hi there!
I got an old Pioneer PD8500 CD player that I use for disc spinning as a transport.
So there is an optical spdif out and a coax digital out, right now I’m using the optical.
Would it make sense to buy an expensive coax (200-400€ f.ex audioquest diamond…) or is that improvement vs optical (for that old player) just nuts?
Many thanks!
I think it would but prior to doing, I wanted to check if you are using a good optical cable? If not, please try Lifatec.
thanks hifimckinney - I’m using a standard optical with 2m lenght.
I have found that coax SPDIF sounds better than Toslink, at least in my experience. I have read that the cheap Toslink cables use low quality fiber that produces more dispersion in the signal and can result in more jitter - keep in mind that in a “proper” SPDIF implementation the DAC clock is driven by the source.
I would not recommend an expensive coax, but something of good quality yes. For example, try a BlueJeans coax.
I use a Cambridge CXC transport which I made a few mods to just for fun:
that’s cool! thanks Muguel! Indeed, an expensive cable makes no sense- if the laser unit of the cd player fails there will be no replacement…I’m looking now for a Mogami coax!
You can get a new inexpensive transport very easily right now, you might want to consider this.
yes- I’ve seen some poppin’ up like Project, Cambridge, Audio Analogue and Nuprime CDT…guess CD’s are back 
Not true actually - the 650nm LED light used in typical TOSLink interfaces won’t experience any significant dispersion (modal, chromatic or otherwise) on a typical home-use length of glass or plastic TOSLink cable - certainly not enough to actually cause jitter on a CD/DVD PCM bitstream. This is all easily measurable of course.
However, TOSLink interfaces are typically much more jitter prone because of the poorly spec’ed transceiver chips used in transmitters and receivers - Jitter is caused during media conversion on-chip.
IIRC, dCS uses pretty well spec’ed Japanese made transceivers chips with very low jitter. That, coupled with the synchronous buffer, reduces the difference with the coax SPDIF on DAC (compared to other DACs).
Still, the coax SPDIF interfaces on most transport will generally perform better all round anyway, so definitely work a try @T38.45
ok, just ordered audioquest carbon coax- so I’ll give it a try!
Ok, understood. Thank you for this insight, makes sense.
Even if dCS’s is great, wouldn’t the transmitter implementation create its own jitter then? Surely it would be less than if both ends are jittery.
I have one of those and it is good. However, I found the BlueJeans in my setup (Cambridge CXC to Rossini) to be slightly better sounding IMSTME (In My System To My Ears… )
Thanks Miguel, but Bluejeans cables are here not available (Germany). My fav were AudioNote and Oyjade but both cost more
Yup, it would. 
