Brass Slide C
Extension

Brass Gated C
Extension

Wood Gated C
Extension - Black

 

These extensions are truly unique. They are easy to install, easy to adjust and do not mutilate the scroll like other extensions.

Our extensions are made of brass or wood. The wood extensions are hand made and the brass ones are machined out. The wood is a little lighter in weight but the brass is more durable. We originally only made brass extensions and recommend them. Because moving parts always last longer and have less long term adjustment issues when made of brass than wood.

Both brass and wood extensions help conduct the acoustic vibrations onto the scroll. This is due to the extension string going around the scroll and pressing the extension body to the scroll. This helps transfer the vibrations from the extension onto the entire scroll. This results in the scroll becoming a part of the vibrational amplitude of the bass itself. Most will notice a richer, deeper increased volume of sound to their 'E' string after the extension is installed, even with the E gate closed.

The slide extension is ONLY for Jazz players. Having no gates allows the player to improvise playing notes, below the slide, on the extension fingerboard with their fingers. The slide extension also does not work for orchestral playing because of the time it takes to move the slide from the E position to the 'general position' of the lowest note needed. The gated extension is for classical orchestra players that want the gates to be set at 'precise positions' of the lowest notes needed. That way when the E gate is flipped open then the lowest note in the music can already be pre-set with another gate above. The gated extension comes with the 5 gates already shown. (Replacement gates can be purchased separately).

Among the many jazz and classical professionals using our extensions are: Principal bass of Boston Pops, Principal bass of Indianapolis Symphony, and Principal bass New Orleans Symphony.

Cost and installation directions below.
(Installation video at the bottom of page.)

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Brass Slide-C Bass Extension

Brass Gated-C Bass Extension

Wood Gated-C Bass Extension - Black

Replacement individual gate for wood C-Extension

Replacement individual gate for brass C-Extension

$700

$700

$850

$65

$65

Brass extension with installation: $1,650.
Wood extension with installation: $1,800.

SLIDE EXTENSIONS

About Slide Extensions

 

•The brass extension with ebony fingerboard has a unique sliding, self-clamping gate.

•The string glides effortlessly on rollers through the body of the extension and around the scroll.

•The extension can be easily adjusted to fit on any bass without cutting into the scroll. (See slide C-Extension Installation Instructions below)

•Extension weighs 3 lbs.

The Lever Arm is under spring tension and automatically clamps the attached Lever Foot on top of the string. The unclamping of the string is done manually by pressing the Lever Arm down, using the Thumbpiece below it as support for the hand. With the Lever Arm pressed down, the Gate easily slides along the length of the Gate Runway to any position. Any notes below the clamped Lever Foot are then fingered.

* The top of the scroll needs to be at least 1.5cm below the "neck projection line" (for standard use).

* The Finger board needs to be about 1cm in side thickness

The top of the scroll needs to be at least 1.5 cm below the projected "neck projection line" (for standard use) (shown in the picture above in dotted blue-green). The finger board needs to be about 1 cm in side thickness.

The Wood Shim and extra long Extension Body are cut down to fit individual scrolls. Instructions and all parts for installation come with the extension. A craftsman with hand plane and tool skills can do the work.

Slide C-Extension Installation Instructions & Pictures

Read through all instructions before beginning any installation work. Also you can view a downloadable PDF.

