Research: Epiphone serial numbers and production estimates (1931–1956)
Author: Felix Wiedler (Version: October 2017, with updates)Below a summary of my research findings regarding Epiphone's serial number (SN) systems and estimated production figures – based on the data analysis of approximately 4300 Epiphone instruments and amplifiers (SN/model pairs, documented in c. 50'000 photos). 1
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Epiphone's stringed instruments of the 1931–1956 period typically show a visible serial number – high-end models the same way as lower-priced instruments. Several different SN systems were used depending on instrument type and time period – generally employing consecutive, ascending numbers following the timeline of production (see detailed analysis in chapter 3):
B. Acoustic instruments 1943–1956, including electric hollowbody
instruments 1950–1956: SN starting at 50000 and ending
around 69637. (SN on label inside
Estimated total production: 19638 units.
C. Electric instruments 1935–1942: SN starting possibly
around 1 and ending around 7219. (SN stamped
Note that the earliest electric instruments from 1935 don't bear a SN. During WW2 electric instrument production was halted.
Estimated total production (with SN): 7219 units.
E. "Special SN" electric guitars 1949, electric Hawaiian guitars
1950–1956: Some electric models from 1949 and all
Hawaiian guitars from 1950 onwards use "special" SN systems. (SN stamped
on headstock or bridge unit.) Estimated total production: 563
Taking into account the assumed lowest and documented highest number of these SN systems, we can calculate a total production estimate of Epiphone instruments: 45579 units. 4
My research has led to a slightly revised dating approach for Epiphone SNs. See Fig. 1 + Fig. 2 "W revised" (referring to Wiedler) vs. "F traditional" (referring to the charts published by Fisch/Fred). 5
Fig. 1: SN dating: acoustic and
1950s electric hollowbody instruments (SN systems A + B). See documented
instruments in registry database.
revised – Wiedler
(approx. first SN)
|F traditional –
(approx. first SN)
Fig. 2: SN dating: electric Hawaiian guitars and pre-1950 electric hollowbody instruments (SN systems C, D, E). See documented instruments in registry database.
revised – Wiedler
(approx. first SN)
|1946–1949||7300 Zephyr Hawaiian
15000 Century Hawaiian
25000 Zephyr Spanish
60000 Century Spanish
75000 Zephyr DeLuxe
85000 Zephyr DeLuxe Cutaway
|1949||3000, 4000 Kent Spanish
75 Kent Hawaiian, Century Hawaiian
100 Alkire Eharp
|1950–1956||9000 Electric Hawaiian|
3. Understanding Epiphone's SN systems – number ranges assigned to model batches
Epiphone's SN systems generally appear to follow this pattern: a range of consecutive, ascending SNs are found on instruments of one single model; a subsequent range of SNs appears on instruments of another single model; and so on (see example Fig. 3).
Fig. 3: Sample excerpt from Registry database.
My understanding of this pattern is that these model-specific SN ranges correspond to production runs – i.e. a run or batch of a model was assigned SNs of a consecutive number range. The subsequent SN range was then assigned to the next following production run of a different model, and so on. This means: Epiphone's ascending SNs reflect a chronology of production. 6
Note that batch sizes varied considerably – from possibly a single special order instrument up to a hundred or more instruments of the same model in a consecutive SN range. 7
Based on these findings that ranges of consecutive SNs were assigned to batches of the same model, we can extend our research: To reconstructing missing model production data – by using interpolation and extrapolation algorithms on our SN data.
Interpolation methods enable us to "fill in" undocumented SN/model pairs within assumed batches – i.e. ranges of SNs exclusively assigned to one model (see example in Fig. 4).
Fig. 4: Interpolation of missing SN/model pairs within an assumed batch/SN range of the same model (example). Note that in many cases the very first and last SNs of a batch cannot be determined as long as there are SN gaps to the adjacent batch of a different model. However all missing numbers between the lowest and highest documented SNs of an assumed model batch can be "interpolated" i.e. tentatively identified (with high probability) to also be examples of that same model.
Applying this interpolation method to my registry data leads to some remarkable results: While my documented SN/model pairs currently represent about 9% of the estimated total instrument production, the addition of interpolated SN/model pairs boosts this ratio to 56% (see Fig. 6 for an excerpt).
According to our theory, the figures presented in column "Registry+interpolated" can be seen as "minimum" production estimates for the respective models, i.e. how many were "at least" produced. I consider these "minimum" estimates as pretty reliable, although they are not to be mistaken as total production estimates.
