IMPORTANT SAFETY INSTRUCTIONS This lightning flash with arrowhead symbol, The exclamation point within an equilatereal within an equilateral triangle, is intended to alert triangle is intended to alert the user to the the user to the presence of uninsulated presence of important operating and “dangerous voltage”...
Page 3
AP4020 Parts List 9/24/2007 YS # Description Qty. YS # Description Qty. YS # Description Qty. YS # Description Qty. 5906 3MM LED 1V9 20MA.4SPCER T&R 3 2448 15.00 AMP CIRCUIT BREAKER 4980 1/4W 470R 5%MINI T&R RES 8832 6-32 X 1/4 PAN PH TAPTITE JS500 5908 3MM LED 1V9 20MA.4SPCER T&R 3 3820...
SERVICE MANUAL SERVICE MANUAL Yorkville Sound • http://www.yorkville.com Yorkville Sound • http://www.yorkville.com The activity LED circuit consists of Q1 and the surrounding circuitry. The audio sig- Y Y o o r r k k v v i i l l l l e e A A P P 4 4 0 0 2 2 0 0 P P o o w w e e r r A A m m p p l l i i f f i i e e r r nal enters the activity LED circuit through R2.
Page 5
SERVICE MANUAL SERVICE MANUAL Yorkville Sound • http://www.yorkville.com Yorkville Sound • http://www.yorkville.com CIRCUIT DESCRIPTION: The voltage amplifier is a mirrored image with circuitry connected to the positive power supply rail being identical (but opposite polarity) to the circuitry connected to the nega- tive power supply rail.
Page 6
SERVICE MANUAL SERVICE MANUAL Y orkville Sound • http://www.yorkville.com Y orkville Sound • http://www.yorkville.com amount of time was spent on the current limit circuitry so that it may simulate the safe This causes Q40 to turn off until the reduced current flowing through Q5 maintains operating area of the output transistors (SOAR curve).
Page 7
SERVICE MANUAL SERVICE MANUAL Yorkville Sound • http://www.yorkville.com Yorkville Sound • http://www.yorkville.com If prolonged current limiting occurs on the amplifier’s output transistors then D204 or D205 (depending on which channel is current limiting) will be forward biased turning on NOTE: Every time you replace blown output transistors on a Q202 (from its off state).
SERVICE MANUAL SERVICE MANUAL Yorkville Sound • http://www.yorkville.com Yorkville Sound • http://www.yorkville.com is 10 volts across R235 or R236 which is enough to turn on Q210, Q208, and Q207 pro- viding 7 DC volts to the fan. Further heating the temperature sensors results in a larger DC voltage across the fan.
Page 9
100N (VCC) BC560C LM13600N 100V TO92 U4:C 1N750ARL 6745 Dual VCA 5102 {Function} 100N 470N 100V BC560C 1/4W MINI MPSA63 5102 4148 1/4W MINI MINI 220N TO92 1/4W 5106 FLMP 1/4W 249R 1/8W TO92 MINI MINI 1/4W 1/4W 1/4W 100K FLMP 249R LM13600N...
Page 10
Top Assy M1128 Pcb Mech M1128 6V00 6V00 ETCH GUIDE 3740 100K 21in 14C 220P 100K 220P 470R 470R 4148 5906 5906 470K R Clip Protect L Clip Channel A Channel B 5906 5908 5908 620R 5908 Power R Activity R55A 220R R55B...
Page 11
M1128.PCB_DATABASE_HISTORY SEE LAYOUT DIAGRAM PRODUCTION NOTES MODEL(S):- AP-4020 DATE VER# DESCRIPTION OF CHANGE LEAD/PIN REFERENCE OCT/97 1.00 FIRST PRODUCTION M1128 DRILL HISTORY APR/17/98 2.00 #5664 RIBBON CABLE CONNECTIONS CHANGED FOR MODEL(S):- AP-4020 PROTECT CIRCUIT DEC/09/98 3.00 PC#5736 TRACES CHANGED POT SUPPORT SCREWS DATE VER# DESCRIPTION OF CHANGE ADDED...
Page 15
.005" .008" ETCH .012" GUIDE .020" BLACK BLACK XFRM CT C208 C207 470U BLACK 470U BLACK BRIDGE 6435 BRIDGE ROUTE 275V GAGE 0.01"/HOLE C210 C209 BRIDGE MOUNTED BY WIRING 470U 470U D240 TO BTM AMP TO TOP AMP PC-C BLUE Q240 -100V MPSA06...
Page 16
SEE LAYOUT DIAGRAM M1127 Database History PRODUCTION NOTES: MODEL(S):- AP4020 DATE VER# DESCRIPTION OF CHANGE OCT/97 1.00 FIRST PRODUCTION R232 150R->270R R233 270R ->470R NOV/13/97 1.01 PC#5514 R232 270R->470R. 1 FOR C1 USE 22N FOR NORTH AMERICAN AND 680N FOR EURO. NOV/25/97 2.00 PC#5532 DELETE TRIAC ADD RELAY.
Page 19
SEE LAYOUT DIAGRAM PRODUCTION NOTES 1. MOUNTING DETAILS FOR 5W ADD #8629 SPACERS ONLY ON 6. USE #2006 SMALL BODY 1R 1W FOR R33 AND R49. M1126 Database History 5 WATT RESISTORS R29 AND R45. MODEL(S):- AP4020 7. MOUNTING DETAILS FOR Q30 TRIAC USE #8799 TO MOUNT TRIAC Q30 DATE VER# DESCRIPTION OF CHANGE...
AP4040 Quick Fix for M1146 & M1126 To speed up the servicing of the AP4020 or AP4040 on your bench, Yorkville Sound’s service department has developed a method to replace the compo- nents most likely to fail when a M1146 amplifier board requires service.
Page 21
. y o r k v i l l e . c o m w w w . y o r k v i l l e . c o m Yorkville Sound Yorkville Sound Inc. Yorkville Sound Yorkville Sound Inc.
Page 23
2N5401 AS35 MBS4992 AUG/26/98 1.10 PC#5806_ADD_33u/16V_33R_IN_SERIES ACROSS_R57A_AND_ACROSS_R64A -145 JUL/12/99 1.20 SPKON_JACKS_ADDED 4700U 4700U AUG/30/99 1.30 BRIDGED_SPKON_B->A E B C E B C C B E AP4040 DATE: AUG/30/99 MODELS: SHEET SCH VERSION: 1.30 YORKVILLE NAME: M1146.SCH PCB#&VER: M1146 TITLE: OUTPUT-BD...