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PS Audio Stellar Review (Phono Preamplifier)

Langston Holland

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The MM cartridge specs that I've found recommend load capacitances between 150-300pF. I chose the mid point for the simulations above. Nevertheless I also found a lot of schematics that only use 100pF, thus I did the following comparison out of curiosity.

MM vs MM TF.png
 

SIY

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Important to keep in mind (Langston, I know you know this) that the actual cartridge output is a convolution of the electrical and mechanical responses. So the flattest electrical response may very well not be the flattest cartridge response. Whatever that means, given the vagaries of the vinyl itself...

Where the electrical analysis is useful is to predict changes in response with loading. See, for example, the first part of my Equal Opportunity Preamp article in Linear Audio a few years back.
 

Langston Holland

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So the flattest electrical response may very well not be the flattest cartridge response.

Makes complete sense. MM cartridge mfg's spec'ing a fairly tight RC load range clued me in on that - but the physics of the little electrical generator with a cantilevered needle gliding through a miniature mountain range and transforming mechanics into (amazingly good) music reproduction seems like it shouldn't work - and I want to figure it out. : )

I'm a loudspeaker and acoustics guy with a live music background, so I'm just now getting into home audio and the stuff that precedes power amplifiers. Thus I claim near total ignorance in most things Amir is good at and I love his rigour in logic and method, so I'm here to learn from him and surprise guests like you! : ) Thanks for the link!
 
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musicforcities

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I'm always suspicious of somthing that weighs heavy when there is no technical reason. I've opened stuff up in the past to find lumps of metal that have no other function than to make the device feel substantial.
I inherited an Ayre CD player (well it plays dvd audio too in two channels). That thing has more aluminum in it than Budweiser uses annually for cans. It is beautiful but also ludicrous. I have never measured it but it sounds soft and diffused like there is a serious dip in the presence region and a high end that rolls off fast. Maybe it’s balanced out is better but I have not tried it.

More revealing is there is a dip switch in the back to toggle two different filters. One is named “listen”. The other is named “measure”. They sound the same to me but just the fact that they called them that is a warning siren!

Below is a photo of the cnc routed aluminum remote, ready for battery replacement. Which requires unscrewing six hex screws, then having the pcb board fall out the back as it’s pulled out by the battery cradle that just hangs on its leads. The two AAA batters only last a few months even if they are not really used. The case could hold four AAAs easily due to the 5/8inch thickness. But instead is solid aluminum. The buttons are mostly non illuminated and ergonomically stink and has limited functionality and cryptic markings. It weighs 8.71 oz and will smash a glass table or dent a hardwood floor. It’s range is approximately 8 feet. On a good day.

It epitomizes high end audio idiocy.

I would send the entire unit to Amir for testing but it would cost too much to ship it. the player weighs 26 pounds. Plus almost 9 oz for the remote.


image.jpg
 
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Phono playback is perhaps the hardest discipline in all things audio. Approaching it from the digital side of things will certainly bump into digital's limitations - and that would be , first and foremost, the frequency response. Phono playback has been shown to exceed FR of > 200 kHz - 40 years ago. Here is the only part of the most comprehensive and meaningful phono cartridge review ever published that is available on the internet - that of International Audio Review , Issue #5, May 1980.
This review deals with more real world issues of phono playback than any other to date. It covered pretty much almost everything that was available at the time - and cartridges that are direct succesors to the 1980 models are pretty much still available - in their evolutionary form(s).
Too bad that IAR aka Peter Moncrieff has placed copyrights etc as he does, preventing from making this document available to public for free. It answers LOTS of questions and dillemas of phono playback world, both from cartridge/stylus point of view as well as from the effects of electrical loading of carts by the preamp and associated cables.

I certainly do agree the SINAD test of phono preamps as of present does not reflect the performance in real life. Although I do agree that, for instance, PS Audio Stellar phono stage is on the expensive side, the unit can not be flawed in real world use. It performs well with most cartridges tried, both MC and MM types - it is quiet and allows music from the LP to get a notch higher. I do not own it, but have heard one in a friend's system recently ; to all those who pooed on it due to SINAD measurements without even seeing it ( let alone heaing ) live, I recommend to do some real world use of gear BEFORE repeating such excercises again.

