ADC's Analogue to Digital Converters - My Experiences so far
Feb 22, 2022 12:00:27 GMT
firebottle, stevew, and 1 more like this
Post by optical on Feb 22, 2022 12:00:27 GMT
So as not to clog up another thread I thought it would be a good (and potentially interesting) idea to have one where people can share their experiences of using ADC's and other such sampling/recording equipment.
It's always fascinated me regarding the process of converting and reconstructing analogue into a digital signal. Namely (and for the rest of this post I am referring to converting) an analogue signal from a record, to a digital one.
I don't profess to know much (or even anything) about the ins and outs (1's and 0's!) but as I tried to put across in another thread, I have tried it a few times with various ADC's in different guises but with the same result.
Initially I just wanted to see what it would sound like, then to rip and catalogue records which were only available on vinyl, then to setup a real-time converting chain from record to DAC to see what effect that had on the sound and indeed if it could get close enough to the original sound of 'just' analogue.
My results, mostly, have usually been a bit lack-luster to say the least and I've never managed to get the sound to match (or in reality what I would deem even acceptable) that of a pure analogue chain (needle to speaker).
The setup of the equipment has always been meticulous, using proper gain stages via various amps to get a nice waveform with some dynamic headroom and no clipping (basic stuff really).
I stand by my statements that using 'cheap' ADC's may be to blame for these less than satisfactory results but mostly I suspect it just isn't possible to get the sound to be as authentic to the analogue playback, for me at least. When I say unsatisfactory I don't mean it's absolutely awful, just when compared to true analogue playback, there is always something missing. The dynamics and bass impact mostly.
For years I had ripped vinyl to a semi-satisfactory level using a very simple audio interface, one of these:
www.amazon.co.uk/Behringer-UCA222-U-Control-Ultra-Low-Interface/dp/B0023BYDHK
It's a tidy little device, and punches well above it's weight. Digitalising stuff is very easy just plug in your analogue output (from a mixer/turntable etc) and a USB cable to a laptop/computer. I run Audacity software which actually enables you to record in 'high' quality, setting latency, bit depth, sample rate etc. I think this thing maxed out at 16/48 but for all intents and purposes that was fine for me at this stage.
However I found it never sounded as good as analogue audio did so I set about finding a way to get the digital output closer to the superior sounding analogue.
The setups I have tried so far include:
www.hifix.co.uk/project-essential-iii-digital
The Pro-ject Essential III Digital is just a basic turntable with a basic ADC on board which outputs as an optical (sp/dif) signal. I plugged it straight into various DAC's (Jolida Glass FX III, SMSL M8 among others). I was easily able to switch between the output from the TT and the output from the DAC. No contest at all, the analogue won this round, easily. No volume matching required (although I did my best) the sound was just dull and flat.
I didn't expect the ADC on board the Pro-ject to be up to much anyway being a 'built-in' offering so no huge surprise there. It was a bit of fun and I moved the turntable on.
Next to try was a 'cheap' little converter box from amazon:
www.amazon.co.uk/Converter-Digital-Toslink-Support-Function-black/dp/B00DHPHIJQ/ref=sr_1_5?crid=3C4WTV5BETM9C&keywords=analogue+to+digital+converter&qid=1645528422&sprefix=analogue+%2Caps%2C964&sr=8-5
This may not be the exact one (as I think I got one that outputted 24/196) but the design is/was the same.
I also powered it with a battery supply so as to not introduce any noise into the chain.
I connected it just after the phono stage output so the signal was converted into a digital one and then routed to a DAC.
Same result, possibly a bit better then the Pro-ject but no comparison to the turntable on it's own. No need for significant adjust of the volume on either the preamp or DAC from normal output levels so I knew the gain staging wasn't to blame here.
By this time I had extensively upgraded my hifi so I was now trying things through a large amount of different DAC's/setups etc.
Okay I thought, we must be able to do better than this. So as a slightly more serious contender I bought this:
www.amazon.co.uk/Behringer-U-PHORIA-UMC204HD-Audio-Interface/dp/B00SAV96JM
Better specs, proper inbuilt preamps to really control the signal, filters and "state of the art" conversion chips (whatever that means). This gave me much more control over the signal and I could listen on a monitoring function through headphones as well as monitoring the waveforms and levels on a laptop using Audacity software which I have used extensively for ripping vinyl prior to these experiments so have built up a fairly good understanding of what it can and cannot do to obtain the best recording possible.
