[SoCalWJS]

First off, forgive if this is in the wrong place.

I am planning on getting into the digital storage world in the near future. I plan on moving all of my CD's onto a digital platform, which seems straight forward enough (SACD's and DVD-A's are more problematic). Once in the digital domain, it seems to me that the choice of DAC is the main issue in determining the quality of the sound. There are tons of threads addressing the various options out there, and I have a couple of options in the $1k-1.5k range that I am considerering for my system.

Vinyl has me confused. There seems to be very little information on converting this analog signal into the digital domain that discusses the quality of the A-D conversion.

I have a preamp with a good phonostage (ModWright LS 100 with tube phono amp). I have a good turntable (SOTA Star , ET1.5 tonearm, and Grado cart)(which is not hooked up due to lack of available space for all of the equipment).


Can anybody point me to anyplace that discusses this part of the conversation? I am hoping that I can set up a temporary setup where I can convert all my vinyl to digital, then take the turntable back down and have all that wonderfull music available in a more convenient format.

Also, is there an A-D converter that also does the reverse (D-A)?? Can I use this same A-D to convert the analog output of 2 channel SACD's and DVD-A's to a digital file at higher than 16/44.1?

Thanks

[WC]

http://www.channld.com/support-soundcards.html

This is a start of a list of DACs and ADCs.

DVD-A's can be ripped on your computer.

[Russtafarian]

I'd like to know more about vinyl A to D as well.  I've already converted my CDs and  DVD-As to files so that area is covered.  I like ChannelD's Pure Vinyl approach but it is Mac only and I am currently using Foobar and/or Squeezebox with a Windows 7 PC.

Is there a PC solution that will allow me to digitize vinyl in hi-rez straight from the cartridge with no RIAA correction and play the file back with RIAA done with a Foobar plug-in?

As for reasonably priced A to D converters for vinyl, I'll bet a pair of CEntrance 24/96 Mic Ports interfaced with my DL103 cartridge by step up transformers would work really well.  Michael Goodman at CEntrance is THE MAN when it comes to high quality, low noise USB A to D and D to A solutions.  A pair of Mic Ports is only $300.  It's not 192, but I'd rather have excellent 96khz conversion than cheap 192khz conversion.

Russ

[toddbagwell]

Michael Fremer of Stereophile has used this to burn cd's for several years

http://www.stereophile.com/hirezplayers/605/index.html


Alesis MasterLink ML-9600 Hard Disk/CD-R Recorder


I haven't listened to vinyl in 20+ years, so i've got no personal experience with it.

Many soundcards have an analog input that will allow for recording from a phono preamp, followed by track splitting and tagging.

Let us know what you end up trying


Todd

[SoCalWJS]

http://www.channld.com/support-soundcards.html

This is a start of a list of DACs and ADCs.

DVD-A's can be ripped on your computer.

Spent some time looking at the ChannelD website and they have a list of A to D (and DAC's) that they say work well with their software, PureVinyl. I have seen that there were many vendors at the various shows I have attended (RMAF last year and T.H.E. Show OC) using PV, and I'm sure it's good software.

They also sell Lynx products, so they are highly recommended on their website. I remember seeing that Lynx had a new product they were demoing at the OC show called Hilo, and I picked up their brocheure and took another look at it. Interesting looking product, but no RCA inputs - looks like you have to use some conversion plugs to get it into another format.

Still can't find anything that does A to D as well as DAC duties. Not quite sure I want to commit to buying so much new hardware (A to D, Computer music server, and a DAC, plus software)

Am I missing something? (as in a simpler method of doing this while maintaining high quality)

*edit:
It appears that the Hilo functions as both DAC and A to D, so I'll have to research further. I/O looks to be a bit different than what I am used to - I'm gettin' old and out of touch. 

[WC]

A furutech GT-40 is a USB DAC, ADC, phono preamp, and headphone amp.

[dlaloum]

I did a lot of research on ADC about 18 months (or was it 2 years?) ago...

My conclusions were as follows...

Best ADC's under the silly money professional level were:

Mytek Stereo192 & Lavry AD10/AD11 (Between $1000 and $1600)

Next notch down in performance has a lot more competition
Mytek Stereo96
RME interfaces
Lynx
eMU 1616m / 1820m
(Pricing between $300 and $800)

My previous ADC was an M-Audio Audiophile 2496 card - which I did not find quite up to scratch.

