Please Measure Your Conn 120S Helleberg! (I did.)

[iiipopes]

Please measure your Conn 120S Helleberg! Conn does not publish specs. Typical Cyborg. And there has been so much variation over the years. For example, I have owned and played at least a half-dozen Bach 18's over the decades. The "nominal" cup I.D. of an 18 is 1.26 inches. I have seen them all the way from 1.25 to 1.29, and a rim all the way from the wide Mt. Vernon slope to a narrow Wick 1 contour. I'm sure it is the same way with Conn mouthpieces, even with modern CNC machining. And personally, I have seen all the way from true flat rims to really rounded rims on Conn Hellebergs. So, please measure your Conn 120S Helleberg and post your measurements. We need to correct all the speculation in all the aftermarket mouthpiece charts which claim to be "authoritative." The closest I have seen is Jim Fox' chart which he donated to Mouthpieceexpress.com and which lists 1.27. I have a 120S in my hand as I type this; it appears to be of fairly recent manufacture. The following comments are personal observations from the mouthpieces I currently own:

Cup I.D.: 1.27-1.28, depending on how far down you measure;
Throat: larger than a P drill bit (.323), which wobbles in the throat, but smaller than a 21/64 drill bit (.328), which will not go through the throat;
Slightly rounded rim, a little bit sharper on the inner rim, but not so sharp as to be uncomfortable. I had a really good rehearsal with it tonight in Community band.

The cup is a good funnel. Very little curve at the bottom. It is deeper than a Bach 18, of course; but the surprising thing is that it is not quite as deep as a Miraphone Rose Orchestra. Since it has been so long since I sold my Wick 1, I can't compare those two. I hope somebody else can. Interesting detail: since Kelly says that their lexan mouthpieces are designed to emulate the tone of their origin counterparts, and not slavishly copy the specs: the cup of the Kelly 18 (not the Kellyberg) is almost as deep as the Conn. Go figure.

Next....

[iiipopes]

I was able to measure another Helleberg 120S, which may be a couple years older than the first one I measured:
Cup: 1.28 inches
Depth: may be just a hair, and I mean probably no more than 1/100 inch, shallower, and which may be more a function of the throat.
Throat: P bit wobbles, but it doesn't wobble as much as the mouthpiece measured above.
Rim contour: same as above.

There must be something a little different to the backbore, because this one has a better response on my Jupiter JTU1110 than the one above has.

[bloke]

I’ve watched most of all production mouthpieces - and most all production instruments - vary and morph slightly, over the years.
Think of the 186.

[iiipopes]

I’ve watched most of all production mouthpieces - and most all production instruments - vary and morph slightly, over the years.
Think of the 186.

Indeed. That's why I mentioned the Bach 18, probably one of the worst offenders. Then again, all change to some degree over time. Another case in point: the Fender Stratocaster afcionados go on and on about the subtleties of production year to year, and so on with other items. The point of this thread is that Conn won't publish their specs, so we are all left to "reverse engineer" what may actually be the nominal specs for a Helleberg 120S, especially in recent years when supposedly CNC is used to keep manufacturing consistent.

[bloke]

CNC doesn’t self-calibrate, and nor does it self-sharpen.

[iiipopes]

CNC doesn’t self-calibrate, and nor does it self-sharpen.

No, it doesn't. It still doesn't change the purpose of this thread: what are the nominal specs of a Helleberg 120S. Unless we could convince a person with access to the blueprints to leak them out of the factory, this is about the best we can do in the meantime.

[bloke]

I would like to know where the model 120 came from…??

For years, the “Conn-Helleberg” was smaller (with an asymmetrical rim profile), and those are the ones that go for a zillion dollars - even when they look like they’ve been dragged down the street on the end of a rope behind a car.

That original “Conn-Helleberg” mouthpiece never actually reappeared, but two other mouthpieces - that are more similar to it than to the 120 - did appear: the Conn-Helleberg 7B, and the Conn 2.
—————-
I remember in the early 1970s, if you bought a Conn-Helleberg (with no other stamping on it), it was what is today called the model 120. The shank was silver plated, and the cup portion was plated with a yellowish-colored (not pure) gold plating.
The one stamped 7B (along with the “Conn-Helleberg” stamping) was/is smaller, and featured the same two-tone plating…
… so how early (before the early part of the 1970s) did that mess start occurring?

…and (again) is the 120 actually based on anything, or did Conn just pull it out of their corporate _ _ tt ?

I too have seen minor 120 discrepancies over the years, but all of the slight 120 variations are more like each other then they are like the 7B - which is more like the original…
…so again: What is this 120 thing?

[iiipopes]

I would like to know where the model 120 came from…??

For years, the “Conn-Helleberg” was smaller (with an asymmetrical rim profile), and those are the ones that go for a zillion dollars - even when they look like they’ve been dragged down the street on the end of a rope behind a car.

That original “Conn-Helleberg” mouthpiece never actually reappeared, but two other mouthpieces - that are more similar to it than to the 120 - did appear: the Conn-Helleberg 7B, and the Conn 2.
—————-
I remember in the early 1970s, if you bought a Conn-Helleberg (with no other stamping on it), it was what is today called the model 120. The shank was silver plated, and the cup portion was plated with a yellowish-colored (not pure) gold plating.
The one stamped 7B (along with the “Conn-Helleberg” stamping) was/is smaller, and featured the same two-tone plating…
… so how early (before the early part of the 1970s) did that mess start occurring?

…and (again) is the 120 actually based on anything, or did Conn just pull it out of their corporate _ _ tt ?

I too have seen minor 120 discrepancies over the years, but all of the slight 120 variations are more like each other then they are like the 7B - which is more like the original…
…so again: What is this 120 thing?

Yes. Again, my point exactly. Hence the title of my post: measure your 120. I reviewed all the old threads on TubeNet as well as here, and yes, the postings of all who actually have or had access to "real" 1930's Helleberg mouthpieces report the same thing. I did find one point in one thread that was interesting where one poster (I don't remember who - but it is in one of the old threads) reported the throats as being @ .327, which is consistent with my observation that a P drill bit, .323, wobbles, but a 21/64 drill bit, .328, won't go through the throat.