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In Reply to: RE: Here's another one, only $300 posted by Lew on July 15, 2016 at 11:29:55
No, I haven't heard it.
OpAmps have very low output impedance and this one is OpAmp based.
I think the best bet for a tube based LCR phono stage would be the 10K type but I have no experience with any of them.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
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Naz built one a few years ago using tube gain stages and 20K-ohm LCR, with inductors precision wound for him by Dave Slagle. Dave's EMIA can also be had with LCR equalization as an option, but I don't know the impedance requirements of his LCR network. LR is another option.
So far, no one seems to have any experience with the Aurorasound Diva.
Naz did his at about 7.3K... Personally I think both the 600r and 10K are silly numbers to use for LCR since they require the caps to be glommed together. Simply moving from 600 ohms to 730 ohms turns that 0.126µ and 5.04µ caps 0.1µ and 4µ. Dropping form 10K to 9300 ohms puts you at 0.33µ and 8200p which are also standard values.
dave
What is the perceived advantage of LCR equalization?
Why does it matter how the RIAA curve is achieved as long as it is achieved with acceptable amplitude accuracy?
Thanks,
John Elison
John,
Your line of logic is very close to the "if it measures the same it must sound the same" line of thinking.
I have no idea why LCR filters sound different than CR filters and I currently have a setup that can take either a LCR or a CR filter and the swap between the two takes only 15 seconds. They both measure within +- 0.5dB of each other and the riaa standard from 30-20Khz and they sound very different from each other. As to why this is I have no idea and if we are to adhere to the science of it the RC sure appears to have the edge on the KISS front.
If you take a typical CR filter and add two nonlinear inductors and 6 more resistors how can you end up with something better? Again it is this type of logic that took many of us down the path of CD's and 200W sand amps.
Having listened to both filters in as close to an apples to apples comparison as you can get, I'll take the LCR because it sounds better. Aside from the extra (costly) parts, the two other differences are the LCR is a T network which is a constant impedance network and the typical CR filter has a fairly large (in value) series resistor to temper the source impedance feeding the filter. I have seen it posed that it is these two factors (constant / low Z for the LCR and the 100K+ series R for the CR) that are the differering factors in the sonics of the two but I'll just stick with my listening experience that tells me LCR just sounds more musical.
dave
Thanks, Dave. I always wondered how it was that 600 ohms came to be the standard for LCR RIAA equalization. I imagine it had something to do with the original Silk filters from Japan??? But you would know better. It's not a good idea if you have to use a CF before the filter in order to make it work. Of course, using standard values for R and C with an L built to enable those choices is the logical way to go. I actually don't recall precisely what impedance Naz used, but my memory told me it was either slightly less than 20K or slightly less than 10K. Of course, you would know best. I have his schematic on this computer but not on the cell phone I was using when I wrote the earlier post.
> Your line of logic is very close to the "if it measures the same it must sound the same" line of thinking.
Actually, I do believe that! Are you saying that you don't?
Of course, there are a number of parameters that affect sound quality and they would all need to be identified and measured. I asked only about one parameter, that of amplitude response.
> I'll take the LCR because it sounds better.
Okay! Why do you think it sounds better?
> Aside from the extra (costly) parts, the two other differences are the LCR is a T network which is a constant impedance network
> and the typical CR filter has a fairly large (in value) series resistor to temper the source impedance feeding the filter.
Okay! Impedance is another measurable parameter and obviously an important parameter when it comes to sound quality. I found this out recently when I bought a phono stage that had a significant impedance mismatch with my Pass Labs X1 line-stage.
Thanks!
John Elison
Hey John
We know you are good with numbers and that can be very beneficial in certain conditions. If we knew everything about energy science could retire.
So with so many variables some know others not the final judgment is your ears. And what Dave did here was the most important thing. He kept everything constant and only changed the riaa network. Then he listened. So if it is a impedance/resistance/capacitance etc...it is not really that important any more. The violin sounds like a wood instrument played with a bow made of wood and horse hair.
Where most hi end stuff misses the boat is the body and tone of the human voice and acoustical instruments. The LCR tube combo does the above in spades. If it is just frequency extremes or dynamics transistors and CD's get the job done just fine.
Enjoy the ride
Tom
> So with so many variables some know others not the final judgment is your ears.
In my opinion, the human ear is the biggest variable of all and the least trustworthy when it comes to audio reproduction.
To each his own!
Actually, I do believe that! Are you saying that you don't?
I take the realistic approach that at some level now two things can ever measure identically. It is really easy to find things that measure the same and make proclamations of equality but to me that is short sighted and just plain silly.
Okay! Why do you think it sounds better?
no idea but I trust the results of observing repeated patterns of behavior.... tubes sound better.... vinyl sounds better.... horns sound better....and leave the bickering about the why to the trolls with an agenda.
