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Rediscovery of sound quality on SONY PCM-1630


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I'm afraid that not so many computeraudiophiles might know SONY PCM-1630 digital audio processor.

Some audiences those who have long carriers in professional audio industry must be familiar with the machine.

 

I'm just a DIY digital audiophile whose major interest is on a modern delta-sigma dac technology.

I bought SONY PCM-1630 digital audio processor at a vintage audio pro shop in Tokyo.

The reason why I was interested in the device was that a DAC function in it might provides a kind of permanent benchmark for sound quality of PCM 44.1kHz/16 bit.

(You can find some descriptions on this type of PCM processors here, https://www.wikiwand.com/en/PCM_adaptor)

 

PCM-1630 only accepts SDIF2 for DA when no U-matic video cassette tape recorder is connected.

In my case, SDTrans384, a DIY SD memory card player designed by Chiaki and distributed within a DIY audiophile community is used to generate a SDIF2 signal set.

Original output formats of the player are just I2S PCM (upto 384kHz/32bit) and Raw-DSD (Quad DSD). By modifing FPGA program, SDIF2 output for 44.1kHz/16,24 bit was obtained. An external ultra low phase noise OCXO of frequency, 45.1584 MHz, manufactured by NDK, Nihon Denpa Kyogyo, was connected to the SDTrans384.

The modified and enhanced player system is not a commercial one at all. It's a DIY grade.

 

Three signals, Word Sync(44.1kHz), CH1 & CH2 PCM serial digital signals are connected to PCM-1630 by 75 ohm co-axial cables.

PCM-1630.jpg

 

I got so impressed by the resurrected sound of PCM-1630 DAC.

 

I feel it has both a superior high-resolution and powerfullness & speed in all ranges.

Though the sound characterisc is all-purpose, it may not be the best one for classical music.

Anyway, I really recognized the importance of knowing achievement level once established in a professional music industry.

 

My next vintage targets are Sonoma DAW and Meitner DSD DAC. However, it might be very difficult to get those machines.

SDTrans384.jpg

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They sell Sonoma DSD Workstations with Meitner Converters to anyone who has a credit card ready! Prices start at around $16,000 for the 8 Track system. :)

 

Super Audio Center Home

 

Hi, Brian!

 

Thank you very much for the Sonoma/Mytek information.

Actually, is the price shown there not for a vintage set but for a new set?

 

The price for the vintage SONY PCM-1630 I got was only 500 USD.

Unfortunately, the price for the Sonoma/Mytek set is far beyond the range I can afford.

 

Furthermore, I am interested in an original product of Meitner DSD DAC rather than Mytek.

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Hi, Brian!

 

Thank you very much for the Sonoma/Mytek information.

Actually, is the price shown there not for a vintage set but for a new set?

 

The price for the vintage SONY PCM-1630 I got was only 500 USD.

Unfortunately, the price for the Sonoma/Mytek set is far beyond the range I can afford.

 

Furthermore, I am interested in an original product of Meitner DSD DAC rather than Mytek.

Super Audio Center will quote prices for a Meitner DSD converter (ADC) rather than Mytek if that is your preference.

 

You'd have to talk with Gus Skinas to see if they have any "vintage" Sonoma or Meitner equipment. The prices on the Super Audio Center web site are for new gear.

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Hi Bunpei, it's interesting that you're using the 1630 as a DAC. If you want to hear a 'true' PCM DAC, there are many options on the market. Haha... but if you want to hear a 'true' PCM ADC (analogue-to-digital converter), you're kind of out of luck. And this is where the 1630 remains really interesting for me.

 

If I could find a 1630 for only 500 USD, I'd snap it up. I'd love to try replacing its internal clock and filters to see if I could get a good sound out of it... as a 'true' PCM ADC.

 

Look after your 1630 - it's a piece of audio recording heritage, and a lot better than people give it credit for, IMHO.

 

Mani.

Main: SOtM sMS-200 -> Okto dac8PRO -> 6x Neurochrome 286 mono amps -> Tune Audio Anima horns + 2x Rotel RB-1590 amps -> 4 subs

Home Office: SOtM sMS-200 -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> Impulse H2 speakers

Vinyl: Technics SP10 / London (Decca) Reference -> Trafomatic Luna -> RME ADI-2 Pro

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... but if you want to hear a 'true' PCM ADC (analogue-to-digital converter), you're kind of out of luck. And this is where the 1630 remains really interesting for me.

 

If I could find a 1630 for only 500 USD, I'd snap it up. I'd love to try replacing its internal clock and filters to see if I could get a good sound out of it... as a 'true' PCM ADC.

 

Look after your 1630 - it's a piece of audio recording heritage, and a lot better than people give it credit for, IMHO.

 

It's very nice to read your comment!

 

For the first time, I also had the similar idea of replacing its internal master clock with a low phase noise OCXO. However, I found the frequency adopted is 14.3325 MHz for sampling rate, 44.1kHz (325 fs!) and discarded the idea.

[You can download an "Operation and Maintenance Manual" from here.https://www.manualslib.com/manual/452275/Sony-Pcm-1630.html The scanned document includes a complete section of both component listing and schematic.]

 

As I use the equipment only as an DAC, I have removed an AD board (it is credited as "Apogee" with a sticker of "Toshiba EMI" logo.)

Whenever I find the same type of equipment in a Japanese vintage professional audio shop, I will let you know.

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For the first time, I also had the similar idea of replacing its internal master clock with a low phase noise OCXO. However, I found the frequency adopted is 14.3325 MHz for sampling rate, 44.1kHz (325 fs!) and discarded the idea.

 

I'm certain good 14.3325 MHz oscillators are available. I'm not sure how easy it'd be to replace the current oscillator in the 1630 with one though. I'm not sure it'd even be worth it if you couldn't also work on the 1630's digital filter.

 

BTW, you'll hear some people claim that digital can be made to be totally transparent. They obviously haven't played around with digital filters - none are perfect in both the frequency and temporal domains simultaneously, and therefore digital cannot be totally transparent by definition...

 

I've owned and have lived with a whole bunch of ADCs now, and none are totally transparent to the original analogue feed. I have a suspicion that something like a 1630, with a properly sorted oscillator and filter, might come closer than any of the current delta-sigma offerings. Just a suspicion though...

 

Mani.

Main: SOtM sMS-200 -> Okto dac8PRO -> 6x Neurochrome 286 mono amps -> Tune Audio Anima horns + 2x Rotel RB-1590 amps -> 4 subs

Home Office: SOtM sMS-200 -> MOTU UltraLite-mk5 -> 6x Neurochrome 286 mono amps -> Impulse H2 speakers

Vinyl: Technics SP10 / London (Decca) Reference -> Trafomatic Luna -> RME ADI-2 Pro

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  • 8 months later...
On 11/21/2016 at 1:33 AM, Bunpei said:

... As I use the equipment only as an DAC, I have removed an AD board (it is credited as "Apogee" with a sticker of "Toshiba EMI" logo.) ...

 

Apogee made a well regarded range of aftermarket upgrades for the Sony 16x0 series.

"People hear what they see." - Doris Day

The forum would be a much better place if everyone were less convinced of how right they were.

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