Decoding Wurlitzer date stamps

[DocWurly]

WOW....

Maybe I am late to the party on this one, but I think I just cracked a code on decoding some number stamps on Wurlitizers.

Some stamps are obvious.  You might find one on a the keybed of, say, a 1972 106P that looks like this:
NOV 7 1972

Or on a 111 from May 11, 1955 that looks like this:
05 11 '55

But there are weirder and more mysterious ones....

To be continued....

[DocWurly]

The numbers stamped onto the actual keys have seemed random to me, and certain numbers on the keybeds have seemed random, too.

My new theory.  With many weird looking numbers, you only need to look at the first 5 digits.  The first digit will be the year. Since we will know the decade, only the last digit of the year is important. The next 4 digits will be the month and day.

So, in this example of a 145B, the keybed is stamped 50323.  That means the stamp is from 1965, March 23.

This works for the numbers stamped onto the actual keys, too.

[DocWurly]

My eureka moment (if I am, in fact, correct) came from looking at the stamps on different parts of a 270 Butterfly piano.  The keybed had a stamp:

830 / 1976

This would seem to mean "August 30, 1976." and that would be in keeping with our understanding of when these were produced.

Well, the keys have a code stamped on them which is harder to decipher:

60831700

But, given the other stamp, it seems likely that that "6" is "1976", the "08" is August, and the 31 is the day after the 30th.

One might also conclude that the "7" is the "7" in '76, but that isn't necessarily borne out with any consistency in the other examples I've seen so far.  It may be, but it may not be.

[DocWurly]

Here are three dates from a 145A, serial number 32034 (which had the famous cracked reed washer problem.... gruesome!).

The transformer is stamped 8316345.  Well, that's sort of helpful.  We know that, as long as this is the original transformer, this dates from after the 45th week of 1963. (831 is the transformer company code.)

This site is helpful for that:  http://week-number.net/calendar-with-week-numbers-1963.html
The transformer is from the week of November 4, 1963.

But the keybed is stamped 40228.  According to my understanding, that means this is from February 28, 1964.  Much more exact.

The stamp on the key is in keeping with this:  4030776.    That means March 07, 1964, a mere week later.  Perfect.

I don't know what the "7" or "6" which follow mean.  We know the "7" isn't the decade, because this was definitely made in the 1960s.  It is possible the "6" IS the decade, and that the 7 is the 7th e. piano of that day?  But I wouldn't swear to that.  It could also be that this is the 76th .... something..... produced in a certain amount of time.  Subject for further research.

[EDIT:  The key stamp on this 145A probably reads 40307760, keeping it in line with the usual 8-number code: March 07, 1964, followed by a mysterious "760."  The last zero is hard to see in this picture.]

[DocWurly]

This is a late-period 200A.  (I don't have the serial number handy, but I remember it had a late-period amp and a high number).  91116074.  I surmise this means November 16, 1979.  Again, no idea what the 074 means.

[cinnanon]

This is a late-period 200A.  (I don't have the serial number handy, but I remember it had a late-period amp and a high number).  91116074.  I surmise this means November 16, 1979.  Again, no idea what the 074 means.

This seems remarkable.  Maybe 74 refers to the technician or actual person who performed this step.  Do the last three numbers have any consistency?  I'll look at my 200A's that were made closely to eachother to see if they are the same last 3 digits.  The one 200A does have the full date stamped on the namerail though.

On the 145A above, the last digits were 2 digits, and now its three.  Maybe there were less than 100 people working on them when the 145A's were being made, and more than 100 people starting the 200A's.

[DocWurly]

Oh, please do!  and it's great that one of them has the full date stamped on it.... you can compare that to the other numbers and see if it matches, within a week or so.

Is this something people here already knew?  I've been staring at these numbers for years, and taking photos of them, hoping it would make sense to me... and only now did it hit me.  A bit of a mindblower.

I'll be disappointed if I'm wrong, I admit... but so far everything is lining up.

[cinnanon]

It seems that this is the quality control stamp.  I think you have the date part correct, but the only other valuable information would be WHO inspected/made it on this date.  There are usually 2-3 identical stampings on adjacent keys on the 200A's at least. What other information would be pertinent?  Lot number?

[cinnanon]

Unless it follows the Year Month Day Minute?

It should be pretty easy to figure out if we have a large sampling of these.

YMMDD???

[DocWurly]

Can you share the specific cryptic numbers on yours, and the obvious date stamp and serial numbers?  These are the two Wurlies that have very close serial numbers, yes?

Or.... are the codes on the keys of your two 200A's exactly the same?

