TubaForum.net

https://ebay.com/itm/133923948843

(bell sold seperately.. but also listed by the same seller)

By definition, the 38K had 3 conventional valves and the 40K had 4 conventional valves. This is wayyy before the invention of the short-throw valves of the 20K. BUT...compare the picture in the listing with this picture of a 40K in the Conn Loyalist souzy pages:

https://cderksen.home.xs4all.nl/Conn40K1923image.html

Notice that even with the differences in the picture angles, the main tuning slide may be shorter in the ebay listing, which may mean the high pitch version - 41K. With that in mind, this bugle and valve block appear to have 4 valves, but shorter tuning slides, so I would surmise with the appearance of the size of the bell tenon that this is the remains of a 41K.

https://cderksen.home.xs4all.nl/ConnSousaModels.html

Thanks! I was meaning to ask the high/low pitch question, and was too lazy to review the model numbers.

I've only encountered these that (if shorter) were only "somewhat" shorter.
The extreme tilt of the lower mouthpipe (during that era - along with the subtle additional tilt of the valveset - to accommodate the 4th circuit) is (a favorite word, here: ergonomically) THREE-tuning-bits-friendly anyway, which seems to do the trick.

Otherwise, those two sides/two sizes of main-slide slide tubes (even the vintage thicker-walled ones) are not rarities (as many can be found in drawers/boxes/piles of junk parts), and installing longer ones (to reduce the necessary pull for 440 or 442) doesn't create an odd appearance.

summary:
I wouldn't worry too much about whether one of these seems to be the (??) A=445ish version or the A=438ish version.
I would just (if/when buying from a picture) probably pray to the not-too-worn-valves gods.

bloke wrote: ↑Sun Nov 14, 2021 5:33 pmSummary:
I wouldn't worry too much about whether one of these seems to be the (??) A=445ish version or the A=438ish version.
I would just (if/when buying from a picture) probably pray to the not-too-worn-valves gods.

Indeed. Bloke answered the second question yet to be asked after I answered the first question. If it is the high-pitched version, you may have enough length in the main tuning slide to pull down to pitch, or use a third bit. If not, it is a rather straightforward matter to put longer inner tubes on the main tuning slide bow.