Conversion of Analog Input to Optical Digital Output through Sony MD Decks

[jmsla]

Hi All,

I am seeking any opinions or comments on the quality of the optical digital output from different Sony MD decks upon converting an analog input signal.

I am currently putting many of my old cassette tapes and vinyl LPs onto minidisc in SP by recording in real-time using the optical input on a portable unit. I am first passing the source analog playback signal through either a Sony JE-520 deck or a Phillips DVD Player / Recorder that has an optical output.

I occasionally perform an A-B test with the same source material and sometimes notice a slight but discernable difference in the quality of the optical output signal from the two different machines. The difference in quality I hear is in the form of what I'll call 'presence' or 'dimension'.

It often depends on the source material i.e., a cassette tape that contains a live recording versus a cassette tape that contains a recorded vinyl LP. Some vinyl LPs sound slightly different as well.

*I should also mention that I do not play my components through a stereo amp/pre-amp setup, so there is no eq coloration or other manipulation of the input signal to factor in.

I will appreciate any opinions, comments, suggestions on this issue as I would like to get the best consistant result within reasonable cost limits. Most likely any used MD deck would be within my budget for example. And I would like to keep this process as simple and straight forward as possible.

Thanks In Advance and

Cheers,

JMSLA -Jim

*I use a 'source controler' for my components. It receives input signals via four sets of 1/4" stereo input jacks and has several output jacks that all recieve the same selected input source. There is only an attenuation control at each of the four inputs and a main output volume control. My speakers are Alesis 620 M-1 Active, which have some eq controls on the back if needed.

[sfbp]

Jim - just a quick question if you don't mind? Why would you prefer the optical input on a portable to that on a deck, given that you want SP recordings?

I would have thought the 520 (analog in to SP recorded) is the best choice, unless it's busted

Stephen

[jmsla]

Hi Stephen,

If I understand you question properly...I'm using the JE-520 MD deck as a 'pass through' device to convert the analog signal, (from the cassette player or turntable), to optical because it has an 'optical out' jack. So, I have only portables to receive the optical input and make the recording.

I am doing this on the observation, (assumption), that a better sounding recording results if the recorder, (portable or deck), is receiving an optical digital signal rather than an analog signal. Is that not correct?

I understand, I think, that any MD recorder will be converting an analog input signal to digital as part of the recording process but, I thought that the 'analog to digital' converter on a deck would possibly be better that that on a portable.

-J

Jim - just a quick question if you don't mind? Why would you prefer the optical input on a portable to that on a deck, given that you want SP recordings?

I would have thought the 520 (analog in to SP recorded) is the best choice, unless it's busted

Stephen

[sfbp]

Hi Stephen,

If I understand you question properly...I'm using the JE-520 MD deck as a 'pass through' device to convert the analog signal, (from the cassette player or turntable), to optical because it has an 'optical out' jack. So, I have only portables to receive the optical input and make the recording.

I am doing this on the observation, (assumption), that a better sounding recording results if the recorder, (portable or deck), is receiving an optical digital signal rather than an analog signal. Is that not correct?

I understand, I think, that any MD recorder will be converting an analog input signal to digital as part of the recording process but, I thought that the 'analog to digital' converter on a deck would possibly be better that that on a portable.

-J

What I do not understand is: why not use the 520 itself to do the recording? You prefaced all this by saying you wanted to record at SP data rates.

Stephen

[jmsla]

Well, having done some A-B comparisons between recordings in SP from an analog signal versus an analog signal first converted to optical digital, I often hear a better result from the recording made with the signal first converted to optical. This deck is the only device I have that can convert and output an optical signal (other than my DVD recorder)

Are you suggesting that when recording in SP it does not matter if the input signal is analog or digital? I'm quite certain I hear a difference. I'll play and record a cassette tape or LP directly on the 520 through its analog inputs and on another MD recorder with the optical output from the 520 and compare again.

If I'm correct that the converted optical signal yields a better sounding recording in SP, then I'm interested in finding a deck or other device that may have a higher quality digital-analog converter. The 520 is a rather old deck after all.

