Klipsch LaScala Timeline

This is a timeline for the evolution of the Klipsch LaScala speaker from inception to the current date.

Date	Event	Media
1963	The La Scala is designed as a portable version of the Klipschorn to be used as a P.A. system for Winthrop Rockefeller's Arkansas gubernatorial campaign. Component designations were: Woofer K-33-J (Jensen), Midrange K-400 horn and K-55-V driver (Atlas), Tweeter K-77 (Electrovoice). Note: In his interview here, Bob Crites states that in a seperate interview, Paul Klipsch claimed that the LaScala was not designed for this reason. We are trying to track down the truth of the matter.
1966	The designation for the Type 1RC crossover network was changed to Type A.
September 1967	Transition to the K-33-M. The records are not clear as to the origin of this driver but it is believed to be an Eminence driver with an Alnico magnet.
January 1968	Transition to The K-33-P Woofer (CTS Paducah KY)
1971	The Type AA crossover network was introduced featuring Zenor diode tweeter protection.
1974	K-56 mid-range driver (Electrovoice 1828) is used for a short period as a temporary replacement as the supply of K-55-V drivers was interrupted.
1975	Transition to The K-33-B Woofer (CTS Brownsville TX)
1975?-1979	K-33-E (Eminence) and the K-33-B were used interchangeably. The records are not specific about the actual start date for the K-33-E but it is believed to be in the early to mid 1970's
1979	The Eminence K-33-E woofer is used exclusively
1983	The Type AL crossover network was introduced incorporating steeper filter slopes for enhanced tweeter protection and smoother response in the crossover regions. The Type AL-2 network was introduced to accommodate the new K-55-M mid-range driver This Electrovoice sourced driver was essentially the same as the previous K-55-V with a smoother response
1987	The Aluminum K-400 horn was replaced with the K-401 structural foam horn resulting in slightly improved distortion figures.
1989	The AL-3 network was introduced to correct for a shift in the output of the K-55-M mid-range driver.
2000	Electrovoice ceases production of the K-77-M and K-55-M tweeter and mid-range drivers. The search for replacement drivers and the acquisition of the EV tooling is sought. Very limited production of a few pairs occurs at the end of 2000 and the early months of 2001 using existing part stocks
May 2001	The Atlas PD-5VH (Current version of the previous K-55-V) is modified slightly and christened the K-55-X. The various components of the K-77-M tweeter are either retooled or sourced from the new owners of the tooling and assembled by a third party. This variant of the tweeter is designated the K-77-F. An entirely new network (AL-4) was created to accommodate these driver changes. Fusing is eliminated in favor of a polyswitch for tweeter protection. The tweeter on the La Scala was flush mounted for the first time using "Z" brackets. A metal input panel with binding posts in a bi-wire configuration replaced the traditional screw type barrier block.
December, 2005	The La Scala II debuted as the first "finished" version of this model featuring a two piece veneered cabinet utilizing 1" MDF instead of the traditional 3/4" plywood. The AL-5 network was introduced to compensate for the improvement in low frequency response resulting from the change in cabinet construction. The HF and LF cabinets stacked together using thick rubber isolating spacers. Finish variants were reduced from 6 to 3.
April, 2006	The horn portion of the K-77-F tweeter was re-tooled to include a recessed flange eliminating the need for the separate "Z" bracket and attachment rivets, the new designation is the K-77-D. This also allowed the updating of pre-Z bracket La Scalas (prior to May 2001) to flush tweeter status without motor board modification.