pmsummer
simul justus et peccator
Klipsch Heritage S/N Date Code decoder
KLIPSCH S/N FORMATS
DATES DESCRIPTION EXAMPLE
1946-1947 ### (001) ending #021
1948-1961 #### (0121) starting #0121
1946-1961 dates can only be found in log book (eng. Library)
Klipschorns of this vintage had the s/n hammer stamped into the tailboard, woofer access door or inside the woofer chamber.
1962-1983 ##letter#### (20Y1234)
1962-1983 Letter format
A=62 F=67 K=72 R=77 X=82
B=63 G=68 L=73 S=78 Y=83
C=64 H=69 M=74 T=79
D=65 I=70 N=75 U=80
E=66 J=71 P=76 W=81
1984-1989(?) YY WW #### (89281234)
1990-1997(?) DOY Y2Y1 #### (135791234)
DOY= day of the year
Y2Y1=2nd digit of year, 1st digit of year
1998-2000 YY WW #### (00281234)
YY=year (i.e. 99,00…)
WW=week of the year
Date code on drivers (1994) Example – 9429 = 1994, 29th week of the year / YYWW
Expanded version from Groomlakearea51 on the Klipsch Forums:
KLIPSCH HERITAGE REFERENCE DATA - (V-2.1 - 03 SEP 2009):
SECTIONS:
I. GENERAL
II. READING HERITAGE MODEL & SERIAL LABEL CODES
III. SPEAKER TYPE CODES
IV. SPEAKER WOOD/FINISH CODES
V. SERIAL NUMBER CODES
VI. DRIVER CODES
VII. DRIVER TYPES BY APPLICATION
VIII. GRILLS TYPES & CLOTH CODES
IX. LOGO DESIGNS
X. HERITAGE PRODUCTION NOTES & TIME LINES
I. GENERAL:
1. This information generally applies to the Klipsch Heritage Series; but also includes some selected information on finishes, grill cloth options and emblems/ logos used on certain later models.
2. The data is generally correct; the author assumes full responsibility for errors.
3. Sources include, but are not limited to:
Discussions, data reviews, and corrections by Klipsch employees;
Discussions and physical data provided by owners of Klipsch speakers; independent technicians and sources specializing in Klipsch;
Klipsch forum threads (extensive source material is available);
Klipsch reference documents, information sheets, data specs, time line sheets, etc.
Direct examination of Heritage series products.
4. Corrections, additions, and in particular photographs, are most welcome, and as Klipsch owners and forum members contribute additional data, the document will be updated.
II. READING THE KLIPSCH MODEL & SERIAL LABEL CODES:
1. All of the "labels" through 1990+ are functionally similar. The Heritage series until 1984 were relatively simple: they were hand written, and first line was the model and wood/finish type, and the second line was the serial number (serials discussed further below).
2. Starting in 1984 and continuing until approximately 1988, the labels were similar, however used a "stamped" serial number identification below the model & finish code. By 1988-1989, the labels were "computer" generated, with the model, finish and other coding in a second "line".
EXAMPLE:
KC-BB
15T252
This tag would be for a Klipschorn, Type-C (non-"collared"), birch, black lacquer finish, serial number: 15T252 (made in 1979)
III. HERITAGE SPEAKER TYPE CODES:
** Does not include the "Rebel" or "Shorthorn" series.
C = Cornwall
CD = Cornwall "decorator" with flush motor board and no grill
BK = Belle Klipsch
H = Heresy
HD = Heresy "decorator" with flush motor board and no grill
LS = La Scala
KB = Klipschorn - Model Type B, "collared"
KC = Klipschorn - Model Type C, no "collar"
KD = Klipschorn - designer type (no grill, made through April 1987)
IV. HERITAGE SPEAKER WOOD/FINISH CODES:
1. Until the late 70's-early 80's (and again in 2008 on Heritage models), customers could special order a number of exotic veneers.
2. It should be noted that until May, 2001 there were almost 100 different finish, grill cloth, and riser 'combinations' or variants that could be ordered for the Heresy’s and up to 75 versions of the Klipschorn.
3. In the mid-late 90's, Klipsch generally ceased most special order veneers and raw birch was also discontinued on most models, except Heresy-II's.
