Early vs late 200 and 200A series Wurlitzer Electric Pianos

As you may know, there are a great many subtle features which changed from the early 200 series instruments to the later ones; direct changes that defined the transition from the 200 series to the 200A series; and then again, subtle changes during the run of the 200A series.  Some of these features help one to immediately pinpoint the era of an instrument, as long as the instruments are relatively untouched and un-“Frankensteined.”*

What are the differences?  This is a partial list.  Please note that the changes may not have been entirely chronological, or linear throughout serial numbers.  Changes were probably introduced gradually, as older parts were used up.

Why were the changes made?  In all likelihood, many were functional: the labeling of knobs is easier to see above the knobs. The chrome faceplates, while aesthetically pleasing, are notorious for producing a blinding glare when used on a stage.  Others may have been matters of economy in manufacturing, or shifting aesthetics.

I will be looking to pinpoint the dates and key serial numbers of the changes in these features, and to add features I may have missed. Some of these lines are placeholders, awaiting more data.  Feedback is welcome.

Compiled with a lot of insight and help from Mark Cimarolli of Pittsburgh Vintage Keys.

(Note: I have no strong agenda in the direction of keeping an instrument “purely original” vs. upgraded, and I have no opinions on the “collectable” or “antique” value of a given instrument.  As a musician serving musicians, my primary concern is on keeping an instrument playable, sounding great, and electrically safe. That said, I am sensitive to the specific concerns of my clients.  Many like retaining and storing old removed original parts, such that they can be supplied to any future owners who might having a “collectable” bent.  I think this is legit.  I think it’s also legit to trash ugly, chewed up knobs, faceplates, and dead amps.  On the other hand: I do think that if you have intact original hairpin legs, for example, even if a little rusty– how cool to get to keep them.)

FeatureEarly InstrumentLate InstrumentChangeover date (approximate)Changeover serial number (approximate)
Series 200 (1968-1974)(First model 200 was mid-late 1968)(First model 200 was 48001)
Lid Coloring techniqueColors (red, beige, black or forest green) are a top layer of plastic over a grey or baby blue base (as if color is "painted" on)Lids are colored the same on all layersEarly 1969Circa 50001
Main fuse locationOn metal stand with potentiometerson terminal to the left of potentiometersEarly 1969Circa 50001
Center action screwNo long center screw holding action in place; the strip of balsa wood beneath the whippens is wider and held in place by a tiny downward-facing screw running through a center bracket.Action is secured by a long screw running through the center bracket.Early 1969Circa 50001 (or earlier)
Music StandWire "Perpendiculars" --Vertical beams meet a horizontal beamWire "verticals" -- no horizonal beam1969unknown, but early
Music Stand posts locationPosition 1Position 2 -- they reported change position slightly, though the exact timing of this is unknown. Lid curvature may change slightly at this time.unknown, tbatba
Aluminum lid trimWiderNarrowerUnknown, but early. (1969?)unknown, but early
RCA input on amp"Raised up" on platform on ampJack fused directly to amp1969tba
Hum ShieldRound Hole for RCA Cable (a few variations)Slot for RCA cabletbatba
Jewel Bezel"Fender Amp" style with facetsSmaller plastic pinlate 1969
Legs"Hairpin" legs, slide into place"screw in" legsBeginning of 1970Circa 53500
Speakers"Stereo" speakers, Left cone for bass (11-0750), right cone for treble (11-0751)Mono speakers--the "bass" speaker (11-0750) is used on both sidesNovember 197057745
FaceplateLettering under knobs (chrome)Lettering above knobs (chrome)Early to mid-1971; possibly late 1969 for student (206) models.
Most likely in 58xxx range. By 59335.
203 Console Speakers2 treble (amp rail) and 2 bass speakers, all facing playing musicianno treble speakers, 4 bass speakers, two facing away from musician1971By 60672. But may coincide with Introduction of model 214, which would place it closer to 56403.

