Page 1 of 36
Updatemydynaco
Dynaco SCA80(Q)
Amplifier and Power Supply Upgrade
(PWRAMP80)
ASSEMBLY MANUAL
© 2016-2017 AkitikA LLC
All rights reserved
Revision 1p18
November 25, 2017
Page 1: ...Page 1 of 36 Updatemydynaco Dynaco SCA80 Q Amplifier and Power Supply Upgrade PWRAMP80 ASSEMBLY MANUAL 2016 2017 AkitikA LLC All rights reserved Revision 1p18 November 25 2017...
Page 2: ...nstall the C9 Connection wires 10 Install the RLYDRV wire 11 Check your work 11 Disconnect the Old Power Supply and Power Amplifier 11 SCA80Q 12 SCA80 Directions 13 Removing the Amplifier Modules All...
Page 3: ...e notice that the Q4 has a square side and a round side 9 Figure 5 Installing the mounting brackets on the power supply PCB 10 Figure 6 Grounding arrangement for speaker common connections on the SCA...
Page 4: ...rosin core solder and a soldering iron 2 Use simple hand tools like screwdrivers wire cutters and pliers 3 Read and follow directions It helps if you 1 know a bit about electronics or 2 have a friend...
Page 5: ...nearby If you ve ignored all the previous advice they can dial 911 or get you to the hospital Read and understand the safety manuals of all the tools you use About Components We reserve the right to...
Page 6: ...igital ohm meter is an easy way to make sure that you ve picked the right resistor It s a great cross check on the resistor color code Measure twice and solder once A lead bending jig can make for qui...
Page 7: ...re typically though not always taped together Install the Resistors In general you install axial leaded components like the resistors by placing the body on the silk screen side of the board and the l...
Page 8: ...Orange Brown R9 511K Green Brown Brown Orange Brown R12 68 1 Watt r Blue Gray Black Gold All resistors are W 1 metal film unless otherwise indicated Install the diodes Diodes are polarized having an a...
Page 9: ...on the package refer to Figure 3 Make sure to install the opto with the correct orientation Figure 3 Pin 1 of the opto isolator is indicated by the dot and the ridge in the package Opto isolator inst...
Page 10: ...itor box capacitor Install the Electrolytic polarized Capacitors Polarized Capacitors watch polarity and voltage rating The negative side of the capacitor is marked with a minus sign That side of the...
Page 11: ...ill until the solder sets Check your work Look over the board to verify that 1 All components are soldered 2 No solder bridges are apparent 3 Polarity of the electrolytic capacitors is correct 4 Diode...
Page 12: ...eyelet 6 5 Cut the short bare wire that connects eyelet 7 to the ground lug Cut it near the ground lug 6 The PC 19 PCB is now free Remove it from the chassis and set it aside It won t be re used SCA80...
Page 13: ...te wires that connect to the COMMON terminals of the speaker connectors on the back panel Cut off the bare wire but leave the other two white wires that connect the lug to the COMMON terminals This gr...
Page 14: ...ire on the switch which is also connected to the same switch terminal 6 Cut and mark the following wires close to the eyelets on the power amp PCBs c Eyelet 12 of right channel front most power amp PC...
Page 15: ...led wire from C11 5 The TOC11 wire from C11 to the TOC11 terminal of the new PCB Insert on the component side and solder on the solder side Ground Wire 6 For an SCA80Q The PGND wire that goes to the f...
Page 16: ...C9 or the diodes backwards there could be a pop and a bang and the insides of a capacitor could come hurtling out of the capacitor Watch for smoke If no smoke then check the voltage across C9 It shou...
Page 17: ...d Brown R29 10K Brown Black Black Red Brown R7 1K37 Brown Orange Violet Brown Brown R17 1K37 Brown Orange Violet Brown Brown R15 11K3 Brown Brown Orange Red Brown Install it if you re upgrading an SCA...
Page 18: ...All resistors are W 1 metal film unless otherwise indicated Install the diodes Diodes are polarized having an anode and a cathode When you insert the diode match the banded end of the diode to the ba...
Page 19: ...film capacitor rectangular box C8 0 1 uF 100 Volt film capacitor rectangular box C14 0 1 uF 100 Volt film capacitor rectangular box C11 0 1 uF 100 Volt film capacitor rectangular box C6 1 uF film pil...
Page 20: ...two original pins to get it to sit flush it s fairly easy to do After you re sure the relays sit flush finish soldering the rest of the pins Fasten the PCB to the Heatsink Follow the diagram in Figur...
Page 21: ...der all the pins associated with U1 and U2 Figure 10 Assembled amplifier on main heatsink Build and Install the Inductor Resistor Combination The kit includes special magnet wire whose insulation is r...
Page 22: ...Watt resistor near the body of the resistor 3 Apply plenty of heat and then solder the magnet wire to the resistor lead 4 Allow it to cool before going on 5 Wrap 16 closely spaced turns of magnet wire...
Page 23: ...Remove of insulation from the end of the wire 7 Wrap three turns of the free end of the magnet wire around the as yet unsoldered power resistor lead 8 Apply plenty of heat and then solder the magnet...
Page 24: ...n Yellow piece to a length of 15 inches 3 Strip inch of insulation from each of the four ends 4 Twist and tin the 4 ends 5 Inserting the wires into the solder side of the board and soldering on the co...
Page 25: ...o the INGND terminal b RIGHTIN wire to the RIGHTIN terminal c LEFTIN wire to the LEFTIN terminal 3 Connect the LEFTOUT wire to a length that comfortably reaches the LEFTOUT eyelet of the amplifier PCB...
Page 26: ...inched wires b Form the wires to satisfy your sense of neatness c All of the label eyelets around the border of the PCB should have a wire installed Test your work Caution Potentially fatal voltages w...
Page 27: ...power 3 Reinstall the 5 screws that hold the cover in place Your upgraded amplifier is ready for use In Case of Trouble This section contains a list of the most often found assembly errors and their s...
Page 28: ...y switching currents from the diodes into a small loop that doesn t include the power transformer limiting interference into adjacent devices like FM tuners R12 taps off some of the 72 volts and provi...
Page 29: ...les to stabilize before they relay energizes This is the action that prevents pops and clicks on turn on and turn off D1 makes the on off timing of the time delay repeatable and largely independent of...
Page 30: ...des less than a 10 change R4 is there to assure that Q2 s leakage currents cannot turn it on AC Voltage Present Detection The following discussion refers to Figure 14Figure 13 The AC Voltage Present D...
Page 31: ...pulled then there will be no input pulses C2 charges and C3 turns on resetting C1 All Together Now So we see that to allow the time delay that leads to relay turn on to begin 1 The DC voltage must be...
Page 32: ...ut 20 dB until just after the speaker relays close When RLYDRV is high the speaker relays are not energized Q4 is turned on and the SOUND node is low which mutes the amplifier input Once RLYDRV goes l...
Page 33: ...a C7LNEG That signal passes through the parallel L1 R10 combination that helps assure the amp s stability in the presence of capacitive loading K3 helps assure the absence of turn on turn off pops and...
Page 34: ...Page 34 of 36 Figure 15 Power Supply Schematic...
Page 35: ...Page 35 of 36 Figure 16 Page 1 of Amplifier Board Schematic...
Page 36: ...Page 36 of 36 Figure 17 Page 2 of amplifier board schematic...