4. Material for raw birch is/was Georgia-Pacific cabinet/furniture grade 7 ply (5 inner standard grade plies and the two outer very-fine grade plies).
5. Risers for the Heritage series were originally optional, and there was a long base for horizontal placement of standard Cornwall's.
6. Heresy risers were generally "straight" until the late 1980's, and were still an option until the late 90's. In the late 1980's the "slant" style became the general standard. Slant risers appeared in the 1970's on Heresy-Is, but are not seen often. Currently the US version Heresy is shipped with slant riser, elsewhere in the world they can be ordered with or without the riser.
7. "Oiled" finish refers to the factory application of a high quality furniture grade wood oil that fills the pores of the wood and seals the finish. The type of oil is similar to a Watco "danish" or "rejuvenating" oil. Oiled finishes require a routine "oiling" with a light non-buildup type of furniture grade wood oil.
8. "Lacquer" refers to the application of one or two thin coats of a clear semi-gloss lacquer sprayed on the cabinet and motor board prior to installation of drivers. That lacquer was obtained from various vendors and currently is a #40 sheen, semi-gloss lacquer from Valspar/OPEC. Lacquer finishes only require a routine wiping off with a clean dry cloth to maintain the finish.
9. For "Black Lacquer" finishes, the factory used a #40 sheen lacquer primer, then #40 sheen black lacquer, with a clear #40 sheen to protect the black finish.
10. Generally, most veneered Heritage products had the rear panels/ sections sprayed with black lacquer primer. Starting in late 1983 and continuing to this day, the rear panels of the Heritage models are now sprayed with a coat of primer, then a coat of "textured" semi gloss, and a top coat of clear lacquer.
11. An option to have raw birch stained was also used, but not often seen. The stain was applied by spraying, and the serial number stickers generally indicated this option. Example: H-WS would have been a Walnut stained Heresy made from "raw-birch". This option was more commonly seen on La Scala's.
CODE ** WOOD FINISH REMARKS
Ash Lacquer Uncommon
AO Ash Oiled Uncommon
BB Birch Black Lacquer Common
BR Birch Raw Common
BL Birch Lacquer Common
BW Birch White Lacquer Rare Spec Order
CL Cherry Lacquer Uncommon **
CO Cherry Oiled Uncommon
D-BR Birch Raw Designer (No Grill)
D-BB Birch Black Lacquer Designer (No Grill)
FL Fir Lacquer Rare
FO Fir Oiled Rare
FB Fir Black Lacquer Late Models Only
F Fir Firzite Rare - Marine Grade
HL Hickory Lacquer (reported-unconfirmed)
MEL Macassar Ebony Lacquer Rare Spec Order
MEO Macassar Ebony Oiled (unconfirmed)
MHL Mahogany Lacquer Rare Spec Order
MHO Mahogany Oiled Rare Spec Order
MHR Mahogany Raw Rare Spec Order
ML Maple Lacquer Rare"Hardrock Maple"
MO Maple Oiled Rare"Hardrock Maple"
MO* Medium Oak Oiled Late 90's Models
OL Oak Lacquer Common (Red Oak)
OO Oak Oiled Common (Red Oak)
PNL* Persian Nut Lacquer Rare Spec Order
RRL* Rambling Rose Lacquer Rare Spec Order
PL Prima Vera Lacquer Rare Spec Order
PR Prima Vera Raw Rare -Early
RL Rosewood Lacquer Brazilian species
RO Rosewood Oiled Brazilian species
TL Teak Lacquer Uncommon
TO Teak Oiled Uncommon
TWL Tigerwood Lacquer Rare Spec Order
TWO Tigerwood Oiled Rare Spec Order
WL Walnut Lacquer Common
WO Walnut Oiled Common
WS Birch (stained) Stain Walnut on Birch
ZL Zebrawood Lacquer Rare Spec Order
ZO Zebrawood Oiled Rare Spec Order
* "Persian Nut" and "Rambling Rose" are not an actual wood species; they were made from linear cut birch or walnut wood which was dyed with specific hues/colors, re-glued into alternating color layers and then rotary cut into the respective veneer types to achieve the effect.
** Lacquer finish on early production Cherry was uncommon.
*** See also the list of new veneers available from Klipsch as of March 2008:
(http://forums.klipsch.com/forums/t/102665.aspx)
Production codes that will be assigned are unknown at this time.
