Welcome to the Home
of the
World-Famous
Adjustable Bottom Caps
Manufacturers of the
Tom Hutchinson &
Glenn Van Looy
Adjustable Bottom Caps
(ABCs)
All in stock and Shipped within 24 Hours
Tom Hutchinson Adjustable Bottom Caps for:
Sopranos Cornets
Cornets
Flugel Horns
Trumpets
Tenor Horns
Glenn Van Looy Adjustable Bottom Caps for:
Euphoniums
Baritones
Available for all Makes and Models
Adams - B&S - Bach - Benge - Besson Prestige (German Made) - Besson Prestige (UK Made)
Besson Sovereign (German Made) - Besson Sovereign (UK Made)
Boosey & Hawkes Imperial (UK Made) Boosey & Hawkes Sovereign (UK Made)
Calicchio - CarolBrass - Courtois - Eastman - Eclipse - Geneva - Gear-4-Music - Getzen
Hirsbrunner - Jinbao Stencils - John Packer JP - Mack - Meister Walter Nirschl - Miraphone
Monzani - Schilke - Smith/Watkins - Stomvi - Sterling Virtuoso - Shires & Co - Taylor
Thomann - Wessex - Willson - Yamaha - York
ABCs with various weight options for centring and securing notes
as played and recommended by Tom & Glenn
Finished in Silver Plate with 24 Carat Gold Trim
Message from Tom Hutchinson
Glenn Van Looy talking about Euphonium & Baritone
Adjustable Bottom Caps
ABC Production featuring Glenn Van Looy playing
Eagle's Flight by Wim Bex
What Is an Adjustable Bottom Cap?
For Sopranos, Cornets, Trumpets, Flugel Horns and Tenor Horns an ABC replaces the 1st or 3rd Valve Bottom Cap. They are the same diameter and thread as the Valve Casing on your Instrument.
1st or 3rd Valve it's your choice. Some players prefer an ABC on the 1st Valve and some on the 3rd, with the BIG advantage being that you can try the 4 Weight options and find the one that works best for you and your instrument.
For Euphoniums the best advantage for Centring and Securing Notes in all Registers is on the 4th Valve and equally so for 4 Valve Besson and Yamaha Baritones. For 3 Valve Baritones, the 1st Valve gives far superior results and benefits.
What Does It Do?
From Students to Professionals of all ages, customers worldwide tell us that using an ABC has a very positive effect in "Centring and Securing the Notes in all Registers, helping to Slot them more accurately".
How Does It Work?
The first diagram details the Waveform of a Note when there is not an ABC weight added to a Valve Casing and shows the degree to which us brass players, as much as we try to keep the note in the centre, can lip the note up and down (shown between the orange lines) from its actual True Centre of the Note shown by the green line.


The second diagram shows how by adding extra weight with an ABC to a Valve Casing, it Attenuates the Note closer to its True Centre. An analogy of this is when we used to turn the dial on an old-style radio to "Tune it in" and get the best reception, that’s the Attenuation achieved by using an ABC.
The science behind the ABC is that adding Mass/Weight, this Attenuates the Lower Harmonic Partials, acting positively in terms of centring/securing the notes.
Will It Work for Me?
The evidence from hundreds and hundreds of ABCs sold Worldwide is Yes and to make sure, you can try one for a Month Without Obligation and see the benefits for yourself - we ship Worldwide.
ABCs are made in the UK to the closest of tolerances by computer-controlled lathes and diamond cutters ensuring the highest quality. Every thread is machined specifically to suit each makes and model of the various instruments we mention.
With our unique 1 Month Approval offer you've got nothing to lose and everything to gain.
Adjustable Bottom Cap (ABC) - Heavyweight 4th Valve Bottom Cap
Reviewed by Dave Werden
On my forum and other places, euphonium players have discussed the benefit of replacing the standard bottom cap of the 4th valve with a heavier version.
Recently I learned of a line of heavy caps made for most valved brasses: the HBC (Heavy Bottom Cap) product. It was designed by musicians and beautifully made . . . .

ABC Production & Electro-Plating
We produce all the parts on CNC Lathes here in Havant, Hampshire. Each component is computer coded to ensure the highest accuracy, with 100% inspection at every stage ensuring the optimum quality.
The ABCs are wired-up ready for electro-plating with a flash of Bright Copper plate applied first which then gives perfect adhesion for the 25 Microns of Bright Silver Plate and 24 Carat Gold Plate on the ABC Threaded End Piece.