Optimal length for digital cables: 1m or 1.5m?


I am debating the purchase of a 1m (RCA connector) NordOst Valhalla and the 1.5m version between the DAC and the preamp. Whilst it may be safer to acquire the longer version, the price difference alone can probably be better used for other improvements.

Some suggested 1.5m is the optimal length so I hope for those elaborating on their findings and if someone had the chance to A/B 1m vs 1.5m of the same digital cable (it doesn't have to be NordOst Valhalla) that would be utmost helpful.

(Sorry if this question has been posted before but I couldnt find entries with a direct comparison between 1m and 1.5m of a digital cable.)
polyglot
If I may ask you a similar question but for the analogue signal xfer: assuming that there is no impedance mismatch between the preamp and power amp, how short can a RCA interconnect be?
If the goal is to minimize the sonic effects of an analog cable, the shorter the better. That may not always be subjectively preferable, though.

The technical factors that are involved in digital signal transmission, and in analog transmission at audio frequencies, are very different. The result being that length considerations for the two kinds of cables are also very different.

I should add, btw, that if a very short length is practical for a digital cable, such as 6 to 8 inches or so, that would often be a good choice. It is the intermediate lengths, that are significantly longer than that but significantly shorter than 1.5 meters, which stand the greatest chance of not being optimal.

Regards,
-- Al
if a very short length is practical for a digital cable, such as 6 to 8 inches or so, that would often be a good choice.
That's interesting info!
Thanks
There in NO one ideal cable lenght. The 'ideal' lenght will depend on the following parameters:

- cable design (with the speed at which the signal travels through the cable beeing the determining factor)
- sampling ratę of the signal beeing sent (there will bedifferent 'ideal' cable lenght for 44.1 and 192kHz files)
- rise time of the digital signal (your transport)

As you can see, even a cable designer have no control over point 2 and 3.