V. HERITAGE SERIAL NUMBERS:
1. Based upon additional information related to the use of letters starting in 1955, the 1962-1983 coding has been modified to reflect that information.
2. The serial number was written on the paper serial tags and die stamped on the back edge of the top panel (inside top portion in LS). This practice was not used on later "MDF" cabinets for Heresy's, etc. Serial numbers can often be found written in pencil on the inside of some of the Heritage series, most notably Klipschorn's and Belle's.
3. While the 1946-1961 manufacturing dates can only be found in the Engineering Library in Indianapolis, accurate specific dates for the day of manufacture may also be found by close examination of the interior of the speaker cabinets. As an example there were often small inspection tags stapled inside the cabinets and penciled notations with dates inside the cabinets. An example of the production inspection stickers was the use of "PRIDE" stickers inside some models. These were used in the early through mid-1980's.
4. Additional letters stamped in the edges of Heritage series made from birch plywood, and on the poplar and ash "lumber core" as the substrate, were "USA" and/or the cabinet builder's and final sander's initial(s). For reasons of protecting their right to privacy, I have not identified the names of those superb craftsmen (and women).
DATES DESCRIPTION EXAMPLE
1946-1947 ### 001-020 (ending at #20)
1. 1946 & 1947 Klipschorn serials #002 - #013 were made by Baldwin Piano.
2. Serial numbers #14-20 were made for purchasers in Paul Klipsch's "tin shack", before the move to the newly built factory. There are no Klipschorn's with a serial number between 21 and 120.
DATES DESCRIPTION EXAMPLE
1948-1961 #### (starting #0121)
From 1948 though 1961, Klipschorn's had the serial number stamped into the tailboard, woofer access door, or inside the woofer chamber.
3. The number Klipschorns produced in 1948 is unknown; a total of 26 were made in 1949
DATES DESCRIPTION EXAMPLE
1955-1983 ##letter#### 20Y1234
1. Letters that look like numbers (e.g. I, O, Q, V) were not used. "S" is frequently misread as a "5" and Y has been confused with an X on occasion.
2. July 29, 1955 was the last day for the four digit serials (i.e. 1811). After that the "number- letter-serial" system went into effect (2 August 1955). The first "number-letter-serial" speaker was produced on the 2nd of August 1955; that serial number was 1A812.
3. In the 1955-1983 serial method the first, or prefix "digit(s)" before the year letter represents the sequence of production for each 1000 units. The suffix digits after the letter code will always be three digits - 001 through 999. For example 1C999 would be the 999th unit built, and 2C999 would be the 1999th built in 1965 C = 1965).
4. These digits before & after the year code apply only to that type of speaker.
5. The year code letter only identifies the year in which that number occurred.
6. As an example, if you have a pair of Klipschorn's and one of the serial numbers is 15T252, then by 1979 there had been 14,151 Klipschorn's made (Klipschorn's made in 1946-1947 were serial numbered from 1 to 20, and in 1948 started with #121, skipping #21 through #120).
7. For a pair of 1979 La Scala's, with serial number 22T403, it means there were 21,403 La Scala's made to that point.
8. Another example: A pair of Belles from 1979 has the serial number 3T242 and 243. This means that in 1979 these Klipsch Belles, the 2,242nd & 2,243rd, were made.
YEAR OF MANUFACTURE (1955 THROUGH 1983 ONLY)
A = 1955-63* F = 1968 L = 1973 S = 1978
B = 1963-64* G = 1969 M = 1974 T = 1979
C = 1965 H = 1970 N = 1975 U = 1980
D = 1966 J = 1971 P = 1976 W = 1981
E = 1967 K = 1972 R = 1977 X = 1982
Y = 1983
* Cornwall's & La Scala's used "A" 1963 and "B" for 1964; the first Cornwall to use a letter code was 3A09, shipped in August of 1963.
DATES DESCRIPTION EXAMPLE
1984-1989 YYWW#### 89261234
1. YY = year (e.g. 89 = 1989)
2. WW = week of the year (e.g. 26= last week in June)
3. The WW can also be a single digit for weeks 01 through 09; e.g. 877#### (mid February 1987)
4. In the early-mid 80's (generally starting in 1984), Klipschorn's had two serial numbers assigned to each speaker; one for the bass bin and one for the top section. The bass bin had an "L/F" at the end of the "type code" (see further below) and the top section had an "H/F" at the end of the type code.