Things were getting better, much better in fact but switching back and forth still highlighted the shortcomings of sampling (and that's the key here I think) and reconstructing an analogue signal after it has left the playback device.
Last thing to try was to plug everything into my trusty Behringer (yes I think they make decent stuff with superb value for money if not the best tech available).
www.amazon.co.uk/Behringer-DEQ2496-Ultra-Curve-Processor/dp/B000CCN152
This has 'studio grade' converters on board and I do know a lot of musicians (from bedroom to rudimentary studio setups) do swear by them so they must be half decent.
This was the best it has sounded yet, possibly due to having the best converters or indeed a good power supply (the others have been silly little 5/9v things) but using both monitoring/recording and routing the digital signal into a DAC still left a very unsatisfactory result compared to just using the TT into a phono stage.
The sound I'm getting from the above two components does far exceed the others I have tried but it's still miles off analogue replay in reality.
A friend of mine has a Pro-ject DS2 USB phono stage which I suspected would be superior to all of my above efforts, it is not. Granted I haven't spent much time with it and haven't tried it in my setup but like the above, it's miles away from a proper analogue chain.
www.hifix.co.uk/project-phono-box-ds2-usb?gclid=CjwKCAiAsNKQBhAPEiwAB-I5zcTh7CjbuZY0WDu-iY-5RqOXt3E9rnB9BIq_rhxoY9_SI6MNFwP4QhoCCtAQAvD_BwE
Ultimately I'm sure you can get a good result using ADC's, however without going up into the higher budgets (which I'm not willing to do based solely on what I've heard so far) I'm not going to find out.
For me if there was anything to indicate that things were getting close I may pursue it a bit further but for me the additional process of digitalising analogue just doesn't seem worth it and ends in frustration if nothing else.
Like I say I know there are quality vinyl rips out there using decent kit but I bet the recording sounded so much better on the equipment making the recording before it got into any converters. It may sound acceptable post digitalising but that's not the point for me.
I'm fully aware that all of this kit is pretty much low end but I haven't seen enough performance from them to justify any additional outlay so far.
I'd like to be proven wrong as I'd like to find something that enables me to get close to the enjoyment of a proper vinyl record in digital form, but I've yet to hear/experience it.
It's always fascinated me regarding the process of converting and reconstructing analogue into a digital signal. Namely (and for the rest of this post I am referring to converting) an analogue signal from a record, to a digital one.
I don't profess to know much (or even anything) about the ins and outs (1's and 0's!) but as I tried to put across in another thread, I have tried it a few times with various ADC's in different guises but with the same result.
Initially I just wanted to see what it would sound like, then to rip and catalogue records which were only available on vinyl, then to setup a real-time converting chain from record to DAC to see what effect that had on the sound and indeed if it could get close enough to the original sound of 'just' analogue.
My results, mostly, have usually been a bit lack-luster to say the least and I've never managed to get the sound to match (or in reality what I would deem even acceptable) that of a pure analogue chain (needle to speaker).
The setup of the equipment has always been meticulous, using proper gain stages via various amps to get a nice waveform with some dynamic headroom and no clipping (basic stuff really).
I stand by my statements that using 'cheap' ADC's may be to blame for these less than satisfactory results but mostly I suspect it just isn't possible to get the sound to be as authentic to the analogue playback, for me at least. When I say unsatisfactory I don't mean it's absolutely awful, just when compared to true analogue playback, there is always something missing. The dynamics and bass impact mostly.
For years I had ripped vinyl to a semi-satisfactory level using a very simple audio interface, one of these:
www.amazon.co.uk/Behringer-UCA222-U-Control-Ultra-Low-Interface/dp/B0023BYDHK
It's a tidy little device, and punches well above it's weight. Digitalising stuff is very easy just plug in your analogue output (from a mixer/turntable etc) and a USB cable to a laptop/computer. I run Audacity software which actually enables you to record in 'high' quality, setting latency, bit depth, sample rate etc. I think this thing maxed out at 16/48 but for all intents and purposes that was fine for me at this stage.
However I found it never sounded as good as analogue audio did so I set about finding a way to get the digital output closer to the superior sounding analogue.
