TromboneChat

Any of you 290 players experience the same thing?

No, but I don't tune 1st against the bumpers, so this 'problem' doesn't exist.

(But, yes, it's sharper than an untrimmed Bach 50... which is good news.)

What mouthpiece?

Here are some thoughts:

1. Are you using a smallish mouthpiece? My King 7B used to play pretty sharp when I used a 5G mouthpiece in it.
2. Are you riding high on the pitch all the time?
3. Has the mouthpiece shank been reduced in diameter so the mouthpiece fits in too far?

If your teacher can't help, see if a Skype lesson with Doug Elliott will. He is great at diagnosing these kinds of problems.

The mpc is a Black 2GP. A little on the small side.

Yup, very small for that horn imo. The players I k ow on them are using medium large stuff and have the tuning slide out maybe a quarter inch tops.

You mean the tuningslide can not be pulled as far as you need? I have one horn that has that problem but it is a german style horn of the brand "Wunderlish" but made in Chicago. That horn is high pitch, close to B with the tuningslide pulled. No modern horn of mine is too sharp for A=440 and a Benge 290 should not have that problem, the opposite is more common to my experience. I have cut a tuningslide on a few horns to be able to play A=442. To me the size of mouthpiece effects intonation. More shallow mouthpieces raise the pitch for me which I have to compensate with either the tuningslide or the main slide. To me a deeper mouthpiece can help to flatten the pitch, but this is just minor changes in pitch. In this case I think it would be an idea to first check the horn for leaks and also make sure you find the sweet spot in the horn. Any horn can be played out of tune if you don't find the sweet spot, where the sound is most relaxed and most sonorous.

/Tom

Thanks everybody!