To @ amirm : phono measurements are tough AND extremely expensive. That is due to test records, which for the most part are simply no longer available, are VERY vulnerable and can be destroyed with a single play. After such hiccup, the record needs to be discarded and replaced by a new, fresh copy. In 2021, that means $ - and lot$ of $$$$. The test records that have stood the test of time and became the de facto standard are almost exclusively vintage, long out of print rarities - and those $$$$ were there for a reason. It is in 4 digit price range NOS sealed copies go for these days. Unless you are an emerging manufacturer of phono cartridges that wants/needs to have these records cost no object ( no way to claim such and such specs for the carts without the test record that can furnish the proof of such claims ... ), you can forget getting any of these records at anything approaching reasonable price.

If you do plan to make any more serious phono measurements, please do observe the suggestions on the KORF blog https://korfaudio.com/blog - particularly regarding the Issue #1 of phono playback, that is to say azimuth.
Although ANY stylus - no matter how expensive and how touted to be "perfect" - should be examined under the microscopre before ever allowing it to play precious/de facto irreplaceable (test) records, there still are defects and caveats in cartridge/stylus department that korf way of doing azimuth will weed out.
You would be surprised how large % of cartridges actualy available for sale can not meet the korf criteria. And should NEVER be allowed past the manufacturing plant door.

Any phono preamp issue(s) are minuscule compared to the azimuth problems of real world cartridges. Please note that almost no "vintage" cartridge review ( before about 2000 ) ever mentions the cartridge has been aligned for azimuth; most reviewers used for their reviews a tonearm with non adjustable azimuth, known to be correct ( mainly SME, later Linn , etc ) - and mounted and measured the cartridge just as any normal user would. The vast majority of comments like " sufficient , but assymetrical crosstalk (curve) ", " distortion in treble in one channel significantly higher than in the other " , etc, hint at the fact that the cartridge under test was OFF in azimuth.
The highest azimuth error in an otherwise impeccable cart/stylus I came across has been 3 and 1/2 degree; most are well within 1 degree, but to achieve symmetrical channel separation equal to or better than 35 dB the azimuth error MUST BE within less than 1/3rd of a degree.
Most arms/headshells that do allow for azimth adjustment do not have precise and repeatable way of dealing with so low error(s) - it is trial and error untill you get it exactly right.
 

AudioSceptic

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I inherited an Ayre CD player (well it plays dvd audio too in two channels). That thing has more aluminum in it than Budweiser uses annually for cans. It is beautiful but also ludicrous. I have never measured it but it sounds soft and diffused like there is a serious dip in the presence region and a high end that rolls off fast. Maybe it’s balanced out is better but I have not tried it.

More revealing is there is a dip switch in the back to toggle two different filters. One is named “listen”. The other is named “measure”. They sound the same to me but just the fact that they called them that is a warning siren!

Below is a photo of the cnc routed aluminum remote, ready for battery replacement. Which requires unscrewing six hex screws, then having the pcb board fall out the back as it’s pulled out by the battery cradle that just hangs on its leads. The two AAA batters only last a few months even if they are not really used. The case could hold four AAAs easily due to the 5/8inch thickness. But instead is solid aluminum. The buttons are mostly non illuminated and ergonomically stink and has limited functionality and cryptic markings. It weighs 8.71 oz and will smash a glass table or dent a hardwood floor. It’s range is approximately 8 feet. On a good day.

It epitomizes high end audio idiocy.

I would send the entire unit to Amir for testing but it would cost too much to ship it. the player weighs 26 pounds. Plus almost 9 oz for the remote.


View attachment 155981
As you say, impressive at first but stupid and wasteful. As for the sound, Ayre was (still is?) known for rolled-off treble with their preferred "listen" filter <https://www.stereophile.com/content/ayre-cx-7-cd-player-measurements>. They were also involved in the Pono player, which did the same thing, despite touting "hi-res" audio. I think it was supposed to improve transient performance at the expense of a flat response, a concept that Charley Hansen strongly believed in.
 

musicforcities

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As you say, impressive at first but stupid and wasteful. As for the sound, Ayre was (still is?) known for rolled-off treble with their preferred "listen" filter <https://www.stereophile.com/content/ayre-cx-7-cd-player-measurements>. They were also involved in the Pono player, which did the same thing, despite touting "hi-res" audio. I think it was supposed to improve transient performance at the expense of a flat response, a concept that Charley Hansen strongly believed in.
Good to know i wasn’t imagining it.

Fortunately it has a digital out — though it’s some wack xlr interface; I soldered an xlr onto a digital coax cable and use either a $100 topping Or $130 smsl Sankrit 10th II…so much better. take that ayre.

If I wanted rolled off highs I’d pop a recent Shure cartridge on my thorens tt. Lol.
 

Helicopter

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Good to know i wasn’t imagining it.

Fortunately it has a digital out — though it’s some wack xlr interface; I soldered an xlr onto a digital coax cable and use either a $100 topping Or $130 smsl Sankrit 10th II…so much better. take that ayre.

