First off, we need to know how much the TP contributes to the actual sound of the Bass. Then comparing two extremes like Ebony and Maple both the exact same size. Cocobolo as many of you know is used for Marimbas. I played behind a Marimba concerto last week and all the keys were Cocobolo.
I have been told the Ebony TPs are a 20th century thing. Out of all the older pre-1920 Basses I have acquired over the last 6 years, 5 out of 11 of them (half) had non-Ebony TPs on them. Some if not all may be original to the Bass. Most seem to be stained Maple but the
TP on my English Gilkes is heavy and might be
some other hardwood used in England 200 years ago. It looks to be original or at least from its 19th century restoration. Out of the 5 non-Ebony TPs, only two of them look to be original as 4-stringers and the Basses being my
Batchelder and
Martini were made as 4s as well. The Gilkes we are not sure about because during its c.1870s restoration & Cut it has
two holes plugged as if it may have been a 3-stringer earlier. My Cornerless Bass has a 3 turned 4 str. TP with
3 holes plugged and 4 new ones drilled. Some of the TPs have just plain holes in them about 3-4mm and no 'loop' like a modern TP with a narrow channel above a larger maybe 10mm hole. One 3-string TP has two holes added so it could even be used as a 5er but the Scroll is
barely long enough to hold 4 gears being a 3-stringer originally.
That being said, and sorry for the rant, I NEVER change a TP that comes on the Bass unless it's broken or just plain garbage. I did get one composite one in on my Bisiach labeled Bass and put an old Ebony one on that came off my Loveri. The Loveri got a fancy carved Indian ebony one that I bought for another Bass but was too small and was perfect for the Loveri. Also, I believe the size of the TP may matter on the Bass so if too small or too big. I might change it if I think it will help but thinking of doing it and doing it are two different things. Once the Bass is strung up and working, I usually don't mess with it.
I put a
Cocobolo Pecanic TP on my 5er because it was converted from a 4.
Switching TPs back and forth with fresh strings is the only real way to tell if it makes much of a difference. Adding a Bow quiver to your Bass may alter the sound just as much if not more than changing TPs. Also, the compensating TP can possibly have a greater effect than wood differences unless the woods are drastically different. If the Bass is not overly responsive to slight changes then the differences might be less. Basses with better acoustical properties, might show the changes more.
Then again, I just might be wasting a whole bunch of cyber ink here rather than doing something more constructive with my time..lol
What was the question again?
