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**Peter Allen** · 04-29-2002, 10:00 PM

Re: Digital input to a sound card

I think I'm in a similar boat. Using my usual technique of starting "cheap & dirty", and improving quality as I can afford it, I am using a good quality MiniDisc deck as a 16-bit 44.1k external ADC, and feeding it to a SB Live! digital input.

But, as "calberga" mentions, there are well-known distortions produced by the SB Live! digital input due to the card's internal operation being fixed at 48kHz sampling rate.

I don't want to ditch the SB Live! - its versatile SoundFont based synth. and ordinary audio output are perfectly adequate for my dilettante activities.

But for serious audio restoration, the obvious first step is best quality transfer to the computer, so the SB Live!'s limitations become a concern.

The cheapest and most directed solution I have seen so far is the Roland USB digital 16-bit 44.1kHZ IO device - or looking ahead to upgrading the resolution of the external ADC, Roland's more upmarket 24-bit 96kHz USB audio IO component.

Does anyone know of the quality of these as digital IO devices, especially compared to the (not unexpected) basic quality of the SB Live! digital IO?

On the other hand, perhaps another question to ask is: how audible are the limitations of the SB Live!'s digital IO? Measurements are one thing - but a 70-80dB noise floor, while not impressive, may only have the effect of having to be more careful of input levels from an LP or 78 source. Specific artefacts due to the enforced 44.1>48>44.1kHz conversions might be another matter, but once again, how audible are these in an everyday context?

Any comments greatly appreciated.

Peter

**Beautman** · 05-01-2002, 10:17 AM

Re: Digital input to a sound card

I've used a Roland (UA-3 or UA-30, I forget which) both for recording to my PC from varous sources to work with Diamdoncut, and to do live-to-laptop recordings on location.

Quality is not on par with genuine pro equipment, but very satisfactory for the money, and I'd guess a meaningful improvement over an SB. For transcribing shellac, you probably won't benefit from anything better.

**quartet87** · 05-01-2002, 01:13 PM

Re: Digital input to a sound card

After installing DCArt and a Yamaha XG Gold card on my pc my m.o. was to copy vinyl flat to minidisc, the from minidisc to pc via optical cable, because the pc and the audio were in different rooms albeit only a few steps apart. The analog out of the sound card was connected to audio in the other room via long standard patch cables. Playing an unfiltered file copied this method in which the ultimate source was vinyl, through the same system I used to monitor the copying from that vinyl to md, usually yielded a great emphasis of high frequency vinyl chatter in the left channel which was barely noticeable while listening to the raw vinyl. However I detected little, if any, brightening of the music when compared to the raw vinyl. After purchasing another pc and placing it next to the audio and transferring the Yamaha card from the old pc to the new one I'm now able to go directly from vinyl to pc using the analog input of the card. However now I cannot discern any difference between the playback of the unfiltered file and the raw vinyl...even all the noise sounds the same. I relate all of that to say it seems to me that as far as restoration/enhancement of any analog recording goes, one just as well use a good quality analog connection from source to pc as opposed to a digital connection. Comments welcomed and thanks.

Danny Gilbert

**Craig Maier** · 05-01-2002, 07:24 PM

Re: Digital input to a sound card

Danny,

There are two possible problems with using the minidisc in the manner that you described. First, transfers to minidisc use lossy compression. That means that some of the signal is thrown out by the MD recorder. For restoration, the more signal that you have the better, so I think that it is preferrable to use a signal directly from a phono preamp into your soundcard. Wavefiles do not compress, so most of the signal will remain intact. Secondly, using exremely long patch cables may effect the "top end" of the audio spectrum due to the loading capacitance of the coaxial cables. This problem is theoretically possible, but I have not run into it since the olde tube days where equipment output impedances were quite high (50,000 Ohms).

