Baldwin Interlude 124 Series User manual

TECHNICAL
ANUAL
BALDWII{ ORGANS
BALDWIN PIANO & OBGAN CO. CINCINNATI,O.

TECITNICAL MANUAL
MODEL 124 SERIES ORGAN
INDEX
NOTE: Manual Reprinted wj.th reduced atdfor updated material causing elimination of soroe page numbers. Pages
bear original page numbers for future reference. A11 original Eaterial and/or Lmproved additions and
revisions are included.
PAGE MODEL 124 SERIES (INCLUDES SPECIFICATION) FIGURE
4........, .Organ Back View - Photo & Description
5. ...... ...Tone Color Raj.sed - Photo & Descrlption
6..........Stop Tab Switches Disassembly - Photo &Descrlption
7. ....Disassemb1y Procedure
9.....,,...E1ectronic Shelf Assembly - Pictorial
9A... ..... .Electronlc Shelf Assembly (Revised) - Pictorial
10..........Mode1 124 Keyboards - Pictorial
11. ..... .. ,.Model 124 Series Block Diagran
12.....Tone Generation and Accessory Board Theory
13...,......Generator Shelf Assembly - Photo & Description . . .
L4...... .. ..2 Note Generator Board Schenatic
15,.........2 Note Generator Board Assenbly - Pictorial 7
I
16..........Accessory Board Asseurbly - Ptctorial
L7 ........ ..Aecessory Board Schematic
18.....Keyswitching Circuit Theory
19..........Keyswlteh Boards - Pictorial 9
2O....... . . .Key Assenblies - Pictorial 10
2L..........So1oManual-Raised-Photo&Descriptlon... 11
22..........Keyswitch Wiring Dlagram
23.....Tone Color Theory
24.....So1o Filter Board Assembly - Pictorial
25..........So1o Filter Schematic
26. . . . .Preamplifier and Expressi.on Control Theory
27 ... .. . .. . .Preamplifier and Reverb Anplifier Board Assembly - Plctorlal
28..... . .. ..Preampllfier and Reverb Amplifier SchemaElc
29..........Preamplifier and Reverb Anplifier Board - Wlrlng Diagram
30. . .. ,.. ...Expression Pedal Asseuibly - Plctorlal
31. . . . . . . . . ,Reverberation Theory
32..... .....Reverb Unit - Photo & Description
33..,..Rhythm Voice Board Assembly - Pictorlal
34..........Rhythn Voice Schematic
35..........Rhythn PercussLon Theory
38,.,.......Rhythn Voice Board Assenbly (Modlfled) - plctorlal
39..........Rhythn Voice Board Schematlc (Modified)
40....,Power Supply Theory
41. . ...... ..Power Supply Board Asseubly - Plctorlal
42..........Power Supply Schematlc
4fA.........Power Supply Board Assembly (Revised) -
42A,.......,.Power Supply Schenatic (Revlsed)
43..,..Power Ampllfier Theory
44..... . ,...Power Amplifler Board Assenbly - Pictorlal
45..... .... .Power Amplifier Schematic
44A,.........Power Anplifler Board Assem6ly (Rev1sed) - plctorlal
45A.........Power Anpllfler Schematlc (Revised)
46....,Electronlc Shelf Power Clrcuit Dlagram
46A,.........Electronic Shelf Power Cj.rcuit DLagram (Revtsed)
1.....Vo1ume Level Setting Procedure
2..........Organ Top Vlew - Upper Lid Removed - Photo &
3..........Accompaniment Manual Underside View - Photo &Descrlption
Description
Pictorlal
MODEL 124A ORGAN
Photo
1
2
3
4
5
72
13
74
15
76
16A
L7
L7A
47 .....Model 124A General Informatlon
48..... ,.. ..Model l24A Orgat Front Vlew -
49..........DescrlptLon Flg. 18
50.... ......L24L Organ Baek Vlew - Photo
51... .. . ....Descrlption Fig. 19
52..........L24A & AC Tone Color Stop Tablets - Photo & Description
53..........124A, & AC Pedal Sustaln Boards - Photo & Descrlptlon . . ,
54..........L24A & AC Solo Bass Keycap Assenbly - Photo
55..........Descrlptlon Fig. 22
56.....Pedal Clrcult Theory
57..........Pedal Sustaln Board Assembly - Plctorlal
58..... .. ...Pedal Swltch Scheuatlc
59..........Pedal and Acconpanlnent Fllter Scheoatlc
60..........Pedal and Accompanlnent Fllter Board Assembly - plctollal
18
19
20
2L
22
Revised 1975
23

