18 replies to this topic

[Fury♫]

sean, on Apr 11 2009, 05:50 PM, said:

I'm lost now! I thought being one RCA from the CD700 it was still 'digital' (obviously I don't know enough about these things yet!)/

Pulse-R, thanks, I'll be in touch

It is still digital, it's just it's "electrical" not "optical".
The 1's and 0's are being sent as electrical pulses. If for some reason voltage comes on the line (interference), then it will send 1's down the line.
Optical cannot be interfered with by electrical signals as it is sending bursts of light down the cable.

[sean]

That makes more sense to me, thanks fury

[Pulse-R]

yes, it is digital sean.

BUT

S/PDIF has the data and clock both in the same signal, and if the encoder or decoder has a poor clock, then the signal will suffer compared to the transport having the DAC built-in.

a full digital audio signal has 3 signal lines - Master Clock (or Bit Clock), Word Clock (synchronises Left/Right channel data) and Data (obviously carries the data).

S/PDIF encodes all this information, as well as some other info, into a single bitstream. Convenient, but if the sending or receiving device has a poor clock, the data gets out of sync. and the data is corrupted.

also having a small effect is the quality of the cable (optical or coaxial).

As mentioned, the only way to get extremely accurate digital to analog is to have all 3 discreet signals connected so that all the data integrity and pico-second accurate timing is maintained.

[sean]

Thanks for that Pulse-R.

Pending the results of the DAC I might give digital a try!

I could have the DAC mounted next to the processor so the RCA lines are very short between them.

Whichever gives the best SQ I spose