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The Ultimate Vinyl Rip system?

Ya this one was said to have come straight off a safety. I don't recall any more noise on it than the commercial releases.
 
wyn palmer said:
Interesting. I know the provenance of the tape recording in this instance so it's certainly not a copy of a DVDA, although based on the sound of the one and only DVDA that I have (Decca, Pavarotti, La Boheme, with the container removed and ripped to PCM on my laptop) that would not be a bad thing. As I alluded to, the tape is pretty noisy, and listening to the noise stepping up as play begins and goes through the progression of recording/copies that it experienced, is well, enlightening, and makes me wish that I could get access to the tape a generation or so earlier. It's not Dolby and it was recorded on a pair of Studer A820s or A810s (I don't remember which).
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By the way- during play the noise is not at all noticeable, it's that during lead in it's disconcerting to hear the sudden end of silence followed by a couple of upward steps before the music starts. I'm certain that I'm not alone in playing DSOTM loudly, and that contributes to the effect. My spouse thinks that ALL of my 15IPS tapes, even newly issued ones, are noisy, so it's definitely in the ear of the beholder.
 
wyn palmer said:
By the way- during play the noise is not at all noticeable, it's that during lead in it's disconcerting to hear the sudden end of silence followed by a couple of upward steps before the music starts. I'm certain that I'm not alone in playing DSOTM loudly, and that contributes to the effect. My spouse thinks that ALL of my 15IPS tapes, even newly issued ones, are noisy, so it's definitely in the ear of the beholder.
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Never been in to tape. Noise isn't something I don't do well with, which is why I take my analog sources to digital as early as possible in the chain. That and running my cartridges full differential means the only noise I pick up in the signal chain is cartridge self-noise, circa -70dB.
 
JP said:
Never been in to tape. Noise isn't something I don't do well with, which is why I take my analog sources to digital as early as possible in the chain. That and running my cartridges full differential means the only noise I pick up in the signal chain is cartridge self-noise, circa -70dB.
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Well, a well designed 5mv sensitivity MM active RIAA stage can have an integrated unweighted S/N ratio of >80dB- I know I have one- and a MC S/N in the mid 60s also unweighted. Add several dBs for A weighting and we're back to the LP being the dominant source. I cannot remember a single instance when the noise did not increase noticeably when the stylus was placed on the platter.
 
JP said:
Never been in to tape. Noise isn't something I don't do well with, which is why I take my analog sources to digital as early as possible in the chain. That and running my cartridges full differential means the only noise I pick up in the signal chain is cartridge self-noise, circa -70dB.
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Also, if I remember correctly, the A weighted S/N ratio of playback on the Otari I have is about 68dB. The problem is that after a couple of playback/record steps that's down to about 63dB, which is inferior to a pristine LP.
To illustrate my point about the MM playback noise.
I have a MM RIAA amp that measures 93uv rms, 20-20kHz, unweighted. It has a 5mV sensitivity and a 0dBV output for a gain of 46dB. That means that the equivalent RMS input noise is 465nV or about 3.3nv/rtHz assuming a constant noise spectral density. That's equivalent to the noise from an ideal resistor of a bit less than 700 ohms- which I believe is a fairly typical winding resistance for a MM cartridge of that sensitivity. You still need to amplify the signal for digitization, and the ADC is not immune to thermal noise issues as well as quantization noise. You would have to have an exceptionally quiet amp to improve on this, which is, of course, entirely possible, but it's debatable that it would make any audible difference.
 
"Input the DC resistance, the inductance, the load resistance and capacitance at the preamp end, and the nominal output voltage, and voila, you know what you’d get with a perfect, noiseless preamp."
Fantastic! :)
Now where can I buy one of those "perfect, noiseless" preamps? :idea:
 
JP said:
https://syclotron.com/riaa-noise-calculator/
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By the way, I ran a simulation using the values given in the spreadsheet- 3k series R, 500pF/47k load, 490mH inductance and the noise at the output of the preamp simulated as 354uv rms unweighted- almost 4x what the preamp simulates (and measures) with a shorted input. That's about 70dB. It's not just the thermal noise of the 3k R, it's also the several dB peaking in the noise transfer function at about 12kHz. due to the inductor/input capacitance resonance.
 
Yep. From a system perspective a lot of the effort is moot the second the stylus hits the groove, of course. I run differential as I can't avoid low-level 60Hz from the cart and arm if I don't, and digitizing ensures noise isn't a consideration for the rest of the chain. I can deal with the -120dB the ADC-1 has :)
 
JP said:
Yep. From a system perspective a lot of the effort is moot the second the stylus hits the groove, of course. I run differential as I can't avoid low-level 60Hz from the cart and arm if I don't, and digitizing ensures noise isn't a consideration for the rest of the chain. I can deal with the -120dB the ADC-1 has :)
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True, but I don't understand what the -120dB is. It certainly isn't the effective SINAD of the ADC with a 46dB amplifier preceding it as that implies an equivalent input flat noise spectral density of about 3.6/100 nv/rtHz or an equivalent source impedance of about 60mohms and that is four plus orders of magnitude lower than the DC resistance of the cartridge.
 
That was in regard to the quantization noise comment. I'm running ~20dB before the ADC.
 
JP said:
That was in regard to the quantization noise comment. I'm running ~20dB before the ADC.
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Yes, Being able to operate that far below FS can be advantageous. I need to operate the Korg at about 1 bit higher levels.
I have an RME ADI 2-PRO FS that I use for recording/playback purposes- perhaps it might make sense to use that in my audio system and sell the Korg/Topping D50 combo.
Anyone interested in the combo going cheap? ;)
 
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