Hi,
"Cost nop Object Cap's" do not mean < 0.1% Tolerance. It just means they are expensive. My own units use custom made non-magnetic silver mica units that 0.5% and get an even closer tolerance as I parallel several. Resistors in the RIAA are 0.1%.
You have seen the actual RIAA response that I designed in. You have seen the channel match (this is without selecting components, just using the components off the shelf).
If you do not like this kind of curve, do not use it. I have no interest in debating the design or it's features much, it is not amenable to DIY anyway.
I was only showing some graphs to illustrate my views on distortion.
Ciao T
"Cost nop Object Cap's" do not mean < 0.1% Tolerance. It just means they are expensive. My own units use custom made non-magnetic silver mica units that 0.5% and get an even closer tolerance as I parallel several. Resistors in the RIAA are 0.1%.
You have seen the actual RIAA response that I designed in. You have seen the channel match (this is without selecting components, just using the components off the shelf).
If you do not like this kind of curve, do not use it. I have no interest in debating the design or it's features much, it is not amenable to DIY anyway.
I was only showing some graphs to illustrate my views on distortion.
Ciao T
Hi,
Isn't that what it says in the Review and on AMR's Website?
While I am not quite as hands-off with AMR as John is Parasound, there are similarities. Not each and every little detail in implementation is under my control.
I typically limit myself to controlling the most important ones.
Ciao T
Isn't that what it says in the Review and on AMR's Website?
While I am not quite as hands-off with AMR as John is Parasound, there are similarities. Not each and every little detail in implementation is under my control.
I typically limit myself to controlling the most important ones.
Ciao T
Throwing away most of already expensive 0.5% caps to select <0.1% its even more expensive so I don't see your point. I would not know why you designed in a custom curve, I guess it compliments the total sonic outcome to your liking. Not interested in lifting it, one machine's medicine may become another machine's poison. Cooks should present their own dishes. But I did not debate that aspect. I asked about the HF tilt fitness idea beyond production practices. No reason to divulge more if its a sensitive matter. Thanks.
Hi,
Well, look at it this way. My RIAA basically slopes around 1dB from the Bass Peak around 40Hz to 20KHz.
I have used this style for years and developed it over time and almost each and every of my published designs uses it too. The logic a little simplistic and does not jive with the audiophile quest for absolute accuracy (which cannot exists in the literal sense of an accurate reproduction, as neither recordings nor pressings are remotely what you'd call accurate).
You trust the EQ Cards in a cutting lathe to at best +/- 0.5dB. So at the worst the EQ in the Lathe will cut LF by 0.5dB too much or it may boost it by 0.5dB. At the high end the result is the same.
Depending on how tolerances accumulate and combine the total net result of lathe and my RIAA will be somewhere between essentially flat and a gently down slope of totally around 2dB from 20Hz to 20KHz. What you never get is a tilt up.
Now think what a truly flat Playback EQ will do under the same circumstances.
Anyway, there is so much variation in actual EQ's employed during cutting (RIAA was not the universal EQ after 1953) all the way into the 80's that arguing RIAA accuracy is a joke, unless the other common EQ curves are also provided.
The commonly employed EQ's can accumulate as much as 9dB deviation (2dB above 1KHz) when played back wrongly as RIAA and very few people have tone controls, equalisers or adjustable EQ Phonostages to do anything about it.
Of course this sort stuff is not commonly talked about, be it RIAA EQ and the lack of it on many LP's that people actually have or the fact that with pivoted tonearms only cartridges with spherical stylii can correctly work.
Or how about the little talked about factoid that most LP's after the late 60's where cut pre-distorted to correct the distortion caused by cutting with a planar device and playing with a spherical, so playing those LP's with a line contact stylus means you get >> 10% added HD.
Or how about the factoid that most LP's cut after the late 70's to al least the early 90's used a digital delay (16Bit/48KHz sample rate) to allow easy and automatic dynamic groove spacing adjustment with LF level? Probabky a lot of the commercial releases still do even today. Before that the master tape was run in long loops to create the delay, BTW.
And that is all only the SNAFU between master tape and lacquer master, never mind all the FUBAR that happens before master tape and and FCUK-UPS after cutting the lacquer until you tale the black disk out of the inner sleeve.
