Digital cable length- SPDIF vs AES/EBU- 1.5 meter for either?

I got a 50 feet AES cable run (using 4 out of 8 channels), it’s freaking perfection, it's the best audio interface by miles until wireless Dante becomes more available.

Pro audio equipment rocks. (Only downside is I’m still selling off my high end audiophile equipments to this day...)

Thank you and indeed it seems reasonable as a minimum length.

I remember the original threads and article claiming this and had bounced it off a very sharp engineer friend of mine at the time and several others. In short, I don't believe it is true; there are more than a few high-quality SPDIF and AES cables on the market which test out perfectly at 1.0 meter.

It depends on the transition time.  1m might be perfectly fine with transports that has 15ns transition times.  In addition, reflections appear only on impedance boundaries.  With a perfect match (rare) there will be no reflections.  Very short cables, under a foot, will also work fine.  Rule of >1.5m is just for general case of typical transport.

Jitter is basically an added noise. Music free of noise might sound clinical and sterile at first. One person even posted, after listening to jitter supressing DAC, that he preferred all instruments "together" (sound blob) instead of hearing individual instruments.  Also, music with added noise can sound more dynamic - like distorted guitar vs clean Jazz guitar.  I believe that jitter destroys everything, but we tolerate it since we got used to it.