1. Take off nut.
2. Cut off the E-string part of the nut. The finished (cut) edge of the remaining nut will be 2.5 mm from the center of the nut A-string groove. (See diagram)
3. Glue the modified nut back on. (Save the unused piece)
4. Unscrew the stopper screw at the end of the extension body.
5. Place extension to the side of scroll so that the round part of the brass is centered over the scroll. Mark (on the extension body) and saw off where it extends past nut edge.
6. Start cutting down the (extension) wood shim while making sure that the extension body continues the trajectory that the E-string would follow toward scroll.
7. Bend the rear L bracket so that it will be flush with the back wall of the peg box.
8. With the wood shim near final thickness, place the extension so it rests on the scroll and nut area. File end so that it butts-up cleanly to the end of the Bass fingerboard.
9. Draw the Bass fingerboard curvature, 0.5 mm higher, on end of extension fingerboard. Hand-plane the extension fingerboard to match the curve of the Bass fingerboard.
10. Cut a little notch for the C-string to go through on the top end of the extension fingerboard. (We have found that the extension itself doesn''t need a nut for the C-string to vibrate cleanly. You can, if you wish, place a piece of lizard skin in the notch.
11. Wind C-string through the extension onto the A-string tuning machine. Even minimum tension on the string will pull the extension body solidly and securely into place.
12. With the string as a guide, final adjustments can be made by:
a) Moving the top part of the extension slightly left or right so that the C-string will be centered on the extension fingerboard. Shape shim accordingly.
b) Cutting down the wood shim so that the clearance of the C-string will be (measuring from the bottom of the string) 5.5 mm of off the bass fingerboard. If you have cut too much off the wood shim, don't worry, you can place a thin piece of rubber between the scroll and the shim.
13. Mark (with awl) the placement of holes on the rear L bracket and side L bracket where the screws will hold them against the back and side peg box walls respectively.
14. Take off extension. Color the wood shim black and drill holes in the L brackets.
15. Put extension back on scroll. Run the C-string through the extension.
16. Drill holes into the peg box walls (through the holes in brass) and screw in L Brackets.
17. Slide on the sliding gate. Gage by eye how much needs to be cut of off the ebony foot.
18. Carve ebony foot (glued to lever arm) to match the curve of the extension fingerboard.
19. Cut a (C-string radius) groove along the length of the ebony foot so that it clamps straight down on top of the C-string.
20. Super-glue lizard skin onto the ebony foot. (Overlap skin onto the sides of foot)
21. Slide the sliding gate to its E-stop position so that the edge of the ebony foot lines up directly with the edge of the extension fingerboard. To secure the gate's position:
a) Drill and tap hole in the same channel that the original stopper screw was in.
b) Screw in the stopper screw. ( Taking into account its surrounding plastic tube)
22. Cut down the E-string side of nut (that was previously cut off) and glue it on the other side of extension as a decorative side. Cut notch to accommodate stopper screw.

GATED EXTENSIONS

About Gated Extensions

•Each individual gate is easily adjustable for height (of the string) and placement along the extension body.

•The gates open and close with ease. (See Extension with Gates Instructions & Pictures.)

•Replacement Individual Gate Assembly - $55

Picture in display shows a Slide C Extension. However, these installation instructions also apply to the Gated Extension.

* The top of the scroll needs to be at least 1.5cm below the "neck projection line" (for standard use).

* The Finger board needs to be about 1cm in side thickness

The top of the scroll needs to be at least 1.5 cm below the projected "neck projection line" (for standard use) (shown in the picture above in dotted blue-green). The finger board needs to be about 1 cm in side thickness.

The Wood Shim and extra long Extension Body are cut down to fit individual scrolls. Instructions and all parts for installation come with the extension. A craftsman with hand plane and tool skills can do the work.

Gated Extension Installation Instructions & Pictures


Read through all instructions before beginning any installation work. Also you can view a view a downloadable PDF and refer to pictures here.

