Digital Phono Preamp

Does anyone have experience with converting the output of an LP pickup cartridge to a digital signal? I have recently converted to using Dutch & Dutch 8c speakers which have built in DAC and amps. These are fed from my Roon Nucleus+ with an 8Tb ssd holding all my ripped cd’s via a dCS network bridge. Leaves my LP’s out in the cold hence looking for the ability to convert the output of my MC phono cartrige into a digital signal which can be fed into the bridge too?

Hi Robert and welcome to the forum. I have some limited experience but, as a serious vinyl user, I have kept an eye on developments.

There are various options but it would help if we started from what you already have access to. It isn’t so much of turning the output of your MC cartridge into digital but the output of your phono amplifier - you will need to bring the tiny signal level of the cartridge’s output to one that is suitable as an input signal to an ADC ( analogue/digital converter). This process would also normally include RIAA eq although it is possible to apply this later in the digital domain. So, before proceeding further, what do you currently use for this?

Pete, I have a range of MC cartridges ranging from Denon DL 103 through a Lyra Olympos SL so predominantly lowish output. I tend to use a step up transformer into a MM input on the phono pre amp. Having sold my Karan Acoustics Reference phono pre as part of a move from the UK to the US I’m using my B system Monk Audio Phono Preamp as a stop gap. It obviously has a line level output. Scanning the internet a few candidates I’ve come across would be the ; Mytek ADC, the M2tech Joplin or a second hand PS Audio NuWave Phono pre - the latter two having RIAA functionality in addition to an ADC. All thought welcome.

The Korg DS-DAC-10R might be an option, it can record to both double-rate DSD as well as PCM:

Thanks Ian. You are a man after my own heart if you like MCs plus SUTs rather than headamps.

OK, I know where to start from now. Unfortunately and thanking @Paul_Bemelmans for his suggestion things do get a bit complex hereon. It is late here in the UK so please excuse me if I leave it now until I post further tomorrow ( UK time).

As I said this is going to be a little complex.

The first thing is to establish exactly what you want to do. Do you want to make files that can be stored on your server and be accessed via dCS Mosaic or Roon? Or do you want to digitise your LPs on the fly and feed that output directly to the Dutch & Dutch speakers?

The former way of doing it is far more laborious as you will need software to create tracks and insert metadata. Remember that otherwise and unless you make an individual recording of each track by manually cuing each one then starting a new file, you will create a whole LP side per file without any way of navigating it. Unfortunately this is not like ripping a CD.

So, if this is the way you want to go I would recommend using something like Vinyl Studio Pro. This means using a computer to create the files and brings us to a choice of ADC.

https://www.alpinesoft.co.uk/VinylStudio/VinylStudio_pro.aspx

I am not going to recommend using any native inbuilt computer ADC . However there are excellent converter soundcards that can be installed such as those from RME ( they also make standalone ADCs ). Even so you will still encounter issues such as providing a clean power supply.

So it may be easier to use a stand alone ADC. Many of these offered to the home user market , such as the Korg previously mentioned are really complete recorders. Here again you need to check that the dedicated software allows the flexibility to create separate tracks from a file rather than stopping and starting the recording process at each track boundary. Also establish that it does not tie you in to their proprietary record/repay world. That latter issue appears to be the case with the Korg as reading their specifications it seems at least from this that replay of the created files is only possible using their Korg AudioGate software . They make no mention of creating standard format files such as .wav .dsf or FLACs etc. Further gapless replay is not supported though this may not be a big issue with needledrops. Perhaps more importantly given their drum banging for DSD there is no DoP support.

There is another point about making digital files from LPs. Unlike ripping a CD where a bit perfect copy of the data is definitive, LP replay is a moving target as better turntables, cartridges and phonostages are always evolving. So if you digitised your vinyl collection using your current 2021 equipment yet next year find a better cartridge you may then want to re-digitise the whole lot.

So my preference would be to go for an on the fly system and not record. So you really need a pure ADC . Unfortunately dCS pulled out of the studio market some years ago but I am still going to recommend looking at pro or semi-pro equipment . For example as well as RME something like a Sonifex Redbox.
https://www.sonifex.co.uk/redbox/rbadda2_ld.shtml
However you may also want to insert a preamp before the ADC for volume control duties. This latter thought brings me to the simplest solution. Why not stick with a standard analogue vinyl replay system albeit with a preamp having balanced out and just feed that to the Dutch & Dutch speakers ( XLR input 1) using their own inbuilt ADC function? OK that doesn’t feature use of Network Bridge but is straightforward.

