will
|
If you are meaning how do tubes modify the sound in using the term modulation, tubes can be used for rectification, for filtering the power, and for "buffering" and amplifying the signal. And in a transparent circuit and resolving system, you can hear them all, so all influence your musical experience.
Seems what most people like about tubes is the smooth and liquid and spacious influences on a harmonically alive sound. The power or signal going through the vacuum imparts tube sound qualities, and this is influenced by the design, construction, materials, shape... all causing sonic variations with the same tube type within a baseline of the more-or-less the same electronic objectives. This is where tube rolling comes in, by exploring different loved tubes, you can adjust your sound to tastes.
With the Zstage, this is one tube only, but you can use two basic tube types, designed for 12AU7, and a more powered up 12AT7, offering pretty different sound qualities. And there are many tube type variations on those types.
So considering that about all tubes within a type have their own characteristic sound... if you want to explore adjusting for your preferences based on system and taste needs... there are lots of sometimes subtle and sometimes less subtle but useful variations to play with. Within one type... variations from being more bass balanced, neutral, or leaner and extra clean... transparency and extension... how well they delineate finer information like "air," textures, decays or how consolidated and focussed the signal is... dynamics vary... and so on....
Along with these potential tuning tools you have a switch that changes the bias of the tube used to be fuller and more intense at what the tube does, or more open and relaxed. So with only one tube in the Zstage, you can stick with stock, or play quite a lot for personal tuning. ...
If you mean which upgrades on the ZStage, they all will help in my opinion, but if you want to get the most you can for less money, I would imagine getting the copper coupling caps and copper bypass caps first might be most influential... Followed by the tube filters, and that followed by the stepped attenuator.
Hope this helps some,
Will
|