Ultimately my measure of quality is that I should not be able to tell whether the original Analogue or the Digital copy is playing - the M-Audio2496 recordings did not achieve that - But when I upgraded to the eMU 1616m, I did achieve this goal.

On my system, with my speakers, setup, etc, I cannot differentiate between a carefully made recording through the 1616m and an original Analogue vinyl record playing. (obviously level matched etc...)

With regards to software, there are lots of platforms, options etc... PV is a mac only solution, so if you are an Apple user that would be a good option - I am a PC/Windows user, so it was not an option for me!

My own research shows that the key specification for ADC performance is the word clock precision.
Also the "sweet spot" for optimum performance of ADC's appears to be 24/96, even with ADC's capable of 24/192, they usually end up sounding better at 24/96.

Perhaps when 24/384 becomes common place the sweet spot will shift to 24/192.... but right now it sounds as if 24/192 is the "stretch" maximum for most chipsets, and they really don't give their best there...

Some other important issues:

Input gain/amplitude control... With converting to digital, it is absolutely critical that you avoid ANY CLIPPING WHATSOEVER (even at the highest/worst click/pop) - as soon as the ADC chips clip, things get nasty sonically.
So you need to be able to adjust the level of the signal being fed to the ADC - either the phono stage needs adjustable gain, or you need a secondary gain/level control stage after the phono stage.
The better semi-pro and pro ADC's do have this type of volume control.
This single feature may be the single most important one in getting the best possible vinyl to digital conversions!

Hope that helps

bye for now

David

[SoCalWJS]

dlaloum

David, thanks for the response. I see you list the Lynx as one of the options in the "one notch down" category. I am guessing that based upon the price point, that would be one of the older models. The new one (Hilo)appears to be quite a bit more - don't know if it would be any better. It looks like the Hilo has the metering to properly set the levels to avoid clipping (I'm starting to get flashbacks to the 70's/80's when I'd make cassette tapes  ).

Still trying to get a handle on how I'd have to set the thing up if I got serious - RCA out from phono preamp outs into one of the inputs (if I understand correctly, an AES input - so, some form of converter) on the Hilo, then via USB to a computer (starting to sell myself out on Mac Mini and PureVinyl), then back to the Hilo via the (same?) USB, AES to RCA conversion to an input on my preamp.

Seems like an awful lot of conversions! 

[dlaloum]

I am very wary of setups that do level setting onboard of a PC card...

Frequently they are messing with the signal AFTER the ADC rather than providing a high quality analogue circuit BEFORE the ADC...

That was one of the problems with the M-Audio 2496.

And yes, many of the models I have listed are a bit vintage as it was a couple of years back I was looking at it - so I just want to highlight the things to look for rather than specific models...

With regards to input level control, you really want to be sure that there is a high quality analogue circuit in there before it gets digitised.

Once the signal is in digital format, it really doesn't matter how many links it goes through  - both the timing and the data content is fixed at that point, and as long as your DAC is capable of putting things together accurately (again the key being word clock accuracy!!) - you should be fine!


A couple of other hints from experience...

Digitise at 24bit.... but as soon as it is in your computer, convert it to 32bit or 64bit, do all of your processing and adjusting at that level, before downconverting as your last step.

If you do this, and clean up the signal, reset levels etc... you will find that 16/44 is an excellent and far more than ample final setup...

So ideally record 24/96, process 64/96 (without ever downconverting through the processing stages... watch out for software or drivers that downconvert without telling you!!) - and finally save the output at whatever your chosen storage format is - but in my experience 16/44 is fine!

AES is one of the digital transfer formats, alongside of SPDIF.... you first need to run your analogue signal through an ADC before you can then transmit it in AES format.

A lot of the PC cards are processing / DSP (Digital Signal Processor) cards, they are designed to actually manipulate a digital signal - they often work with an external ADC, which receives the analogue signal, converts it to digital, and then transfers it to the DSP card. Transfer to the DSP can be via SPDIF, AES or proprietary connections.

My own 1616m does the ADC in an outboard box, then transfers the data stream to an inboard DSP via a proprietary connection.

The RME babyface is a device I would consider looking at if I was shopping now...
The Lynx Hilo didn't exist last time I looked, but it looks like the right thing too

Although it seems to me that all the inputs on the Hilo are balanced... so assuming your phono stage is an unbalanced standard RCA output - you will/ may need to convert, or run through some adapters into the balanced input.

And from the Hilo the output could go to the computer via USB

Mind you at $2500 this is by no means an economy setup!!!

