James Randi’s attack on high performance audio - Page 58  

I wish I tagged the link to a post where someone placed a speaker cable with boxes on it through a spectrum analyzer and it didn't show anything beyond normal cable loss at 10kHz-20kHz region. The box was a RF filter.

i am not qualified to argue or justify the design of the darTZeel amps.

OTOH i do have lots of experience listening to many high end amplifiers both in my room and many other high end systems.

assuming that the speaker has a reasonable level of efficiency and a reasonable load (over 89db efficient and 4 ohm or better nominal) the darTZeel is my favorite amp.

the darTZeel has 2 different modes; DC compensation 'on' or 'off'. the dart is more refined and transparent with a slightly sweeter tonal character with the DC compensation 'off'. the dart has a bit more grip and can more easily deal with tougher loads with the compensation 'on'.

i use my dart with the DC compensation 'off'.

the attraction of the darTZeel sonically is that it combines the best attributes of solid state (low noise floor, low end punch and lineararity, lack of color, extended high frequencies, and low hassel factor) with the best of tubes (breath of life, a pure smooth mid-range, smooth natural high frequencies, and an overall sweetness)......and it does not sound like solid state or tubes.....it sounds like music.

regarding Herve Deletraz; please read all the stuff on his website......then read the reviews, then read his 2001 article in Stereophile regarding impedence in cables. if you have questions e-mail him; he is a gentleman and will gladly answer any questions.

then listen to his products.

as far as Krab's continual inference that somehow the darTZeel amp is 'unusual'......it is only so in the sense that it is so minimalist. there is no protection circutry in the signal path.

the very best sounding amps all are about 'less is more'.......trading a level of 'idiot-proofing' for ultimate levels of refinement. just like cables when you are at a high level of overall system refinement removing 'veils' from the signal path makes large performance gains.

if there is a better preamp or amp out there i have not heard them.

i just posted the below comment regarding a possible testing protocol for my pending blind test......any comments?

from the MDC forum on the JREF website;

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without specifically debating ABX as it's concepts are not that familar to me; i agree that there is no real protection from intentional or unintentional hints being dropped in the above protocol.

my only justification is that i am not going thru this process to waste my time or the time of JREF or my friends. i need to know now whether my claims are real. it is more important to get this step out of the way than to complicate it or slow it down unneccessarily. i do not want a false result......as i proceed further this likely will cost me a good deal of my money one way or the other. if i can get hints i will stop the testing and we will begin again.

if we can find ways to eliminate any possiblity of hints then we will do it.

the sequence of tests as to 'A' and 'B' would be selected by flipping a coin by the switchers and recorded prior to the start of the test in a place where only them and the switching observer were present. from that point on they could have no contact with myself or my observer.

i suppose i could leave the room each time with a guide and go to another part of my barn. the cable switchers would switch the cable and then drape a cloth cover over the cables. the switchers would then leave and go outside. i would re-enter the room without having contact with the switchers. i could still be blinded but maybe have a guide to sit me. there could be one observer who would insure i did not look under the drape while listening and then record my choice. the cable switchers would record their information and the observer would record my choice. at the end of the test series the two recorded choices would be compared.

.......or something like that where the personal interaction oportunities would be eliminated. the set-up of my barn would allow this to be quite easy to do.

you could even have one observer for the cable switching and another observer for my trial so there would be no communications at all between the two processes. there could be a 'traffic cop' outside the room who would sound the 'all clear' when either party left the room to go to their waiting area. this person would have no knowledge of anything inside the room and would provide an information buffer.

we could even have a video recorder recording continuously all thru the test to record the fact that no one lifts up the covering cloth while i or my observer is in the room as an additional control. it would have to be completely silent and unobtrusive.

any comments?

understand that my motivation is only for the truth........

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Herve's provocative and controversial view on impedance matching for connections is far from being validated that I'm aware of. I'll attempt to email him but what I've read, his views already contradict accepted empirical data.

Mike for what it's worth the logic i.e. if I hear it, there is something there is an artistic statement. It could be certain type of distortions sounds good to you, while on the other hand something that is truly transparent seems inferior are harsh. The danger here is that people who hear something they like may in turn associate said better sound with higher accuracy.

fair enough.

it all comes down to one's reference for what is real......which is purely subjective.

regarding Herve's impedence article......if you were to hear his 50 ohm BNC cables compared to other cables you would possibly give him the benefit of the doubt. i don't have the technical knowledge to debate it but listening tells me his approach is more correct than any other i have heard.

I'd say that's no danger at all. The thing is, when it comes to music enjoyment, the proof is in the pudding. If it sounds good, it is good. Measurements, accuracy, etc., are the 'means' to the end, and not the end itself.

Mike I applaud your fairness as well. I certainly can relate to your passion for subject matter and I'm waiting with bated breath on the results of your testing. I wish the ingredients (amp & cable combo) were different. i.e. the information I've read regarding your amp leads me to believe it's quite possible for your cable to make a big difference, I think it's likely the amp will actually sound and perform much better considering how it interacts with different speaker loads coupled with how Herve intentionally imparts a custom sonic signature to his design.

thomas

Yes, of course. If I'm not misstaken, Mike use tube amps.

my darTZeel preamp and amp are solid state; i have no tubes in my system currently.

That's some knife you use -- it induces laughter instead of pain.

If it sounds good, it is good, but the purported reason 'why' its sounds good may be wrong , or even imaginary. That's where audiophiles often depart from reason... they claim to know why.

And what sounds good to one person may sound like doo doo to another. That is why when a claim is made by some company that XYZ will produce more bass, it can be measured to see if it is true. And many companies will say that the product they sell will increase bass or hi end etc... OK well that can be tested. Now if someone says XYZ has better "soundstage" well thats simply a artistic statement and may be true to one fellow while another may not hear it or like it.

It is easy for audiophiles to mix up science with art.

Hmph... that's quite a gift you have, to know what all 'audiophiles' think. Besides, aren't you the one who's hung up 'why' it sounds good? I certainly haven't made that claim.

Well, we'll see if we can sit down and listen this weekend, I'm curious as much as anything to see not only what the findings might be with Mike listening, but I'm curious to hear myself. I've been pretty busy lately, so I haven't followed the thread, I'm sure that whatever we do report back will be assaulted for being improper methodology. but having done projector shootouts before, I'm familiar with that kind of criticism.

thanks Chris for offering to assist. i have at least 2 other 'helpers' recruited at this point and possibly one or two others. they are techies; one is an engineer and the other a digital audio workstation designer (among their other many talents).

i'm the only non-techie in this group.

Does this test include a apples to apples? In other words comparing say Zip cable to Pears or whatever? Something besides the magic black box cables that we have no idea what they are really doing? Again I do not doubt there may be easy to hear difference betwen the opus and whatever as we have no idea what the black box is adding or subtracting.

Eveyln,

What's your take on the the reasons the high end audio scene is dry as a bone ?


I remember your Santa Ana store and your move to Tustin along with quite a few stores at the time ( Middelton White and Kemp, Ear Drum, Havens & Hardesty etc. )

I enjoyed it all and now?

Richard Hardesty at one time mentioned he thought it was partialy the high dollar wire
scenario (new potential audiophile comes into store__ but he won't get that sound unless he spends 400$ on interconnects and 800$ on those speaker cables..?.,."".)

I never bought into the wire debate myself, but do you agree with Mr. Hardesty?

Regards
David

Chris, will you have the opportunity when you visit to do some preliminary measurements with test tones and a VOM with each of Mike's cable selections?

the only high end 'expensive' speaker cables we will use for this session will be my Transparent Opus. if i pass the test with the Opus then i will have to either get JREF approval for it or find a substitute. getting that issue figured out will be my next step after this weekend (asuming i can pass this test).

i do have some 'zip' cord which assuming we have time we will try for a couple of tests. the source of my 'zip' cord is unknown to me....if someone can specify a specific generic 'zip' cord i can purchase at the local Home Depot which 'should' be similar to the 10 guage Monster i will stop and purchase some so at least others can try that to get an idea of what we are listening to.

Speco; you have made it clear that you don't consider the Transparent Opus a legitimate test for the Monster or any other 'just cable' numerous times. regardless; this is my test and this is the way i'm going to do it. you are most welcome to purchase the Monster cables and find expensive cables on your own (the Pear Anjeau?) and do your own test.

I don't think there's any need for you to incur any more expenses Mike. What lengths are the wires/cables that you'll be using?

my Transparent Opus are 12 feet long, the Monster cables which Randi spec'd only come in 10 foot lengths. we can have 'zip' cord of any length....10 feet is what i will cut assuming i do that.

Just make sure you level match and you'll be fine. Don't sweat the length difference. You would want to level match even if the lengths were identical anyway!

Just for grins, you should also use the Home Depot extension cords. The ones that many people rave about when they are used as speaker cables.

I can see pros and cons level matching when comparing speaker cables. On one hand, if you don't level match, and there is a dramatic difference between cables, then that also says something about the cables. On the other hand, if the 'boxes' on the Transparents attenuate the signal in any fashion compared to the Monsters, then level matching would be desirable to compare the actual difference in sound. So maybe there should be both a level matched test and a test with nothing changed but the cables.

Yes, it says that they have different impedances.

The fact that bulk electrical differences in cables can affect the sound is utterly uncontroversial. The longer a cable, the more resistance it's going to have. On the other hand, length isn't the only factor: the larger the cross-sectional area, the less resistance it's going to have. So given two different cable brands you can't just assume that you can cut them the same length and expect them to have the same impact on the electrical signal.

The reason that we objectivists insist on a level match is that differences in volume alone are often misinterpreted as more subjective quality differences. Sometimes the louder one seems to sound better when it really just sounds, well, louder. So it really isn't that informative if differences that are audible before a level match go away after a level match. After all, once the test is done, you're going to adjust your volume level to whatever subjectively suits you and the level differences will stop mattering.

So frankly I see no "pro" whatsoever about skipping the level match.

I didn't say 'skip it'. I said do an additional test without it. I don't see what would be 'controversial' about that.

the way the volume control works on the darTZeel preamp would make it unlikely to be able to level match. there is no numeric readout and the volume knob does not move when using the remote. there would be no way to do it unless you set it with an SPL meter at each cable switch (which would add quite a bit of time to each switch).

for myself; i would prefer that the volume be turned all the way down and i would adjust it myself for each trial. since there is no readout i would have no clue which cable is which from this issue. i typically adjust each track for volume anyway.

from my 'sighted tests' i have not noticed any difference in gain between the cables but i would not be surprised if there was one......however it cannot be much. when i listen for differences gain is not significant.....dynamic contrasts, however, can be a significant issue.

I'm just saying that it wouldn't be as informative a test as you're making it out to be, that's all. But hey, if it's your test, whatever floats your boat
Mike, that's a very interesting approach. Seems reasonable to me, though in fact it seems like if anything it might handicap you more. But as I just told Rutgar... if it's your test...

OK well thanks for clearing that up. I will not have to wait for any results then. Thanks for doing a completely useless test.

Speco, does that mean you are certain he will be able to tell the difference? I for one am not. After all, those network boxes could roll off way high---note CharlesJ's last post above. So for me it's not a useless test. Yes I won't be shaken if he passes, but think about if he doesn't!