Usually the "authorities" take any chance to claim that all this is not real, in complete ignorance of and opposition to the actual state of things as well.
Meanwhile here I am reading the debates here about 0.1% RIAA EQ capacitors and the difference between -80dB and -100dB 2nd HD in Phonostages and I wonder what planet most here are from and what you all have been smoking and most crucially where I can get some...
Get real and enjoy your vinyl (best mixed with a glass of 1995 Pinot Noir or some 30 Year Laphroaig and maybe a cute girl by your side or on your lap) and forget fretting about some of the silly side of tech, +/-0.1dB, +/- 0.5dB, 0.01% 2nd HD or 0.001% 2nd HD, 0.4nV or 0.6nV Ein and so on.
Ciao T
PS, I can of course make a Phono with 0.0001% THD, -156dBV (A) Ein and +/-0.05dB RIAA EQ accuracy, I just no longer see the point why anyone would want to make or want such a thing. It falls into "life is too short" and "Work is the enemy of the drinking class" categories.
I can see why it may be worth doing for commercial sale (claim the "best" Phono, just like the Halcro Poweramps), but here on this board we are talking about gear strictly for our own use and pleasure, not that cute little working girl that must please each and every customer and go with whatever kinks he may have.
Well, look at it this way. My RIAA basically slopes around 1dB from the Bass Peak around 40Hz to 20KHz.
I have used this style for years and developed it over time and almost each and every of my published designs uses it too. The logic a little simplistic and does not jive with the audiophile quest for absolute accuracy (which cannot exists in the literal sense of an accurate reproduction, as neither recordings nor pressings are remotely what you'd call accurate).
You trust the EQ Cards in a cutting lathe to at best +/- 0.5dB. So at the worst the EQ in the Lathe will cut LF by 0.5dB too much or it may boost it by 0.5dB. At the high end the result is the same.
Depending on how tolerances accumulate and combine the total net result of lathe and my RIAA will be somewhere between essentially flat and a gently down slope of totally around 2dB from 20Hz to 20KHz. What you never get is a tilt up.
Now think what a truly flat Playback EQ will do under the same circumstances.
Anyway, there is so much variation in actual EQ's employed during cutting (RIAA was not the universal EQ after 1953) all the way into the 80's that arguing RIAA accuracy is a joke, unless the other common EQ curves are also provided.
The commonly employed EQ's can accumulate as much as 9dB deviation (2dB above 1KHz) when played back wrongly as RIAA and very few people have tone controls, equalisers or adjustable EQ Phonostages to do anything about it.
Of course this sort stuff is not commonly talked about, be it RIAA EQ and the lack of it on many LP's that people actually have or the fact that with pivoted tonearms only cartridges with spherical stylii can correctly work.
Or how about the little talked about factoid that most LP's after the late 60's where cut pre-distorted to correct the distortion caused by cutting with a planar device and playing with a spherical, so playing those LP's with a line contact stylus means you get >> 10% added HD.
Or how about the factoid that most LP's cut after the late 70's to al least the early 90's used a digital delay (16Bit/48KHz sample rate) to allow easy and automatic dynamic groove spacing adjustment with LF level? Probabky a lot of the commercial releases still do even today. Before that the master tape was run in long loops to create the delay, BTW.
And that is all only the SNAFU between master tape and lacquer master, never mind all the FUBAR that happens before master tape and and FCUK-UPS after cutting the lacquer until you tale the black disk out of the inner sleeve.
Usually the "authorities" take any chance to claim that all this is not real, in complete ignorance of and opposition to the actual state of things as well.
Meanwhile here I am reading the debates here about 0.1% RIAA EQ capacitors and the difference between -80dB and -100dB 2nd HD in Phonostages and I wonder what planet most here are from and what you all have been smoking and most crucially where I can get some...
Get real and enjoy your vinyl (best mixed with a glass of 1995 Pinot Noir or some 30 Year Laphroaig and maybe a cute girl by your side or on your lap) and forget fretting about some of the silly side of tech, +/-0.1dB, +/- 0.5dB, 0.01% 2nd HD or 0.001% 2nd HD, 0.4nV or 0.6nV Ein and so on.