Model 124 Series Organ
Index (Contrd.)
PAGE FIGI]RE
61.....Auto Rhythn Theory
65..........Auto Rhythm Trlgger Board Asseuibly - Pictorial . . 24
66.....'.....Auto Rhythm TrLgger Schematic
67 ....... . ,.Auto Rhythur Trigger Board - Wlring Diagran
68..........Auto Rhythrn Block Diagram
MODEL 1248 ORGAN
69. . . . .Model 1248 General Informati.on
70.,........L248 0rgan Front View - Photo & Description
77..........1248 & BC Tone Color Stop Tablets - Photo & Description
72..........7248 & BC Organ Back Vlew - ?hoto & Description . . 27
73.....,..,.Major/Minor Touch Bar Assenrbly - Photo & Description . . . 28
74......,...L248 & BC Solo Bass Keycap Assenbly - Photo 29
75..........Description Fig. 29
76..........WonderChord and Pedal Sustaln Boards - Photo 30
77 .....PedaL Sustain Board Assembly, Schematic & T'heory
77A.. . .Pedal Sustain Board Asseuibly, Schematic & Theory (Revlsed)
78,.........Pedal and Accompanlment Filter Schematic
79.....,. . ..Pedal and Accompaniment FLlter Board Assembly - Pictorlal 31
80.....Muted Reed Circuit Iheory
81.,,.......Muted Reed Board Assembly - Pictorial 32
82....... .. .Muted Reed Schematic
83.....WonderChord Block Diagram
84. ....,.. ..WonderChord Clrcuit Theory
88..........Rhythm Pattern Chart
89..........Simplified Keyswiteh Loglc Diagram (For Key "C") . .
90..........Sinplified Root/Flfth and Root 0o1y (First) Logic Dlagram
91.........,Sirnp1ified Tempo Indicator and /13 Pedal Pulse Inhiblt Diagram
92A....WonderChord Board No. 2 - Wiring Diagram (Revlsed)
93A....WonderChord Board No. 2 Assembly (Revised) - Plctorial
94A. .. .WonderChord Schematic (Revised)
95.......,..WonderChord Control Head SchenatLc
96..........WonderChord Master Chart
97 .. -... .. ..WonderChord Transistor Functions
MODEL 124AC & BC ORGANS
98.,..,Mode1 L24 AC & BC General Information
99.......,..Model 7248C Orgat - Photo
MODEL N124A AC&B BC ORGANS
100. . . . .Mode1 N124 General Information
101. .. . ,.. ...N124 Organ Back View - Photo
7O2..........Description Fig. 38
103.,........cenerator Shelf Assenbly - Photo & Descriptlon . . .
104..........Power Supply & Amplifier Shelf Assenbly - Photo & Descrlptlon
105..........WonderChord & Voice Board Assenbly - Photo & Descrlption . . ,
106..........N124 Organ Top View - Photo & Descrlptlon
107..........Tone Color Raised - Photo & Descriptlon
108..,..,....So1o Manual Raised - Photo & Description
109.....Tone Color Board Assembly (N124A) - Plctorial
110.....Tone Color Board Asseobly (N1248) - Plctorial
111. ... ,.. . ..Tone Color Board Schematic
111A... .... ..Tone Color Schematic (Revlsed)
172..... . .. ..Tone Color Board Wiring Dlagram
113.,...Switch Wiring Schematic
114. ,...Power Circuit Diagram
115,....WonderChord Control Schematlc
MODEL N124R ORGANS
116. .. ,.Model N124R General Informatlon
117..........N124R Front View - Photo 47
118..........N124R Rear VLew - ?hoto 48
119,.........Rea1 Rhythn Controls - Photo 49
720..........Description Fig. 49
721... .... .. .Rea1 Rhythm Assembly 50
122...... ....Real Rhythn Block Diagram . . 51
723.....Real Rhythn Theory
732..........Rhythn Sequence Chart
133.... .... ..Rea1 Rhythn LogLe Waveform Chart
134..........Rea1 Rhythn Master Chart
135..........Rea1 Rhythm Logic Board Assenbly 52
136..........Logic Board & Control Schenatlc
137. .. . , . .. . .Voice Board Schematic
138.,... ... ..RhyEhm Voice Board Assembly 53
139....,Power Clrcult Dlagram
25
26
33
34
35
36A
37
38
39
40
4L
42
43
44
45
46
ll