1. Take off the strings.
2. Take off nut.
3. Cut off the E-string part of the nut. The finished (cut) edge of the remaining nut will be 2.5 mm from the center of the nut A-string groove. (See diagram)
4. Glue the modified nut back on.
5. Replace strings G and D. Wind the A string onto the previous E tuner.
6. Place extension body along side the fingerboard and scroll.
7. Draw curvature of scroll onto wood shim and rough cut out shape and place carved shim on top of scroll.
8. Saw off excess extension body so that it butts up to end of the Bass fingerboard.
9. If the sides of the bass fingerboard are thinner than 11mm then the bottom of the brass extension body needs to be filed down.
10. Draw the Bass fingerboard curvature, 0.5 mm higher, on butt end of the extension fingerboard. Hand-plane the extension fingerboard to match the curve of the Bass fingerboard.
11. Start final cutting of the (extension) wood shim while making sure that the extension body continues the trajectory that the E-string would follow toward scroll.
12. With the wood shim near final thickness, place the extension so it rests on the scroll and (neck) nut area. Cut a little notch for the C-string to go through on the top end of the extension fingerboard. (We have found that the extension itself doesn't need
13. Wind C-string through the extension onto the A-string tuning machine. Even minimum tension on the string will pull the extension body solidly and securely into place. With the string as a guide, final adjustments can be made by:
a) Moving the top part of the extension slightly left or right so that the C-string will be centered on the extension fingerboard. Shape shim accordingly.
b) Cutting down the wood shim so that the clearance of the C-string will be (measuring from the bottom of the string) 5.5 mm of off the Bass fingerboard. You will be taking the C-string and extension on and off several times. If you have cut too much off the wood shim, don't worry, you can place a thin piece of rubber between the scroll and the shim.
14. Find the right hole (on extension body) for the front L Bracket .
15. Screw both L brackets to the bottom of the brass extension.
16. Put extension back on scroll. Run the C-string through the extension.
17. Bend L brackets so that they are flush with pegbox wall.
18. Drill holes and screw L brackets to pegbox walls.
19. Place gates onto extension and regulate their height.
20. Final placement of gates will be adjusted when the string is tuned.

Instructions For Extension Gates Set Up & Adjustment


Instructions For Extension Gates Set Up & Adjustment

Once the extension has been fitted to the instrument, and the fingerboard has been dressed, i.e., shaped, it is time to mount the gates and find the correct position for each one. Both supplied wrenches will be required for step 4, all others can be accomplished with the wrench of standard thickness.

In the case of a 3/4 size instrument the gates will be positioned as follows: The E gate will rest in line with the nut, the approximate position of the other gates will be C gate at 10 1/2 inches from the end of the fingerboard, the C# at 7 7/8 inches, the D at 5 1/4 inches, and the D# at 2 3/4 inches.

1) Loosely attach all gate assemblies to the track on the side of the extension and bring them to their approximate positions. ‘Hand tighten’ the side nut, and then ‘back off’ slightly so that the gate pillar can be rotated

2) Rotate the gate pillar clockwise or anti clockwise as required so that the gate ‘cinches’ the string against the fingerboard as it moves over the string. Now gently tighten the side nut and check that the gate comes to rest at right angles to the fingerboard just as it cinches the string tightly. This adjustment may require a trial-and-error approach; don’t lose patience!

3) At this point an electronic tuner can help to find the precise position necessary for each gate to produce the desired pitch; just loosen the side nut enough so that the gate assembly can be moved up or down the track to raise or lower the note as needed.

4) To finalize the gate adjustment, check to see that all gates move freely but not loosely; each one must resist movement when not engaged. To adjust this characteristic the two nuts at the top of the gate pillar must be loosened (or unlocked) from one another so that they can rotate independently. This procedure will require the use of the thinner wrench being placed on the ‘lower nut’, while the standard one is used on its companion.

5) Now: to add more friction simply rotate the lower nut downward (clockwise), or upward (anti clockwise) to reduce friction. When the right resistance has been found, hold the lower nut in position while tightening the upper nut against it, thereby locking the two nuts together. By doing this neither nut will be able to rotate even as the gate is moved.

View a downloadable PDF

What to do if the scroll is at or above the neck projection line:

The Gated C-Extension will still work even if the scroll is at or above the neck projection line and no cutting of the scroll will be needed; When our extension is on a bass with the scroll that is 1.5 cm below the neck projection line then all gates open and close on the string normally. This is done by using only the top two fingers of the left hand (and the thumb underneath the brass extension body). When the scroll is higher then the neck projection line then the C string is very high above the extension fingerboard due to the fact that the extension itself is resting on top of the elevated scroll. So you have to press the 'C' string down with the bottom two (pinkie) fingers of the left hand before you can close the 'E' gate with the usual top two fingers. Once the 'E' gates is closed with this two step process then the 'C' string is pressed down and any other gate can be opened and closed with the usual one step process.

INSTALLATION VIDEO