206 classroom speakers2 treble (amp rail) speakers, similar to 200no treble (amp rail) speakers, 2 bass speakers, facing student musicianNot yet known.
Not yet known.
Ceramic Z-Capacitor bridging wall mains.Not presentOn terminal, near fuse197160672
Grille pattern on lidEach grille has a top and bottom section with a gap between them. Grille holes are in a simple "zig zag" or diagonal patternGrille has complex pattern with lines of wide-spaced holes at top, bottom, and double-line in middle. Dots are in vertical (non-diagonal) grid with complications at the edges.Mid-197268001 or so (may vary with model)
KnobsBlack circle on plastic "chrome", no white dotBlack circle on plastic "chrome", white dot
"L" after serial numberNoneAppears on instruments manufactured in Logan Utah1972beginning intermittently around 65001L, steady around 71501.
Handwritten inspection "latest date" on lowest keyAppears on all "non-L" instruments from 1968 to 1972 --usually initialed by "CM" or "RT"Disappears starting with "L" instruments made in Utah in 19721972Any "L" instrument (beginning intermittently around 65001L)
Pedal styletbatba
Amp Heat Sink shape(There are 3 distinct heat sinks. This will be filled in later)tba
FeatureEarly InstrumentLate InstrumentChangeover date (approximate)Changeover serial number (approximate)
Transition from 200 series to 200A series(First model 200A was late 1974)(First model 200A was around 91801, then numbers seemingly doubled back to ~86501 after 9xxxx range was used up)
amp200 amp, last revision200A amp, v 1debut (1974)debut (circa 91825>99999, followed by 86XXX)
Hum-reducing shielding on pickup and transformer wires Not presentPickup hum shield, transformer wire hum shield, introduced. Wire-shielding still intermittently missing from first 200A 9xxxx instruments.late 1974 and/or early 1975debut (as above)
Colors of portable modelsBlack, Beige, Red, Forest GreenBlack (usually), Avocado Green (1976 only)debut/1974 (black) and 1976 (Avocado Green)debut (as above)
Faceplate finishChromeBrushed/matte1974debut? (to be confirmed)
Lid HingesSharp cornersRounded Cornerslate 1974 or early 1975debut? (to be confirmed)
5 "reed damping plates" on treble keyboard, second octave from the topPresent on all pre-A 200 instrumentsDisappears a couple months into debut of 200A series, but appears on some instruments with speakers on amp-rail January 1975Circa #92665
Potentiometers (Volume and Vibrato controls)Fixed placementCan be moved, realigned to be centered in the faceplatedebut (1974)debut? (to be confirmed)
Aux Trim pot under instrumentNeverAlwaysdebut (1974)debut (as above)
FeatureEarly InstrumentLate InstrumentChangeover date (approximate)Changeover serial number (approximate)
200A series features(First model 200A was late 1974)(First model 200A was around 91801, then numbers seemingly doubled back to ~86501 after 9xxxx range was used up)
Speaker locationAlnico, amp rail, as on prior late 200 seriesCeramic, square or round-backed, attached to lid with flower screws (distinct varieties from 3 manufacturers, used interchangably at the same time)May 197586691 (Any instruments from 91825 to 99999 predate instruments from 86001 to 86665)
Amp Rail speaker stumpsStill contains "stumps" of holders for amp rail speakersNo traces of rail speaker holdersmid-1975circa 88389
Hum ShieldLeftover from 200, cutouts don't match new heat sinks, new amp schematic on lid reeds "200 amp" (no mention of "200A" on schematic)Hum shield better accommodates new amp's heatsink and footprint
Damper pad changing point
Middle range of pads extends to first 5 notes of treble reedbar.Middle range of pads confined to lower reed bar1975 or early 1976.Probably after speakers move to lid, but exact point unclear.
Official 200A amp revision, w/ rewiring Aux Trim pot value is 100K, wiring returns to boardAux trim pot changes value to 1K, wiring moves directly to aux plug; aux component value changes; early boards are black.early 1976102905
Z-Capacitor bridging wall mains.Orange Ceramic WaferPill-shaped Blue Capacitor1977
Sustain mechanism springLarge spring on independent bracket, tightly positioned between E-32 and F-33 action (all K-60-5 instruments)Smaller spring, attached to L-bracket in middle of action (all K-60-6 instruments)Between Oct and December 1977by 122500
Reed thicknessThinner, as on 200 seriesReportedly thicker (to be verified)unknownunknown
AC Cable plugOval 3-pin Hewlett Packard style plug (PH-163)Uses modern IEC plug (C6/C13)1978 or 1979unknown
Damper pad felt colorFelt on top of damper pads is usually redFelt on top of damper pads is green, for a portion of 1977; then back to red.
Mid-1976, at debut of model 270; through August 1977106563 green debut; 114xxx intermittent return to red.
Bass PickupsAre parallel to bass reeds, just above themAngle upwards, diagonally away from bass of the reedsunknown--changed by July 1978.unknown
Chrome "Wurlitzer" logo on rear of lidNot presentPresentJan 1979129895
GrilleEarlier grille is the same as the later "pre-A" 200 grille: grid-like array of dots/holesGrille grid pattern has subtle "wobble" or zigzag, with alternating lines. EDIT-- it appears that this variation, while common, is accidental, and probably has something to do with warping/ expanding of this hole-heavy area of plastic while cooling. Patterns vary between instruments, and even some very late instrument lids have the simple grid pattern.
April 1980By 138034
FeatureEarly InstrumentLate InstrumentChangeover date (approximate)Changeover serial number (approximate)