However, the data also allows for calculating rough estimates of total production numbers for each model and period – by employing approximation (extrapolation) methods. Extrapolation algorithms tentatively attribute undocumented SN/model pairs in gaps between two (assumed) adjacent model batches – see example in Fig. 5.
Fig. 5: Extrapolation of SN/model pairs between two assumed model batches (example): The 6 undocumented SNs 55236–55241 are likely to include models of the previous batch (=Triumph) and/or subsequent batch (=Blackstone), although their relative distribution is not known. Our applied extrapolation algorithm equally assigns 50% of the missing SNs to the previous model and 50% to the subsequent model – in this example 3 Triumphs and 3 Blackstones. Note: Theoretically, such SN gaps may include a small batch of a third model.
Note: These extrapolated totals in the right column of Fig. 6 are ballpark figures and do not claim to be exact. But they give a rough idea – e.g. if total production of a model was likely in the dozens, in the hundreds, or in the thousands.
5. Examples of model production estimates
Below some examples of estimates for certain models/production periods.
|Total El Hollowb '50s||552||3109||4891|
|Total Ac + El Hollowb '50s||3201
|Percent Ac + El Hollowb '50s||9.2%
|El Hollowb pre-1950||347||2933||4087**|
|El Hawaiian all||468||4083||6552**|
- The estimated total production sums up to approx. 45500 units – roughly 30000 acoustic guitars + mandolins, plus 15500** electric stringed instruments.
- Acoustic archtop guitars account for approx. 27000 units – leaving all other instrument types far behind. Triumph and Zenith were the highest production models, with estimated totals of more than 5000 units each over the years.
- Other acoustic instrument types were a relatively small affair – approx. 2000 flattop guitars and 1000 mandolins in total.
- Electric instrument production 1935–1956 includes approx. 9000** electric Spanish hollowbody guitars, plus 6500** electric Hawaiian steel guitars.
- During the 1950–1956 period, electric and acoustic instruments were produced in similar numbers – around 5000 units of each type in total.
- The registered + interpolated SN/model pairs combined cover 56% – i.e. about every second manufactured instrument – of the estimated total production 1931–1956.
- * Note: For models produced in very small numbers (e.g. Tudor, Empire, Windsor, some flattops, etc.) the extrapolated totals are inherently unreliable due to the relatively small data sample – i.e. the calculated figures are typically too high.
- ** Note: Totals based on a theory of separate SN systems for pre-war electric instruments and amplifiers. 11
The chart in Fig. 7 shows an example of model-related data on a timeline – for the pre-war Emperor:
- Documented in our registry database are 80 Emperors with a SN from the pre-war period.
- By adding interpolated SNs (from within assumed batches, as explained in Fig. 4) we can conclude with high probability that at least 236 pre-war Emperors were produced.
- Adding extrapolated SNs (from the gaps before the first and after the last documented SN of assumed batches, as explained in Fig. 5) results in a ballpark estimate of around 379 pre-war Emperors in total.
- The SNs appear to be grouped in 11 Emperor model batches (plus one batch of Soloist cutaway models); pre-war production of the Emperor seems to have peaked around 1939 – 3 batches, totaling likely more than a hundred Emperors built in a year.
||Est. total extrapol||Extrapol
The chart in Fig. 8 shows an example of a comparatively high interpolation ratio due to a low number of large model batches:
- Acoustic instruments of 1947 (W year) are currently assigned to SN range 55850–57099 = 1250 units.
- According to our data, 5 different instrument models were produced in this SN range – grouped in 10 model batches: 3 batches of Blackstone, 1 batch of Broadway, 2 batches each of DeLuxe, Spartan + Triumph.
- Based on the data of only 112 registered SN/model pairs, interpolation allows for reliable identification of 1094 SN/model pairs = about 89% of the estimated 1250 instruments in that range/period.
- About 138 SNs are placed outside assumed model batches and can not yet be reliably assigned to models (see column "Extrapol"). However estimated model totals can be calculated by extrapolation methods (see column "Est. total extrapol").
- The Broadway batch in the SN range 56338–56479 is a good example to demonstrate our extrapolation method: Currently there are 15 unidentified SNs in the gaps to the adjacent model batches – 3 SNs before the lowest and 12 SNs after the highest identified SN. Theoretically, the unidentified SNs could include any number of Broadway models between 15 (all) or 0 (none). Our approximation (extrapolation) algorithm calculates 8 additional Broadways (50% of 15 = 7.5, rounded to 8).
