The first upsampling CD player?

I once had the so-called first CD player using upsampling, the Gryphon CDP 1.

My question to someone like Paul or Ted, but also others if they know from DAC history: Is it true that the Gryphon was first…and if so, why Gryphon? I remember other companies at the digital forefront of that era.

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Gryphon’s site mentions “In 1998, The Gryphon CDP-1 CD player introduced the world to the sonic improvements offered by 88.2 kHz asynchronous sample rate conversion, the world’s first implementation of this advanced technology, now ubiquitous in digital audio.”

The PCM1704K upsampling chip came out in 1998 (I think, at least there are datasheets from then). Theta and Wadia used it in their players then. SimAudio a little later.

Tho it might be a matter of semantics, asynchronous upsampling is different from upsampling the way I think you mean it. The PCM1704K did 8x oversampling with a 96k input which is probably more like what you were talking about.

At WaveFrame (where I met Gus) we were using sigma delta converters from Crystal Semiconductor which upsample in digital audio workstation products in '87 - '88. We also offered asynchronous sample rate conversion to go from 44100 to 44055.9 and vice versa then too.

I’m sure there were a lot of others in that same timeframe.


Thanks much Ted! Unfortunately without considerable googling, I still don’t get differences between various kinds of upsampling. I thought there’s just one kind of upsampling. I could imagine, that in some professional applications, it might have been introduced much earlier, but the communication for this player implied, that it was the first commercial playback device for the end customer, using, what later was further improved.

I wasn’t very deep in design details at the time and just later realized the advertising for it. Couldn’t believe that Gryphon was so early with such developments, I reckoned brands like Wadia or Theta, you mentioned, should have been there already.

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In synchronous sample rate conversion the input and output clocks are synchonized, e.g. small multiple or divisors of each other - for consumer CD players there has to be some sort of PLL, etc. to generate the output clock from the input clock.

In asynchronous sample rate conversion the input and output clocks are independent. In consumer devices the DAC can be running with it’s own clock (perhaps at the same nominal clock rate as the input.) To not drop or repeat samples the sample rate converter needs to, in essence, do a digital reconstruction of the input signal and then resample that for the output. The advantage is that incoming jitter doesn’t affect the DAC’s clock. The disadvantage is that incoming jitter is irreparably imprinted in the audio data. Jitter on the input has a different sound when processed asynchronously than when it directly affects the output clock.

Asynchronous upsampling requires more hardware to get right and hence was a later development in chips. Synchronous upsampling was there from the beginning in some CD players (tho most people don’t realize it.)

Gryphon’s marketing is bragging that they were the first with a new (at least to consumer audio) kind of upsampling, not that they were the first players with upsampling. I don’t know if they are correct about that or not.


Thanks again! Then it’s anyway interesting that they and not the typical leading companies of the time introduced it to consumer audio…

My first CD player in 1986 was a Philips CD160, which boasted 4x oversampling. It was their first with a 16 bit DAC. They used the same 4x oversampling with their previous 14 bit models, because oversampling was supposed to give a greater effective bit depth. I have never quite understood this, Let me be honest, I have never understood this AT ALL,


I had the CD150 14Bit/176.4kHz machine in High School. Couldn’t afford the just announced 16bit version :slightly_smiling_face:. It served me well for about 6 years then the mechanism started to act up and that was it !


The CD160 served me flawlessly for over 20 years. Then we moved house and I no longer had space for separates. It lives in the attic now.

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My first up sampling cd player was a Sony CDP 979
with 8x oversampling 45 bit dual burr brown 56 dacs .

Not bad for it’s time…