5. This coding was is used on Chorus, Forte & Academy
DATES DESCRIPTION EXAMPLE
1990-1997 DOYY2Y1#### 135791234
1. DOY = day of the year (e.g. 135 = 14 May)
2. Y2Y1 = 2nd digit of year, 1st digit of year (e.g. 79 =1997)
3. This coding was is used on Chorus, Forte & Academy
DATES DESCRIPTION EXAMPLE
1998- 2000 YY WW #### 00281234
1. YY = year (e.g. 00 = 2000)
2. WW = week of the year (e.g. 28 = 2nd week in June)
3. This coding was is used on Chorus, Forte & Academy
VI. HERITAGE DRIVER CODES:
1. Driver Manufacturing Date Codes: Example: 9429 = 1994, 29th week of the year (1994).
2. This numbering system is derived from the Electronics Industry Association (EIA) coding. The EIA did not issue Klipsch with an EIA prefix.
3. For further information on the EIA system, see:
http://www.provide.net/~cfh/pots.html
Note: This site has additional manufacturers (including non-Klipsch components and an excellent resource for dating non-Klipsch equipment by the EIA "manufacturer & date-code" system.
4. Klipsch Driver Manufacturer Codes:
Example: K-33-E would be the "Klipsch", part type 33 (15") woofer from Eminence. The suffix letter code generally referred to the Klipsch assigned origin/ manufacturer of the driver.
B = CTS (Chicago Telephone Supply), Brownsville TX
P = CTS in Paducah KY (woofers only)
R = Rola (an additional "R" either stamped or handwritten also indicated replacement (often seen on K22's and K- 24's)
D = K-77-D; From 2006 to the present. Essentially a K-77-F (see below) with an integral recessed mounting flange. Permits flush mounting of the tweeter from the rear, per the “Z” brackets for pre Feb 1983 Klipschorns (KH Update kit: part # 1006969)
F = Philippines supplier that purchased the EV tooling (e.g. K-77-F)
EV = Electro Voice (early K-33's e.g. "EV-15WK", also EV 1828 was used as the K-56 for Cornwall in 1974)
G = Atlas (for K-55-G for Cornwall 1981-1983)
J = Jensen (Also used for University drivers in mid- 1950s; e.g. K-5-J - University model 5A HF, and SAHF)
H = Heppner (K-52-H in Cornwall-II’s)
K = Klipsch (Pyle - Klipsch purchased Pyle and drivers were assembled in Hope Arkansas and at Pyle in Huntington, Indiana)
E = Eminence (Primarily woofers)
V = Atlas (see also notes below)
M = Electro Voice (also for the Eminence K-33-M in 1967)
X = Atlas (e.g. K-55-X)
Ti = Titanium series (new design with titanium diaphragms)
5. The V on the midrange & tweeters can also indicate 'video shielded'
6. A significant number of "replacement" drivers, e.g. late model K-53's, K-76's will have no manufacturing code or date code, e.g. "blank" as in nothing at all.
7. On Heresy drivers, the number K53 indicates the driver/horn combo part number, which is a K52 driver and K701 horn.
8. Electro Voice also produced the "round magnet" T-35 tweeter, but later versions were simply labeled K-77. The first shipment of Electrovoice T-35 tweeters designated as the K-77 were received on 26 August 1959. The K-77 is first used in a Klipschorn with the serial number 1445 on 15 October, 1959.
9. Electro Voice also produced a K-56 (EV-1828) as a temporary replacement for K-55's in 1974. Found on Cornwall's, La Scala’s, and Belle's produced in that year.
10. Atlas produced the K-55X's (PD-5VH); and the PD-5VH is the K-55V (still available from Atlas and other vendors)
11. Stephens (P52LX2) woofers were used from 1949 through 1953 on the Klipschorn's. In 1953, the Stephens P103LX2 was used. In 1954 University mid/and high drivers were also used.
12. From 1950 through 1961, the Stephens woofers were used interchangeably with the Electro Voice EV-15WK woofer and the early Jensen K-33-J's in the Klipschorn's.
