Absolutely correct, but I have always had this little doubt about phono carts, especially MC. People make much of "ground noise", currents in ground conductors either contributing to current noise at the input stage, or causing voltage noise. In a single-ended phono input, one side of the phono cartridge is connected to that "ground".
Now a classic opamp has no connection to "ground", it has +/- inputs and +/- power supply connections. Is there a way to connect a phono cartridge output to a differential input, with a load resistor across the input pins, with no reference to "ground"? The cartridge doesn't have a connection yo ground, the opamp doesn't have a connection to ground, except in the feedback circuit. Is there a way for the cart to see only that resistive load without ground currents having any direct influence, yet still control the gain of the opamp ( without just putting the opamp output current back on the cartridge coils.
A typical balanced phono input has each end of the coil loaded by 1/2(Rload) with the two Rs referred to ground, but why ? Why does it have to connect to ground when the amp doesn't?
I know that I know nothing about this stuff, it's just one of those questions that lingers in my brain (or someplace).
Real amplifiers have bias current and can not have an undefined DC common mode voltage either. What you want here is a transformer.
And what transformer would that be Scott? I have looked high and low for a truly acceptable input transformer for MC. Never found a good enough one. Perhaps you have been luckier, or maybe someone else. Remember, they can have both high level and very low level (low frequency) distortion. Apparently, they all sound different as well.
Balanced inputs for MC cartridges will require 4 times as many input jfets (or a transformer) to get the same noise level as the Vendetta. (0.4nV/rt Hz)
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Would you please understand his question, why do you need a DC return path for amplifiers vs galvanic isolation was the question.
Still, what transformer would be good enough for you, Scott? In my experience MC phono cartridges are just little coils floating in space. Grounding one side does little, if anything, to change the signal from them. Hum could be a potential problem, but reasonable (2 meters or so) shielded cable seems good enough, so long as you don't have a noisy power transformer too close to the input cable.
I do not understand why these discussions on the Vinyl come back so regularly.
The digital offers us, today, performances of incomparable quality: 110dB signal-to-noise ratio, distortions to the limit of the best modern measuring devices, at least 40KHz of flat level bandwidth and phase...
Vinyls are (very) bad copies of magnetic masters that are owned by record companies. They can (and do) reproduce those originals and distribute them with complete fidelity in various digital formats.
Why to live in museums ?
I mean, listening to old vinyls do have a charm (i do-it from time to time), but why discuss or care of so calling 'top' quality in this matter ?
It's a little like wanting to inflate a Ford T engine !
The digital offers us, today, performances of incomparable quality: 110dB signal-to-noise ratio, distortions to the limit of the best modern measuring devices, at least 40KHz of flat level bandwidth and phase...
Vinyls are (very) bad copies of magnetic masters that are owned by record companies. They can (and do) reproduce those originals and distribute them with complete fidelity in various digital formats.
Why to live in museums ?
I mean, listening to old vinyls do have a charm (i do-it from time to time), but why discuss or care of so calling 'top' quality in this matter ?
It's a little like wanting to inflate a Ford T engine !
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Well that poor rectification will pulse the light and hence, this will be traceable in the recovered DC from the photovoltaic converter, so... ;-) ?
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I think part of it is the challenge. If your digital source is that good, then all you need is a clean line stage and a power amp. But vinyl is so crude that it takes a heroic effort to get something good out of it. It is technically challenging. I have heard a lot of vinyl setups that just couldn't sound very good, and it is very satisfying when those old records start sounding right.
What I am trying to do here, is to get people to rethink some assumptions about what works in audio circuit design and how master audio designers think. Many presume lots of things, then reject practical solutions. Others, never try for SOTA, because they just don't care enough about audio quality in their own home. I have to do SOTA, because I design audio products for a living, and I have to keep my reputation up in order to get new projects. It's a little different from many of you who work in other industries for your living.
SOTA means; the one realisation, at a given time, which performance wise exceeds all other implementation with equal function. The undisputed top performer - the best.
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MC SUT
I am using this and am quite happy :
https://www.mennovanderveen.nl/cms/images/producten/MC10/2018-10-29_MC10-en.pdf
Patrick
I am using this and am quite happy :
https://www.mennovanderveen.nl/cms/images/producten/MC10/2018-10-29_MC10-en.pdf
Patrick
Ritual, nostalgia.
Also, a lot of pop albums do sound better on vinyl because the engineer didn’t remove every bit of dynamic range on the vinyl pressing, unlike the CD.
I think that digital sucks still! And people have shown its problems that still exist, to me recently. Analog still sounds sweeter to me. I can fall in love with the girl singer on occasion. I can't do that with digital.
Digital is modern, like electric cars. Sure its new, but is it fun?
Digital is modern, like electric cars. Sure its new, but is it fun?
There is a lot of challenges, in Digital. To design or find a good wifi streamer, to work with DSP (FIR and IIR) in order to optimize both speaker sets (crossovers, phase alignment ) and room acoustics, to design the analog audio stage out of the best actual DAC to make-it sounding as you(tehy) like, to play with various amplifiers classes (A, AB, (CFA, VFA), H, D) in order to get the best sound possible out of each speaker of a multiway enclosure ...
A lot of things to learn, a lot that can be improved.
What to occupy full-time experienced designers in concern with the way things sound aside with younger ones, that seems more performance oriented.
If they do not do-it, wifi is dead: an industrial market.
Please, John, if you are as good as you think you are (and I think you are) , you have to use your talent for useful things. Things of our time.
You don't like "digital" ? So: take a Sabre ES9038 , as an example, and work on its analog side to make-it sound as you like.
(That is what I have done with all my old digital equipment. And my future project, as much digital and dematerialized I will can).
Yes, it is fun. A lot more than to repaint old cars and recook old recipes. And, cherry on the cake, I'm sure you will enjoy digital after this.
There is a lot to enjoy in the infinite little and subtle details this technology is able to reproduce.
Remember the time where audio moved from tubes to solid state. You were one of those who made solid state to sound better than tubes, while it was awful at the beginning. The challenge is the same.
I used 4x 2SK372GR matched (equivalent to 8x 2SK170) in the Wurcer phono.
So not quite on par, but close. 😉
https://www.diyaudio.com/forums/ana...ential-single-phono-preamp-6.html#post5420830
(Post #292)
Patrick
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