The setups I have tried so far include:
www.hifix.co.uk/project-essential-iii-digital
The Pro-ject Essential III Digital is just a basic turntable with a basic ADC on board which outputs as an optical (sp/dif) signal. I plugged it straight into various DAC's (Jolida Glass FX III, SMSL M8 among others). I was easily able to switch between the output from the TT and the output from the DAC. No contest at all, the analogue won this round, easily. No volume matching required (although I did my best) the sound was just dull and flat.
I didn't expect the ADC on board the Pro-ject to be up to much anyway being a 'built-in' offering so no huge surprise there. It was a bit of fun and I moved the turntable on.
Next to try was a 'cheap' little converter box from amazon:
www.amazon.co.uk/Converter-Digital-Toslink-Support-Function-black/dp/B00DHPHIJQ/ref=sr_1_5?crid=3C4WTV5BETM9C&keywords=analogue+to+digital+converter&qid=1645528422&sprefix=analogue+%2Caps%2C964&sr=8-5
This may not be the exact one (as I think I got one that outputted 24/196) but the design is/was the same.
I also powered it with a battery supply so as to not introduce any noise into the chain.
I connected it just after the phono stage output so the signal was converted into a digital one and then routed to a DAC.
Same result, possibly a bit better then the Pro-ject but no comparison to the turntable on it's own. No need for significant adjust of the volume on either the preamp or DAC from normal output levels so I knew the gain staging wasn't to blame here.
By this time I had extensively upgraded my hifi so I was now trying things through a large amount of different DAC's/setups etc.
Okay I thought, we must be able to do better than this. So as a slightly more serious contender I bought this:
www.amazon.co.uk/Behringer-U-PHORIA-UMC204HD-Audio-Interface/dp/B00SAV96JM
Better specs, proper inbuilt preamps to really control the signal, filters and "state of the art" conversion chips (whatever that means). This gave me much more control over the signal and I could listen on a monitoring function through headphones as well as monitoring the waveforms and levels on a laptop using Audacity software which I have used extensively for ripping vinyl prior to these experiments so have built up a fairly good understanding of what it can and cannot do to obtain the best recording possible.
Things were getting better, much better in fact but switching back and forth still highlighted the shortcomings of sampling (and that's the key here I think) and reconstructing an analogue signal after it has left the playback device.
Last thing to try was to plug everything into my trusty Behringer (yes I think they make decent stuff with superb value for money if not the best tech available).
www.amazon.co.uk/Behringer-DEQ2496-Ultra-Curve-Processor/dp/B000CCN152
This has 'studio grade' converters on board and I do know a lot of musicians (from bedroom to rudimentary studio setups) do swear by them so they must be half decent.
This was the best it has sounded yet, possibly due to having the best converters or indeed a good power supply (the others have been silly little 5/9v things) but using both monitoring/recording and routing the digital signal into a DAC still left a very unsatisfactory result compared to just using the TT into a phono stage.
The sound I'm getting from the above two components does far exceed the others I have tried but it's still miles off analogue replay in reality.
A friend of mine has a Pro-ject DS2 USB phono stage which I suspected would be superior to all of my above efforts, it is not. Granted I haven't spent much time with it and haven't tried it in my setup but like the above, it's miles away from a proper analogue chain.
www.hifix.co.uk/project-phono-box-ds2-usb?gclid=CjwKCAiAsNKQBhAPEiwAB-I5zcTh7CjbuZY0WDu-iY-5RqOXt3E9rnB9BIq_rhxoY9_SI6MNFwP4QhoCCtAQAvD_BwE
Ultimately I'm sure you can get a good result using ADC's, however without going up into the higher budgets (which I'm not willing to do based solely on what I've heard so far) I'm not going to find out.
For me if there was anything to indicate that things were getting close I may pursue it a bit further but for me the additional process of digitalising analogue just doesn't seem worth it and ends in frustration if nothing else.
Like I say I know there are quality vinyl rips out there using decent kit but I bet the recording sounded so much better on the equipment making the recording before it got into any converters. It may sound acceptable post digitalising but that's not the point for me.
I'm fully aware that all of this kit is pretty much low end but I haven't seen enough performance from them to justify any additional outlay so far.
I'd like to be proven wrong as I'd like to find something that enables me to get close to the enjoyment of a proper vinyl record in digital form, but I've yet to hear/experience it.