Although these estimates are still somewhat speculative and approximate at best, they are certainly based on a much larger data sample of higher quality than that on which previous research was based. And the estimates will keep getting more precise as the database of documented SN/model pairs is growing.6. SNs of Epiphone amplifiers
Epiphone used several different SN systems for their amplifiers over the years (see Fig. 9). (SN stamped on logo plate or control plate.)
The amps' SN systems appear to be less straightforward than those used for the stringed instruments. We observe that in some periods certain SN ranges appear to have been reserved for certain models – with ascending numbers, however not always applied in strictly chronological order. Therefore, our dating of amps is mainly based on features (e.g. EIA date codes of electronic components). 9
Furthermore, it is questionable wether all numbers in the respective SN ranges were indeed assigned to manufactured units – making it unfeasible to calculate production figures by interpolation or extrapolation methods (as done with stringed instruments). 10
For these reasons I don't present total production estimates for Epiphone amplifiers at this stage of my research. 11
Fig. 9: SN dating: amplifiers. Note model-specific SN ranges in some years. See documented amps in registry database.
/ amplifier models (approx first SN)
|1936||1 Electar, Model C, Model M|
|1937||700 Model C, Model M|
Model C, Model M, Super,
3000 Model EL, Model M
4000 Model M
9000 Century, Coronet
10000 Century, Coronet
|1946||8500 Zephyr, Dreadnaught
40000 Century, Zephyr
|1955–1956||1000 Century, Zephyr, Dreadnaught|
General note: My estimated SN dating and production figures are approximations that are subject to correction as new evidence material surfaces.
1) Our research includes acoustic and electric instruments of the guitar and mandolin families. Epiphone banjos and bass viols (which had their own SN systems each) are out of the scope of my research. Recommended links: Epiphone Upright Bass Research project (see note 7) and Banjo Hangout – Dating an Epiphone Banjo from the 1925-1930s era.2) When electric model production was relaunched in 1946, new ranges of SNs were applied to most models – with numbers consisting of a model-specific prefix (2–3 digits) and a serial suffix (3 digits, ascending consecutive numbers starting with 000):
- 15xxx = Century Hawaiian
- 25xxx = Zephyr Spanish
- 60xxx = Century Spanish
- 75xxx = Zephyr DeLuxe
- 85xxx = Zephyr DeLuxe Cutaway
- 100xxx = Console
An exception (and not included in this figure) is the Zephyr Hawaiian model which carried on with the pre-war SN system (see C), starting around SN 7300 in 1946 and ending around SN 7908 in 1949 (=approx. 609 units in total).
3) The year 1949 brought significant changes to
Epiphone's model lineup and likewise to their SN systems. Early
examples of the newly introduced Kent Spanish model have "special" SNs
in the 3000s and 4000s (stamped on headstock), before switching to SN
system B by 1950. Documented examples of the new Kent Hawaiian show
"special" SNs in the 75 to 171 range (stamped on headstock). In the
early 1950s all electric Hawaiian guitars switched to SNs in the 9000s
(stamped on bridge unit). Due to the yet unclear logic behind the
applied "special" SN systems, production totals for these models are
difficult to estimate and therefore very approximate.
Also included in this group is the Alkire Eharp, an electric Hawaiian model custom built for and exclusively sold by musician Eddie Alkire in the late 1940s; the model had its own SN system starting around 100.
4) Generally, our production estimates are based on the assumption that every number in the respective SN ranges was assigned to a manufactured instrument. Theoretically there is a possibility that certain numbers may have been omitted and not used for whatever reason. Certainty in this matter will grow as the gaps of undocumented SNs in our Registry continue to be filled with data.
5) Fisch, J. and L.B. Fred (1992), Epiphone: The House of Stathopoulo, p.291ff.
Fisch/Fred's "traditional" Epiphone SN dating charts presented slightly revised data originally published in Tom Wheeler's important book: Wheeler, T. (1982), American Guitars: An Illustrated History, p.40. Wheeler had based his Epiphone SN dating on inventory records of a music store – Pettey Music Co in Pittsburgh PA. This fact suggests that Wheeler's SN/year chart related to the date when an Epiphone instrument was present at that store – which typically must have been at least a few months after it had entered production at the factory.