13. These codes also apply to drivers used in Chorus & Forte’s
KLIPSCH S/N FORMATS
DATES DESCRIPTION EXAMPLE
1946-1947 ### (001) ending #021
1948-1961 #### (0121) starting #0121
1946-1961 dates can only be found in log book (eng. Library)
Klipschorns of this vintage had the s/n hammer stamped into the tailboard, woofer access door or inside the woofer chamber.
1962-1983 ##letter#### (20Y1234)
1962-1983 Letter format
A=62 F=67 K=72 R=77 X=82
B=63 G=68 L=73 S=78 Y=83
C=64 H=69 M=74 T=79
D=65 I=70 N=75 U=80
E=66 J=71 P=76 W=81
1984-1989(?) YY WW #### (89281234)
1990-1997(?) DOY Y2Y1 #### (135791234)
DOY= day of the year
Y2Y1=2nd digit of year, 1st digit of year
1998-2000 YY WW #### (00281234)
YY=year (i.e. 99,00…)
WW=week of the year
Date code on drivers (1994) Example – 9429 = 1994, 29th week of the year / YYWW
Expanded version from Groomlakearea51 on the Klipsch Forums:
KLIPSCH HERITAGE REFERENCE DATA - (V-2.1 - 03 SEP 2009):
SECTIONS:
I. GENERAL
II. READING HERITAGE MODEL & SERIAL LABEL CODES
III. SPEAKER TYPE CODES
IV. SPEAKER WOOD/FINISH CODES
V. SERIAL NUMBER CODES
VI. DRIVER CODES
VII. DRIVER TYPES BY APPLICATION
VIII. GRILLS TYPES & CLOTH CODES
IX. LOGO DESIGNS
X. HERITAGE PRODUCTION NOTES & TIME LINES
I. GENERAL:
1. This information generally applies to the Klipsch Heritage Series; but also includes some selected information on finishes, grill cloth options and emblems/ logos used on certain later models.
2. The data is generally correct; the author assumes full responsibility for errors.
3. Sources include, but are not limited to:
Discussions, data reviews, and corrections by Klipsch employees;
Discussions and physical data provided by owners of Klipsch speakers; independent technicians and sources specializing in Klipsch;
Klipsch forum threads (extensive source material is available);
Klipsch reference documents, information sheets, data specs, time line sheets, etc.
Direct examination of Heritage series products.
4. Corrections, additions, and in particular photographs, are most welcome, and as Klipsch owners and forum members contribute additional data, the document will be updated.
II. READING THE KLIPSCH MODEL & SERIAL LABEL CODES:
1. All of the "labels" through 1990+ are functionally similar. The Heritage series until 1984 were relatively simple: they were hand written, and first line was the model and wood/finish type, and the second line was the serial number (serials discussed further below).
2. Starting in 1984 and continuing until approximately 1988, the labels were similar, however used a "stamped" serial number identification below the model & finish code. By 1988-1989, the labels were "computer" generated, with the model, finish and other coding in a second "line".
EXAMPLE:
KC-BB
15T252
This tag would be for a Klipschorn, Type-C (non-"collared"), birch, black lacquer finish, serial number: 15T252 (made in 1979)
III. HERITAGE SPEAKER TYPE CODES:
** Does not include the "Rebel" or "Shorthorn" series.
C = Cornwall
CD = Cornwall "decorator" with flush motor board and no grill
BK = Belle Klipsch
H = Heresy
HD = Heresy "decorator" with flush motor board and no grill
LS = La Scala
KB = Klipschorn - Model Type B, "collared"
KC = Klipschorn - Model Type C, no "collar"
KD = Klipschorn - designer type (no grill, made through April 1987)
IV. HERITAGE SPEAKER WOOD/FINISH CODES:
1. Until the late 70's-early 80's (and again in 2008 on Heritage models), customers could special order a number of exotic veneers.
2. It should be noted that until May, 2001 there were almost 100 different finish, grill cloth, and riser 'combinations' or variants that could be ordered for the Heresy’s and up to 75 versions of the Klipschorn.
3. In the mid-late 90's, Klipsch generally ceased most special order veneers and raw birch was also discontinued on most models, except Heresy-II's.
4. Material for raw birch is/was Georgia-Pacific cabinet/furniture grade 7 ply (5 inner standard grade plies and the two outer very-fine grade plies).
