On an aside from the object of your post above, perhaps you can direct me to the post regarding your Universal Head Amp.
The above suggests testing of a Head Amp that either magnifies voltage or effectively shorts the coil and magnifies the resulting current into the short, as would be the case in feeding the MC output into the inverting terminal of an operational amplifier and using a resistor in the feedback path.
As can be imagined, in the current mode the shorted winding resists the movement of the stylus as can affect the sonics. There is another factor that comes to mind as such relates to bandwidth and dielectric effects in the cabling between the cartridge and the Head Amp. Under perfect feedback conditions the potential between the centre conductor and the shield is driven to zero potential difference, meaning the effective capacitance diminishes along with the attraction of electrons into the dielectrics. This is to suggest that current mode can increase the effective bandwidth and diminish dielectric absorptive characteristics that might otherwise be prevalent under voltage mode conditions. Hence the internal cabling cannot be necessarily ignored as irrelevant to improved or diminished sonics.
Just to add a personal experience to the ongoing discussion.
A number of years ago, the German magazine Stereoplay added a CD to one of their issues.
This CD contained 192/24 recordings directly taken from Vinyl, recorded with their reference equipment worth many ten thousands of dollars like Ortofon MC cart, Clearaudio TT and Dcs A/D.
I happened to have most of the LP's, all having excellent recording quality, so I was curious to compare both.
However when playing the CD, it sounded a bit too dry and clean, not like the Vinyl version.
That's why I inserted a 192/24 A/D directly followed by my DAC in the chain while playing the LP.
The rather astonishing result was that now the LP played through A/D and Dac sounded exactly the same to my ears as the CD, dry and clean.
So either something gets lost in the digital domain or my Dac , a Bel Canto 3.5 with PCM1792, isn't good enough to let the digital version sound as the Vinyl's originals.
So far I haven't tried another DAC, the Mola Mola could be a contender, but the price is rather prohibitive.
Another option would be to build Marcel's BJT's Dac version, but the supply of components is troublesome.
Hans
A number of years ago, the German magazine Stereoplay added a CD to one of their issues.
This CD contained 192/24 recordings directly taken from Vinyl, recorded with their reference equipment worth many ten thousands of dollars like Ortofon MC cart, Clearaudio TT and Dcs A/D.
I happened to have most of the LP's, all having excellent recording quality, so I was curious to compare both.
However when playing the CD, it sounded a bit too dry and clean, not like the Vinyl version.
That's why I inserted a 192/24 A/D directly followed by my DAC in the chain while playing the LP.
The rather astonishing result was that now the LP played through A/D and Dac sounded exactly the same to my ears as the CD, dry and clean.
So either something gets lost in the digital domain or my Dac , a Bel Canto 3.5 with PCM1792, isn't good enough to let the digital version sound as the Vinyl's originals.
So far I haven't tried another DAC, the Mola Mola could be a contender, but the price is rather prohibitive.
Another option would be to build Marcel's BJT's Dac version, but the supply of components is troublesome.
Hans
It's a big misunderstanding that load on the Cart's coil output can have any effect on the stylus movement.
Hopefully in a few weeks a paper will be published with measurements showing that the stylus doesn't "see" the coil and its load and vice versa.
And yes, current amplification means that the coil is looking into the virtual input of an inverting amp, ideally having an impedance of zero Ohms.
Further to this, the inductance of an MC Cart is generally in the low uH , making a cable's capacity irrelevant while giving a resonance frequency in the hundreds of KHz when using voltage drive.
For a MM the situation is quite different, but a current amp for an MM is not the way to go.
Here is the link.
https://www.diyaudio.com/community/threads/designing-a-universal-diff-in-diff-out-head-amp.322453/
Hans
Before digital (a long time ago) I had a grad student do the calculations on mechanical to electrical in an MC cartridge. It was in the fractional percentage afaikr. However using the drive into a short, current mode, you are pulling current through a really nonlinear magnetic circuit. I don't know how significant this is. It would be easy to test.
Just as an epitaph to the discussion members over at ASR seem to be willing to make the extra effort:
https://www.audiosciencereview.com/...er-r1280t-vs-rcf-arya-pro5.43343/post-1535423
Serious persons in audio field seem to appreciate the effort:
https://www.audiosciencereview.com/...er-r1280t-vs-rcf-arya-pro5.43343/post-1536236
And regarding using recorded sound waves for comparing DACs here is an example using the DeltaWave software:
https://www.audiosciencereview.com/...hen-tested-with-real-music.43344/post-1535472
Admittedly the results are rather hard to decipher but quite interesting nevertheless.
