Dating a Traynor amp using the three-, four-, or seven-digit serial number orthe codes on filter capacitors/circuit breakers.Three-digitserial numbersFour-digitserial numbersSeven-digitserial numbersFilter caps/Circuit breakerscodesOther datesetc.Three-digitserial numberson a Bass-Mastermight indicate that the amp is from 1965 or 1966, before the four-digit serialnumbers were used.The circuit in [that amps] is built on a phenolic turret board instead of theFender style fibre board used [later.][...] it appears that Traynor/Yorkville used three digit serial numbers up until 1968. [An example is an] YBA-1A Bass Master Mark II [...] with the serial number M 601 [...] [whose] potentiometers date from 1968 [...] [and on which] 'Range Expander' is screened below the controls, not above.(Eric Knudsen,Rob Mercure,Scott)Four-digitserial numbersseem to follow this pattern[I assume my Bass-Master, YBA-1 is from 1971, serial n. 5XXX]1966 0XXX1967 1XXX1968 2XXX1969 3XXX1970 4XXX1971 5XXX(dhr)Seven-digitserial numbersare coded as followss/n: 1020629First digit: Last digit of year of production (1 ^= 1971, 3 ^= 1973)Second and third digit: Month of production (01 ^= Jan., 11^=Nov.)Last four digits: Numbered unit produced within that year?(JRogersjr)Filter caps/Circuit breakerscodesdates coded as followsMallory capacitor code 235-7051Y:235 is Mallory's EIA code, 51st [week] of 1970Mel Rain Corp circuit breaker code 834-7305:[834 is Mel Rain Corp's EIA code,] 5th week of 1973Mel Rain Corp circuit breaker code 834-7328:[834 is Mel Rain Corp's EIA code,] 28th week of 1973(Eric Knudsen)Other datesetc.Dates on schematics etc.Often there are schematics inside an amp with sometimes hand-writtenrevision dates on them, or on other pieces of paper, e. g. quality controletc.(-)
The history of Traynor Amps, from the early beginnings in 1963 to the break-up between Peter Traynor and Jack Long of Yorkville Sound Ltd. in 1976.Details of the various Traynor amp models, and opinions about them.Dating a Traynor amp using the three-, four-, or seven-digit serial number orthe codes on filter capacitors/circuit breakers.Common modifications for tube amps, especially suited for Traynor tube amps.Interesting sites and places on and off the net, concerning tube amps, their use, their sound, and their maintenance.
traynor amp serial number dating
Since I primarily collect amps by Fender, and guitars by Gibson, Fender,Martin, National, Epiphone, Gretsch and Rickenbacker, I really can't helpthem with these other less popular brands. As you have probably noticed,there is plenty of information here to help date the brands that I aminterested in. But where does that leave everyone else?Well I'm not one to leave you out in the (informational) cold, so here'ssomething that I use quite often in dating amplifiers and electric guitars.It's called the "source-date code", and it can help determine the approximate age of an electric instrument by the date its componentswere manufactured.Source-Date CodesOn American made vintage gear, the pots and speakers provide an excellent opportunity to date a piece of equipment by referencing their "source-datecode".The source-date code found on pots and speakers gives the manufacturerand date (roughly) when the components were made. It may have been some time before the part was installed at the factory, but it still provides a good approximation of when the gear was made. This is especially helpfulon (less popular) gear that doesn`t have reliable serial#`s or other information to date them.The source-date code will signify the earliest possible date thatthe instrument or amp could have been made. This isn't going to be exact, butit will give you a "ball-park" age. And remember, even the dates indicatedby the pots aren't that exact. For example, if you buy a brand new CTSpot today, they are dated a month or two in advance! It's worth mentioningsince a lot of people rely on pot dates.That said, it's not uncommon for pot manufacturers to post date potsanywhere from a few weeks to as much as 18 months. (The standard todayis no more than 18 months, but back in the 1950s and 1960s, who knows?)Some large parts distributors would even return parts if the date code was"expired" and want "fresh" parts in return. This seems silly,as we're talking about electronic parts not eggs. But if you think about it,parts like electrolytic cacpacitors, this could be an issue. Then theparts maker (like CTS) would have to eat the returned inventory, or sellit off to someone that didn't care about date codes, and probablyat a discounted amount. What I'm saying is that pot and capacitory date codes are nota reliable