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DSP crossovers and Phono Stages

CosmicJazz

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DSP crossovers and Phono Stages, share your thoughts....

It's a big compromise to the phono signal?
 

PaulD

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DSP xovers and RIAA eq are both typically far more accurate than analogue versions of the same, so no it cannot compromise the phono signal if implemented properly... I think Scott W wrote an article in Linear Audio about doing RIAA digitally and showing how good it was when done well.
 
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CosmicJazz

CosmicJazz

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yep, don't makes much sense digitalize vinyl and back to analog again... just for the benefit of actively cross over the speakers with more accuracy on the digital domain, but maybe is a question of what is a bigger compromise, the double conversion of the phono signal vs the less accurate analog crossover...
 

digitalfrost

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I run everything trough my PC, since I do DRC, crossover, effects all in the box.

So for my vinyl setup to work at all, I needs to go through the PC. Given the bad bit-depth and noise of vinyl, you don't need an expensive interface for the AD step. The benefits of the DRC absolutely outweigh any drawbacks to me.
 

Julf

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yep, don't makes much sense digitalize vinyl and back to analog again... just for the benefit of actively cross over the speakers with more accuracy on the digital domain, but maybe is a question of what is a bigger compromise, the double conversion of the phono signal vs the less accurate analog crossover...

The analog source will be orders of magnitude less accurate than any digital conversions.
 
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CosmicJazz

CosmicJazz

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Interesting, appears this is a consensus, even Accuphase abandoned the analog crossovers in 2001...

Doubts: as digital to analog converters and analog to digital converters always keep evolving, the quality of your vinyl listening will always be dependent of this factor right?
 

JP

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I do INAMP -> ADC -> DSP RIAA -> DSP Crossover -> DAC. The faster you get the signal in to the digital domain the less susceptible it will be.
 

Julf

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Doubts: as digital to analog converters and analog to digital converters always keep evolving, the quality of your vinyl listening will always be dependent of this factor right?

No, not really. As I wrote, modern DACs and ADCs are already orders of magnitude more accurate than vinyl, so the vinyl will always be the limiting factor.
 

digitalfrost

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The faster you get the signal in to the digital domain the less susceptible it will be.
I actually have my turntable on the back wall, behind the listening seat, opposite of the speakers. I have the preamp and the ADC there, and then I run a 15m USB cable to the PC. All the analog cabling is as short as possible.
 

PaulD

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yep, don't makes much sense digitalize vinyl and back to analog again... just for the benefit of actively cross over the speakers with more accuracy on the digital domain, but maybe is a question of what is a bigger compromise, the double conversion of the phono signal vs the less accurate analog crossover...
Nope, the AD-DA process is transparent (plenty of AES papers to provide evidence). The RIAA EQ and xover are far more accurate when done digitally. Much of what people refer to as the sound of different phono preamps is probably inaccuracies in the RIAA eq (if loading and levels are matched etc). Your argument maybe show a bias against digital processes, but that is unfounded, digital processing its now far better than we can do in an analogue world.
 

orangejello

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I would like to take the signal from my SUT and digitize it before sending it to my RME ADI-2 DAC via coax. (USB and optical are already taken on the RME.) Does anyone know what kind of hardware is available? I am aware of the PSAudio NuWave as an option. Does anyone know how the A/D processing work in the PSAudio? Does it take the MM input and just digitize it, or does it go through it's preamp first? Basically, I am trying to move the A/D as far upstream as possible and output to coax.
 

restorer-john

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Good quality phono preamplifier RIAA stages in standalone preamplifiers were more than accurate enough 30+ years ago. Their noise levels, overload characteristics, and THD were already at figures that were orders of magnitude better than the format itself was capable of.

For people who want to tweak everything and process additional parameters in the digital domain, sure great idea, but for someone who just wants to play and enjoy vinyl with the best preamplifier they can, I'd still be hunting down some of the statement preamplifiers made in the late 70s and 80s.

Someone with a complete digital phono front end can run a THD test from input to output at levels from a few uV to 320mV and see if they can beat the overall 90dB MM S/N and less than 0.001% THD (end to end) at 5V (20V max swing) out all the way out to 100KHz (not just a 20-20K RIAA deviation) on this preamp from 1983...

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And these figures were from a very good, but nowhere near TOTL preamplifier.
 
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