If I wanted rolled off highs I’d pop a recent Shure cartridge on my thorens tt. Lol.
sounds like AES, which is basucally the same as digital coax but wired for an XLR cable... should be better on 100m runs and such due to noise rejection and so on.
 

musicforcities

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sounds like AES, which is basucally the same as digital coax but wired for an XLR cable... should be better on 100m runs and such due to noise rejection and so on.
Yes that is right I think. The manual at least had a pin out diagram to make my life easier. It’s another example of Ayre stupidity nevertheless I think. I suspect they used it because it seems “esoteric” and because they don’t really want you to use it. after all, how many people so many keep their mega buck slab of aluminum CD player 100m away from the a DAC and amp. Long way to walk to change discs. And the remote only works from 8ft.

Maybe the AES is useful for connecting the Ayre to a berringer or Crown Amp with a built in DAC. ;-)
 

AudioSceptic

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Yes that is right I think. The manual at least had a pin out diagram to make my life easier. It’s another example of Ayre stupidity nevertheless I think. I suspect they used it because it seems “esoteric” and because they don’t really want you to use it. after all, how many people so many keep their mega buck slab of aluminum CD player 100m away from the a DAC and amp. Long way to walk to change discs. And the remote only works from 8ft.

Maybe the AES is useful for connecting the Ayre to a berringer or Crown Amp with a built in DAC. ;-)
If you only use the Ayre as a transport and use an external DAC, why not rip your CDs (lossless, of course) to a computer or NAS and play them from there? So much more convenient and, if you also use a portable player, you've already got the files, which you can use as they are or convert to MP3 or AAC to fit more in. :)
 

JP

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Phono playback has been shown to exceed FR of > 200 kHz - 40 years ago.

I've seen evidence of cartridge response exceeding 100kHz, but nothing remotely close to that ever actually cut. Is there any detail on the step response test IAR used?

The highest azimuth error in an otherwise impeccable cart/stylus I came across has been 3 and 1/2 degree; most are well within 1 degree, but to achieve symmetrical channel separation equal to or better than 35 dB the azimuth error MUST BE within less than 1/3rd of a degree.

Have you tested the audibility of asymmetrical channel separation?
 

Thomas_A

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Phono playback is perhaps the hardest discipline in all things audio. Approaching it from the digital side of things will certainly bump into digital's limitations - and that would be , first and foremost, the frequency response. Phono playback has been shown to exceed FR of > 200 kHz - 40 years ago. Here is the only part of the most comprehensive and meaningful phono cartridge review ever published that is available on the internet - that of International Audio Review , Issue #5, May 1980.
This review deals with more real world issues of phono playback than any other to date. It covered pretty much almost everything that was available at the time - and cartridges that are direct succesors to the 1980 models are pretty much still available - in their evolutionary form(s).
Too bad that IAR aka Peter Moncrieff has placed copyrights etc as he does, preventing from making this document available to public for free. It answers LOTS of questions and dillemas of phono playback world, both from cartridge/stylus point of view as well as from the effects of electrical loading of carts by the preamp and associated cables.

I certainly do agree the SINAD test of phono preamps as of present does not reflect the performance in real life. Although I do agree that, for instance, PS Audio Stellar phono stage is on the expensive side, the unit can not be flawed in real world use. It performs well with most cartridges tried, both MC and MM types - it is quiet and allows music from the LP to get a notch higher. I do not own it, but have heard one in a friend's system recently ; to all those who pooed on it due to SINAD measurements without even seeing it ( let alone heaing ) live, I recommend to do some real world use of gear BEFORE repeating such excercises again.

To @ amirm : phono measurements are tough AND extremely expensive. That is due to test records, which for the most part are simply no longer available, are VERY vulnerable and can be destroyed with a single play. After such hiccup, the record needs to be discarded and replaced by a new, fresh copy. In 2021, that means $ - and lot$ of $$$$. The test records that have stood the test of time and became the de facto standard are almost exclusively vintage, long out of print rarities - and those $$$$ were there for a reason. It is in 4 digit price range NOS sealed copies go for these days. Unless you are an emerging manufacturer of phono cartridges that wants/needs to have these records cost no object ( no way to claim such and such specs for the carts without the test record that can furnish the proof of such claims ... ), you can forget getting any of these records at anything approaching reasonable price.