Model 124 Series Organ
Index (Contrd.)
LIST OF DMWINGS IN NI'MERICAL ORDER
DRAWING DESCR]PTION PAGE
8501-0534268. .Preanplifler & Reverb Amplifler - Wiring Diagran 29
-0535618. .Auto RhythD Board - Wlrlng Dlagram 67
C501-048703B ..2 Note Generator Schematlc L4
-05L929C. ,Power AnplifLer Schematic . . . 45
-O5L929J. .Power Ampllfier Schenatlc - Revlsed 45A
-052889A. .WonderChord Board No. 2 - Wiring DLagran 92
-0528898. .WonderChord Board No. 2 - Wiring Dlagram - Revised 92L
-053181C. .Peda1 & Accompaniment Filter Schematlc - 1248 & BC 78
-0534258. .Preanplifier & Reverb Ampllfier Schematic 28
-053439C. .Accessory Board Schematlc . . L7
-053458. .,Pedal Switch Schematic - 124A & AC 58
-0534598. .Power Supply Schematlc 42
42A
59
25
L37
LLz
115
139
57
77
77A.
10
11
30
9
9A
95
34
-053459D. .Power Supply Schematic - Revised
-059912A. .WonderChord Control Schematic - N124B
-0535358, .Pedal & Accompanlment Fllter Schematic - 124A & AC
-053540A. .Solo Fllter Schematlc
-059244D. .(TMD) Real Rhythm Volce Board Schenatic
-059783 .. .Tone Color Board Wlrlng Diagran - N124
-060238A. .Porder Circuit Diagran - 124R
C579-323. .....Peda1 Sustaln Board Assembly -
-372... ...Pedal Sustain Board Assembly -
-372A... ...Peda1 Sustain Board Assembly -
-059837C. .Tone Color Board Schematic -
-059880. ..Switch Wlring Diagram - N124
-059966. ..Power Circuit Diagram - N124
-0601688. .(TMD) Logic Board & Control
- Modified
724A & AC
1248 & BC
Revlsed
-376.. ....Mode1 124 Keyboard
-377A. ..,.Model 124 Series Block Dlagram . .
D500-053250. ..Expresslon Pedal Assenbly
-053554C. .Electronic Shelf Assenbly
-053554E. .Electronic Shelf Assembly - Revised
D501-053169B ..WonderChordControlHeadSchematlc
-0531878. .Rhythro Voice Board Schematie
-053187E. .Rhythn Volce Board Schematic
-053194A. .Keyswitch Wlring Diagram
-0534918. .Electronic Shelf Power Circuit Diagram
-053491F. .Electronic Shelf Power Clrcuit Diagram - Revised
-053601C. .Auto Rhythn Trigger Schematic
-0539508. .Muted Reed Schematic
39
22
46
46L
N124
66
82
111
113
. 7t4
BoardSchematic.. L36
D579-375L. ....WonderChord Block Diagram 83
-378.. ....Auto Rhythm Block Diagram 68
R501-053045A ..WonderChord Schenatic 94
-053046D. .WonderChord Schematlc - Revised 94A,
lll

lnteflUilG rp""iricarions *
Solo
16'Flute
16'Cello
16'Saxophone
8'Flute
8'String
B'Clarinet
Flute Accent
Reed-String Accent
Accompaniment
8'Diapason
8'Flute
8'String
4'Flute
Pedals (124A)
Bass Soft
Bass Medium
Bass Full
Pedals (1248)
String Bass
Pedal - Loud-Soft
Pedal Sustain
Muted Reed (124B only)
Continuously Variable
Vibrato
Light-Full
Reverberation
Tone Control
Bright-Deep
AutoRhythm (124A only)
Basic Rhythms - Waltz,
Fox Trot, Swing, Rock,
Latin
On-Off
Tempo - Continuously
Variable
Rhythm Volume -
Continuously Variable
Downbeat lndicator
Light
WonderChord
('124B only)
Rhythm Patterns -
Waltz, Fox Trot, Swing,
Rock, Latin
On-Off
Chord Sustain
Rhythm Only
Tempo - Continuously
Variable
Rhythm Volume -
Continuously Variable
Downbeat Indicator
Light
Major-Minor Bar
Cassette Tape
Player/ Recorder
(optional; model
124B only)
Manuals: 44-note solo
and accompaniment
manuals
Pedals: 13-note
pedalboard
Amplification: A self-
contained, transistorized,
single-channel system
with 25 watts (rms)
of power.
Headphone Jack
Dimensions: Height 36",
D eplh 24Vt ", W idlh 451/2 "
Weight: 176 pounds
Style: Contemporary
Finish: Walnut
,lnterlude Organs are designated the Model 124
Series. Ihe 124A is lnterlude with AutoRhythm;
the 124B, lnterlude with WonderChord. The
letter "C" is added to the model number when the
organ is equipped with cassette.