**quartet87** · 05-03-2002, 01:29 PM

Re: Digital input to a sound card

Right you are Craig. I noticed the difference while transferring from md to pc. I monitored the playback of the md from the analog out of the deck while the pc was recording it from the same deck's optical out. As soon as was recording was done and the file saved, I would play the file back thru the same speakers and the sound was noticeably (to me anyway) softer as opposed to just hearing it from the md's line out. Still, the unfiltered file was noticeably brighter than the raw vinyl. I attribute that to the md codex. However at the time that was the only method available, being that direct from phono to pc was logistically impossible. My new setup with the new pc is more ideal...going directly from vinyl or tape to pc. It just appears to me that using an a/d converter for transferring analog audio to pc is overkill, provided that one has a good quality analog input system on one's pc. Thanks!

Danny Gilbert

**Peter Allen** · 05-07-2002, 10:52 PM

Re: Digital input to a sound card

Just a couple of comments.

1. An MD recorder with properly implemented compression codec plus decent analogue sections and AD/DA decoders should not give a significantly brightened sound, whatever the source. I don't understand why this would happen when you record from MD to HD. Any differences you hear from the MD output should theoretically be no more than the audible differences between CD players, which are caused by the audio design.

As I have said elsewhere, the potential problem with HD recording from MD lies not in the use of MD per se,but what happens if you start processing that HD file significantly, through, eg, noise reduction. If you just use the MD as a transfer medium to make a CD-R copy on the computer there is no problem.

2. Good luck to you if the analogue input on your computer gives perfect results. You are quite right to say that an external ADC is unnecessary in those circumstances.

However, not all of us are that lucky or confident. In general, all else being equal, digital inputs on good quality sound cards (such as the Yamaha) should give the same or better results than analogue inputs.

The computer is an inherently hostile environment for analogue signals, and the analogue connection from HiFi to PC brings in yet another possibility of interference and earth loop hum pickup.

Garbage in = garbage out, and generally the quicker you can get your analogue source signal to digital the better. After all it's going to end up digital on the hard disk whatever method is used.

In fact noise is a lot harder to control these days in hi fi. Whereas earlier systems were all analogue and units all in one place, these days the modern audio system might incorporate digital audio components, HF analogue video VCRs, DVD, cable TV and digital TV broadcast set-top boxes, AV multichannel amps etc etc.

Sometimes I wonder that any of it works at all! However in terms of vinyl or 78 transfer, it is necesssary to keep the SNRs involved in perspective. Working with those media is a different kettle of fish than realizing the 96dB dynamic range of CD/MD, let alone the 120dB range of newer audio formats (what's the background noise level in your listening room anyway?).

Cheers,
Peter

**quartet87** · 05-10-2002, 04:47 PM

Re: Digital input to a sound card

Thanks for your comments, Peter.

I have always noticed an ever so slight brightening by minidisc (at least I think I do), especially when I have taken the time to confirm that with an a/b test. My suspicions were confirmed later when reading that the "pro's" then preferred DAT over MD due to the MD lossy compression. However for my broadcast use the MD was a huge leap from higher end cassette...after all it was just for FM...so it's good 'nuff. This was about seven years ago.

After the new pc was set up and the Yamaha card installed, enabling me to go directly from vinyl to pc, my ears presented me with a little gift in that I couldn't discern any difference between the raw vinyl and the unfiltered file. I have no reason not to trust my ears still, even though they are 47 years old. So I figure if I can't hear any difference, for all practical purposes the sound card's analog input is just fine. I was particularly pleased earlier this week when I treated a cut from a mint RCA Living Stereo lp. It was a gospel quartet with piano and a little bit of accoustic guitar. I ran INF preset first pass vinyl HQ, then Blender anti ping-pong, then VVA harmonic Sweet spot, then CNR with high threshold on the high end at 10db attenuation, then high pass rumble filter. The result was sweet...quiet, transparent, warm with natural sibilance. DCArt is just too cool!

