XB-40 maintenance
Hi Winslow,
I have enjoyed reading posts on different sites regarding your respect for the XB-40. I too share my appreciation and its the main diatonic I play.
I picked up a few extra used ones recently and was able to compare two XB-40's in the same key side by side, and noticed that one of them was less air tight, and the some of the X-Reeds weren't responding as well (and in one case - not responding).
Thought maybe it was a valve problem, or that the plates weren't screwed on tight enough, so I took it the culprit apart and inspected the valves and tightened up the plates etc. It helped a little, but still seems leaky and not responding as well in general as the other one, and one or maybe two xreeds don't seem to be responding at all.
Is this a valve problem? Or perhaps the reeds need gapping? Or embossing?
When I inspected the valves, they all looked OK. I mean that in the sense that there were none of them curling up, and they all covered the slots. Can they look OK, but in actuality they aren't doing their job properly? Maybe they are just getting old, and need replacement, even though they look fine?
Thanks for your advice Winslow!
ps - I have a sub-30 customization kit coming from BlueMoon harmonicas (includes a new comb and new external valve plate) that is supposed to solve the sub-30s sub performance. Will be interesting. I might need to learn how to emboss and gap the reeds properly on the sub30 to optimize its performance, as the custom kit may not be enough to make the sub30 sing. Right now I prefer the XB-40, but am hoping that the sub30 can come alive (upside - still making them!).
Thank you for your advice Winslow. I will definitly take a more thorough look. This will take me a deeper step into learning how to maintain this baby :)
Was interesting to see how the valves on the xb-40 are attahed to the comb, rather than the reed plate, as on my chromatics. Is this a unique design feature of the xb-40?
Yes, attaching the valves other than to the reedplates is to my knowledge a first on the XB. Rick tried many wild-looking experiments before arriving at this solution, which I consider to be the most elegant one, especially when you compare it to the extreme difficulty the X-reed guys are encounteing in trying to get their overvale plate concept to work in practice.
It's tough to diagnose the problem you're experiencing without inspecting the instrument.
If the respsonder reeds (X-Reed is a term unique to Brendan's line of harps and the actual name of his company) sound normally when plucked and are gapped within the normal range of such reed (not down inside the slot or riding high above it) then they're not likely the source of the problem.
Remember that there is a second set of valves hidden inside the comb and that you have to disassemble the top and bottom halves of the comb to get at them. A missing valve might drain air away.
Valves don't wear out, though they can get so clogged with gunk or twisted out of shape that they're best replaced. But in such cases the problem will be obvious due to buzzing, sticking, etc.
Reassembling the XB is trickier than most other harmonicas. You have to get the top and bottom havles of thecomb AND the mouthpiece all in alignment. And then you can still get the front edges of the reedplates propped up on a little step at the fornt of the comb, which introduces serious leakage. Examine that edge carefully to make sture that the reedplates aren't tilted up.
The comb might not be flat, but I haven't experienced that as a cause of serious leakage on an XB.