Best phono stage

ack

VIP/Donor & WBF Founding Member
May 6, 2010
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Nelson knows his stuff! Glad y'all got it sorted!
Yes, Nelson and his staff know their stuff. I have to admit my modified XP-25 is now KILLER, after the latest arm modifications I've made. I've been listening in awe all day long, and the sound is so three-dimensional, shockingly real and non-fatiguing, exceptionally articulate, with you-are-there presence. I love this A90 - what an engineering feat, if you drive it appropriately. I had some contractors working downstairs today, and after playing some piano, one of them made a point to come upstairs and express his amazement at the sound, saying that he though there was a real person playing the instrument. A little over the top, but it drives the point home.
 

PeterA

Well-Known Member
Dec 7, 2011
5,049
82
48
North Shore of Boston
Yes, Nelson and his staff know their stuff. I have to admit my modified XP-25 is now KILLER, after the latest arm modifications I've made. I've been listening in awe all day long, and the sound is so three-dimensional, shockingly real and non-fatiguing, exceptionally articulate, with you-are-there presence. I love this A90 - what an engineering feat, if you drive it appropriately. I had some contractors working downstairs today, and after playing some piano, one of them made a point to come upstairs and express his amazement at the sound, saying that he though there was a real person playing the instrument. A little over the top, but it drives the point home.
I recall a few years ago when you first came to hear my system, that you enjoyed the sound. I was pleased to learn that you had been so impressed by the Pass XP-25 that you immediately placed an order for your own unit. I'm glad that it is now giving you what you want and that you heard its potential that time years ago. The newer Pass XS Phono is even better, but it is substantially more expensive. I am looking forward to hearing the new XP-27 in my system.

When will the new Spectral phono be released?
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,260
34
48
Boston, MA
I recall a few years ago when you first came to hear my system, that you enjoyed the sound. I was pleased to learn that you had been so impressed by the Pass XP-25 that you immediately placed an order for your own unit. I'm glad that it is now giving you what you want and that you heard its potential that time years ago. The newer Pass XS Phono is even better, but it is substantially more expensive. I am looking forward to hearing the new XP-27 in my system.

When will the new Spectral phono be released?
Peter, you didn't have the XP-25 when I first listened to your system. You bought it after I purchased mine. The Spectral phono is lightyears away again. Spectral is releasing a stereo version of the DMA-500s, then the phono will follow.
 

jcarr

New Member
Mar 24, 2012
48
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Tokyo
www.lyraaudio.com
also ask Jonathan Carr why the Atlas and other Lyra Carts are recommended at 800 ohms and less based on cable capacitance even for highly stable phonos stages.
Please keep in mind that the numbers that I give in the Lyra cartridge user's manuals are for phono amplifiers that are not necessarily unconditionally stable. For each capacitance value, I believe that the tables give three numbers, which have each been chosen so that the amount of peaking will be suppressed to +6dB, +3dB, or 0dB. From there it is left up to the individual user's judgement (and ears) as to how much peaking they wish to allow.

Regarding our own phono amplifier designs, the earlier versions of the Connoisseur 4-series phono stages were equipped with a 47kohm input impedance, and gradually reduced over time to the present 3k. But the reason was never ultrasonic stability (since the basic design always possessed the bandwidth, stability and high output levels required to tolerate input peaking and output overload), rather, mitigating the effects of input bias currents and how doing so enabled us to reduce the amount of DC servo correction. In essence I felt that the subjective sonic benefits arising from decreased DC servo activity, outweighed the sonic detriments of reducing the input resistor value.

I believe each individual cartridge's level of induction is the answer.
The reactance between all inductances (dominated by the cartridge coil) and all capacitances (the sum total of coil parasitic capacitance, tonearm internal wiring, tonearm-to-phono amplifier cable, and capacitance at the phono amplifier input) is what causes the ultrasonic / radio frequency resonant peaking to occur, and the respective inductance / capacitance values will determine the ballpark figures for where the resonance will occur.
The resonant energy can be dissipated by the phono amplifier input resistor; reducing the resistor value will dissipate greater amounts of resonant energy.
However, the input resistor also presents the phono cartridge with extra work that it must perform in addition to tracking the LP groove, and the lower the resistor value, the more the maximum output voltage of the cartridge will be reduced.

These are just a few of the many variables that the phono amplifier designer should keep in mind.

kind regards, jonathan
 

PeterA

Well-Known Member
Dec 7, 2011
5,049
82
48
North Shore of Boston
Peter, you didn't have the XP-25 when I first listened to your system. You bought it after I purchased mine. The Spectral phono is lightyears away again. Spectral is releasing a stereo version of the DMA-500s, then the phono will follow.
Thanks for the reminder Tasos. You are correct. According to my system page and emails I tracked down the timeline. I had the Pass Xono when you first heard my system in July, 2013. You then bought your XP-25 in August, 2013 upon hearing the Xono and being unwilling to wait for the new Spectral. I then bought my XP-25 in Nov, 2013 having tried to buy one at an affordable price going back to Feb, 2011. I had to wait for the price to come down before I traded in my Xono.
 
