king 2341 leadpipe

[Donn]

perhaps that idea comes from my guitar/bass experience and what i've learned about bridges and nuts.

Yes, that's a pervasive problem in players' perceptions of the principles that prevail in the present premises. Strings make virtually no sound on their own, but rather drive things - a soundboard or pickup magnet - so it's critical to avoid energy loss between the string and the thing it's driving. A brass instrument is very different - tone is generated in a squishy mess of tissue, teeth and bones, interacting with the shape and length of the horn.

While that "gap" we're talking about may be nearly mythical, the principle is not - little steps in the horn profile near the mouthpiece are very much part of the shape of the horn. Where this matters for you - I don't really know anything about it, but it seems to me you'd do well to make sure tape goes all the way to the end of the shank, so when it's inserted into the receiver there isn't any air space around there.

[MikeW]

And now I'm confused.

I have collected figures for the tip diameter of mouthpieces from various TN posts, as follows:

• American 0.520" (according to the Bach MP manual, this should be .519)
• PT normal 0.530" (fits receivers on old Mirafone, new King) - Bloke's "P" size, Doug Elliot's "M" size.
• European 0.540" (sometimes quoted as 0.538")

According to this, the 0.530 mouthpiece size is midway between the European and American receiver sizes, and could fit both/either (with different seating depths).
The .530 receiver size would accept either the American or European mouthpiece size, but they would insert to different depths, producing different gaps (ok: end-of-MP-to-choke-point-dimensions)
I'm not clear that this agrees with the dimensions discussed in this thread. Should I be correcting my notes ?

[Matt Walters]

Mike W,
Don't worry about your notes or the way this discussion has turned. Don't worry about "Gap" versus any other term that describes the distance between the end of the mouthpiece shank and the beginning of the leadpipe.

Something happens to the response (beginning of the note) when you change the "whatever" just before the beginning of the leadpipe proper. Even sleeved pipes that go all the way out to the end have a smallest point from which the taper begins its flair towards the bell.
Wrap a little piece of paper around the shank of your mouthpiece and re-test play your tuba. If you are a sensitive enough player, you will feel and/or hear a difference.

Please keep in mind:
1) Some people can tell the difference in subtle tweaks to musical instruments and others can't.
2) Some musicians sound great regardless of equipment.
3) Some instrument players "sound like crap" no matter how nice or finely tweaked equipment they have.
4) Too many of the instrument players who "sound like crap" have no idea how bad they sound.
5) Most of us instrument players are somewhere in between... with a bias towards "sound like crap".

[Donn]

i.e. NO exposed REVERSE TAPER area whatsoever.

How would one go about doing this thing, that few have ever tried?

Just guessing at where the receiver is sleeved over the leadpipe, on my 1240, that would make the receiver about 2¼ inches deep. But it does seem, just probing around and exercising my imagination, that there might be a narrow point somewhat closer, I guess cut into the receiver itself as is done with trombones, maybe within practical reach of a mouthpiece shank. Is there a good way to locate that point, without special equipment?

Once I've found it, assuming my mouthpiece rests somewhat short of that point, I would have to take something off the shank taper to get in there.

I have collected figures for the tip diameter of mouthpieces from various TN posts, as follows:

• American 0.520" (according to the Bach MP manual, this should be .519)
• PT normal 0.530" (fits receivers on old Mirafone, new King) - Bloke's "P" size, Doug Elliot's "M" size.
• European 0.540" (sometimes quoted as 0.538")

I would keep looking until I found a list like

• Small .490
• American .520
• European .530
• Large European .550

I'm no expert, but this is the list that has been held up as a reference in the past.

[Dan Schultz]

Just guessing at where the receiver is sleeved over the leadpipe, on my 1240, that would make the receiver about 2¼ inches deep. ....

It's not quite that deep. Like I mentioned earlier.... get a dental pick and run it into the receiver until you feel a very slight scratch or line. It should be about 2" from the end of the receiver if you have a classic 1240/41 receiver like this one. At that point the mouthpiece taper stops getting smaller and the leadpipe starts getting larger.

This falls in line with what Bloke has said about there not really being a 'gap' except for the slight step at the small end of the mouthpiece.

[Donn]

It should be about 2" from the end of the receiver if you have a classic 1240/41 receiver like this one. At that point the mouthpiece taper stops getting smaller and the leadpipe starts getting larger.

This falls in line with what Bloke has said about there not really being a 'gap' except for the slight step at the small end of the mouthpiece.

Yes, but it doesn't really fall in line with the idea of getting the mouthpiece shank end down there. I'm happy to report that a bass trombone mouthpiece will seat around 1¾ inches, which is pretty close - but a Denis Wick "classic" small shank bottoms out on the cup body, and so I think would most tuba mouthpieces if trimmed down to the .470 or so that it would take to get all 2 inches in there.