VOLI]ME LEVEL SETTING PROCEDURE
FOR MODEL 124 SERIES ORGAN'
1. Depress all the manual stops including Pedal Sustain and
Accent stops. Do not include Muted Reed or Reverb. Tone
control tab should be j.n Bright posltion.
2, Depress the Expression Pedal fu1-ly down.
3. P1-ay C-E-G-C chord (mlddle C and notes above middle C) on
both SOLO and ACCOMPAIIIMENT manuals; also play 1ow C on
PEDAL. Keys to be played are indicated with arrows on
Drawing D579-376. Set the VoLIIME LE\rEL to set the voltage
across the 12" speaker to 6.0 V RMS.
It should be noted that the above level setting will give
a sati.sfactory volume for most conditj.ons; however, it may
be necessary to adjust setting s1lghtly to compensate for
individual taste or acoustical environment.
NOTE: Volume Level control ls located on the tone color and can
be reached fron the back of the organ (Fig. 19).
On N124 series Volume Level control is located on the tone
color board (Fig. 45).

REMOVE SCREWS W!TH
UPPER tID BUSHINGS TO
GU IDE S IOTS RAISE TONE COI.OR
FIG.I _ ORGAN TOP VIEW - UPPER tID REMOVED

(
IIEIYI
FIG. 2 ACCOIVIPANIIV|ENT I,IANUAL UNDERSIDE VIEl.l
DESCRI PTION
REI'IOVE FOUR (4) SCREI.IS TO RAISE SOLO I,IANUAL
5
PHONE JAX ASSY. (UNINSULATED IVIOUNTING)
REI'IOVE FOUR (4) SCREI,IS TO REI*IOVE ACCOIVIP. BASS KEYCAP
ACCOI'IP. Sl.lITCH ASSY.
Sl,lITCH COVER
(
REF1OVE FOUR (4) SCRE}IS TO REI'IOVE ACCOIIIP. TREBLE KEYCAP
lvlODEL AND SERIAL NUI'IBER NAI,IEPLATE
PART NUI'IBER
B500-053451
D500-053195
D502-052385

MUSIC DESK
PTEXIGTASS
c 501 - 053450
BACK
PANEL
Dr 57-0s3597
F IG.3 - ORGAN BACK V! EW
REVERB
VOTUME CONT ROt
coNTROL
POWER
CORD
8508-0276s8

FIG. 4 - TONE COLOR RAISED
I TEi\1 DESCR I PT I ON
POI^IER SI^/ITCH
VIBRATC) & PEDAL STOP TAB ShIITCH ASSY
5
6
ACCOIvlP. ST(]P TAB Sh/ITCII ASSY,
SOLO STOP TAB ShIITCH ASSY.
SOLO FILTER BOARD ASSY.
PEDAL & ACCOI,,IP, FILTER BD. ASSY. - I24A & AC
1C
RHYTHII V(] I CE
REVERB LEVEL SET POTENTIOI'{ETER (lOOK OH|4S)
VOLUIVIE LEVEL SET POTENTIO|,IETER (1OOK OHivlS)
PREAIVIPLIFIER AND REVERB PREANP BOARD ASSY.
BOARI] ASSY.
- l24A & AC
48&BC
- l24B & BC
PART IiUIvlBER
B506-052168
c500-05337 I
B500-053099
-053577
c500-053286
B500-055465
B500-053185
B500-053189
c500-05t499
8509-040785
B509-040781
c500-05342L

It
i:",:'
ei"
..,/t
9TR IN G
BASS
FIG. 5 - STOP TAB SWITCHES DISASSEIIBLY
ITEI4 DESCRIPTION PART NUMBER
Sl^lITCH TAB ASSY. I4OUNTII.IG HOLES
PEDAL TO[{E COLOR SWITCH BOARD ASSY. 8506-053234
CONTACT l^lIRE A506-037787
CONTACT SPRING A506-033399
PEDAL Sl^IITCH TAB ASSY. (1248) c500-053577

