Integrating a turntable into a digital system

[levimax]

Not sure what there is to disagree about.

Let‘s start from first principles and run some numbers. Take a MM cartridge e.g., the venerable Shure V-15 which BTW, I rather like. Its output is 3 mV peak at 5 cm/s peak groove velocity. Now back in the day Shure measured groove velocity on commercial records and the maximum was measured to be around 70 cm/s. The will mean a maximum theoretical output of 42 mV. Note that in real life the the stylus will be unable to actually track such groove modulations, but is not relevant to this analysis. So with 32 dB gain the output of the phono stage will be 42 X 40 =1.6 V (rounded of). No self respecting ADC is going to overload at this level; concerns about digital overload are unfounded.

In practice the LP is, at best, a 10-11 bit medium, more or less. Where’s the harm in applying digital gain if playback level is too low? Perhaps I’m missing something?

Just wondering if you have a TT hooked up to your system through an ADC? I do and I would never try it without level control before ADC, there are just too many variables and I have experienced them first hand.

RE: 1.6 volts max sounds good in theory .. now add in 10 dB headroom for clicks and pops ( some say 20 dB) and several more dB in case you play 45 's and suddenly 1.6 volts can be 6.4 volt peaks which will clip most ADC's.

RE: Low level. Nothing wrong with applying digital gain if you have it but if you are using Room EQ, which will often eat up 10 or 20 dB of digital gain, you may not have enough left to boost a TT if the level happens to be too low.

 

[dualazmak]

Interesting. What is the name of this Jazz album? Can you provide a link?

- Bill Evans (piano) with Eddie Gomez (bass) and Eliot Zigmund (drums): "You Must Believe In Spring"; 1977 Studio Album
____CR00455 Craft Recordings (2021 Made in U.S.A.)
____All-Analog recording from the original tapes by Kevin Gray at Cohearent Audio
____2-LP set cut at 45-RPM and pressed on 180-gram heavy and thick vinyl at RTI (actually 188-gram each)

- The exact CD re-release with three bonus tracks:
____UCCO-5612 Craft Recordings (2022 re-mastered CD re-release, Made in Japan)

The LPs and the CD have arrived on my desk yesterday from Amazon Japan.

I will soon wash the LPs (with aqueous neutral pH detergent and hard plastic brash) and then will further clean-up by actual trace with 3.5 gram stylus pressure at 86 RPM for five times using Numark PT01 portable TT (please refer to my post here).

The details of my coming comparative listening using DENON DP-57L TT plus DL301MkII (MC) in my DSP multichannel multi-driver multi-amplifier setup (please refer to my post here and here) will be shared on this thread and/or on my project thread, hopefully within a month or two.

 

[JeremyFife]

Just wondering if you have a TT hooked up to your system through an ADC?

FWIW, I run my Pro-ject TT (Ortofon OM20 MM cart) via a zen Phono amp into the ADC of my miniDSP Flex (and then DAC, obviously).
No measurements, but I haven't noticed clipping. Perhaps I've been lucky, but it all seems to work well.
Just putting this in as a real world example.

 

[mike70]

I think SNR in vinyl depends on frequency, is not the same at 1khz than at 22khz.
So, with that theoretical 11 or 12 bits maybe you can lose information. I use 48/16 to listen to vinyl with DSP with more peace of mind.

Also, is not the same to use a dj mm cartridge with a conical stylus to a mc cartridge with a shibata stylus ... I mean to extract all you can from the grooves.

 

[JP]

Stylus shape, sure. MC is not inherently better than MM, at least not for the last ~50 years.

 

[morillon]

Stylus shape, sure. MC is not inherently better than MM, at least not for the last ~50 years.

for decades enthusiasts without limits of means or financial considerations have valued the mc
manufacturers brands of mm or mc cartridges too... like audiotechnica ortofon denon etc very present here etc too...
then..your affirmation commits only you
;-)

 

[JP]

for decades enthusiasts without limits of means or financial considerations have valued the mc
manufacturers brands of mm or mc cartridges too... like audiotechnica very present etc too...
then..your affirmation commits only you
;-)

Haven’t the slightest idea what that’s supposed to mean, other than the part that seems to infer the fashion status of MC.

 

[morillon]

so the mc fashion has been going on since the 60s
;-)

 

[mike70]

so the mc fashion has been going on since the 60s
;-)

for me is not a fashion, in objective and subjective tests.

there're spectacular MM cartridges and can be as good as a MC cartridge, but not the "usual" MM cartridge, not at all.
the key in MC cartridges is the SUT / headamp, normally people use MC cartridges with low quality preamplification and is like using standard gas in a Lamborghini.

 

[JP]

for me is not a fashion, in objective and subjective tests.

there're spectacular MM cartridges and can be as good as a MC cartridge, but not the "usual" MM cartridge, not at all.

That there are more inferior MM cartridges than MC doesn't mean that MC are inherently better than MM.

 

[mike70]

That there are more inferior MM cartridges than MC doesn't mean that MC are inherently better than MM.

well, technical reasons for superiority exists ... above that, you can implement a good MM cartridge better than a "so and so" MC cartridge, that's clear.

CDs are inherently better than vinyl ... that doesn't mean the recordings are really better on CD in any case. Is the same.

 

[JP]

well, technical reasons for superiority exists

Such as?

CDs are inherently better than vinyl ... that doesn't mean the recordings are really better on CD in any case. Is the same.

No, it's not.

 

[mike70]

Such as?


No, it's not.

For me is yes and yes ... I respect your opinion. That's all.

 

[JP]

For me is yes and yes ... I respect your opinion. That's all.

What are these supposed technical reasons?

