La Scala - AL-4 Upgrade kit/instructions

Models Covered
All La Scalas Produced From 1963 to April 2001. Not applicable to the “Runt” La Scala equipped with a 12” woofer.

K-33-E Woofer
The speaker to be updated should be equipped with a K-33-E woofer. The introduction of the K-33-E occurred sporadically from 1975 through 1979. If the speaker to be modified is not equipped with a K-33-E Woofer it is recommended that it be updated.

• K-33-E Woofer (part # 121501)

Tools List

• No. 2 Phillips screwdriver - Long shaft: Total length 10” (25.4 CM) or longer
• Electric driver drill with adjustable clutch
• Drill bits (3/32”, 1/8”)
• Wire cutter / crimping tool (optional)
• Soldering Iron (optional)

La Scala AL-5 Upgrade Kit 1006974

Two kits are required to update a pair of speakers.

1) 116646 AL4 Network Assembly: Crossover network with wire.
1) 1007002 K-77-D tweeter with Logo
1) 128029 K-55-X midrange driver
1) 070250 K-55-X Driver Logo
1) 157041 Midrange Driver Gasket
8) 062510 Screws #8 x 1 (Attaching network to cabinet)
1) 060327 Input panel
6) 062541 Screws #6 x ≤ (Attaching input panel to cabinet)
2) 113027 Red binding posts
2) 113028 Black binding posts

Installation Instructions

These instructions assume that the speaker is disconnected.
• This task is recommended for the experienced installer only!
• Be sure to keep track of all hardware and its proper location!
• If a power screw driver is used to install screws be sure to properly adjust the clutch torque to avoid stripping out screw holes!
1. Detach all of the driver leads from the screw barrier strip on the old crossover network.
2. Remove the screws that attach the old network to the cabinet, remove it and set it aside.
3. Remove the old tweeter by removing the four screws securing it to the motor board. The spacer washers will be needed with the new tweeter.
4. Remove the midrange driver from the mid horn by unscrewing it counter clock wise.
5. The wire going to the woofer compartment is attached to a small, two screw barrier block underneath the midrange horn. Remove the woofer wire from this barrier block (removal of the midrange horn may be required). Take note of any markings on the wire and on the barrier strip that may indicate polarity.
Typically the positive terminal is marked with Red paint. Alternately this wire can be left in place and either spliced to the new network woofer output wires or directly soldered to the new crossover PC board.
6. Since older La Scalas do not have a location for the input panel some planning may be required regarding its installation (two basic options are available). The input panel can be secured to the upper rear corner of the cabinet’s back surface using three or four of its 6 screws (supplied). The other
option is to attach it to the top surface of the floor of the midrange / tweeter compartment. Typically it would be positioned toward the rear edge of this compartment, behind the location of the original crossover network. This can be done with angle brackets or similar hardware. The input panel will be
installed in a later step.
7. Identify and tag the various driver and input wires on the new network. The woofer output wires are marked with Red (+) and Black (-) boots and have un-terminated ends that are soldered. They can also be identified by “+W”, “-W” markings on the new network circuit board. The midrange output wires are marked with Yellow (+) and Black (-) boots and have female push on connectors. They can also be identified by “+M”, “-M” markings on the new net work circuit board. The tweeter output wires are marked with Green (+) and La Scala AL-4 Upgrade Kit (1006974) Black (-) boots and have female push on connectors. They can also be identified by “+T”, “-T” markings on the new network circuit board. The four
input wires are marked with Red (+) and Black (-) boots and have “U” shaped spade lug connectors. They can also be identified by “+HFIN”, “-HFIN”, +LFIN” and “-LFIN” markings on the new network circuit board.
8. After determining the method and installation location of the input panel, secure the new crossover network to the cabinet in approximately the same location as the old network (making any necessary compensation for the mounting of the input panel). New pilot hole locations will likely need to be
marked and drilled (1/8” drill bit) as the screw locations are different than the old network. Install the network so the input wires are oriented toward the rear of the cabinet, closest to the input panel location.
9. Locate the woofer output wires on the new network and connect them to the barrier block, under the midrange horn, observing proper polarity (Red to Red and Black to Black). The ends of these wires are stripped and tinned with solder. You can either crimp on a spade lug of appropriate size (to fit 16 AWG
wire and also fit the barrier strip) or slide the tip of the wire underneath one side of the loosened barrier strip screw and then tighten. Alternately (as described above) you can splice the old woofer input leads to the new woofer output leads on the new network or unsolder the new woofer output wires from the network PC board and solder the old woofer wire directly to the new network. 10. Locate the tweeter output wires on the network and carefully connect the push-on terminals to the tweeter. The tweeter positive (+) terminal will be marked with either a “+” symbol, a dot of paint or a colored sticker.
11. Install the new tweeter in the cabinet with the spacer washers. As with the network the screw hole locations will likely be different new pilot hole locations may need to be marked and drilled (3/32” drill bit). Mark your drill bit with a piece of tape as a depth guide to prevent drilling all the way through the
motor board.
12. Re-install the midrange horn, if removed.
13. Replace the original, rubber driver gasket in the throat of the midrange horn with the new part (supplied).
14. Install the new midrange driver by screwing it on to the rear of the midrange horn (clockwise) taking care not to cross the threads and hand tighten snugly. Attach the round driver logo to the back of the midrange driver after the driver is installed on the horn. Peel the protective paper off the back of the logo,
center and properly orient it, then press it into place.
15. Locate the midrange output wires on the network and carefully connect the push-on terminals to the driver observing proper polarity. The mid range driver positive (+) terminal will be marked with either a “+” symbol, a dot of paint or a colored sticker.
16. Install the binding posts in the input panel using the color coded insulators on each side of the metal input panel to prevent the binding post shaft from contacting the metal input panel. Install a Red binding post assembly in each of the panel holes marked with a positive (+) symbol and a Black colored post
assembly in each of the holes marked with a negative (-) symbol. While installing the posts a small screw driver or hex key can be inserted into the hole drilled through the binding post shaft to maintain the desired orientation (typically vertical) during tightening. Snug gently! Do not over tighten as the
binding post shaft can break with excess torque!
17. Locate the two pair of network input wires. Attach the “U” shaped spade lug connectors on these leads to the back side of the binding posts on the input panel. Place the spade connector between the pair of nuts on the back of the binding post shaft and snug using two wrenches to counter torque the nuts.
Snug gently! Do not over tighten as the binding post shaft can break with excess torque! Take care to observe proper polarity (Red Tagged wires to Red binding posts) and to pair the correct wires with the proper set of binding posts. Pair the “LF IN” posts on the input panel to “LFIN” wires on the circuit
board and “HF IN” posts on the input panel to “HFIN” on the circuit board.
18. Install the input panel to the cabinet in the pre-determined manner and location (step # 6 above). If you are attaching it to the back edge of the cabinet, place the panel in the desired location, mark the screw hole locations and drill three or four pilot holes using a 3/32” drill bit. Use the supplied #6
screws to secure the panel to the brace.
19. Connect the speaker leads from your electronics to the binding posts labeled “HF IN” and “LF IN” making note of proper polarity (+ to + and – to -). A single wire type connection will require the presence of jumper wires that connect the two RED (+) binding posts together and the two Black (-) binding posts
together. Connect to either set of binding posts. For a bi-wire type connection, remove these jumpers.
20. Reposition your La Scalas and enjoy!