I think that to use the term "synergy" properly, it should be distinguished from issues of "compatibility." Compatibility involves factors which are generally much less subtle than the ones to which I would apply "synergy," and can generally be assessed via specifications (assuming meaningful specs are available).
So a preamp with high output impedance, working into a power amp with unusually low input impedance, would represent an incompatibility. So would a situation where both components have extremely high gain or sensitivity, or where both have extremely low gain or sensitivity (i.e., the volume control would wind up being used only at the very bottom or very top of its range).
System synergy, on the other hand, involves more subtle sonic effects, which generally cannot be determined from specifications, and which often (but certainly not always) cannot be explained technically. For instance, a system may have a tendency to glare or be harsh in the treble, or to handle sharp transients sloppily. That may, just to cite a hypothetical example, result from using a preamp and a source component with very wide bandwidth and an extended top end, that put a lot of high frequency energy into a power amp that can't handle it cleanly, perhaps because it uses lots of negative feedback resulting in transient intermodulation distortion.
There are innumerable other comparable kinds of sonic mismatches that can be envisioned technically, and a lot more that can be sensed sonically but aren't readily explainable technically. As was said above, using components from the same manufacturer can make it easier to avoid those kinds of bad combinations. But mixing and matching, based on listening evaluations, reading reviews, and following the experiences of others, I think can often result in better sound due to the wider range of choices.
Regards,
-- Al
So a preamp with high output impedance, working into a power amp with unusually low input impedance, would represent an incompatibility. So would a situation where both components have extremely high gain or sensitivity, or where both have extremely low gain or sensitivity (i.e., the volume control would wind up being used only at the very bottom or very top of its range).
System synergy, on the other hand, involves more subtle sonic effects, which generally cannot be determined from specifications, and which often (but certainly not always) cannot be explained technically. For instance, a system may have a tendency to glare or be harsh in the treble, or to handle sharp transients sloppily. That may, just to cite a hypothetical example, result from using a preamp and a source component with very wide bandwidth and an extended top end, that put a lot of high frequency energy into a power amp that can't handle it cleanly, perhaps because it uses lots of negative feedback resulting in transient intermodulation distortion.
There are innumerable other comparable kinds of sonic mismatches that can be envisioned technically, and a lot more that can be sensed sonically but aren't readily explainable technically. As was said above, using components from the same manufacturer can make it easier to avoid those kinds of bad combinations. But mixing and matching, based on listening evaluations, reading reviews, and following the experiences of others, I think can often result in better sound due to the wider range of choices.
Regards,
-- Al