Ciao T
PS, I can of course make a Phono with 0.0001% THD, -156dBV (A) Ein and +/-0.05dB RIAA EQ accuracy, I just no longer see the point why anyone would want to make or want such a thing. It falls into "life is too short" and "Work is the enemy of the drinking class" categories.
I can see why it may be worth doing for commercial sale (claim the "best" Phono, just like the Halcro Poweramps), but here on this board we are talking about gear strictly for our own use and pleasure, not that cute little working girl that must please each and every customer and go with whatever kinks he may have.
Most of my records are OK near flat Riaa, when I tilt it even 0.2dB down broadly, most I perceive dull enough. I can hear the odd HF hot Elvis in film or disco best between them, but rarely. And then I say, here is a cut that's off. I use Denon with spherical stylus. But to stay on safe side in production and to make unknown people's record collections surely 100% playable it takes a curves computer. Which in a way you offer. Impressive user interface for a phono stage. Congratulations.
Hi,
If you use the same RIAA that is often referred to here as "Salas" I can understand that. There are other factors than FR in all of this.
The PH-77 does not sound dull at all (in part this is down to parts choices) despite the (intentionally) tilted down EQ.
Good
It really depends how varied your LP collection is. If it is almost all recent audiophile re-issues RIAA alone suffices.
If it is a collection that varies between countries of origin (in mine both east & west germany, UK, eastern block [Melodia, Supraphon, Hungaroton], US originals including Mono Blue Notes and Verve) over a range of time RIAA only is not sufficient.
I find it is less tonality as such, but perceived dynamics and sound scaping that become "right" with the correct EQ.
Take a Deutsche Gramophon or Archive Productions LP that was cut with the Decca EQ (many are, some later ones are actually CCIR as they where cut in East Germany) and play it back at RIAA. It sounds thin, dynamically challenged and rather flat. Switch to Decca and you ask "is this the same record?"!
It is really very obvious, demonstrating it with a nice selection of LP's at shows illustrates just how obvious.
Thanks, we try.
Ciao T
If you use the same RIAA that is often referred to here as "Salas" I can understand that. There are other factors than FR in all of this.
The PH-77 does not sound dull at all (in part this is down to parts choices) despite the (intentionally) tilted down EQ.
Good
It really depends how varied your LP collection is. If it is almost all recent audiophile re-issues RIAA alone suffices.
If it is a collection that varies between countries of origin (in mine both east & west germany, UK, eastern block [Melodia, Supraphon, Hungaroton], US originals including Mono Blue Notes and Verve) over a range of time RIAA only is not sufficient.
I find it is less tonality as such, but perceived dynamics and sound scaping that become "right" with the correct EQ.
Take a Deutsche Gramophon or Archive Productions LP that was cut with the Decca EQ (many are, some later ones are actually CCIR as they where cut in East Germany) and play it back at RIAA. It sounds thin, dynamically challenged and rather flat. Switch to Decca and you ask "is this the same record?"!
It is really very obvious, demonstrating it with a nice selection of LP's at shows illustrates just how obvious.
Thanks, we try.
Ciao T
Not only in the Jfet one. I tended to flat in my valve and op amp phono stuff across the years also. Same thing with loudspeakers too. This week I was changing in my neighbour's 3way the mid+HF top perched closed box to Hemp FR-8 open baffle + ribbon TW and after listening sessions I measured. Another system... Damn, tended to flat again.
The RIAA is a STANDARD. It is verifiable and reproducible. Keeping to the standard, at least as a reference is very important to keep other frequency response deviations from being masked or compensated for. It is difficult to compare components that deviate very much, because EVEN double blind tests will show differences and this is really serious.
Couldn't agree more. If someone wants EQ, there are lots of easy ways to do EQ that's more controllable, adjustable, and (importantly) defeatable. There's a psychological barrier that many audiophiles have about admitting to the use of tone controls...
A Boulder owner likely leases a 2nd one to swap EQ cards at her master's voice.
(brain flush, a sports car driver can't have cruise control)
Last edited:
Very interesting discussion.
I think Thorstens comments on RIAA accuracy and distortion on vinyl playback at a sytems level are absolutely correct. However, for my part, I think its very easy now days to get <0.1% distortion, low noise and <0.2dB RIAA accuracy so this is my approach.
