More transparent cables will reveal input or output tube changes even more so than veiled over cables. The same in reverse with more transparent tubes vs. more veiled over tubes when comparing - both matter.
As an experiment I recently custom ordered a lower cost $95 mainstream Mogami W2534 Quad RCA cable pair with Neutrik and Amphenol connector ends.
- With these cables, reportedly "neutral", and nothing exceptional about the design, decent copper used and decent connector ends used. To begin with I’m not hearing extra texture or tone with tube changes. So, if its "not there" to begin with, it’s questionable.
- With my higher end Cardas interconnect cables, any tube changes, input or output, I simply hear a differences in changes, more.
In summary, I’ve concluded more than 20+ times over decades that better cables and more transparent tubes allow you to hear other changes upstream or downstream even more. With that said, fine tune tone, texture, and soundstage from there on both sides +/-, in small increments is one way to approach it.
Back to the old "everything matters" reference. There is an interdependency with both, imo.