BALDWIN L24 SERIES ORGAN
DISASSEMBLY PROCEDURE
1. Back (Flg. 3)
a. The back is secured by fourteen (14) serews. Remove the top nlne (9) screws and loosen the re1aining
five (5) screws across the bottom slots. Lift upward and remove.
2. Lid Assenbly (Fig. 19)
a. Follow Step 1a.
b. Remove three (3) screlTs securing the back side of the 1id to the top rail (Fig. 19) and slide the 1id
toward front of the console ln order to clear the lid guide s1ots. Lift 1id assembly from console.
3. Tone Color Assenbly
NOTEr Beglnning wj-t}i, 1172266 tone color board must be loosened before raising tone color panel or board will
break:
a. Fo11ow Steps 1 and 2.
b. Prior to 1172266 ONLY - (Fi.g. 3)
1. Remove two (2) screws wlth rubber bushings from each side of console (Fig. 1). The tone color
panel, hinged in the rear, will now pivot upward from the normal position.
11. Remove tone color box cover or pan by loosening the four (4) lower scre\{s and removing the
six (6) remaining screws.
c. Beginning with 1172266 - (Fig. 38)
1. Follow Step 1 - Tone Color board hangs down from Tone Color panel assembly and component side
is exposed. Two (2) screws secure board to pane1,
11. On sone organs, the Tone Color board is attached to the top of the 1or7er frame with four (4) screws.
111. Loosen tone color board assembly FIRST, then to raise the tone color panel - proeeed as in 3b
1 and 11.
4. Tone Color Solo Switch Assembly (Figs. 2, 5 & 20)
a. Fo11ow Steps 1 and 2 and ralse tone color as in Step 3.
b. Tab mounting block may be removed by removing four (4) screws from underside of tone color assembly
(Fig. 2); access to the swiEch contacts may now be accomplished.
c. Tab may be removed by removing tab detent spring from tab throw adjusting serew and lifting tab out.
d. The Solo tab throw adjustment screws are accessible for adjustnent of tab thrord.
5. Solo Keys and Keysartiches
a. Follow Steps 1, 2 ar,d, 3.
b. Keys uay be removed by loosening mounting screw of a key channel. Sharp or black key must be removed
first (Fig. 10).
c. Access to Solo keyswitches rnay be obtained by rernoving the four (4) screws, two (2) at the bass end and
two (2) at the trebte end, beneath Accompaninent manual (Fig, 2). The Solo manual, hinged in the rear,
w111 now pivot upward from the manual position.
d. Remove dust cover over keyswitches by loosening three (3) screws from top and three (3) screws from
the botton of the dust cover. Screws are fitted in slotted ho1es, therefore, the dust cover must be
reEoved by lifting.
e. Keysr^ritch assembly may be dlsassembled by renoving nuts from switch posts.
6. Accompani.ment Keys and Keyswltches
a. Fo11ow Steps 1 and 2, raise tone color as in Step 3 and raise Solo manual as in Step 5c.
b. Keys Day be renoved by loosening mounting screw at the rear of key channel. Sharp or black key must
be renoved flrst.
c. Access to Accompaniment keyswltches is accomplished by removing cover. Cover ls removed by loosening
three (3) screws from the front of keyswitches. Keyswltches are located beneath Aecompaniment."rrrrai
(Fig. 2).
d. Keyswitch assembly nay be dlsassenbled by renovlng nuts from swLtch posts.

7. Solo Bass KeycaP Asseuibly (Flgs, 2, 11 & 18)
a. Fo11ow Steps 1 through 3 and ralse Solo nanual as ln SteP 5c.
b. Solo bass keycap asserobly may be removed to servlclng posltion by removing four (4) scre\,rs with washers
on the underside, whlch secure Solo bass keycap assembly to the Solo manual assembly (Fig. 11).
c. Push button switch assembly roay be removed by removlng two (2) screr^Is from the slde mounting bracket
(Ftgs. 22 & 29).
8. Accompanlment Bass or Treble Keycap (Ftgs. 2 & 18)
a. Fol1ow Steps 1 through 3 and ralse Solo manual as ln Step 5c.
b. Re4ove four (4) screws with washers from the underside of Accompani.Dent manual.
NOTE: Eor models wlth cassette (C nodels), follow Step 14 to obtain access to Accompanlment
treble keYcaP securing screliTs.
9. Expression Pedal Assembly
a. Fo11ow Step 1.
b. Remove the two (2) wood screws whi.ch secure the expresslon pedal assembly to the rear bottom board
of the console.
c. PulI the expression pedal assembly toward the rear of console in order to clear the screw from slotted
hole and 1lft out.
10. Reverb Unit (Figs. 14 & 19)
a. Eollow Step 1.
b. To remove reverb unlt, renove four (4) scre$rs securJ-ng unit to mounting bracket on treble end of console.
11. Pedal Clavler (Flgs. 79, 2L, 27 & 30)
a. Follow Step 1.
b. Remove cover from pedal switches and remove leads to pedal cireuit board (Figs, 21 & 30).
c. Re6ove stx (6) screr{s securlog clavier to bottom board, tilt console slightly backward, press natural
keys down until sharp keys elear front of case and remove the clavier from the rear of console.
L2. Auto Rhythn Trigger Board Assembly (1244 & AC)
a. To gain access to the Auto Rhythn Trigger board assenbly, remove the back (Step 1).
b. The unlt ls located on the bass end of console above the pedals (Figr 21). Re.move by disconnectlng
pIugs, then remove one plastlc extrusion securing the board to console and slide board out,
13. WonderChord Board Assembly (1248 & BC)
a. To gain access to the WonderChord board assembly, remove back (See Step 1).
b. WonderChord board assernbly is located on bass end of console above the pedals (Flg. 30). To remove,
disconnect plugs, then remove rwo (2) plastic extrusions securing board to console and s1lde board out.
L4. Cassette Unlt (124AC & 124BC)
a. Remove plugs fron front of cassette (Fig. 37).
b. Remove two (2) scre$/s securlng cassette to drawer - bottom front and bottom rear.
c. Pul1 drawer forward and lift cassette out.
d. To remove cassette drawer, remove four (4) screws securing drawer to keybed.
15. Real Rhythn Assenbly (125R) - (Fig. 38)
a. Fo11ow Step 1.
b. Dlsconnect plugs and remove two (2) screws securing unit to side panel.

