Hi all.
I just ask myself why there is no standard high quality digital RIAA diy boards out there.
I think a simple 24/96 ADC paired with an i2s USB input, a software like jRiver and an USB DAC are enough.
What i missed?
My goal is to play vinyl in real time through PC and DAC I still use every day with my liquid files.
Of course a buffer/gain stage is needed to match gain and impedance of turntable.
I speak about digital RIAA via jRiver.
I just ask myself why there is no standard high quality digital RIAA diy boards out there.
I think a simple 24/96 ADC paired with an i2s USB input, a software like jRiver and an USB DAC are enough.
What i missed?
My goal is to play vinyl in real time through PC and DAC I still use every day with my liquid files.
Of course a buffer/gain stage is needed to match gain and impedance of turntable.
I speak about digital RIAA via jRiver.
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Do you mean to turn your PC into an RIAA phono stage, using the DAC to feed an analog preamp? If so, what's the point of that? To get custom EQs?
The extra amount of processing and equipment necessary doesn´t make much sense.
You can have needle - phono stage -preamp, why would you want to make it:
needle - adc - pc - dac - preamp?
You can have needle - phono stage -preamp, why would you want to make it:
needle - adc - pc - dac - preamp?
I mean:
i just use PC and DAC and, of corse, i'm a digital guy ;-)
Why i cannot simply put on my PC a digital real time audio file with no RIAA eq?
With jRiver (or similar) i can do an optimal RIAA eq, so i have only to implement an high quality ADC via usb, ro obtain an high quality cheap phono stage.
EDIT: sorry for t9, i'm mobile now.
i just use PC and DAC and, of corse, i'm a digital guy ;-)
Why i cannot simply put on my PC a digital real time audio file with no RIAA eq?
With jRiver (or similar) i can do an optimal RIAA eq, so i have only to implement an high quality ADC via usb, ro obtain an high quality cheap phono stage.
EDIT: sorry for t9, i'm mobile now.
Because the signal from cartridge is too small for good quality conversion. Perhaps you might get away with it if you used an analogue pre stage with just the upper time constant to get a decent strong signal with good SNR.
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Actually, it can, especially for those of us who work in the digital domain right up to the power amps. If you have a good ADC/DAC, you don't even need a preamp after it, simplifying things further.
For MC, likely true, though one could use a step-up transformer. For MM, I'm not sure, the opamps used in good sound cards are pretty quiet.
No,
if I implement a good analogue line (only first stage of a standard analogue phono stage, with stepped attenuator) buffer/gain stage to match carthridge impedance.
Goal is a cheap high quality RIAA.
But to get high quality RIAA you'd need a high quality ADC and a high quality DAC. Why would those be cheaper than a high quality analog EQ stage? I'm not aware of a high quality DAC as a PC soundcard.
It could make sense if you whatever you did it in (PC or mini DSP type thing) if you were using that for room EQ and/or active crossover etc. too.
Brian
Brian
The low level inputs on my external sound interfaces have typically 6K or so input resistance so I would recommend a proper cartridge termination and a buffer with gain like an SSM2019 or THAT1512. That way the cart could also be wired differential. Those parts would also do all but the low output MC's. The digital RIAA is well covered and a miniDSP would work as well as any number of other software or hardware solutions. A search for our member Jittipee's (I think I got that right) digital RIAA site has the correct coefficients for up to 192k. The set floating around the web has a trivial error (50.5Hz rather than 50.05Hz) as the low time constant.
I also think the phase errors quoted are overstated by a lot. In my simulations I found it mostly was an additional small processing delay. It also is MHO that the surface noise dithers a converter at 24bits so much that all the dynamic range arguments are moot.
EDIT - I'm speaking of IIR biquad version here.
behold Moving Coil Adapter 768kHz
It can be done:
6moons.com - industry features: An Awesome 3some
www.behold.eu - Deutsch - Produkte - behold Classic - Andere Komponenten - MCA768
www.behold.eu - Deutsch - Produkte - behold Classic - Andere Komponenten - MCK768
www.behold.eu - Deutsch - Produkte - behold Classic - Audio Prozessor
It can be done:
6moons.com - industry features: An Awesome 3some
www.behold.eu - Deutsch - Produkte - behold Classic - Andere Komponenten - MCA768
www.behold.eu - Deutsch - Produkte - behold Classic - Andere Komponenten - MCK768
www.behold.eu - Deutsch - Produkte - behold Classic - Audio Prozessor
Very interesting.
Even if i don't think it's a cheap solution.
Anyway,
do you know of an hi-fi quality adc board?
24/96 or 24/192 or better?
With a digital output (USB, i2s, aes/ebu, s/pdif)?
Possibly cheap 😎 ?
CHANNEL D - Professional and Audiophile Quality Software for Vinyl, iTunes, and commercial applications
They have been doing it for years and have won awards. I might be tempted but for it being Mac only. Also they charge somewhat for their flat gain phono stages. But if you have a mac mini lying around and can design a low noise gain stage that can handle unequalised RIAA up to line level $299 is not scary money given the feature set. Heck even Fremer likes it.
They have been doing it for years and have won awards. I might be tempted but for it being Mac only. Also they charge somewhat for their flat gain phono stages. But if you have a mac mini lying around and can design a low noise gain stage that can handle unequalised RIAA up to line level $299 is not scary money given the feature set. Heck even Fremer likes it.
He doesn't say. Atkinson uses dCS puccini. Fremer rips on an L22 so it is possible he plays back on it.