Over and out.
https://www.audiosciencereview.com/...er-r1280t-vs-rcf-arya-pro5.43343/post-1535423
Serious persons in audio field seem to appreciate the effort:
https://www.audiosciencereview.com/...er-r1280t-vs-rcf-arya-pro5.43343/post-1536236
And regarding using recorded sound waves for comparing DACs here is an example using the DeltaWave software:
https://www.audiosciencereview.com/...hen-tested-with-real-music.43344/post-1535472
Admittedly the results are rather hard to decipher but quite interesting nevertheless.
Over and out.
Did a similar experiment years ago with a mic, and mic pre as the source. Was using a Lynx 2 sound card at the time, which was highly rated. Some people even described it as mastering quality. Tried with and without digital conversion, and at different digital sample rates. Guess what? Hi res sounded much better. And no digital at all sounded cleanest and most natural of all.
Later I repeated the experiment in front of musician who was interested in recording. Just ran through the various combinations without expressing any opinion of my own. At the end I asked him what he thought. He said, "can we record the CD without the soundcard?"
As a general principle any detection device always impacts that be detected. However this now seems likely irrelevant in the case of MC or MM carts as you have the clear evidence. Thanks for clearing this up for me.
I am currently working on a current input phono stage driven from a couple of battery powered voltage to current head amps for MM and MC cartridges. Hence in my case the cable between these head amps and the phono stage is subject to causing bandwidth limiting by its capacitance being in parallel with whatever resistance is used to convert the current to an input voltage. As this resistance drops to near zero for a current input phono stage the bandwidth goes up.
As someone that is also concerned about the influences of dielectrics in cabling, maintaining equal potentials between the signal carrying conductor and other conductors (as can be the shield) reduces the attraction of electrons to other variant potential surfaces, seemingly would minimize electron migration into and out of the dielectrics. For a current input device the input is at virtual ground hence there is no potential difference between the signal and ground.
To add some anecdotal remarks. As mentioned earlier I purchased 3 highly spec'd DACs reviewed by ASR (along with a goodly supply of Kraft dinner for my sister in order to make ends meet). On these devices I played Ryan Adams "Live at Carnegie Hall". This is a decent recording as seemingly would not be nearly as good as on Markw4's ESL's with his DAC. It is expected that this is a digital recording that on my system on vinyl sounds superior, leading me to believe that my DAC's aren't that good, that the phono is decent and the digital equipment used in the production of this recording s very good.
What I get from the vinyl is greater weight, authority and presence. Ultimately it seems to have more life, not necessarily more analytical resolution.
I am currently working on a current input phono stage driven from a couple of battery powered voltage to current head amps for MM and MC cartridges. Hence in my case the cable between these head amps and the phono stage is subject to causing bandwidth limiting by its capacitance being in parallel with whatever resistance is used to convert the current to an input voltage. As this resistance drops to near zero for a current input phono stage the bandwidth goes up.
As someone that is also concerned about the influences of dielectrics in cabling, maintaining equal potentials between the signal carrying conductor and other conductors (as can be the shield) reduces the attraction of electrons to other variant potential surfaces, seemingly would minimize electron migration into and out of the dielectrics. For a current input device the input is at virtual ground hence there is no potential difference between the signal and ground.
To add some anecdotal remarks. As mentioned earlier I purchased 3 highly spec'd DACs reviewed by ASR (along with a goodly supply of Kraft dinner for my sister in order to make ends meet). On these devices I played Ryan Adams "Live at Carnegie Hall". This is a decent recording as seemingly would not be nearly as good as on Markw4's ESL's with his DAC. It is expected that this is a digital recording that on my system on vinyl sounds superior, leading me to believe that my DAC's aren't that good, that the phono is decent and the digital equipment used in the production of this recording s very good.
What I get from the vinyl is greater weight, authority and presence. Ultimately it seems to have more life, not necessarily more analytical resolution.
Andrew,
Don’t forget the coil resistance, that will determine the amount of current flowing, and also take into account that only low micro amperes are flowing.
But not all Carts are responding well to current drive as it seems, especially the higher impedances > 50R prefer voltage drive according to Stereophile.
I have a 38R cart that responds very well.
That’s my only reference.
Hans
Don’t forget the coil resistance, that will determine the amount of current flowing, and also take into account that only low micro amperes are flowing.
But not all Carts are responding well to current drive as it seems, especially the higher impedances > 50R prefer voltage drive according to Stereophile.
I have a 38R cart that responds very well.
That’s my only reference.