[cinnanon]

Here is my 200A, balance rail is stamped Nov141975HORSH (don't remember if its HORSH but it is something like that, like someones name...) I'll open it back up.

Here are the keys for it, stamped as well.

50812151
Aug 12, 1975, which aligns with the stamp above..sorta.  The keys would have had to be made (or stamped) before the balance rail (which is totally possible).  The stamping is in between the balance rail pins so it probably was stamped before it was pinned.

[cinnanon]

These are the two Wurlies that have very close serial numbers, yes?

Yes this is the later one of the two.

[DocWurly]

When you have the other one open to compare.... THAT will be interesting.

[cinnanon]

I will open it when I get home tonight

[DocWurly]

Using this technique, I am now dating a 145B which was bought in December 1964 (the earliest date I had on this model) to having keys from April 28, 1964. 

That seems early!!  A memo went out on the flaw in the 140A/145A in August 1964.  Did that post-date the debut of the B line?*

So, anyway, it seems possible that this, and the other early 145B's, started their lives with the intention of becoming 145A's, and there was a "stop the presses" moment where they had to replace the reed bars (or at least the screws) and rename them B's.  They would have already been planning to debut the 140B amps at some point in 1964, anyway, which would have resulted in the new model name even without the need to fix the "A" problem.

Or, who knows how it worked over there?  What was the turnaround time between manufacturing a model and getting it into the stores?  Did they stockpile them before shipping them out?

*[EDIT: The B models must have debuted in stores after August 17, 1964, in spite of this April manufacturing date stamp:  Note #17, the famous memo about "reed compatibility," came out on August 17 and made no mention of the 140B, the 145B, or the 720B.]

[DocWurly]

What I _really_ wanna know, Cinn, is the date of your 146B.    well, both, all.

[cinnanon]

Model 214 S/N 8024x, stamped on the balance rail NOV271973GASH, keys are stamped 10110894 (Jan 10, 1971), amp is stamped Feb 2, 1973

200A S/N 88668 NOT stamped on the balance rail, keys stamped 50829869, xformer stamped 203715

200A S/N 88659 stamped WILBURN814 1975 on the balance rail, LEFT keys stamped 50812151, RIGHT keys stamped 50817197

[DocWurly]

OK!  Well, that's all interesting and weird data.
it seems to be saying that some of your Wurlies were made from all sorts of pieces that were lying around for a while.

The transformer of that 200A.... I'm not sure what "203715" would be.  5th week of 1971?  aren't those usually 7 digit codes?

I've never seen an amp stamp.  Where would I find one?

The more I think about it, BTW, the more I am sure I am right.  They have to be dates.

Digits 2 and 3 are always months.  The only combos are those from 01 to 12.
Digits 4 and 5 are always days of the month.  You will never see anything beyond a "31."  You won't even see a "30" if the 2 and 3 are "02."
And, the first (year) digit is generally in a range that is possible given our known understanding of a given model.

That said, these numbers are also telling us some new things!
*Sometimes the latest date is on the balance rail or keybed.
*Sometimes the latest date is on the keys.  In the case of that 214, the keys are NOT the best source for dating that instrument.
*Sometimes the L and R halves of a set of keys are from different sources (Which makes sense.   It might not always be possible, or necessary, to make a set of keys from one piece of wood, as long as you split it in the middle.)

I have yet to see a 200A series model with a stamp showing evidence of 1974 or earlier. And, I've only seen one 200 from 1968.... in this thread:  http://ep-forum.com/smf/index.php?topic=7767.msg50826#msg50826

[cinnanon]

What I _really_ wanna know, Cinn, is the date of your 146B.    well, both, all.

I finally opened it up to see what was inside. I forgot how clean this one was...almost pristine. The key says 60607310 and the keybed says 60505 (tough to see in the pictures...couldn't get it to show right...but it is definitely 60505). No date on the amp though....but the can cap does say 140B on it, and you can see the metal hood covering the bulb and LDR....  Check it out...

[DocWurly]

Fantastic.  As I suspected, the 146B precedes the 146. 

Well!  Probably.  Although one never knows for sure.  They could have taken existing, fully assembled 1966 140B's, later on, and called them 146B's.  But, we have a 146B with 1966 date stamps and a 3xxxx serial number, and we have a 146 stamped October 1967 with 4xxxx serial numbers.

[DocWurly]

On the 145A above, the last digits were 2 digits, and now its three.  Maybe there were less than 100 people working on them when the 145A's were being made, and more than 100 people starting the 200A's.