ASS'Y (REtr DsOr-O55t94)
w\TH 3 52239 8-4SCPL
lzz" LG
.6 ENOTE C.EN BDs OF GEN BDS ASS'Y c5Oo.O48/.9G,
REF C5OI -048703 (? NOTE GEN BD SCHEM\TIC)
MOUNTED WITH ONE EACH 52267-6.4BLOX.TYPE\7
R H. SCREW Yz, Ls.
oo..
r
"l<r
(
Bsoo-o5t9e6 8500-o529s8
\249-O?2731
s2267-6-4BLOX
szozc-4-3scPL
A?41-O?8t?l I T-NuT'10-24
TIO FLATWASHER
SCRV4RUWD
-zzo-to i RESTSTOR ?ztt vtw \o
POWER TRANSFORMER
LECTRONIC SI1E
HOT SHOWN :9 ELECTRONIC SHELF ASSY

\o
. qEN CONNECTOR STR\P ASS'Y.(REF- D5OI.O53I94)
MOUNTED TO STR|P W\TH 3 S4239.6-4SCPL
rE HH.TyPE l? scREw Vz"LG
t'rNq-Lt.6 aNorE qEN BDS oF GEN BDS Ass'y csoo-048/.96,
REF C5OI-O487O3(ZNOTE GEN BD SCHEM\TIC)
MOUNTED WITH ONE EACH 52261.6-4BI,OX-TYPE\7
R H scREw 7y' uq-
\€\o
8500 05t926 8500-o52956
D.t E-2o-7.( -..M
5 lnsoT-o
Lrru,gr8 c-B dl?cl.lz
AZ49-OZZ731
o) lr
J50
2?e.
A516
rT. lZ
lB REQ q'r'Y OF tT l6wl
IREQ C N 15.303
D-r -r 4-2-'13
15 i + ls202z-5scPL i'r0 FLATWASHER
AZ44- 00s3zl
Sl34 -4 i SOLDER (IRON) xor s,{ow{
SocoezlJrs Co-- tlaT sat.qP I t
FILTER CAP 1 GND CABLE
s2267-6-4BI.OX
FELT, MAROON
A?41-O?4;t?l
SCR 'G R H WD. TYPE 17 YZLG
T-NUT'IO.Z4
ELECTROTIIC SHELF XSSY.

PITCH
SCLO KEYBOARD
ACCOMP KEYBOARD
WONDER CHORD
1248 O NLY
1t
PEDALS NOTE S I NDI CATED WITH AR ROW S ARE
USED WHEN SETTI NG VOLUME LEVELS
P! TCH 8,
NOTE tr
18 19 20 21 22 23 24
FFrx G6!8 A4X B
18+.-SOLO W.O.+ 24
8 <--ACC. W.O.4 24
13 14 15 16 17
cc* DDf8 E
AtL DRAWIT{GS AND SPECIFICATIOl{S ARE ANO REMAII
TO IT. ATL SPECIFICATIOTIS ARE COIIFIDEI{IIAI AI{D
IIIEY ARE SEI{I. t{0 DRAWIIIGS. SpECtFtCAItoilS 0t
FURTIISHED TO MAI{UFACIURERS OR OTHERS FOR AI
A'{Y MATII{ER LICEIISING THE HOTDER OR ANY OTHEI
MANUFACIURE. USE OR SELL AilY PAIEfiIED Ii{YENT
UNLESS OTHERWISE SPECIFIED
TOLERAI{CES ARE:
l0

N9 NOTE Frequency
P
E
D
A
L
D
I
V
,iu;
)tv.
2
o
c
T
A
V
E
t3 c 64406
14 gx( 69.296
15 D73.416
16 9X 77.7E2
17 E 8.2.407
w
o.
D
I
v.
18 F87.3c7
19 F* 92.499
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P8t]{T DtSIntEUIrolr MODEL 124 KEYBOARD
D. H. BALDWIN CO.
ctNctNNAT!, OHIO 579 - 376
DECTMAL +.005 AflcLEtla.
FMCT|oNAL + .015