5. Risers for the Heritage series were originally optional, and there was a long base for horizontal placement of standard Cornwall's.
6. Heresy risers were generally "straight" until the late 1980's, and were still an option until the late 90's. In the late 1980's the "slant" style became the general standard. Slant risers appeared in the 1970's on Heresy-Is, but are not seen often. Currently the US version Heresy is shipped with slant riser, elsewhere in the world they can be ordered with or without the riser.
7. "Oiled" finish refers to the factory application of a high quality furniture grade wood oil that fills the pores of the wood and seals the finish. The type of oil is similar to a Watco "danish" or "rejuvenating" oil. Oiled finishes require a routine "oiling" with a light non-buildup type of furniture grade wood oil.
8. "Lacquer" refers to the application of one or two thin coats of a clear semi-gloss lacquer sprayed on the cabinet and motor board prior to installation of drivers. That lacquer was obtained from various vendors and currently is a #40 sheen, semi-gloss lacquer from Valspar/OPEC. Lacquer finishes only require a routine wiping off with a clean dry cloth to maintain the finish.
9. For "Black Lacquer" finishes, the factory used a #40 sheen lacquer primer, then #40 sheen black lacquer, with a clear #40 sheen to protect the black finish.
10. Generally, most veneered Heritage products had the rear panels/ sections sprayed with black lacquer primer. Starting in late 1983 and continuing to this day, the rear panels of the Heritage models are now sprayed with a coat of primer, then a coat of "textured" semi gloss, and a top coat of clear lacquer.
11. An option to have raw birch stained was also used, but not often seen. The stain was applied by spraying, and the serial number stickers generally indicated this option. Example: H-WS would have been a Walnut stained Heresy made from "raw-birch". This option was more commonly seen on La Scala's.
CODE ** WOOD FINISH REMARKS
Ash Lacquer Uncommon
AO Ash Oiled Uncommon
BB Birch Black Lacquer Common
BR Birch Raw Common
BL Birch Lacquer Common
BW Birch White Lacquer Rare Spec Order
CL Cherry Lacquer Uncommon **
CO Cherry Oiled Uncommon
D-BR Birch Raw Designer (No Grill)
D-BB Birch Black Lacquer Designer (No Grill)
FL Fir Lacquer Rare
FO Fir Oiled Rare
FB Fir Black Lacquer Late Models Only
F Fir Firzite Rare - Marine Grade
HL Hickory Lacquer (reported-unconfirmed)
MEL Macassar Ebony Lacquer Rare Spec Order
MEO Macassar Ebony Oiled (unconfirmed)
MHL Mahogany Lacquer Rare Spec Order
MHO Mahogany Oiled Rare Spec Order
MHR Mahogany Raw Rare Spec Order
ML Maple Lacquer Rare"Hardrock Maple"
MO Maple Oiled Rare"Hardrock Maple"
MO* Medium Oak Oiled Late 90's Models
OL Oak Lacquer Common (Red Oak)
OO Oak Oiled Common (Red Oak)
PNL* Persian Nut Lacquer Rare Spec Order
RRL* Rambling Rose Lacquer Rare Spec Order
PL Prima Vera Lacquer Rare Spec Order
PR Prima Vera Raw Rare -Early
RL Rosewood Lacquer Brazilian species
RO Rosewood Oiled Brazilian species
TL Teak Lacquer Uncommon
TO Teak Oiled Uncommon
TWL Tigerwood Lacquer Rare Spec Order
TWO Tigerwood Oiled Rare Spec Order
WL Walnut Lacquer Common
WO Walnut Oiled Common
WS Birch (stained) Stain Walnut on Birch
ZL Zebrawood Lacquer Rare Spec Order
ZO Zebrawood Oiled Rare Spec Order
* "Persian Nut" and "Rambling Rose" are not an actual wood species; they were made from linear cut birch or walnut wood which was dyed with specific hues/colors, re-glued into alternating color layers and then rotary cut into the respective veneer types to achieve the effect.
** Lacquer finish on early production Cherry was uncommon.
*** See also the list of new veneers available from Klipsch as of March 2008:
(http://forums.klipsch.com/forums/t/102665.aspx)
Production codes that will be assigned are unknown at this time.
