Bach Brass Trumpet Valve Guide Set

The celebrated vintage Bach Strads all had brass valve guides making them more open and resonant. It is interesting to see that the Artisan series is trying to recreate this sound by offering two sets of valve guides; one plastic and the other brass. Fitting them to my LR 180 ML 43 S has subtly opened the instrument up and, in my opinion, changed the tone for the better. However, it may not be to everyone's taste but it works for me. The only problem is that they make the valves slightly noisier.