Okay! Impedance is another measurable parameter and obviously an important parameter when it comes to sound quality. I found this out recently when I bought a phono stage that had a significant impedance mismatch with my Pass Labs X1 line-stage.
When a difference is perceived and a measured difference is found the natural response is "that must be the cause" . Sadly I have rarely found that to be the case and while it is fun to banter about possible causes, actually attaching a valid proof to a subjective response is futile and those that typically do it always seem to have something to sell you.
dave
When a difference is perceived and a measured difference is found the natural response is "that must be the cause" . Sadly I have rarely found that to be the case and while it is fun to banter about possible causes, actually attaching a valid proof to a subjective response is futile and those that typically do it always seem to have something to sell you.
Thank you Dave. That's pure 'gold'.....
Well, I put greater faith in measurements than in human hearing. In other words, I believe that measurements have higher resolution and much greater objectivity than anyone's ears.To each his own!
Edits: 07/19/16
nt
It also might explain why the best selling and most popular speaker in the world is Bose. ;-)
But the brain to which those ears are attached. Bose is popular for the same reason those big-eyed waifs became popular. It was fashionable to have them in the living room.I remember when I bought my house and the then current owner proudly cranked up the volume on her Bose tiny speaker system. She didn't know any better, but all the cool kids had Bose. She thought it sounded great! And she was happy with it.
Of course, we're at that point (we hope) where it's all good, but some like this and some like that. So even if it measures the same, some like the thing that gets to the measure this way, and some like it to get there that way.
It's only important that you like the way you make the sound get to your own ears. Heck... even Bose makes the 901... don't sell a lot of them, but it's a decent speaker.
Edits: 07/18/16
With 8 or 9 two-inch, fifty-cent drivers per side? I guess it would sound a bit better than "The Wave" radio, but only if you have a 500W amplifier.
I have a funny story about the Bose 901. I was at the Air Force Base Exchange in Kiaserslautern, Germany not too far from Ramstein Air Base. Paul Klipsch was there talking to customers because he sold a lot of Klipsch speakers through the Military Exchange system in Europe. This must have been sometime around 1984 or 1985. Anyway, I was talking to Paul Klipsch and he told me he had just installed an anechoic chamber at his manufacturing facility. In our discussions I brought up the Bose 901 and Paul became very excited jumping up to get his three-ring binder containing all his test reports. He had conducted a distortion test of the Bose 901 in his new anechoic chamber and he wanted to show me the results. He did an IM distortion test using frequencies of 100-Hz and 10,000-Hz and he was able to measure 125% intermodulation distortion from the Bose 901 speakers. Both frequencies had amplitudes well within the Bose 901 capabilities, but the fact that the same driver was used to reproduce both frequencies simultaneously resulted in long excursions of the 100-Hz test tone modulating the 10,000-Hz test tone to such an extent that IM distortion exceeded 125%. This sort of thing cannot happen with ordinary speaker, which use separate transducers to reproduce those two frequencies. Anyway, extremely high levels of IM distortion represents one of the major problems with the Bose 901 speaker system.Best regards,
John Elison
Edits: 07/20/16
Thanks for that story. If ever a measured parameter correlated with aural experience, this is one perfect example.
Yep. Roughly $1400 for the pair. Or $400 on ebay, or even cheaper in the thrifts!
I do my share of bashing Bose but the one time (recently) I heard them I thought they sounded good. NOT $1400 good, but good.
I understand Bose makes you buy stands and a special equalizer to go along with them... I'm not sure if that is included in the $1400 you pay for them. But hey... look at my Bose Speakers!
I don't want to bash them if you like them. I suppose that's possible to do.
Back in the 70s, when I was a real neophyte, an audio cognoscenti of my acquaintance who was at the time running two pairs of Quad 57s driven by a Marantz 9, with a 7C front end, described the then very popular Bose 901 as "sand in the public eye". True or not, I love the metaphor.Back in the late 60s, when I was in college, Amar Bose hit the scene in Boston as an important theorist. He was a professor at MIT, and he promoted the idea of filling the room with direct sound. His first product, or at least the first one I ever saw at Tech Hi-Fi in Cambridge, was a quarter of a sphere that was designed to sit on the floor in a corner of the room, right up against the floor and the two walls where they meet at 90 degrees to form a corner. The quarter-sphere had a radius of about 3 ft, so it took up significant space. The surface of the partial sphere was a geometrical array of individual single drivers, driven full range. I don't know what it cost, but it was probably very expensive for those days. I think the 901 was the end-point in an attempt to get the same or a similar effect in a simpler less space-taking device.
Edits: 07/20/16
The nice ting about it is we are all allowed to believe whatever we want. I feel ultimately the burden of proof falls upon those making the technical claims (for or against) and while measurements are indeed factual and accurate, their interpretation is hugely subjective and I find this to be far more variable than human hearing.
dave
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