As for my listening room conditions...far from ideal. I use headphones for previewing INF and a few other filters and CNR general settings. For tweaking CNR settings I monitor from the speakers...although I wait for the air conditioning to shut off. How's that for your typical home sound lab? (grin)

Anyway, my vinyl to sound card analog-in yielded excellent results. But after a year's ownership of DCArt, I'm still learning how to use it and I love it.

-Danny Gilbert

**Peter Allen** · 05-15-2002, 09:48 PM

Re: Digital input to a sound card

I don't doubt your ears, Danny! Mine are two years older than yours, and battered enough.

Do you notice the brightness on MD generally, or is that your experience with 7 year old equipment (not sure if I understood you right)?

My experience is with a Sony ATRAC 3.5 home hifi deck bought some years ago and still in use.

In testing after purchase, I copied a selection of testing CD tracks (via analogue and digital connections) and compared the analogue outputs of the CD and MD players. The MD copy sounded slightly dulled and muddled (this is in super-critical "never mind the music, have I bought a lemon" listening mode). Whether the copy was analogue or digital did not matter.

Then to evaluate one of the variables, I also listened to the source CDs directly via digital through the MD's analogue output. The original CDs now also sounded slightly dulled and muddled compared to their sound heard through the CD player's DAC and analogue output stage.

My conclusion was that basically the MD player's ADC conversion and ATRAC codec were contributing very little distortion to the sound RECORDED on the MD, although the MD player's analogue output stage was slightly inferior to that of my CD player. As far as this thread is concerned, that confirmed the MD deck had good potential as an outboard ADC.

To put it in perspective, I have heard much bigger sound differences between different CD players at the same price level.

I had to pay my pro/high-end-home retailer (in both senses). He had said he could sell me a higher model Sony MD which would sound better for another $200, more than I could afford, but a recording made on the cheaper machine would sound just as good played back on the more expensive machine. In other words, in terms of archiving quality I wasn't losing anything (this is before CD-R). My listening tests confirmed that.

I always find the operation of markets and timing intriguing with regard to technology takeup. When I first bought my MD, the retailer told me that, in Australia, MD was hugely popular in radio stations because of its combination of quality and convenience, whereas the general public had not taken to it as in Japan. Now they tell me a large part of the Australian market for MD is for mono 4s recording of lecture notes (shades of the beginnings of cassette as a dictation machine)!

Regards,
Peter

**quartet87** · 05-16-2002, 01:41 PM

Re: Digital input to a sound card

Up until about a year ago the only MD deck I ever owned was one of the early Sony models. This one has optical in and out, however being one the earlier models it doesn't have the sampling rate converter to make it possible to input a rate higher than 44.1...my sound card's optical out rate is locked at 48...hence I never could make a digital transfer from pc to MD. Going from MD to pc optically was no problem. After buying DCArt I purchased another MD deck used thru Ebay. I can't recall the model number but it's one of Sony's budget decks...minimal display, no optical out, etc. So I'm using far from state-of-the-art MD technology. I know that was part of the problem. I did intend to upgrade my MD capabilities after buying the new pc, by placing an order for a Sony MDS-JB940 with a Florida online store who had priced it to for $289 plus shipping. Looking at the specs of the 940 I figured the performance, for all intense purposes, was as good as it gets and should take care any transfer shortcomings I had been experiencing. However after waiting 45 days for the seller to receive a shipment and not getting it, and trying the analog input of the sound card, I decided I didn't need a machine like the 940 and cancelled the order. Right now I'm content with the younger budget deck, especially since I can make a digital transfer to it from pc. Although playback from it produces a slightly brighter sound from the wav, it's good enough for broadcast use, being basically a temporary media until I gather up enough filtered cuts to fill a cd.

My current setup, enabling direct vinyl to pc transfer, I believe has yielded a huge improvement in my restoration results, not to mention now having the pc in the same room with the sound system. Finally I am getting the rich and quiet sound I could hear in my mind's ear, for the most part. As my dad used to say, I'm as happy as if I had good sense.

Have a good one,
Danny Gilbert