SOLO SWNCH DECK
+9v
8' W.O.
ACCOMP
m
DECK
D501 -
- 05 3194
124A &AC PEDA
WITCH ASSY
c5
c4
16'W.O.
SO LO
TRIGGE
AMP
ACCOMP
T RIGGER AMP
SOLO
FILTERS
c 501- o53540
ON GENERATOR
BD.ASSY.(F,FX)
ON GENERATOR
BD, ASSY.( DX. E)
JUMPER ON
124Aa Ac AccoM P.
[--T FILTERS
*o TSTr?1"'o csor - osgr at
R16 R17
R29
i-
I
l-[eoa;1-*,*.E-- --r PEDAL
FILTER
c501 -o53535
AMP.
-05345 PEDAL I
sw. A-ssY. L___ I
cs 79 -372
GEN O N GENERATOR
BD. ASsY.tct ol
luseD.g^ue4a
PEDAL
FILTER I
c501 -053181
R39
D1
w. c.
PEDA
w. c.
PEDAL
GAT E DEF EA T1E
N
USE
MUTED
R EED
soLo 16 '
DIVIDE R
DIVIDER
!r=oo. GArE ^111 11
PEDAL
DIVI DER STRING
BAS S
GAT E
1241

JO LO TAB
iWITCHES
ACCOM P.
TAB
SWITCHES
FLUTE
ACCEN T
PHONE
JAX
EARPHONES
SPEAKER
A513 -O2 4925
8r}
1zil
8n
6"
MUTED REED
D501 -O53950
MUT ED REED CIRCUIT
INCLUDED ON 1248 &R
MO DELS
POWER
A MPLIF IER
c501-o51929
RE VER B
CIRCUIT
c so1 - o53425
o
ON
R1
fv\
R2
/!t
R4 VO LUME TWEETER
Uzqa\
1248, BC
E4^8 tN
]EDAL TAB
SWITCHES
r&A
GENERATORS
c501 -o48703
V IBRATO AC CESSORY
BOAR D
csol -o53439
PEDAL
FILTER
AMP LIFIE R
c5
)EDAL TAB PEDAL
SWI TC HES L OU D/SOFT --
TO AL L KE YSW ITCH DECKS
REED
ST RIN G
ACCEN T
16r
SAXOPH.
T ONE
DEEP / BRIGHT
PREAMP
c501-
- 05342s
RHYTHM
VOICE
GENERAT.
D501053187
ONDER
CHORD
UNIT
D579-375
124AC
&
124BC
XPRESS.
PEDAL
RHYT HM
CLAMP
BASS
SOF T
BA SS
MEDIUM
BASS
FULL
ST RING
BAS S
PEDA L
SUSTAIN
VIBRATO
osc.
6.4H2
MODEL 124 SERIES
BLOCK DIAGRA2-24 -7 2
579-377
rr[,E33 oTilrrwtlt tttctnED D€ctrrt = .G lrc.E:l li'
fU.tlllGE3 ttEr Ft5llilll t .0U
1l
3&R MODELS O N LY

