This page? The middle of the "Designed from scratch" section.Originally Posted by scott fitlin
http://www.stereophile.com/solidpowe...mbl/index.html
Gosh, I'd feel robbed if my amp's frequency response cut off at only 200khz in one of its operating modes!Actually, at $26,600 a pair, I just might.
Clark in Peoria
Information is not Knowledge; Knowledge is not Wisdom
Too many audiophiles listen with their eyes instead of their ears
Thats the amp. They make mention of choosing PS caps very carefully, and that the electrolytics they used have only 1% of the distortion commonly found in most electroltyics. Speed of the caps charging and discharging, rectifiers, and everything play a role in sonic signature of equipment.
I believe it, I tried different, and higher quality PS caps in a mixer/preamp, the difference in sound was alot.
scottyj
Thom, I appreciate your skepticism when it comes to power supply design, I really do. There is so much voodoo and b.s. in high end audio that it generally requires a bulldozer rather than a shovel to manage it. Still, there are alternative theories, techniques, parts and circuit selections that have proven their validity to me by the only method I feel I can trust to sift through everything- listening. I cannot really explain technically why directly heated triodes, mercury vapor rectifiers, simple non feedback circuits etc. tend to sound better to me when listening carefully, but they do.
So what does one do when one's observations are in conflict with conventional theory, dismiss one's own findings in favor of the theory? I cannot bring myself to do that. Julian Hirsch would have had us believe that all amplifiers sound the same, but not many people really believe that anymore. Right here on LH the folks frequently discuss the sound of various higher power transistor amps and their usefulness for driving their JBLs.
The choice to trust and follow one's own perceptions carries a certain burden unless one keeps their yap shut about it. I'm not sure what happened to the little boy, but messengers do get killed on occasion!
Clark, those large transmitting tubes with their white hot filaments do look grossly inappropriate for the job at hand, but I have heard some of the most sweet, detailed, tactile, believable sound from them. I'm no theorist, but I have read many times that the simple triode is the most intrinsically linear amplifying device known to man. So far I have not seen any transistor guys rushing in to argue the point. Apparently, for whatever reason, the directly heated tubes have the lowest measured distortion of the breed, and this extends further to the very high current filament jobs.
I have found with receiving tubes that the high current, lower mu DHTs tend to sound more clear and lively. The 26 was the first voltage amplifier designed to run either AC or DC on the filament, and with its high current filament it does sound better to me than either the earlier starved filament battery set voltage ampflifiers or the later indirectly heated cathode tubes. Why exactly? I dunno. There does seem to be a correlation between high filament current and dynamic sound, but I'm not the one to explain why.
Lynn Olson has done quite a bit of investigation into the discrepancies between conventional theory and the perceived superiority of some of the early audio devices and circuits. For those interested I'd suggest wading through the articles in the link below. His conjecture is based on much study and measurement, not just the unsupportable "I like it" observations of guys like me.
http://www.nutshellhifi.com/library/index.html
Right on! Meter men drive me nuts when they use measurements as the final arbiter. That is what ears attached to brains with functioning BS detectors are for. Measuring is OK to guide the design process. Its verification function is limited, to say the least.
There is another school of thought on that. Alan Kimmel has proved to my ears that triodes are the best voltage amplifiers and that pentodes (and MOS-FET's, he adds) are better current amps. I have already worn out my welcome with this link, but I'll give it again here and duck.I'm no theorist, but I have read many times that the simple triode is the most intrinsically linear amplifying device known to man.
http://www7.taosnet.com/f10/mustage.html
I didn't know that. Peorius Ignoramus, I guess.Apparently, for whatever reason, the directly heated tubes have the lowest measured distortion of the breed, and this extends further to the very high current filament jobs.
I'll follow the link. The topic looks fascinating. Thanks!Lynn Olson has done quite a bit of investigation into the discrepancies between conventional theory and the perceived superiority of some of the early audio devices and circuits. For those interested I'd suggest wading through the articles in the link below. His conjecture is based on much study and measurement, not just the unsupportable "I like it" observations of guys like me.
http://www.nutshellhifi.com/library/index.html
Clark
Information is not Knowledge; Knowledge is not Wisdom
Too many audiophiles listen with their eyes instead of their ears
Clark, maybe part of the reason those big transmitting tubes sound good is that they are being run at a tiny fraction of their capabilities for hi fi, like the high efficiency speakers most of us like. They have such long, relatively straight plate curves that they can be set up with low distortion loadlines at many different voltages. I heard two different pairs of single ended 750TL amps at RMAF last weekend, and they both sounded wonderful. Though the 750TL is rated at 10,000 maximum plate volts, these amps had only about 550 and 1,200 volts on the plate.
Indeed, I remember reading the 70,s issues of Stereo reveiw, and High Fidelity magazine and they always use to say that if the measurements were identical, we should be able to hear no difference between amps.