Actually, I just found photos of another 145A I worke on. It was from earlier, maybe Oct 1963, and it had 8 digits in the stamp, not seven.  So... I guess at that point the stamp wasn't consistent?

[cinnanon]

8 sounds right.  5-digit date code plus 3 digit other code is what I've been seeing.

[DocWurly]

Right.  But early on, one example, and not the earliest, was only 7.  It could have been a malfunctioning stamp, I suppose.

[pgroff]

Another data point -  a model 200 (and possibly a very late example of this model):

Serial number: 82911 L (made in Logan, UT?)
Internal stamping on action: 40325302 (1974, March 25?)
Also stamped "A-60-5" (including quotation marks).

Transformer stamp: 8317406 (6th week of 1974?)

Amp looks all-original, labeled 16333 on the transistor heat sink.

PG

[DocWurly]

Thank you!  That is indeed the highest serial number, and the latest confirmed date, I've seen for a 200.  Is this one black?

There is still big gap in my records between the latest 200-series date on an instrument (this one, March 25, 1974) and the earliest 200A-series date (August 17, 1975).  I'm sure there are plenty of examples that will close up the gap.... I just don't know them, yet.

[pgroff]

Yes, 82911L is black.

Remembering the two Wurlys that I had in the 1970s (which my parents bought new from North Syracuse Music, NY), IIRC my first one was a 200A and a year or so later we actually traded that in for a 200 which was also new. So there was some overlap in the time that these models were for sale as new (or NOS) from the dealers.

PG

[DocWurly]

Yes, 82911L is black.

Remembering the two Wurlys that I had in the 1970s (which my parents bought new from North Syracuse Music, NY), IIRC my first one was a 200A and a year or so later we actually traded that in for a 200 which was also new. So there was some overlap in the time that these models were for sale as new (or NOS) from the dealers.

PG

Good data, and it makes a LOT of sense.

There's a lot of vagueness at certain transition points from one model to the next, too.  I'm now hearing that there were early 140B's, with the same washer flaws as some 140A/145A's, and enough other features in common with those (long damper arms, knob positions), that it sounds like the only thing that made them 140B's was the redesigned amp.  And certainly, looking at the date stamps of a super-early 145B (April 28, 1964)--and seeing the look of the reed washers in the photos-- it seems like it would have been generally assembled in the 145A era, which begs the question, what, other than a coupla knobs, made this amp model a B vs an A?  As someone else posted, it could have been simply a new naming to keep it in line with the 140B's that were coming out at the same moment.  (The 145B had the same tube amp as the 145A and the even earlier 145.)

[DocWurly]

On the 145A above, the last digits were 2 digits, and now its three.  Maybe there were less than 100 people working on them when the 145A's were being made, and more than 100 people starting the 200A's.

This was a good catch by you; I re-examined the evidence of that 145A and it's actually the typical 8-digit code.  There's a "0" at the end of the number, which I didn't notice when I remarked on it before.

[DocWurly]

A GREAT place to look for a stamp is on the so-called "main rail."  This is the vertical piece that holds the hammer assembly and the whip assembly.  My 200A seemingly has no stamp on the keybed or balance rail, nor on any paper shims under the balance rail, but it has an upside-down stamp on the main rail.

Model 200A
Serial number: #133952L
Key Stamp: 90724530  (July 24, 1979), on keys 32, 33, 34.
Key Stamp: K6015_ 66006 (seemingly NOT a date stamp), on key 64.
Keybed Stamp: None
Main Rail Stamp: 90808246 (August 8, 1979)   "A-60-5'  (What does this mean?)
Transformer stamp: 203715     EIA606-906

According to this page:
http://www.triodeel.com/eiacode.htm
The crucial info on the transformer is "EIA606-906"

606=Woodward-Schumacher.
9 is 1979, and I'd guess that "06" is the 6th week of the year, or the week of February 5th.
http://week-number.net/calendar-with-week-numbers-1979.html

[DocWurly]

200A S/N 88668 NOT stamped on the balance rail, keys stamped 50829869, xformer stamped 203715

It's the other transformer number that you want (if there is one), perhaps starting with EIA606.  And next time you have it open, see if there is an upside-down number on the right side of the main rail.  interesting that we now have two examples with a date stamp on that rail, and with another line saying "A-60-5" including single or double quotes.

[pgroff]

The 9th pic in this ebay auction also shows the upside down date code on the main rail, and part of another stamp is also visible that may also read "A-60-5." It's Model 200, Ser. No. 74027 L.

http://www.ebay.com/itm/Early-WURLITZER-200-Vintage-Electric-Piano-Pro-Serviced-Tuned-/132012881450

PG