If you do plan to make any more serious phono measurements, please do observe the suggestions on the KORF blog https://korfaudio.com/blog - particularly regarding the Issue #1 of phono playback, that is to say azimuth.
Although ANY stylus - no matter how expensive and how touted to be "perfect" - should be examined under the microscopre before ever allowing it to play precious/de facto irreplaceable (test) records, there still are defects and caveats in cartridge/stylus department that korf way of doing azimuth will weed out.
You would be surprised how large % of cartridges actualy available for sale can not meet the korf criteria. And should NEVER be allowed past the manufacturing plant door.

Any phono preamp issue(s) are minuscule compared to the azimuth problems of real world cartridges. Please note that almost no "vintage" cartridge review ( before about 2000 ) ever mentions the cartridge has been aligned for azimuth; most reviewers used for their reviews a tonearm with non adjustable azimuth, known to be correct ( mainly SME, later Linn , etc ) - and mounted and measured the cartridge just as any normal user would. The vast majority of comments like " sufficient , but assymetrical crosstalk (curve) ", " distortion in treble in one channel significantly higher than in the other " , etc, hint at the fact that the cartridge under test was OFF in azimuth.
The highest azimuth error in an otherwise impeccable cart/stylus I came across has been 3 and 1/2 degree; most are well within 1 degree, but to achieve symmetrical channel separation equal to or better than 35 dB the azimuth error MUST BE within less than 1/3rd of a degree.
Most arms/headshells that do allow for azimth adjustment do not have precise and repeatable way of dealing with so low error(s) - it is trial and error untill you get it exactly right.

The KORF blog has some interesting findings but the description made for azimuth has some errors. A small deviation of the azimuth does not cause those effects in some of the pictures. One have to depict the actual stylus geometry, and not a triangle-shaped stylus.

The cartridge should be aligned with the generators, and not the stylus. Any cartridge whose stylus and cantilever is not aligned with the cartridge body/generators should be discarded. An off-set generator will bleed more signal to one channel that often is not in phase with the main signal, causing distortion components to rise. The KORF blog shows increasing distortion with faulty azimuth, but the conclusion that this is a stylus effect has not been proven. It could equally be channel crosstalk effects.
 

anmpr1

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Here is the only part of the most comprehensive and meaningful phono cartridge review ever published that is available on the internet - that of International Audio Review , Issue #5, May 1980. This review deals with more real world issues of phono playback than any other to date. It covered pretty much almost everything that was available at the time
The Karat Diamond is... the first cartridge whose HF reproduction capability exceeds the 256K sampling resolution of our digital FFT analyzer (obviously making a mockery of the 50K sampling resolution of today's digital audio recorders).

Can you explain this? Is J. Peter saying that his Dynavector MC phono cartridge will reproduce a 128 kilohertz 'in the groove' signal (256K being the Nyquist sample rate for a 128K signal)? And, if so, any idea what test LP was he using to validate his claim? And at this FR do we know level, channel separation and dB range down or up from 'flat'?

I know some CD-4 test records are claimed to go up to 50K. Is he even using an actual record, or some sort of other method to establish FR?
 

musicforcities

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If you only use the Ayre as a transport and use an external DAC, why not rip your CDs (lossless, of course) to a computer or NAS and play them from there? So much more convenient and, if you also use a portable player, you've already got the files, which you can use as they are or convert to MP3 or AAC to fit more in. :)
Oh I have ripped most everything to losseless. So I hardly ever use it; the occasional SACD or DVD audio mainly. Though for SACDs I have to use the internal DAC (using the measure filter…not that I hear much difference.) or if someone brings something over. It is pretty great at tracking beat up CDs, I’ll give it that. Nice pioneer head and transport

Ot sits next to my Thorens td126mkII on the shelf of obsolete tech. I guess it’s weight may help dampen the shelf for the turntable. Which I do use more often.

The Ayre was given to me by my father. If I put it in the closet he asks about it when he comes over. Sentiment and the fact that’s a beautiful looking thing make it hard to get rid of.

Though at wish he would have kept his Luxman m4000 and c1000 (as even the matching tuner) and given those to me! (Electrical gremlins emerged in the early 1990s; Luxman was MIA, and he couldn’t find anyone in those pre internet days who could fix them. I think he gave them to Salvation Army. I was Overseas at school. If he had asked me I would have asked he put them in the closet for me. These days, they are readily reparable. The m4000 power amp especially was an engineering sight to behold inside and out.
 
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pinpoint_oxford

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Hello everyone! This is my first post here after a few weeks of reading various threads. I bought this preamp before seeing anything on this forum. I quite like it and I'm glad it somewhat holds up based on what I see here, albeit expensive. Maybe naiive of me, but part of the reason I bought this preamp was also the story and engineering philosophy of making something that uses all discrete components.