As a teenager in the late 70,s and early 80,s what used to puzzle me was why amps that didnt measure as well, sounded better than amps that had super, ultra low distortion measurements like .00003% THD!
As well as power measurements didnt tell the entire story either! Why do big, heavy amps with medium power ratings sound more powerful than other amps? Sometimes amps rated at twice the power?
If you rely soley on measurements, they are misguiding, I believe!
Ears are the true indicator of what anything really sounds like. If I like it, I like it, it doesnt really matter what the scope says!
scottyj
I certainly agree, Scott. There are many unknown factors in audio, which is in part why it is so challenging and fun. It would probably be a bummer if we managed to achieve perfect performance, as where would we go from there? We know we can never achieve perfection, which strangely seems to fuel our efforts to try.
In addition there are investigation by Steve Bench (http://members.aol.com/sbench102/aboutme.html) about non linearities of capacitors "The Sound of Capacitors - Capacitor Linearity **Expanded**" http://members.aol.com/sbench102/caps.html
____________
Peter
DRAT!
From all appearances, I thought I was the only one still using a 'scope....
http://audioheritage.org/vbulletin/s...&postcount=196
My take on it is this, music itself is not perfect. Certain things sound good to the ear, things like certain distortions.
As of late, we have gear that is closer to perfect than ever before. Really low distortion, surpisingly accurate performance. We dont like perfect. Perfect doesnt sound musical. Thats why many of the great vintage things from the past sound good to us, they are musical sounding because they were designed to have a sound of their own, meaning they werent totally perfect and uncolored, but, they possesed a sound that is quite like music sounds like.
Wasnt this in fact, the philosophy of Altec? The speakers didnt neccesarily measure ruler flat, but they were designed to sound like music, and to make recorded music sound lifelike and realistic!
scottyj
Subjectivists would like it to be that way, but JBL has done extensive research in this area. There's even a VP of figuring this out at Harman. Their bottom line of saleability depends upon it.
Employing a combination of measured parameters, extremely high correlations are now achievable. Linear (not necessarily "flat") frequency response is a major factor.
See Toole in AES Journal, June, 2006.
I agree. But, some things measure great, yet dont sound great. And other things measure less than great, even measure only fair, yet sound great.
Linear? I agree this is an important factor too. Especially for bass.
Years ago, we had some cabinets with Gauss 18,s, they sounded INCREDIBLE! The kick, the bassline definition, everything. I always loved these Gauss loaded cabinets, and I used to ask the tech why Gauss sounded so good? He always said that they were very linear, and that is why they made such good bottom end. The sound these things made was terrific.
I have read Dr. Floyd Toole,s article, I agree with some of it, but, regardless of what the article states, my ears still like what my ears like!
scottyj
If the artists, producers, and engineers responsible for the PRODUCTION of our musical program material would get their heads out of their nether regions, and realize that samples, loops and other digitally generated and enhanced tricks of the trade aren't MUSICAL, listeners would have no need or desire to enhance the output of their REPRODUCTION gear, and the pursuit of perfection in exactly recreating a performance could continue.
The pursuit of simplicity and convenience is turning society into unemotive droids, we here just happen to be a little more reluctant to change than others.
Traditional musical production (via analog, acoustic, or voice) is rife with imperfections that are absolutely necessary for it to be truly pleasing to our ear; the stretched tuning of a piano, intonation of guitars, and so on. Real musicians are well aware of this, but are also prone to the same desire to make things easier as the rest of us, and technology has obliged profusely. Trying to compensate by using reproduction gear that adds its' own harmony is, well, just a band-aid (literally).
I agree, except, I dont think this is the wants of musicians or producers and other recording industry types like engineers, etc. I think it is what the Audio Industry and record labels wanted.
It is the industries that wanted cheaper, and more convenient things for the consumers to have. Simply put, making real music meant using session players, instruments, recording studios, producers, arrangers, recording engineers, mastering labs, mastering engineers, and vinyl, tape, and CD products.
Electronically made music really requires none of the above! One person with a computer can make, record, and master their own music. And the labels dont have to pay huge monies for all the above, they dont even have to have the music on a CD, record, or tape. It just has to be available via a "pay-for-download site" and they make money, with little or no money actually put into the music, and no product actually in the consumers hands.
Audio gear is also expensive to manufacture the right way!
Now all this is true, IMHO, and also off topic! Back on topic, however, I would not think any of todays modern manufacturers would want to make Feild Coil speakers, regardless of how they sound! Look at all the other things neccessary for feild coil speakers. Extra PS, more components of speakers themselves. Why would they want to do this at all?
Even DSP loudspeaker controllers offer both the industry and consumers economical alternatives to the old ways! 1 box has it all vs TOTL EQ,s, TOTL delay units, TOTL compressor/limiters, TOTL crossovers, etc.
With the exception of the small " Niche market " industry, this is where we are at, like it or not!
scottyj
At a Petecostal prayer meeting who's going to say they don't feel anything? It's not even related of course, or is it?
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote