I've never listened to a pure triode designed amp so this is definitely a FWIW.
I have three amps were you can select triode/ultralinear on the fly. One, (a Cary) in triode sound much the same as two other's in ultralinear. In ultralinear it becomes slightly hard. All have low negative feed back.
With the speakers (3 different pairs)I have used with these three amps, best described as relatively neutral 3 way cone designs with a gentle impedence curve, unltralinear produces what I consider natural and 'linear'. When put into triode the mid-range power seems to deminish and the center sound stage recesses. A very relaxed sound but on a lot of music it sounds a bit thin.
I suspect triode might be a mode that would sound best used with more aggressive speakers (no shortage of those in the high end).
I do like to use triode for background music however. Apart from it being 'relaxed' at about half power the tubes and amp run cooler and I suspect last a lot longer.
I have three amps were you can select triode/ultralinear on the fly. One, (a Cary) in triode sound much the same as two other's in ultralinear. In ultralinear it becomes slightly hard. All have low negative feed back.
With the speakers (3 different pairs)I have used with these three amps, best described as relatively neutral 3 way cone designs with a gentle impedence curve, unltralinear produces what I consider natural and 'linear'. When put into triode the mid-range power seems to deminish and the center sound stage recesses. A very relaxed sound but on a lot of music it sounds a bit thin.
I suspect triode might be a mode that would sound best used with more aggressive speakers (no shortage of those in the high end).
I do like to use triode for background music however. Apart from it being 'relaxed' at about half power the tubes and amp run cooler and I suspect last a lot longer.