indicator of guitar build dates. Though they are one piece of the puzzle and something to consider, don't put too much faith into a pot date.The source-date codes are under the framework of the "ElectronicIndustries Association", which is a non-profit organization representingthe manufacturers of electronic parts. The EIA source-date code is anumeric code, assigned and registered by the EIA. It can be stampedor marked on any product to identify the production source (vendor) anddate of manufacturer. Source-date codes have been published by the EIA since 1924. The EIA can be contacted via mail:Electronics Industries Association, 2001 Pennsylvania Ave NW, Washington,D.C. 20006.Consideration and exceptions: Source-date codes weren't an industry standard until after WWII.But I have seen them used on Stackpole pots on electric National guitars as earlyas 1935. The first time date-source codes were published was 1924,so I guess you could see them as early as the late 1920's.Most Fenders from 1966 to 1969 have 1966 dated CTS pots. Apparently CBS/Fender bought a large stock of pots in 1966 that lasted till 1969. On popular Fender models, the pot date can be very close to theactual date of the instrument. On less popular Fender instruments, such as LapSteels, pots can be as much as two years earlier than the actual date of the instrument.Gibson didn't start using pots with source-date codes till 1953 or 1954.Originality.Of course this all assumes the pot or speaker is original. You have to make thatcall. I would suggest checking the solder joints - are they clean? Are the wires of the right era (cloth insulation for older stuff)?If so, you can check the pot or speaker for the source-date code, and determine an approximate age from that.How the Source-Date Code Works.The source-date code on a pot is a 6 or 7 digit code impressed into the casing of the potentiometer. For speakers this code can be 5, 6, 7 or 8 digits long, and it's ink-stamped or paint-stamped on the "bell housing" of the speaker.In either case, the code works the same. The first 3 digits on a pot,or the first 2, 3 or 4 digits on a speaker are the source or manufacturer code.The remaining 3 or 4 digits are the date code. In 3 digit dates code, the 1st digit is the last digit of the year. On 4 digits datecodes, the 1st and 2nd digits are the last two digits of the year.In either case, the remaining 2 digits are the week of manufacture (01 to 52). With this in mind, remember if the last two digits of the source-date codeare greater than 52, you're not looking at the source-date code! Also it's worth mentioning:Sometimes there is a space or hyphen between the manuafacturer code and the year/week code.3 digit date codes were used in the 1940's and 1950's. Stackpole forexample converted from three to four digit date codes in late 1959.4 digit date codes were used in the 1960's and later (this makesdetermining the year much simplier!)On 3 digit date codes, you have to "guess" the decade of the pot or speaker. Usually this isn't too difficult.Pots used by Fender. The middle one is a CTS pot (Chicago Telephone Supply, manufacturer #137) from the 30th week of 1966. The pots on the left and right are Stackpole pots (manufacture #304). Note the different position of the markings, evenon pots from the same maker.Left: The source-date code (285709) on a speaker. In this case, the speakeris made by Rola (285) in the 9th week of 1957 (709). The decade, thoughnot directly shown by the source-date code, was easily determined becausethis particular amp was only made during the 1950s. Note the font styleof the source-date code number always seems to be the same, for all speakermanufacturers.Right: Same thing here. Jensen (220) speaker made in the 41st week of 1959 (941).Pot Source Codes.Here are the most common pot manufacturers (the first 3 digits of the source-date code):106 = Allen-Bradley134 = CentraLab137 = CTS (Chicago Telephone Supply, pots and speakers)140 = Clarostat304 = Stackpole381 = Bourns Networks615 = IRC (International Resistive Company) - see belowFender Products.During the 1950's, Fender used mostly Stackpole (#304) pots. Then in roughly early 1963,they changed to CTS (#137) pots. In 1967 (after CBS bought Fender), Fender boughta HUGE supply of pots from CTS. This supply lasted for over five years. So guitars andamps made as late as 1973 can still have 1967 date codes from this huge 1967 stocking.All during Fender's life as an amplifier maker, then used speakers made byJensen (#220), CTS (#137), Oxford (#465), Utah (#328) and Altec-Lansing (#391). Till about 1961, Jensen was the only Fender speaker supplier. Then from 