Oct 30, 2017
496
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USA
Please keep in mind that the numbers that I give in the Lyra cartridge user's manuals are for phono amplifiers that are not necessarily unconditionally stable. For each capacitance value, I believe that the tables give three numbers, which have each been chosen so that the amount of peaking will be suppressed to +6dB, +3dB, or 0dB. From there it is left up to the individual user's judgement (and ears) as to how much peaking they wish to allow.
Thanks Jonathan for your usual well explained perspectives. I simply wanted to point out that even in your more stable phono column on the table (+6db) a max recommended level was 880 ohms for the Altlas so as to not confuse folks that 47k is the holy grail.

Regarding our own phono amplifier designs, the earlier versions of the Connoisseur 4-series phono stages were equipped with a 47kohm input impedance, and gradually reduced over time to the present 3k. But the reason was never ultrasonic stability (since the basic design always possessed the bandwidth, stability and high output levels required to tolerate input peaking and output overload), rather, mitigating the effects of input bias currents and how doing so enabled us to reduce the amount of DC servo correction. In essence I felt that the subjective sonic benefits arising from decreased DC servo activity, outweighed the sonic detriments of reducing the input resistor value.
I find this extremely interesting. I use your Atlas and it is absolutely stunning. I do have one question related to your comment about bias currents and DC correction. My Soulution 721 Preamp has a DC-Protection circuit in the signal path that tends to activate quite regularly when I listen to the Atlas. Based on my ears I use 500 ohms of load on the cartridge and have my ARC Ref 10 Phono Preamp gain on high. (I use high even though ARC recommends high for carts with .5mV or less and the Atlas is .56 mV but imo it sounds better on high. ) Any thoughts on why this DC triggers so often with the Atlas? I use the Nordost Odin phono cable 1.25 meters.


"DC-PROTECT:
Your preamplifier 721 is protected against DC-offset at the inputs IN 1...IN 4. The input signal is permanently monitored for DC-components. As soon as a DC-offset is detected a coupling capacitor is switched into the signal path. This capacitor is by- passed if the DC-offset has ceased for at least 15 seconds. The display shows the symbol for the capacitor (╪).
While switching between inputs the capacitor is activated automatically for security reasons. This is not a malfunction of your source device."



The reactance between all inductances (dominated by the cartridge coil) and all capacitances (the sum total of coil parasitic capacitance, tonearm internal wiring, tonearm-to-phono amplifier cable, and capacitance at the phono amplifier input) is what causes the ultrasonic / radio frequency resonant peaking to occur, and the respective inductance / capacitance values will determine the ballpark figures for where the resonance will occur.
The resonant energy can be dissipated by the phono amplifier input resistor; reducing the resistor value will dissipate greater amounts of resonant energy.
However, the input resistor also presents the phono cartridge with extra work that it must perform in addition to tracking the LP groove, and the lower the resistor value, the more the maximum output voltage of the cartridge will be reduced.
This relates to my comments earlier in the thread (#316, 322, 326, 336). I now many in our hobby have battled with the trade between setting cartridge load to stop ultra high frequency versus the negative effects of voltage attenuation on the input to a voltage gain device. What I find so interesting is that you and Ralph make it sound like making a phono stage with absolute high frequency stability is the obvious solution to this problem. My question is, if this is such a straight forward solution, why have we all wrestled with this for so long. I was under the impression stability itself comes with some level of sonic compromise be it through internal resistance or otherwise.
 

Atmasphere

[Industry Expert]
May 4, 2010
807
1
18
St. Paul, MN
www.atma-sphere.com
This relates to my comments earlier in the thread (#316, 322, 326, 336). I now many in our hobby have battled with the trade between setting cartridge load to stop ultra high frequency versus the negative effects of voltage attenuation on the input to a voltage gain device. What I find so interesting is that you and Ralph make it sound like making a phono stage with absolute high frequency stability is the obvious solution to this problem. My question is, if this is such a straight forward solution, why have we all wrestled with this for so long. I was under the impression stability itself comes with some level of sonic compromise be it through internal resistance or otherwise.
Stability rarely involves sonic compromise- quite the other way, actually! Unstable audio circuits are always compromised.

The reason 'we all wrestled with this for so long' is that many designers, some of them quite well-respected, simply didn't know that the resonant peak was there, didn't suss out the implications and so on. IOW they simply thought that a phono circuit was like any other circuit: some gain, low noise and some EQ- no biggie...
 