V. HERITAGE SERIAL NUMBERS:
1. Based upon additional information related to the use of letters starting in 1955, the 1962-1983 coding has been modified to reflect that information.
2. The serial number was written on the paper serial tags and die stamped on the back edge of the top panel (inside top portion in LS). This practice was not used on later "MDF" cabinets for Heresy's, etc. Serial numbers can often be found written in pencil on the inside of some of the Heritage series, most notably Klipschorn's and Belle's.
3. While the 1946-1961 manufacturing dates can only be found in the Engineering Library in Indianapolis, accurate specific dates for the day of manufacture may also be found by close examination of the interior of the speaker cabinets. As an example there were often small inspection tags stapled inside the cabinets and penciled notations with dates inside the cabinets. An example of the production inspection stickers was the use of "PRIDE" stickers inside some models. These were used in the early through mid-1980's.
4. Additional letters stamped in the edges of Heritage series made from birch plywood, and on the poplar and ash "lumber core" as the substrate, were "USA" and/or the cabinet builder's and final sander's initial(s). For reasons of protecting their right to privacy, I have not identified the names of those superb craftsmen (and women).
DATES DESCRIPTION EXAMPLE
1946-1947 ### 001-020 (ending at #20)
1. 1946 & 1947 Klipschorn serials #002 - #013 were made by Baldwin Piano.
2. Serial numbers #14-20 were made for purchasers in Paul Klipsch's "tin shack", before the move to the newly built factory. There are no Klipschorn's with a serial number between 21 and 120.
DATES DESCRIPTION EXAMPLE
1948-1961 #### (starting #0121)
From 1948 though 1961, Klipschorn's had the serial number stamped into the tailboard, woofer access door, or inside the woofer chamber.
3. The number Klipschorns produced in 1948 is unknown; a total of 26 were made in 1949
DATES DESCRIPTION EXAMPLE
1955-1983 ##letter#### 20Y1234
1. Letters that look like numbers (e.g. I, O, Q, V) were not used. "S" is frequently misread as a "5" and Y has been confused with an X on occasion.
2. July 29, 1955 was the last day for the four digit serials (i.e. 1811). After that the "number- letter-serial" system went into effect (2 August 1955). The first "number-letter-serial" speaker was produced on the 2nd of August 1955; that serial number was 1A812.
3. In the 1955-1983 serial method the first, or prefix "digit(s)" before the year letter represents the sequence of production for each 1000 units. The suffix digits after the letter code will always be three digits - 001 through 999. For example 1C999 would be the 999th unit built, and 2C999 would be the 1999th built in 1965 C = 1965).
4. These digits before & after the year code apply only to that type of speaker.
5. The year code letter only identifies the year in which that number occurred.
6. As an example, if you have a pair of Klipschorn's and one of the serial numbers is 15T252, then by 1979 there had been 14,151 Klipschorn's made (Klipschorn's made in 1946-1947 were serial numbered from 1 to 20, and in 1948 started with #121, skipping #21 through #120).
7. For a pair of 1979 La Scala's, with serial number 22T403, it means there were 21,403 La Scala's made to that point.
8. Another example: A pair of Belles from 1979 has the serial number 3T242 and 243. This means that in 1979 these Klipsch Belles, the 2,242nd & 2,243rd, were made.
YEAR OF MANUFACTURE (1955 THROUGH 1983 ONLY)
A = 1955-63* F = 1968 L = 1973 S = 1978
B = 1963-64* G = 1969 M = 1974 T = 1979
C = 1965 H = 1970 N = 1975 U = 1980
D = 1966 J = 1971 P = 1976 W = 1981
E = 1967 K = 1972 R = 1977 X = 1982
Y = 1983
* Cornwall's & La Scala's used "A" 1963 and "B" for 1964; the first Cornwall to use a letter code was 3A09, shipped in August of 1963.
DATES DESCRIPTION EXAMPLE
1984-1989 YYWW#### 89261234
1. YY = year (e.g. 89 = 1989)
2. WW = week of the year (e.g. 26= last week in June)
3. The WW can also be a single digit for weeks 01 through 09; e.g. 877#### (mid February 1987)
4. In the early-mid 80's (generally starting in 1984), Klipschorn's had two serial numbers assigned to each speaker; one for the bass bin and one for the top section. The bass bin had an "L/F" at the end of the "type code" (see further below) and the top section had an "H/F" at the end of the type code.