1962 and later you see Fender using speakers from all the above mentioned makers.National, Valco, Supro Amplifier Products.Note the use of "550" as a source code on these products. Actually, it's not a source code but is a manufacturers code for allNational, Valco, Supro products. Found as second stamping on speakers as adate code 550XXX from 1947 through the 50's and 60's (all the 1940's ampsare generally field coil Rola spkrs).Manufacturer Source Codes.Below are many manufacturer source codes (which are the first 2,3, or 4 digitsof the source-date code).Common Guitar Speaker Manufacturers: 67 = Eminence137 = CTS (Chicago Telephone Supply)220 = Jenson285 = Rola308 = Stromberg-Carlson328 = Utah336 = Western Electric391 = Altec-Lansing416 = Heath465 = Oxford589 = Bogen649 = Electro-VoiceSome tidbits on Jensen:Fender used Jensen speakers until 1972 when all Jensen production (and one engineer) was switched to The Rola Company in Cleveland OH (Rola was a division of Jensen). Prior to the re-structuring of Jensen in '71-'72, Jensen quality had suffered terribly. When Rola started to make speaker for Jensen in 1972, Rola initially used the Jensen 220 manufacturer code, but by the end of 1972 changed to the 285 Rola code. Regaining OEM customer confidence after the Jensen years was a long process due to the Rola-Jensen ties.Other Speaker Manufacturers (thanks to P.Bechtoldt and H.Murphy):24 = Becker101 = Admiral106 = Allen-Bradley 119 = Automatic mfg.125 = Bendix130 = Panasonic132 = Talk-a-Phone145 = Consolidated150 = Crecent169 = Hitachi185 = Motorola188 = General Electric213 = Dearborn Wire230 = Littlefuse232 = Magnavox235 = Mallory - North American Capacitor244 = Muter245 = National251 = Ohmite252 = Dukane258 = Perm-O-Flux 260 = Philco270 = Quam-Nichols274 = RCA277 = Emerson280 = Raytheon300 = Speer381 = Bourns285 = Rola286 = Ross296 = Solar312 = Sylania336 = Western Electric 343 = Zenith371 = Best374 = Cletron394 = Foster Transformer423 = North American Philips (Norelco) 433 = Cleveland449 = Wilder466 = Delco532 = Ward Leonard549 = Midwest555 = Waldom Electronics575 = Heppner649 = Electro-Voice 706 = Pioneer719 = Carbonneau722 = Milwaukee Resistor 742 = Esquire748 = Russell756 = Universal767 = Quincy787 = Sonatone789 = McGregor794 = Harmon Kardon795 = Atlas816 = Dale 828 = Midland840 = Ampex847 = University918 = Oaktron932 = Atlas 1056 = Fisher1059 = Channel1098 = Pyle1113 = Acoustic Fiber Sound1149 = Curtis Mathes1191 = Micro MagnetTubes/Transistors Codes111 = Amperex (USA) 125 = Bendix158 = DuMont185 = Motorola 188 = General Electric Co (USA)210 = Hytron (CBS-Hytron) 260 = Philco 274 = RCA (Radio Corp of America) 280 = Raytheon 312 = Sylvania (Hygrade Sylvania Corp)322 = Tung-Sol 366 = Western Electric 337 = Westinghouse 343 = Zenith Radio Corp (CRT's)466 = Delco980 = Texas InstrumentsCapacitor Codes:102 = Aerovox Corp109 = American Condensor 134 = Centralab135 = Chicago Condensor 163 = Aerovox Hi-Q Division 178 = John E Fast188 = General Electric 235 = Mallory 240 = Micamold 242 = Millen 273 = Radio Condensor Company 296 = Solar 303 = Sprague (every Gibson lover's favorite!) 438 = Gudeman 446 = Good-All 461 = Barker & Wiiliamson 472 = Pyramid 516 = United Condensor 569 = Electrical Utilities Corp616 = Illinois Capacitor (Condensor)648 = American Radionic 658 = Sangamo 705 = Ajax 710 = Standard Condensor 732 = RMC (Radio Materials Corp)885 = Condensor ManufacturersTransformers & Coil Codes: 138 = Stancor (Chicago-Standard)141 = Coil Engineering172 = Ensign Coil 183 = Freed 194 = General Radio 218 = Jefferson Electric 238 = Thordarsen-Meissner 239 = Merit Coil & Transformer305 = Standard Coil352 = Essex (Transformer Division)366 = New York Transformer391 = Altec Lansing-Peerless 394 = Foster Transformer 412 = General Transformer 418 = United Transformer Corp (UTC)489 = Radio-Television Products Corp452 = Empire Coil 503 = Caledonia 524 = Triwec Transformer 549 = Midwest Coil & Transformer 550 = Standard Winding Co 572 = F & V Coil Winding 606 = Woodward-Schumacher637 = Central Coil682 = Electrical Windings 757 = Grand Transformers 773 = Forest Electric776 = Ogden Coil & Transformer830 = Triad 831 = Better Coil & Transformer 843 = Klipsch 878 = Acro Products (Acrosound)883 = Mohawk 892 = American Transformer 897 = Tresco906 = Coilcraft 908 = Aerocoil 928 = Acme Coil & Transformer933 = Magnetic Coil Mfring934 = Oaktron 1005 = Northlake 1052 = Pacific Other Manufacturers 139 = Cinch (Sockets, connectors)152 = Crosley (Radios)194 = General Radio (Test Equip)199 = Hallicrafters (Ham & SW gear)222 = E F Johnson (Sockets, ham xcvrs)248 = Arvin (Sears radios & TVs)254 = Packard Bell (TVs radios computers)260 = Philco (Radios & TVs) 262 = Philmore (Hardware)277 = Emerson (Radios & TVs)343 = Zenith (Radios & TVs)416 = Heath (Electronic kits)772 = Muntz (Cheap TVs)787 = Sonotone (Phono cartridges)Examples of Source-Date Codes.With all this information in mind, can you identify the following manufacturer and date of these source-date codes?220 7001 Jensen speaker, 1st week of 1970.137341 CTS, 41st week of 1953 (or 1943 or 1963, but probably 1953 as source-date codes weren't used much during or before WWII, and 4 digit date codes weren't used till the 1960's and later).304-6110 Stackpole pot, 10th week of 1961.137848 CTS, 48th week or 1948 or 1958.4656755 Not a source-date code. Can you see why? If you can't, read the above information again! Here's another example:304809 ^^------- week of year (01 through 52), in this case 9th week ^--------- last digit of year (0 through 9), in this case 1958^^^---------- manufacturer's source code, in this case StackpoleIRC Pots (as used on many Gibson Les Pauls).IRC (International Resistive Company) used a different source-date codesystem. For example, here's a typical 1950s IRC code seen on a 1955 Les Paul Junior pot:6154190 500k 543^^^----------------- 615 is the source code for IRC ^^^^------------- 4190 is IRC part# (0689 & 2632 also common) ^^^^-------- 500k is the pot value in ohms ^------ last year's digit (0 t0 9), hence 1955 ^^---- week (01 to 52), hence 43rd weekJensen Speaker Codes.Jensen was a very popular maker of guitar amplifier speakers during the 1950s and 1960s. Fender and Gibson used them, anddid many other makers. There are some other codes used onJensen speakers, as shown below. The first set of codesshows the type of magnet, size and quality ofthe speaker. The "P12R" identifies the type of magnet, the size, and the quality of the speaker.The prefix code letter identifies the type of magnetused in the speaker. Prior to the 1950s, Field or ElectroMagnetic magnets were used.Instead of a permanently magnetic magnet, electricity was usedto make the magnetic field. These became obsolete with good Alnico magnetsand weren't used much past the 1940s.For the best guitar tone, it is generallyagreed "permanenent" Alnico V was the magnet of choice. AlNiCo was the mainstay for decades because it produced a strong magnet which worked great in speakers. It was largely discontinued because of higher cost compared to newer materials (there are other rare earth metals now, such as samarium-cobalt and neodymium-iron-boron aka NIB that are now often used). AlsoCeramic magnets were cheaper to make than Alnico, hencetheir usage in the 1960s instead of Alnico.Here are some of the Jensen prefix codes:F = "Field" magnet, which is a powered magnet (often with a small transformermounted on the speaker). EM = Electro Magnetic or Electronic Musical (electronic musical instrument speaker, 6"x9" to 15")P = "Permanent" magnet, Alnico V. At some point in the 1960s Jensen stopped using Alnico V magnets(and used ceramic magnets instead), but kept the "P" prefix!PM = Permanent Magnet, mostly AlNiCo type (or other earth metal combinations)C = ceramicNEO = Permanent Magnet NIB type (newest variety)The number is the size of the speaker. Jensen madespeakers from 4" to 18" sizes.The suffix code letter identifies the quality of the speaker.Jensen speakers came in varying quality levels. They hada Professional series, a Concert series, and a Standard series. The closer the suffix code letter is to "A",the higher the quality of speaker. For guitar amplifiers,the Concert series is considered the best (the professionalseries is too efficient and doesn't "break up",the Standard series is too whimpy and can't handle any power).Here are the series code letters:Professional series: letters J,K,L (made in 18" and 15" sizes only).Concert series: letters N,P,Q,R (made in 8", 10", 12", 15" sizes). Best for guitar amps.Standard series: letters S,T,U,V,W,X (codes U,W,X only came 8" and smaller).Gibson Anolomies.Gibson used some pots with strange codes during the 1960s that were confusing.These codes don't make a lot of sense, so are noted below.CBA-811-1053: circa 1965 (Gibson parts list)CBA-811-1831: circa 1965 (Gibson parts list) CBA-811-1158: late 1960s.C-70-05675-0: circa 1965CBA-5124: circa 1965CBA-811-3701: unknown dateCBA-811-3703: unknown date70020: circa 1971 & 1977 Gibson parts list 70028: circa 1978-1981 Gibson parts list70035: circa 1981 Gibson parts listGibson / Fender / Martin / Gretsch / Epiphone / NationalRickenbacker / D'Angelico / Hofner / Kay / Danelectro / DobroPicture Gallery / HomeContact the vintage guitar info guy 2ff7e9595c
Comments