Here is another photo from our collection featuring Bob with several top call studio trumpet players from the 70s.
The Experimenting Continued
Originally, I made six different sleeve sizes that allowed a player to adjust the gap within 1/16″. It quickly became obvious that players required further fine-tuning, so I divided the sizes into 1/2 and 1/4 sizes, allowing players to adjust the gap within 1/64″. Due to the limitations of the manual lathe I was using, I could not reliably adjust the gap in smaller increments. Frustrated by this limitation and wanting to make even smaller adjustments to the gap, I turned my attention from the mouthpiece to the trumpet receiver.
Adjustable Gap Receiver
In 1979, I invented the first adjustable gap receiver for the trumpet. The gap could be adjusted within .001” by using a precision threaded bit. Over the next few years, I tested the gap extensively compiling several journals full of notes, observations, and most importantly, players’ perceptions.
I was surprised to discover that trumpet players can perceive a change in the gap as little as .006”! I also confirmed my belief that two different players playing on the same mouthpiece and same trumpet often will required a different gap.
I converted many trumpets with my adjustable gap receiver (The B.R.A.S.S., which stands for Bob Reeves Adjustable Sleeves System), but there were practicality issues with this system that made me reevaluate making gap adjustments using the mouthpiece. Thanks to advances in machining technology, adjusting the gap by using a converted mouthpiece and removable sleeves became feasible.
The Bob Reeves Sleeve System
The system as it exists today requires a mouthpiece to be converted for sleeves, which is much easier and more economical than replacing the receiver on a trumpet.
We can convert any trumpet mouthpiece to accept our sleeves, the process of which does not alter any other part of the mouthpiece — the backbore and overall length of the mouthpiece remain the same.
Our removable sleeves come in half sizes, ranging from #1 to #7. We also have quarter sizes available from time to time. The #1 sleeve has the largest shank size, which will produce the largest gap, while the #7 sleeve has the smallest shank size, producing the smallest gap.
Check back for Part III when we will discuss how you can find the optimal gap for your set up.