TONE GEMMTION AND ACCESSORY BOARD
2 NOTE GENEMTOR BOARD
The tone generation system consists of six (6) two note generator board assemblies which produce 49
frequencies (notes) in the range from C3 (Note /125) at 130.8 Hz Eo C7 (Noce il73) aE 2093,0 Hz,
Each 2 note generator sub assembly is of similar layouE and consists of Ewo masEer oscillator circuiEs
and an integrated seven stage bipolar frequency divider. The generators are continuously operating when the
organ is turned on, supplying frequencies to the Solo, Accompaniment and ?eda1 keyswitch decks.
MASTER OSCILLATOR: (Refer to Generator Board Schematic C501-048703)
fne masEer oscillator circuit consisting of an NPN silicon transistor (QI) and associated circuitry is
an L-C type oscillator, which is relatively insensitive to climatic temperature variaEion.
Ilighest frequency notes (top octave) are produced by the master oscillaEors which are accurately facEory
preadjusted and can be retuned by means of a tuning slug. Master oscillators produce frequency range from C7
(Note /i73) at 2093,0 Hz Lo Cll6 (Note /162) at 1108.7 Hz. The above frequencies are also applied to integrated
frequency dividers where they are divided in half by each stage, so creating a EoEal of four (4) octavely re-
Iated frequencies.
Vibrato oscillaLor frequency of 6,4 Hz, from the accessory board assembly, is applied via R5 resistor Eo
the base of Q1 master oscillator transistor, which modulaEes t.he master oscillaEor frequency and produces the
vibrato effecc. Resistor Rl in the master oscillator circuit is factory preselecEed Eo accuraEely control
the rrQrr of the resonant circuit which assures a uniform vibrato extent for all masEer oscillators.
FREQUENCY DIVIDERS
The frequency dividers (FD) are bipolar inEegrated circuiEs consisting of seven (7) dividers. Referring
ro Schemaric Diagram C501-048703, master oscillator (M.0. /lf) ouEput is applied to the inpuE of FD /13 with ics
outpuE internally connecEed to FD /14 input. Output of FD 1l'4 is exEernally connecEed to FD /16 inpuE.
Master oscillator (M.0. /I2) ouLput is applied to Ehe input of FD /il with its outpuE internaLly connecEed
to FD /i2 input. output of FD 112 is exEetnally connected to FD /15 input.
The Iast divider stage, FD 1l7, on the 2 note generator board assembly is used for the following circuiEs:
Board /11 - cll & D - ID ll7 - used for Pedal Divider
1ll2 - Dif & E - FD 117 - used for Accompaniment LI.O. (Wipeout) Divider
lf3 - F & Flt - ED 1t7 - used for Solo W.o. (Wipeout) Divider
114 - c&Gil - EDlfT - notused
1f5 - A&A/l - TDlfl - notused
116 - B&C - EDlfl - usedfor4thCDividerNote/125(C3)
Each integraEed circuit divider supplies Ehe ouEput signal from an inEernal emitter foIlower, acEing as a
buffer sEage, in order to obtain the necessary low ouEpuE impedance. The negative generaLor supply volEage
(-5V) supplies the emitEer followers through the resistor pack 4.7K ohn emitEer load resistors.
ACCESSORY BOARD: (Refer to Accessory Board Schematic C501-053439)
VIBRATO OSCI],I,ATOR
The vibrato oscillator, located on the accessory board, consists of a "Twin T'r oscillator circuit (Q5 and
Q6) adjusted Eo produce a 6.4H2,6 volt P-? (peak to peak), vibrato ouEpuE signal. Vibrato voltage applied
to Ehe master oscillator varies the conduction time of QL, which in Eurn shifts the oscillator frequency at
the 6.4 Hz rate. ResisEor R17 is initially selected to set the vibrato oscillator frequency Eo 6.4 Hz.
Switches located on the tone co1or, labeled "Light Vibratorr and rrFu1l Vibrato'r, cont.rol Ehe exEent of
the master oscillator frequency deviation. AE FulL Vibrato Ehe total frequency deviation i.s 2.5%.
SOIO AND ACCOMPANIMENT TRIC,GER AMPLIFIERS (WI?EOUT CIRCUITS)
SoIo and Accompaniment Trigger Amplifier circuits utilize wipeout acEion and together with the divider
circuit provide the bottom seven (7) notes, /118 Lo 1f24 of the 16r Solo octave and boEtom seven (7) notes,
ll18 to 1t24 of Ehe 8rAccompaniment octave, which are monophonic at the above pitches.
Both wipeouE circuits are identical so that Ehe following operational deseription for the Solo circuit
also applies for the Accompaniment circuit.
Referrlog to Sr,ritch Schematic D501-053194, Ehe r^ripeout switch decks consist of seven (7) notes, sEarting
from the bass end of the manual. lnput frequencies, Notes /130 through 1136, are supplied (crosswired) from Ehe
same decks of the Solo or Ehe Accompaniment manual.
When a note in the above range is depressed, signal from the generaEor is attenuated by a resi.stor divid-
ing network aE Ehe header output point. Attenuation of the signals appearing at the header output point is
gradual, so thaE the signal hearest the bass end of the manuaL will be of the greatest anplitude. The remain-
der of the nores toward the treble end of the wipeouE range wiLl have gradually lower amplit.ude,
The Solo header ouEput point is directly coupled to the base of Q1 transisEor located on the accessory
board. QI is biased in such a way that only the exEreme peaks will be applied to Ehe Q2 transistor, uhere
it is amplified and applied to the Solo wipeout divider. In this case, if two or more notes in the wipeout
range are depressed, only the note closest to the bass end will be detected, arnplified by Q2 transistor and
applied to the divider.
The Solo wipeouE divider is located on the two note generator board /13 (F & F/l) and the
wipeout divider on Ehe two noEe generaEor board 112 (Dlt & E) assembly.
Wipeout dividers will divide Ehe above inpuE frequency in half which is then applied to
header networks.
CASSETTE REGUIATED POWER SUPPLY
Referring to the Accessory Board schematic, a series reguLator circuit consisting of Q7, Q8 and Q9 and
associated circuit is used to provide Ehe -7 V.D.C. regulaEed source for Ehe casseEte recorder, The output
voltage (-7 V.D.C.) is sensed by R27-R28 and applied to Q7, a reference ampLifier.
The emitter voltage of Q7 is set by Ehe emitter base junction of Q8 with iEs base connected to ground,
and remains constant. Therefore, any voltage change across R27-R28 wilI cause Q7 to draw more or less cur-
ent, varying the conduction of q9, Ehe series regulating element.
Accompaniment
appropriate
t2