What I do not understand is: why not use the 520 itself to do the recording? You prefaced all this by saying you wanted to record at SP data rates.

Stephen

[sfbp]

My assumption is (possibly faulty) that the 520 adequately encodes to digital, and therefore is a good place to record the signal. I don't think that ONLY using the 520 as an A->D device would have advantages over simply recording what it digitises.

Remember this deck was just before MDLP was introduced, so probably SP encoding didn't get a whole lot better (although I dare say some of the higher end decks from about the same time may beat it in certain areas, and I can not be sure whether it's the A->D or the subsequent ATRAC recording on disk which would be different).

It's true that it is NOT Type-R, which should be better at compression. If that's the difference then I stand corrected. But I don't think it's anything to do with inherently using a given machine to encode "from analog" or "from digital" as by the time it encodes it will have been digitised by the same circuit you are using when you simply pass through the signal in A->D mode.

Off the top I would expect a device designed purely to record and encode SP might be better than a portable (which perforce has a smaller chip count and less stable power supply than a deck) that has to double duty at recording SP and other bit rates. But I cannot honestly claim any real knowledge as to which components affect what. The SNR for some of the 9xx series decks are better by a few dB. The only one to beat it by a mile is the semi-pro range such as JA333ES which claims 106dB (over 96 for the 520). The JA20ES and JA50ES have high values too, I hasten to add. Whether this difference in SNR is a valid indicator of better recordings, or audiophile bragging rights, I am not sure.

However I WOULD definitely expect what you are doing to produce better recordings than analog line to the portable. But that's not a fair comparison, IMHO.

Stephen

[jmsla]

Stephen,

Well, I had the chance to re-record a cassette tape to MD SP directly on the 520 deck w/ analog input. The tape contains a very clean recording of a well kept vinyl LP recorded for me many years ago by a musician friend. The album is no longer available in any form.

So far I can report that the MD recording made on the deck is equally as good if not a little better than the MD I recorded in SP on a Hi-MD portable (NH 900) with a converted optical input. I think your assessment of the limitations of the portables is spot on.. I'll try some other less pristine cassettes such as live recordings from the 70's early 80's and some LPs and report back. Now I'm wondering if I would hear improvement if I input an optical signal to the MD deckle. I can easily try that as I have a DVD machine with optical out.

You know your subject for certain. Now my query changes to opinions about a better deck. My 520 is a bit quirky...there seems to be a problem with the analog RCA input jacks; one or the other will spontaneously cut out occationally...a real pain.

Thanks for the guidance.

Peace,

-James

[sfbp]

Just a couple of observations:

1. Don't necessarily trust your average random DVD player to give you good output.

2. The 520 is the base unit for the amazing MDS-W1 which is praised to the skies by audiophile philippeb. Check out that other thread, maybe you would be interested?

3. I really like the next generation after the 520 which is the 440/640/940 range, and all record in MDLP as well as SP. I have the 640. But my 630 (SP only) has done sterling service for a few years recording from vinyl (admittedly I use the analog output of my 1996 kenwood because it has the only decent phono preamp in the house). The 630 and 640 are both Type-R, which is as-good-as-it-gets IMO. Sure the fancy ones may be slightly better, but for what you and I want, I think these 6xx models are plenty good enough.

Maybe you can fix the jacks with contact cleaner.... I dunno.

Stephen

[jmsla]

Thanks for those suggested decks. They also happen to be the ones that allow TOC cloning.

I'll try cleaning the RCA input jacks on my 520 and see if that corrects my 'cutting out' problem. RCA jacks can be difficult to clean because of the tiny hole in the middle. I think that is where my contact problem is.

btw-The link you provided takes me to a recent post about MiniDisc Lifespan started by Zahne. Is that the correct thread?

-ja

[sfbp]

The link you provided takes me to a recent post about MiniDisc Lifespan started by Zahne. Is that the correct thread?

Yes, and for some reason it has been stubbornly refusing to show up in "View New Content".

[jmsla]

Ok...I see the relevant discussion now. Tthat will be and interesting read.

thanks