PeterA

Well-Known Member
Dec 7, 2011
5,049
82
48
North Shore of Boston
Ralph, my Pass phono has a dial for capacitive loading along with the resistive loading that we have been discussing. Could you please explain what capacitive loading is and why it is needed? The range is 100 to 750 in six increments. I have set mine at 100 which is the lowest setting and basically left it there since I bought the unit. I once briefly played around with the various settings, but I did not notice a sonic difference. Of course, I did not know what to listen for. Thank you.
 
Oct 30, 2017
496
0
16
USA
Stability rarely involves sonic compromise- quite the other way, actually! Unstable audio circuits are always compromised.

The reason 'we all wrestled with this for so long' is that many designers, some of them quite well-respected, simply didn't know that the resonant peak was there, didn't suss out the implications and so on. IOW they simply thought that a phono circuit was like any other circuit: some gain, low noise and some EQ- no biggie...
Thanks Ralph. Glad guys like you came along.

Ralph, my Pass phono has a dial for capacitive loading along with the resistive loading that we have been discussing. Could you please explain what capacitive loading is and why it is needed? The range is 100 to 750 in six increments. I have set mine at 100 which is the lowest setting and basically left it there since I bought the unit. I once briefly played around with the various settings, but I did not notice a sonic difference. Of course, I did not know what to listen for. Thank you.
That is a great question. It has always been lost on me why anyone would ever want more capacitance than the absolute minimum knowing the bad effects it has when combined with cartridge induction. People go to extreme lengths to get low capacitance phono cables yet some stages have this option??????
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
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48
Boston, MA
Capacitance is critical for MM. Pass also believe it makes a difference for MC but I disagree and took mine out
 
Oct 30, 2017
496
0
16
USA
Ahh, that makes sense. Thanks guys.
 

Atmasphere

[Industry Expert]
May 4, 2010
807
1
18
St. Paul, MN
www.atma-sphere.com
Ralph, my Pass phono has a dial for capacitive loading along with the resistive loading that we have been discussing. Could you please explain what capacitive loading is and why it is needed? The range is 100 to 750 in six increments. I have set mine at 100 which is the lowest setting and basically left it there since I bought the unit. I once briefly played around with the various settings, but I did not notice a sonic difference. Of course, I did not know what to listen for. Thank you.
As mentioned, capacitance is used for loading MM cartridges. Jim Hagerman covered this in the article I linked earlier; there are several calculators embedded in that article which can be helpful. Here is the link again:
http://www.hagtech.com/loading.html
 

ack

VIP/Donor & WBF Founding Member
May 6, 2010
5,260
34
48
Boston, MA
And since virtually no one reads the links in their entirety, here is the summary

Summary
  • Minimal loading capacitance is best
  • Moving coil types have far greater frequency response
  • Load resistance tunes damping
The line is bold has been a well known fact for years
 
Mar 3, 2018
11
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I used to own the FM 122. Only piece I regret selling. Its a wonderful phono stage.

Just make sure you have enough overall gain in your system to work with the low 56db gain in the fm phono.
Hello, I have seen you have TW Acustik/Thoress phono, Accuphase C-37, Esoteric E-03 in your signature.
Do you talk about them ?
I have an Esoteric E03 and I search to improve the phono stage. My turntable is a VPI Classic 3 in rosewood with an audio-technica ART9.

Thank yoy very much
 
Sep 26, 2017
4
0
1
What is better to colour up a grey weekend than a highend -shoot out- with two friends and three phonostages.

Our opponents were two well known candidates from Germany, -Absolute Phono inside- from Clearaudio, the Thöress Phono and a newcomer, the AS Phonolab from Audiospecials, also from Germany.

If you want to judge precise transients and authenticity, a real challenge for even the best phonostages is „Friday night in San Francisco – Paco de Lucia, Al die Meola and John MC Laughlin.

Preamp was the KODA Takumi K-10 that fitted perfect.

First, the Clearaudio got a decision.
Absolute O.K. But not more. A bit boaring, but nothing we expected from a phonostage over 10000 Dollars.

The two candidates left constituted another league.

The Thöress, in all points wonderful and colourful, such as expected from a tube phono. Better stage, more depth and transparancy well focused. Really good, that was great fun. The heaven turned from grey to blue.

We were really satisfied. Until we switched over to the AS Phonolab.

In all points a further step up. Clear sound, precise attack, a transients playback from the guitar strings that shows what precision and dynamic a vinyl record can offer.

Wide stage with depth, much space between the three musicians, well focused on the point, we could nearly see their shapes. Easy to understand what intention the Audio engineer mixed up in the recording studio.

Common sense. Really fast, sharped focused and so colourful. Natural high frequencies without any sharpness. Best transients playback ever heard yet. A perfect conjunction between precision and authenticity.

We assumed the reason. The AS from Audiospecials has its roots in the PRO Audio section. A look inside tells stories about professional engineering. Such qualities are not coincidence. Sometimes the unexpected things are the best.

But the way is the reward and so we look for further opponents. May be an EMT, but not easy to get.

141126_5.jpg
 
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