 

[Neddy]

I use an Motu 8PreUSB ADC, which has pretty good performance, and not inexpensive used.
(This converts analog to USB digital, eight channel...and LOTS of other features I never figured out.)

I got it originally for converting HDMI content for movies (via Oppo DA), but an added benefit is that I can easily use it with other analog sources.
(I just reparied my old cassette deck and am working to digitize some old cassette tapes (some being bootlegs), and recently had to buy some LPs that never got released on CDs.)
Since I use the Motu regularly for 7.1 movies, I know the ADC>USB works fine, no headachys there.

So I can now also use it for cassette and phono converstion to USB/mp3/flac.

I've tested LP -> Hagerman Bugle -> MotuUSB -> USB PC and it worked fine.

I have not yet tried analog cassette yet, but did test it on another PC, so that part seems pretty impressive (via default ADC motherboard).

Anyway, for about $100 it should be pretty impressive - I will be working on that this weekend.

* I have not figured out how to convert from 8 channels to stereo USB, but expect it should not be a major issue.
** So after buying used LPs, I found that Apple Music does have these recordings even tho never released on CD, so at least I can recreate playlists.
Next will have to see how I can copy those to my library, even if I have to pay for it. Sigh.

Very similar to what Dualazmak has done, but not nearly as carefully calculated and tested, esp on gain and EQ tweeking (buy can do if so wanted).

 

[wgh52]

Folks,

thanks to all for the valuable und educating input to my questions! But in order to not distract/hijack this thread too much, I have started my own thread about "Which ADC for Phono..." to address the specifics of my project there and I hope for your valued participation and help to progress and finish it successfully.

Best Regards,
Winfried

 

[dualazmak]

- Bill Evans (piano) with Eddie Gomez (bass) and Eliot Zigmund (drums): "You Must Believe In Spring"; 1977 Studio Album
____CR00455 Craft Recordings (2021 Made in U.S.A.)
____All-Analog recording from the original tapes by Kevin Gray at Cohearent Audio
____2-LP set cut at 45-RPM and pressed on 180-gram heavy and thick vinyl at RTI (actually 188-gram each)
View attachment 275157

View attachment 275158

- The exact CD re-release with three bonus tracks:
____UCCO-5612 Craft Recordings (2022 re-mastered CD re-release, Made in Japan)
View attachment 275159

The LPs and the CD have arrived on my desk yesterday from Amazon Japan.

I will soon wash the LPs (with aqueous neutral pH detergent and hard plastic brash) and then will further clean-up by actual trace with 3.5 gram stylus pressure at 86 RPM for five times using Numark PT01 portable TT (please refer to my post here).

The details of my coming comparative listening using DENON DP-57L TT plus DL301MkII (MC) in my DSP multichannel multi-driver multi-amplifier setup (please refer to my post here and here) will be shared on this thread and/or on my project thread, hopefully within a month or two.

I posted/shared here on my project thread the details of my comparative listening sessions.

 

[al2002]

Just wondering if you have a TT hooked up to your system through an ADC? I do and I would never try it without level control before ADC, there are just too many variables and I have experienced them first hand.

RE: 1.6 volts max sounds good in theory .. now add in 10 dB headroom for clicks and pops ( some say 20 dB) and several more dB in case you play 45 's and suddenly 1.6 volts can be 6.4 volt peaks which will clip most ADC's.

RE: Low level. Nothing wrong with applying digital gain if you have it but if you are using Room EQ, which will often eat up 10 or 20 dB of digital gain, you may not have enough left to boost a TT if the level happens to be too low.

I have a set of Cosmos ADC and ASPs for a future record archiving project, but don’t presently use it. My Linn DSM converts alll analogue inputs, including Phono, to digital using the internal ADC, an AKM IIRC, never noticed overload.

Agree about the approx 10dB headroom for clicks or pops, but that is relative to normal-high playback modulations, say, 5-20 cm/ sec groove velocity, not 90 cm/s. BTW, that 90 cm/s was measured on a 45 rpm disco single, not a 33.3 rpm LP.

One last point, looking at Shure’s data on groove modulation, most of the high velocity data points were, as expected, at HF, so RIAA eq would bring the output level down, further reducing the possibility of overload.

Edit: Shure, not Sure.

 

[mike70]

I have a set of Cosmos ADC and ASPs for a future record archiving project, but don’t presently use it. My Linn DSM converts alll analogue inputs, including Phono, to digital using the internal ADC, an AKM IIRC, never noticed overload.

Agree about the approx 10dB headroom for clicks or pops, but that is relative to normal-high playback modulations, say, 5-20 cm/ sec groove velocity, not 90 cm/s. BTW, that 90 cm/s was measured on a 45 rpm disco single, not a 33.3 rpm LP.

One last point, looking at Sure’s data on groove modulation, most of the high velocity data points were, as expected, at HF, so RIAA eq would bring the output level down, further reducing the possibility of overload.

Clean your records.

If they aren't damaged physically, you don't need to suffer THAT kind of clicks / pops. I have a RCM since many years and I'm shocked by the difference in the listening experience and noise level reduction.

One of the few "night and day" / "blow me away" real difference I experienced in audio.

 

[dualazmak]

Clean your records.

Yes, it is really important.

Just for reference,,,
As I recently wrote here on my project thread;
Before putting the LPs onto my audio rig, I carefully and rigorously washed them with aqueous (distilled water) diluted neutral pH kitchen detergent and a hard plastic brash; after complete drying-up, I further cleaned the LPs by actual 86-RPM trace with 3.5-gram stylus pressure using NUMARK PT01 portable TT for five times (see #965). Of course, each time I cleaned-up the PT01's cartridge stylus with a small fine brush and pure isopropyl alcohol. These are my “routine” cleaning procedures for old LPs as well as newly purchased LPs.