Hans
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Regarding speaker measurements, sometimes people don't measure everything that matters. Doesn't look like they did that in the recently linked thread at ASR. For one example, compare the measurements there with those in the attached document.
Other than that, back in the days of hi-fi stores some hi-fi salesmen discovered what many people still don't know: Only test one pair of speakers in a room at a time. Remove all other speakers from the room when they are not actively powered on for test.
Even ChatGPT understands why: https://www.diyaudio.com/community/threads/chatgpt-ideas-about-amplifier-design.394541/post-7277417
Other than that, back in the days of hi-fi stores some hi-fi salesmen discovered what many people still don't know: Only test one pair of speakers in a room at a time. Remove all other speakers from the room when they are not actively powered on for test.
Even ChatGPT understands why: https://www.diyaudio.com/community/threads/chatgpt-ideas-about-amplifier-design.394541/post-7277417
There should be nothing strange in that vinyl sounds different (or superior) to CD or well measuring DAC. Vinyl has higher distortions and noise which many may find exciting as compared to the dry and clean sound of a CD/DAC. But this is comparing apples and oranges, not apples to apples which the earlier discussion was about.
Instead of trusting hi-fi salesmen or ChatGPT I suggest you read what Floyd Toole had to say about testing speakers.
Wasn't the observation by Hans to the effect that running the vinyl output through a digital ADC->DAC chain altered the vinyl sound so that it then sounded like a CD instead of like vinyl? IOW, the digital conversion processing was not transparent.
I also have the excellent Lynx soundcard for measuring purposes.
But it’s no match to my battery fed Belcanto DAC driven from an asynchronous USB to S/PDIF ST-fiber box for a complete galvanic isolation from JRiver on my computer.
But nevertheless it can’t match Vinyl on my ESL’s.
Hans
Same sort of thing here. So far nothing (not digital, nor MC) beats the sound of optical cart vinyl reproduction on ESLs.
Gee, is it okay if I read Sean Olive instead? Below is a graphic of what Sean says listeners should learn to discern. How many of those factors which relate to speakers were measured in the ASR thread?
That's not to mention the measured factors that were found to be important in the NS-10 document: Time-domain performance can matter too.
I was not commenting on that observation as I don't know any details of the setup.
The damping on an MC cart feeding into a virtual ground aka transconductance amplifier was discussed on the long vinyl thread here on the forum some years ago and the conclusion was that the MC generators are not reciprocal - ie they work as a generator one way, but there is no damping back onto the stylus the other way.
You have uA flowing in the coils that are uH level inductance. You're never going to get damping that will affect the performance materially given the forces on the stylus. I think if George is around he may be able to enlighten us on the earlier discussion on this topic.
Separately, the A*R crew are doing some serious testing and making attempts to move audio back in the direction of science. I laud their efforts, although I think they are sometimes blinded by the science
As Nelson says, it just entertainment. Relax!
You have uA flowing in the coils that are uH level inductance. You're never going to get damping that will affect the performance materially given the forces on the stylus. I think if George is around he may be able to enlighten us on the earlier discussion on this topic.
Separately, the A*R crew are doing some serious testing and making attempts to move audio back in the direction of science. I laud their efforts, although I think they are sometimes blinded by the science
As Nelson says, it just entertainment. Relax!
I don't understand why you are now fixated on the measurements as the results themselves are totally irrelevant. What is important is how the testing was conducted. I have no doubt that Sean Olive would also appreciate that test just as Floyd Toole did.
As we continue to segue from talking about dacs to talking about phono pres, one last couple of observations about dacs: First, Andrea Mori DSD dac operating at DSD256 IME comes closest to being able to accurately reproduce the sound of vinyl. The sound is spacious and less artificially dry than other digital I have heard so far. Still not truly 'transparent' though.
Second, another clue that digital is lossy is that nobody seems to notice tape artifacts on CDs recorded from tape, nor notice many limitations of vinyl when it is recorded to CD. If CD were truly transparent, it many cases it should sound exactly like tape or exactly like vinyl. It doesn't.
Second, another clue that digital is lossy is that nobody seems to notice tape artifacts on CDs recorded from tape, nor notice many limitations of vinyl when it is recorded to CD. If CD were truly transparent, it many cases it should sound exactly like tape or exactly like vinyl. It doesn't.
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While I have no doubt that Belcanto DAC sounds good the USB-to-SPDIF-fiber transformation seems less optimal.
I run my battery powered dacs/adcs through my asynchronous USB board that has digital isolation on every signal going to/from dac/adc (I2S, I2C, GPIO). No need for SPDIF or fiber.
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