Unfortunately whatever route you choose the technical limits of the Dutch & Dutch digital processing will make any provision of hi-resolution PCM or DSD digitisation via any ADC redundant. The 8C supports a maximum sample rate of 48KS/s anything above being downsampled. Further DSD input is not supported.

Thanks Pete that is very usefull. To your first question digitising on the fly is the route I want to take. Your final comment re using a preamp highlights my dilemma, this is the route I initially adopted but my conrad-johnson GAT with it’s single ended outputs wasn’t optimal for feeding the D&D 8’s which ideally need balanced audio inputs otherwise, as I found, you get hum. Also my digital inputs had to go via a DAC ( Naim ND555) to derive an audio output fed via the GAT into the speakers which of course then convert the signal back to digital! Digital direct fed through the dCS with volume controlled in Roon gives both the best sound and a much simpler set up but brought me back to the LP issue :upside_down_face:

Circling back on this old thread…

I’m now using my Bartok as a digital pre. This has caused a bit of a headache with my turntable. I purchased a dirt cheap ADC from Amazon. it converts a line level input to a 24/48 stream output from a S/PDIF RCA or optical Toslink. I connected my phono stage into the ADC and ran the Toslink out into my Bartok - and it sounds really good! Good enough for casual listening.

I have no interest in digitizing my vinyl collection but I do like to listen to stuff I don’t have digitally or stuff that sounds better on Vinyl (e.g a lot of old pop recordings that have been ‘digitally remastered’ sound worse to me than my Vinyl copy)

I’m now looking for a little better ADC. The market is full of audio interfaces that are designed to interface with a computer - like the Korg mentioned above.

Any recommendations for a good 2 channel ADC that can be used convert a line level signal to a digital S/PDIF?

Mytek make an ADC which is decent. Alternatively if you want a one box solution McIntosh MP100 or MP1100.
I went for the 1100 and am really happy with it.

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The McIntosh solution looks nice. I thought it was pricy until I has a look at the new RME ADI-2/4 Pro SE!

it would be nice to have a phono stage and ADC in a single box, but some of these solutions esp on the pro side can be a bit expensive for a secondary listening source! I could probably find a second hand dCS ADC for less!

I think here is one on sale in BC currently. I just looked at the 67 page manual and this is clearly not made for the consumer market :wink: . Aside from this the analogue input is XLR balanced only . You may need a custom interface made if your phonostage does not have balanced out.

eeek! more work than I’d like do do at this point.

Even with my cheap-as-chips ADC, vinyl playback through the Bartok sounds really good! In reality even the poorest quality ADC is going to have a better SINAD and linearity than the best vinyl. So perhaps it doesn’t matter all that much for a secondary source.

These all in one solutions look nice but I like my phono stage, the character of which seems to come through the ADC/DAC process

This is a discontinued option but it was positively reviewed

You can watch the audio marts for a used copy

Ayre Acoustics made something similar but also discontinued. They and the dCS ADCs very rarely if ever come up on the second hsnd forums here in the US anymore unfortunately :upside_down_face:

It is too bad. I remember the Ayre product and It does just what I need - AD conversion.

There are tons of ‘audio interface’ options out there but most I’ve looked at are USB based and meant for pro audio or home studio applications.

it is kind of hard to find a simple high quality two channel ADC

I’m just curious - which ADC are you using? I’m wondering whether it’s the same “cheap as chips” one that I have used on my best friends LP12… :smiley:

(BTW - Have you SEEN the price of chips nowadays?!?!?!)

BR

Phil

Hi Phil

This is the one I got from Amazon $24 CND! Don’t think it even has a brand name!

Yup … thats pretty much the same one I used for my mate, just from Amazon Canada instead of Amazon UK.

We were surprised just how useable it was - my friend just told me not to ever tell him what it was I’d dropped down behind his phono stage and he said he’d never look…. :joy:

P


Best affordable ADC I’ve managed to find