5. This coding was is used on Chorus, Forte & Academy
DATES DESCRIPTION EXAMPLE
1990-1997 DOYY2Y1#### 135791234
1. DOY = day of the year (e.g. 135 = 14 May)
2. Y2Y1 = 2nd digit of year, 1st digit of year (e.g. 79 =1997)
3. This coding was is used on Chorus, Forte & Academy
DATES DESCRIPTION EXAMPLE
1998- 2000 YY WW #### 00281234
1. YY = year (e.g. 00 = 2000)
2. WW = week of the year (e.g. 28 = 2nd week in June)
3. This coding was is used on Chorus, Forte & Academy
VI. HERITAGE DRIVER CODES:
1. Driver Manufacturing Date Codes: Example: 9429 = 1994, 29th week of the year (1994).
2. This numbering system is derived from the Electronics Industry Association (EIA) coding. The EIA did not issue Klipsch with an EIA prefix.
3. For further information on the EIA system, see:
http://www.provide.net/~cfh/pots.html
Note: This site has additional manufacturers (including non-Klipsch components and an excellent resource for dating non-Klipsch equipment by the EIA "manufacturer & date-code" system.
4. Klipsch Driver Manufacturer Codes:
Example: K-33-E would be the "Klipsch", part type 33 (15") woofer from Eminence. The suffix letter code generally referred to the Klipsch assigned origin/ manufacturer of the driver.
B = CTS (Chicago Telephone Supply), Brownsville TX
P = CTS in Paducah KY (woofers only)
R = Rola (an additional "R" either stamped or handwritten also indicated replacement (often seen on K22's and K- 24's)
D = K-77-D; From 2006 to the present. Essentially a K-77-F (see below) with an integral recessed mounting flange. Permits flush mounting of the tweeter from the rear, per the “Z” brackets for pre Feb 1983 Klipschorns (KH Update kit: part # 1006969)
F = Philippines supplier that purchased the EV tooling (e.g. K-77-F)
EV = Electro Voice (early K-33's e.g. "EV-15WK", also EV 1828 was used as the K-56 for Cornwall in 1974)
G = Atlas (for K-55-G for Cornwall 1981-1983)
J = Jensen (Also used for University drivers in mid- 1950s; e.g. K-5-J - University model 5A HF, and SAHF)
H = Heppner (K-52-H in Cornwall-II’s)
K = Klipsch (Pyle - Klipsch purchased Pyle and drivers were assembled in Hope Arkansas and at Pyle in Huntington, Indiana)
E = Eminence (Primarily woofers)
V = Atlas (see also notes below)
M = Electro Voice (also for the Eminence K-33-M in 1967)
X = Atlas (e.g. K-55-X)
Ti = Titanium series (new design with titanium diaphragms)
5. The V on the midrange & tweeters can also indicate 'video shielded'
6. A significant number of "replacement" drivers, e.g. late model K-53's, K-76's will have no manufacturing code or date code, e.g. "blank" as in nothing at all.
7. On Heresy drivers, the number K53 indicates the driver/horn combo part number, which is a K52 driver and K701 horn.
8. Electro Voice also produced the "round magnet" T-35 tweeter, but later versions were simply labeled K-77. The first shipment of Electrovoice T-35 tweeters designated as the K-77 were received on 26 August 1959. The K-77 is first used in a Klipschorn with the serial number 1445 on 15 October, 1959.
9. Electro Voice also produced a K-56 (EV-1828) as a temporary replacement for K-55's in 1974. Found on Cornwall's, La Scala’s, and Belle's produced in that year.
10. Atlas produced the K-55X's (PD-5VH); and the PD-5VH is the K-55V (still available from Atlas and other vendors)
11. Stephens (P52LX2) woofers were used from 1949 through 1953 on the Klipschorn's. In 1953, the Stephens P103LX2 was used. In 1954 University mid/and high drivers were also used.
12. From 1950 through 1961, the Stephens woofers were used interchangeably with the Electro Voice EV-15WK woofer and the early Jensen K-33-J's in the Klipschorn's.
13. These codes also apply to drivers used in Chorus & Forte’s
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