In contrast, our "W” date always refers to the estimated date when the respective Epiphone instrument/SN entered production – i.e. NOT the date it was finished, left the factory, or was sold by a store. It can be assumed that shipping/sale dates of individual instruments from the same production period (or even the same batch) could vary considerably – i.e. some selling quickly, while others remained unsold for months or longer (see note 6).
This (partly) explains the differences to the "traditional" dating, which ultimately relied on Tom Wheeler’s research based on inventory lists of one single retail store.
6) Epiphone's SN systems appear to be similar in
concept to the SNs of C.F. Martin & Co: instruments within a
(typically model-specific) production batch were assigned a
consecutive SN range – i.e. the ascending SNs reflect the chronology
of instruments entering production as part of model
batches. Which means: SNs are not inherently related to the
date of shipping to a customer/dealer (see note 5).
In contrast, Gibson's SNs (pre-WW2) generally appear to relate to the completion/shipping date of an individual instrument: i.e. Gibson instruments of the same production batch may bear SNs which are sometimes wider apart – indicating some examples shipped quickly (receiving a lower SN), while other examples remained uncompleted for some time and shipped significantly later (receiving a higher SN); for marking/identifying instruments of the same production batch Gibson used a second numbering system – the Factory Order Number (FON); see Joe Spann's invaluable research published in: Spann, J. E. (2011), Spann's Guide To Gibson 1902-1941.
8) The Epiphone Upright Bass Research Project by Wendy Staley is documenting Epiphone basses and their SN systems. According to the research, an estimated total of approximately 3087 basses was produced during the 1940–1956 period, with SNs assigned to the following production years:
- 1940–1942: SN 100–715 (SN stamped at pegbox, earliest at bottom)
- 1946–1951: SN 716–1682 (SN stamped at end of fingerboard)
- 1952–1956: SN 1706–3187 (SN stamped at bottom)
9) The somewhat irregular and partly confusing SN scheme for amps started around 1938, with the higher amplifier models (Model M/EL, Zephyr, Dreadnaught) switching to SNs stamped on their control plates, while the lower models (Century, Coronet) continued to receive SNs on (pre-)stamped Electar logo plates as before. Subsequently until WW2, it appears that specific SN ranges were reserved for each group – distinguished by the initial digit(s) of the 4–5 digit numbers:
- 3xxx, 4xxx = Model M/EL
- 5xxx, 7xxx, 8xxx = Zephyr/Dreadnaught
- 19xx–2xxx, 6xxx, 9xxx, 10xxx = Century/Coronet
- 30xxx = Dreadnaught
- 35xxx = Zephyr
- 40xxx = Century
10) Example: there is only one amplifier documented with a SN in the entire 4000s range (SN 4042: Model M AC-DC).
11) In an earlier stage of our research we assumed that the earliest electric stringed instruments and amps used one shared SN system (as opposed to two separate systems covering the same number range): This theory was based on the fact that there wasn't any example of an identical SN on units of each type documented – until at least 3 exceptions surfaced:
- SN 1342: Model M Spanish + Model M Amplifier
- SN 2488: Model M Hawaiian + Century Amplifier
- SN 5220: Model M Hawaiian + Zephyr Amplifier
Carter, Walter, and Jimi Stratton. Epiphone: The Complete History. Hal Leonard Corporation, 1995.
Carter, Walter. The Epiphone Guitar Book: A Complete History. Hal Leonard Corporation, 2012.
Fisch, Jim, and L. B. Fred. Epiphone: The House of Stathopoulo. Amsco Publications, 1996.
General or other makers:
Gruhn, George, and Walter Carter. Acoustic guitars and other fretted instruments: a photographic history. GPI Books, 1993.
Gruhn, George, and Walter Carter. Gruhn's guide to vintage guitars: an identification guide for American fretted instruments. GPI Books, 1991.
Gruhn, George, and Walter Carter. Gruhn's guide to vintage guitars: an identification guide for American fretted instruments. Updated and revised 3rd edition. Hal Leonard Corporation, 2010.
Johnston, Richard, and Dick Boak. Martin guitars: A history.
Vol. 1. Hal Leonard Corporation, 2008.
Johnston, Richard, and Dick Boak. Martin Guitars: A Technical Reference. Vol. 2. Hal Leonard Corporation, 2009.
Spann, Joseph E. Spann's Guide to Gibson 1902-1941.
Centerstream Publications, 2011.
Wheeler, Tom. American guitars: an illustrated history. Harper & Row, 1982.