However, I find that a ½ inch bit passes through the receiver with room to spare, so it would appear that even at 1¾ inches, that trombone shank end is probably past the narrowest point. I have a hunch that the receiver taper only goes so far, maybe not much more than the normal 1 inch insertion depth, and the rest of the way it's straight. Which I guess would mean, we're all wrong - there is no gap, and there is no choke point, in this particular receiver anyway. It would be particularly interesting to know how far the taper really goes in the newer receiver. I guess at .530 you'd only need another 3/16 inch to fully seat a standard shank?

[Dan Schultz]

.... Yes, but it doesn't really fall in line with the idea of getting the mouthpiece shank end down there. I'm happy to report that a bass trombone mouthpiece will seat around 1¾ inches, which is pretty close - but a Denis Wick "classic" small shank bottoms out on the cup body, and so I think would most tuba mouthpieces if trimmed down to the .470 or so that it would take to get all 2 inches in there....

Donn.... there is no 'choke point' in either the receiver image I posted earlier or the one that Conn/Selmer is selling as a replacement. That shank taper runs all the way to where the leadpipe begins.

And yes.... the ID of the end of the leadpipe on your King is (and should be) a bit greater than 1/2".

I measured the new style King receiver and the counterbore that the leadpipe to fits into is .574". The diameter at the bottom of the taper inside the receiver is .520". Most leadpipes have a wall thickness of about .020". Assuming the leadpipe just fits into that .574" counterbore and has a wall thickness of about .020", the ID of the small end of the leadpipe would be about .534"... or slightly larger than most tuba shanks. Basically, that means that your bass trombone shank would never 'bottom out' against anything except possibly the outside of the cup of the MP or any decorative bead that might be there.

Of course... this is all pure conjecture because we simply don't know what tolerances various manufacturers apply to their products.

That is precisely why things are designed as they are. This is all just an attempt to make sure everything will fit everything and doesn't give much consideration of how stuff performs.

The LAST think Conn/Selmer wants to hear is "your tubas suck because my favorite mouthpiece doesn't fit".

[Donn]

Donn.... there is no 'choke point' in either the receiver image I posted earlier or the one that Conn/Selmer is selling as a replacement. That shank taper runs all the way to where the leadpipe begins.

That means there is a choke point, no? The leadpipe is theoretically tapered per conical horn, so the two pieces have the opposite taper. If the tapers extend all the way to the joint, that's a narrow point.

And yes.... the ID of the end of the leadpipe on your King is (and should be) a bit greater than 1/2".

So the .490 shank that went in 1¾ inches has clearly passed the end of the taper, which must end before it gets down to .500 - maybe a little past the normal 1 inch insertion, but not much.

The receiver is 2½ inches long, so the leadpipe inserts well over 1 inch into the receiver? I don't have a dental pick, but with whatever I have on hand for a probe, I feel that joint where you said I would, about 2 inches in - over an inch past the end of the taper. That's why I'm saying, the taper doesn't go from one end of the receiver to the other - it couldn't, or I think it would end up around .468. It stops a little past 1 inch. If your surmise about the .534 leadpipe ID applies to mine as well, it would have to be counter-tapered from the less-than-.520 narrow ID to meet the leadpipe.

I measured the new style King receiver and the counterbore that the leadpipe to fits into is .574". The diameter at the bottom of the taper inside the receiver is .520". Most leadpipes have a wall thickness of about .020". Assuming the leadpipe just fits into that .574" counterbore and has a wall thickness of about .020", the ID of the small end of the leadpipe would be about .534"... or slightly larger than most tuba shanks.

Weird. So doesn't that mean that it's straight, past the taper? Yours must be .530 at about 1 inch, right? Morse taper from there would get to .520 in less than a quarter inch? That would account for why the OP's standard shank was totally swallowed, though.

[MikeW]

I would keep looking until I found a list like
Small .490
American .520
European .530
Large European .550

I have no hands-on experience to offer on this topic, and can only judge by what I have read. Unfortunately, the council of guru's seems to be split about what the name "Euro" actually means.

The big-endian faction hold that the name "Euro" belongs to a shank with a tip diameter of 0.538" (attributed to Euro mouthpieces from eg. Laskey or Giddings&Webster). According to Alan Baer, .530 is not a Euro shank: this is the measurement that PT mouthpieces use, and it's right in the middle (between American and Euro). Bloke also referred to .530 as "an in-between size" for which he makes the "P" shank. I'm also fairly sure that Doug Elliot calls this size "M" for Miraphone.

The small-endians go with a tip diameter of 0.530". Matt Walters assigned the "Euro" name to this size in his ground-breaking summary of shank sizes. I believe this shank fits the receivers on older Miraphones, and newer Kings.

[Dan Schultz]

... Weird. So doesn't that mean that it's straight, past the taper? Yours must be .530 at about 1 inch, right? Morse taper from there would get to .520 in less than a quarter inch? That would account for why the OP's standard shank was totally swallowed, though.

Donn.... I've done my best to tell you what I know to be the truth and backed it up with facts and figures. I simply can't put what's going on here in any clearer terms. You'll have to drop by the shop some day and I'll show you a mix of various receivers on and off the leadpipe.