Of course, I respect the different choices and tradeoff's made by other designers - I guess that's what makes this activity so interesting.
I think Thorstens comments on RIAA accuracy and distortion on vinyl playback at a sytems level are absolutely correct. However, for my part, I think its very easy now days to get <0.1% distortion, low noise and <0.2dB RIAA accuracy so this is my approach.
Of course, I respect the different choices and tradeoff's made by other designers - I guess that's what makes this activity so interesting.
While this may be true I have yet to find hard data. Using fresh RCA STR series test records (1980) I was unable to get a meaningful difference in distortion with stylus geometry. I posted a nice survey of stylus geometries (and actual tracking profiles) a few weeks ago, the line contact ones still did not even approach the sharpness of a cutting stylus. The distortion in general is horrifying but low order and vanishing at 0 signal.
EDIT - Come to think of it, these days one could optically scan and digitize the horizontally cut 1kHz tracks on the record well enough to settle this once and for all.
Last edited:
Scott,
The questions are:
1) What frequency and level did you measure?
2) Was the test LP cut using a tracing simulator?
Hmmm, that sounds a lot like a zero feedback single ended tube circuit...
Though the HD from LP is usually way higher than that from this kind of electronics.
Ciao T
The questions are:
1) What frequency and level did you measure?
2) Was the test LP cut using a tracing simulator?
Hmmm, that sounds a lot like a zero feedback single ended tube circuit...
Though the HD from LP is usually way higher than that from this kind of electronics.
Ciao T
Scott,
The questions are:
1) What frequency and level did you measure?
2) Was the test LP cut using a tracing simulator?
Hmmm, that sounds a lot like a zero feedback single ended tube circuit...
Though the HD from LP is usually way higher than that from this kind of electronics.
Ciao T
It would at least have been 1kHz at 3.54cm/s rms left then right. I remember using the spot frequencies also that were -14dB below this. But also 1/3octave noise bands (very telling) the low frequency IM "mess" gets worse as the frequency increases. I doubt if the CBS Labs STR series had any pre-distortion (there is an AES paper on their development). Any suggestions on a known good source?
B&K or Ortofon test records should certainly be better. The CBS series is really primitive by comparison. The Japanese made a number of test records as well. JVC and Denon come to mind.
However, parsing about distortion coming from a phono cartridge is relatively trivial. Analog magnetic tape was not much better, being typically near 1% at operating level and doubling every 3dB. YET, it could sound wonderful! AND direct disc could sound even better.
Yes, we had the SAME concerns about the difference between what we were measuring with our SMPTE IM distortion meters in our electronics designs, 40 years ago when Bascom King and I went to see Dick Heyser. He told us that it was another dimension of distortion that was involved, and primarily relating to negative feedback. This led me to explore Matti Otala's work that I still follow, today (with some success, I might add), Bascom going back into tube design and 2 stage phono processing like I use today. I, TOO, had to be taught, by example, what it really took to make a very successful phono stage, like the Vendetta Research. Learning these things is a slow process, it certainly took me a decade, before I got it together. Please keep this in mind everyone, when wondering where these 'crazy' ideas came from, and whether you actually understand them well enough to discount them, without trying them.
However, parsing about distortion coming from a phono cartridge is relatively trivial. Analog magnetic tape was not much better, being typically near 1% at operating level and doubling every 3dB. YET, it could sound wonderful! AND direct disc could sound even better.
Yes, we had the SAME concerns about the difference between what we were measuring with our SMPTE IM distortion meters in our electronics designs, 40 years ago when Bascom King and I went to see Dick Heyser. He told us that it was another dimension of distortion that was involved, and primarily relating to negative feedback. This led me to explore Matti Otala's work that I still follow, today (with some success, I might add), Bascom going back into tube design and 2 stage phono processing like I use today. I, TOO, had to be taught, by example, what it really took to make a very successful phono stage, like the Vendetta Research. Learning these things is a slow process, it certainly took me a decade, before I got it together. Please keep this in mind everyone, when wondering where these 'crazy' ideas came from, and whether you actually understand them well enough to discount them, without trying them.
Actually, that's quite a bit better. At 0 dB, the vertical IM from phono cartridges is 10% or worse.
Really? I had no idea. What causes the measurements to be difficult? Frequency stability?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.