Hoping to educate myself here more. Fortunately, I was only talked into buying expensive audioquest cables once. Won’t make that mistake again.


Cheers!
 

milosz

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In the past I, too, have fallen to the "all discrete componentry is better than using ICs" notion. My thinking was, parts could be hand-selected in an all-discrete design - semiconductors could be closely matched where that would yield improved linearity, and resistors could be closely matched to design values. My assumption was that with IC manufacturing the characteristics of the integrated semiconductors and resistors could vary widely, and then the resulting problems covered up by tons of negative feedback. And maybe that was true with the old 741 op amps, but perhaps manufacturing of ICs has progressed to the point where tolerances of internal components is now equal to or better than run-of-the-mill discrete parts. Do they laser-trim IC resistances? I do not know. They certainly could.

I now think that there is nothing inherently wrong with good, modern ICs as gain stages. However, circuit designers can still get it wrong - which is true with either ICs or discrete parts- so it seems that nowadays it's really the design that is important, not the "IC or discrete philosophy" that's followed.
 

Frank Dernie

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In the past I, too, have fallen to the "all discrete componentry is better than using ICs" notion. My thinking was, parts could be hand-selected in an all-discrete design - semiconductors could be closely matched where that would yield improved linearity, and resistors could be closely matched to design values. My assumption was that with IC manufacturing the characteristics of the integrated semiconductors and resistors could vary widely, and then the resulting problems covered up by tons of negative feedback. And maybe that was true with the old 741 op amps, but perhaps manufacturing of ICs has progressed to the point where tolerances of internal components is now equal to or better than run-of-the-mill discrete parts. Do they laser-trim IC resistances? I do not know. They certainly could.

I now think that there is nothing inherently wrong with good, modern ICs as gain stages. However, circuit designers can still get it wrong - which is true with either ICs or discrete parts- so it seems that nowadays it's really the design that is important, not the "IC or discrete philosophy" that's followed.
I sort of see what you mean but in the case of ICs the manufacturing quantities combined with the huge tooling cost for manufacture mean the likelihood of an inadequate design making it into production is almost infinitely less likely than a discrete design, bodged on a breadboard by an incompetent and sold to the technically gullible with fancy styling and gobbledygook.
IMHO
 

milosz

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The design I was referring to in my comment was the design of the audio component using the IC opamps, not the design of the chips themselves. If you don't engineer the overall circuit correctly, even the best opamps can result in sonic problems.
 

pinpoint_oxford

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In the past I, too, have fallen to the "all discrete componentry is better than using ICs" notion. My thinking was, parts could be hand-selected in an all-discrete design - semiconductors could be closely matched where that would yield improved linearity, and resistors could be closely matched to design values. My assumption was that with IC manufacturing the characteristics of the integrated semiconductors and resistors could vary widely, and then the resulting problems covered up by tons of negative feedback. And maybe that was true with the old 741 op amps, but perhaps manufacturing of ICs has progressed to the point where tolerances of internal components is now equal to or better than run-of-the-mill discrete parts. Do they laser-trim IC resistances? I do not know. They certainly could.

I now think that there is nothing inherently wrong with good, modern ICs as gain stages. However, circuit designers can still get it wrong - which is true with either ICs or discrete parts- so it seems that nowadays it's really the design that is important, not the "IC or discrete philosophy" that's followed.
I am not an engineer, but my thinking was more to do with ICs being a tried approach to building a piece of kit, rather than a novel design. I know that thinking is flawed, but the story ps audio sold with this preamp intrigued me with the second iteration being an iconoclast yet "sounding" better than the first, better measured, design.

Despite that, I do plan on keeping this preamp long-term. I do think it sounds great and gives me very low noise which was something I was trying to fix with my record setup.
 

LTig

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I am not an engineer, but my thinking was more to do with ICs being a tried approach to building a piece of kit, rather than a novel design. I know that thinking is flawed, but the story ps audio sold with this preamp intrigued me with the second iteration being an iconoclast yet "sounding" better than the first, better measured, design.
This is BS but typical advertising speak of PS.
Despite that, I do plan on keeping this preamp long-term. I do think it sounds great and gives me very low noise which was something I was trying to fix with my record setup.
And rightly so. FR is very good. Both distortion and noise are not SOTA but still swamped by the noise of vinyl and the distortion of the pickup, so no need to get something "better".

My DIY MC phono preamp measures better in FR (20 Hz to 20 kHz +/-0.03 dB) and probably has also lower noise and disortion but I'm sure I'm not able to hear a difference in a proper controlled DBT.
 
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