDs are conducted in sound booth and headphones, usually, as they are after threshold detection.
You need numbers? Check out the citations.

Which citations? Remember when you fell flat on your face the time you finally admitted that your darling DBT studies are all done with mid-fi gear?

Proof? What proof?

Where are any of your citations supporting your claims?

Unlike you, I'm not dependent on the (flawed) studies of others to form my opinion. I actually have direct experience. I don't need citations.

rw

[mtrycraft]

[]Which citations? Remember when you fell flat on your face the time you finally admitted that your darling DBT studies are all done with mid-fi gear? [/b]

Actually, that is only your characterization of equipment. But then, you never have posted any citations, so you have no real basis on anything real.

More flawed papers.

"Level Discrimination as a Function of Level for Tones from .25 to 16khz", Florentine, Mary, et al, Journal of Acoustic Society of America, 81(5) May 1987, pg 1528-1541.

"On the Relations of Intensity JND's to Loudness and Neural Noise", Zwislocki, J and Jordan H., Journal of Acoustics Society of America, 79(3), Mar 86, pg 772-780.

"Auditory Intensity Discrimination at High Frequencies in the Presence of Noise", Viemeister, Neal F., Science, vol 220, 16 Sep 83, pg 1206-1208.

"Subjective Loudness of Typical Program Material" Soulodre, Lavoie and Norcross, Convention Paper 5892, 2003 AES.




Unlike you, I'm not dependent on the (flawed) studies of others to form my opinion. I actually have direct experience. I don't need citations.

rw

No, of course you don't need citations, you have experience. LOL.
That is what all the alien abductees say too. Or, the John Edwards crowd. Or, the creation crowd. On it goes, your experience is golden. Golden what is another issue though. Enjoy the your dream world.

[E-Stat]

More flawed papers.

"Level Discrimination as a Function of Level for Tones from .25 to 16khz", Florentine, Mary, et al, Journal of Acoustic Society of America, 81(5) May 1987, pg 1528-1541.

"On the Relations of Intensity JND's to Loudness and Neural Noise", Zwislocki, J and Jordan H., Journal of Acoustics Society of America, 79(3), Mar 86, pg 772-780.

"Auditory Intensity Discrimination at High Frequencies in the Presence of Noise", Viemeister, Neal F., Science, vol 220, 16 Sep 83, pg 1206-1208.

"Subjective Loudness of Typical Program Material" Soulodre, Lavoie and Norcross, Convention Paper 5892, 2003 AES.

Since these studies all predate your admission that you are unaware of any studies regarding high end equipment, I gather this is simply more irrelevant data to the question I have posed to you on several occasions. Conclusions from any well run study for anything are completely valid for that which is tested. The corollary, naturally, is that they are likewise mute on that which has not been tested. You also seem to think that there have been no improvements whatsoever in the reproduction chain in the past twenty years or you would not continue to regurgitate studies from 1983. It is the unscientific part where results from one study are extrapolated to that equipment the likes of which has never been tested (according to your lack of such references).

rw

[mtrycraft]

Since these studies all predate your admission that you are unaware of any studies regarding high end equipment, I gather this is simply more irrelevant data to the question I have posed to you on several occasions. Conclusions from any well run study for anything are completely valid for that which is tested. The corollary, naturally, is that they are likewise mute on that which has not been tested. You also seem to think that there have been no improvements whatsoever in the reproduction chain in the past twenty years or you would not continue to regurgitate studies from 1983. It is the unscientific part where results from one study are extrapolated to that equipment the likes of which has never been tested (according to your lack of such references).

rw

You asked about JNDs. I gave them to you. Now you don't like it.

If there are aubily better components in the chain, excluding speakers, There is nothing published that is reliable to any degree, but you know that, nothing is reliable for you exept your ears.
Or, you can start posting your citation list of current data.