Using it as a DAC it will provide a balanced output - so again you will most likely need some converters/adapters for unbalanced out into your amp/receiver/system.

If your budget reaches into this price bracket, you should also take a look at the Lavry and Mytek products...

And read the reviews at soundonsound and gearslutz websites....

Bye for now

David

[Russtafarian]

David,

Have you looked at some of the pro recording interface products like the TC Impact Twin or Apogee Duet 2?  These have mic preamps in the ADC path with enough gain to record the cartridge directly (with proper impedance termination).  They are both recommended by Channel D and are at or below $600 so very cost effective.  Channel D emphasizes recording the phono signal directly without RIAA correction, then applying the RIAA curve at playback. 

The Lynx Hilo looks like a great product but it doesn't have preamps to do direct cartridge recording.  At Newport, they were using an external preamp into the Hilo for their analog demo.

I'm just parroting what I read off Channel D's website but they seem to be on the cutting edge of vinyl digitization.  I recall reading in the Stereophile review that they sell RCA to XLR adaptors that impedance match cartridges to these devices.  I think I'm talking myself into PureVinyl.

Russ

[SoCalWJS]

Maybe I ought to post this elsewhere, but, since I started it here......

I noticed on Channel D's website of supported soundcards, it says all Apple soundcards. I noticed that the Mini has a mini pin audio input.

Can I just take the output from my phono preamp and use an RCA to mini pin converter, then do everything inside PureVinyl on the Mini?

Seems simple, but I don't know how much level setting (to prevent clipping) I can do within PureVinyl, or anything about the Mini's capabilities for making any changes.

[toddbagwell]

Your topic is fine here, obviously it needs to be posted somewhere.

Just don't ask about recording your digital downloads onto wax cylinders 

in all seriousness, i don't have any issues with the thread in this circle.

Later,
Todd

[dlaloum]

David,

Have you looked at some of the pro recording interface products like the TC Impact Twin or Apogee Duet 2?  These have mic preamps in the ADC path with enough gain to record the cartridge directly (with proper impedance termination).  They are both recommended by Channel D and are at or below $600 so very cost effective.  Channel D emphasizes recording the phono signal directly without RIAA correction, then applying the RIAA curve at playback. 

The Lynx Hilo looks like a great product but it doesn't have preamps to do direct cartridge recording.  At Newport, they were using an external preamp into the Hilo for their analog demo.

I'm just parroting what I read off Channel D's website but they seem to be on the cutting edge of vinyl digitization.  I recall reading in the Stereophile review that they sell RCA to XLR adaptors that impedance match cartridges to these devices.  I think I'm talking myself into PureVinyl.

Russ

Hi Russ,
The Duet i the original version I briefly looked at, but it is a Mac only product - so quickly fell off my list, and I did not investigate it further...
The Duet led to my investigating the RME babyface, which is its main competitor (which I recommended) - the RME supports both Mac and PC platforms.

I did quite a bit of experimenting using the Mic Preamps on my 1616m and appropriate load adjustments, but it proved quite tricky!

1) You need a very high quality Mic Pre, so you don't introduce more noise/distortion
2) Both channels need to be level matched, most of these pro/semipro pieces of gear have seperate level adjustment dials, and it is very very difficult to get the channels matched to within 2db let alone doing better

The next bit is looking at doing RIAA in the digital domain....
Again not so simple...
1) it needs to be done with minimum phase high grade calculations (RIAA corrects not only frequency amplitude, but also frequency phase). and
2) to eliminate digital error based noise, the calculations need to be at least at 32bit resolution, and preferably 64bit
3) A typical RIAA recorded LP, has the bass 20db lower than flat, and the highs 20db higher than flat.... so in terms of headroom, recording "flat" to then apply digital RIAA requires an additional 40db of headroom (!!!!) - you need to be able to take the peaks of the bits that are recorded 40db up (from the ones recorded at lowest level), and still be able to take the quietest details from the ones recorded 40db down.
Assuming a very compressed 60db dynamic range - that makes 100db

Doing the EQ at the analogue stage, and then recording from there, allows you to maximise your actual digital dynamic range and use it effectively ...and even then the dynamic range is one of your biggest constraints.

I did quite a few experiments using the mic pre's and digital RIAA.

Right now I think the optimum might be analogue RIAA with digital EQ to achieve flatter frequency response than is possible with a normal cartridge setup. (I think digital resolution needs to increase by an order of magnitude or two before digital RIAA will tryly come into its own...)

bye for now

David