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SX-939 worth the effort?

At this point, I would replace all the silicon except the diodes that check out (Check the STV's for their correct forward voltage). Test all the resistors comparing to the good channel, desoldering one leg if the readings are inconsistent.
The amp boards on the 1010 have several components that age poorly. Best to rebuild it (At this point). A failure by applying voltage where it doesn't belong - causes unexpected damage to components. I know that sounds funny but its true. You cannot trust any transistors that tests good.
The process will not take that long if you stay organized.
All the work in gaining access to the amps and outputs, your money and time ahead to make sure everything is correct and ready for the DBT. Every time you have to go back in to fix or check an issue you increase the probability of self induced damage. Missing solder, incorrect component positions, incorrect polarity, broken wire wraps, ect.
 
zebulon1 said:
Is the PS up to speed?
Click to expand...
Bob thanks for chime in. When both amps were disconnected all pin voltages are fine. So I expect PS is fine. After connecting both amps only Pin 10 voltage is amiss! I checked all resistors in amp boards they read fine. Following your advice, I will replace all transistors including output transistors. It will take some time and I will send a pm to you and Larry when I finish the replacement. For output transistors what are the correct replacements?
Thank you again!
 
larryderouin said:
mj21193g & mj21194g
Click to expand...
Before placing order I would like to confirm the right replacement parts for amp boars. Here is what I am buying

2SA726 by KSA992FTA
2SC1451 by KSC1845FTA
2SC945 by KSC945CGBU
2SA733 by KSA733CGBU
2SB528 by MJE15031G
2SD358 by MJE15030G
2SC1448 by KSC2073TU
2SA740 by KSA940TU
Output transistors by MJ1193G and MJ1194G

Please confirm
 
sanjib said:
Before placing order I would like to confirm the right replacement parts for amp boars. Here is what I am buying

2SA726 by KSA992FTA
2SC1451 by KSC1845FTA
2SC945 by KSC945CGBU
2SA733 by KSA733CGBU
2SB528 by MJE15031G
2SD358 by MJE15030G
2SC1448 by KSC2073TU
2SA740 by KSA940TU
Output transistors by MJ1193G and MJ1194G

Please confirm
Click to expand...
Sorry corrections
2SA726 by KSA992FTA
2SC1451 by KSC3503DSTU
2SC945 by KSC945CGBU
2SA733 by KSA733CGBU
2SB528 by MJE15031G
2SD358 by MJE15030G
2SC1448 by KSC2073TU
2SA740 by KSA940TU
 
Pioneer SX-1010 recap list
This is "mattsd" list that I use:
Thank you Matt and MTF
Notes:
This list has the 5 %, 63v, WIMA films listed/incorporated, ECQ's are no longer available.
Some E-caps my require a voltage increase up if unavailable.
The cap height on the PS is most critical as the head room between the bottom cover is at issue.

Muting Assembly (AWM-039-A)

AWM-039-A: C1: .47uF 50v CEA: 505-MKS2C034701CJSSD .47uF 50v
AWM-039-A: C2: 47uF 50v CEA: 505-MKS2C034701CJSSD 47uF 50v

Equalizer Amp Assembly (AWF-013-0) (Q1 & Q3 and Q2 & Q4 should ideally be gain matched, this is optional though)

AWF-013-0: C1: 2.2uF 25v CSSA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWF-013-0: C2: 2.2uF 25v CSSA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWF-013-0: C5: 470uF 6.3v CEANL: 647-UKL1C471KPD 470uF 16v
AWF-013-0: C6: 470uF 6.3v CEANL: 647-UKL1C471KPD 470uF 16v
AWF-013-0: C9: 100uF 6.3v CEANL: 647-UKL1E101KPDANA 100uF 25v
AWF-013-0: C10: 100uF 6.3v CEANL: 647-UKL1E101KPDANA 100uF 25v
AWF-013-0: C11: 10uF 10v CEANL: 647-UKL1C100MDDANA 10uF 16v
AWF-013-0: C12: 10uF 10v CEANL: 647-UKL1C100MDDANA 10uF 16v
AWF-013-0: C19: 100uF 25v CEANL: 647-UKL1E101KPDANA 100uF 25v
AWF-013-0: C20: 100uF 25v CEANL: 647-UKL1E101KPDANA 100uF 25v
AWF-013-0: C21: 220uF 16v CEANL: 647-UKL1C221KPDANA 220uF 16v

Q1: 2SA725: 512-KSA992FBU
Q2: 2SA725: 512-KSA992FBU
Q3: 2SA725: 512-KSA992FBU
Q4: 2SA725: 512-KSA992FBU
Q5: 2SC1313: 512-KSC1845FTA
Q6: 2SC1313: 512-KSC1845FTA
Q7: 2SC1313: 512-KSC1845FTA
Q8: 2SC1313: 512-KSC1845FTA

Control Amp Assembly (AWG-027-0) (Check C49-52, the A version of this board has them as 100uF 16v CEA instead of 47uF 16v CEA like the manual states)

AWG-027-0: C1: .33uF 25v: CSSA: 505-MKS20.33/63/5 .33uF 63v
AWG-027-0: C2: .33uF 25v: CSSA: 505-MKS20.33/63/5 .33uF 63v
AWG-027-0: C7: 100uF 10v CEA: 667-EEU-FM1E101 100uF 25v
AWG-027-0: C8: 100uF 10v CEA: 667-EEU-FM1E101 100uF 25v
AWG-027-0: C13: 2.2uF 25v CSSA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-027-0: C14: 2.2uF 25v CSSA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-027-0: C15: 4.7uF 50v CEA: 667-EEU-FC1H4R7 4.7uF 50v
AWG-027-0: C16: 4.7uF 50v CEA: 667-EEU-FC1H4R7 4.7uF 50v
AWG-027-0: C23: 4.7uF 25v CEANL: 647-UKL1H4R7KDDANA 4.7uF 50v
AWG-027-0: C24: 4.7uF 25v CEANL: 647-UKL1H4R7KDDANA 4.7uF 50v
AWG-027-0: C25: 10uF 16v CEA: 667-EEU-FC1H100L 10uF 50v
AWG-027-0: C26: 10uF 16v CEA: 667-EEU-FC1H100L 10uF 50v
AWG-027-0: C29: 100uF 10v CEA: 667-EEU-FM1E101 100uF 25v
AWG-027-0: C30: 100uF 10v CEA: 667-EEU-FM1E101 100uF 25v
AWG-027-0: C31: 4.7uF 50v CEA: 667-EEU-FC1H4R7 4.7uF 50v
AWG-027-0: C32: 4.7uF 50v CEA: 667-EEU-FC1H4R7 4.7uF 50v
AWG-027-0: C39: 4.7uF 25v CEANL: 647-UKL1H4R7KDDANA 4.7uF 50v
AWG-027-0: C40: 4.7uF 25v CEANL: 647-UKL1H4R7KDDANA 4.7uF 50v
AWG-027-0: C41: 10uF 16v CEA: 667-EEU-FC1H100L 10uF 50v
AWG-027-0: C42: 10uF 16v CEA: 667-EEU-FC1H100L 10uF 50v
AWG-027-0: C45: 100uF 10v CEA: 667-EEU-FM1E101 100uF 25v
AWG-027-0: C46: 100uF 10v CEA: 667-EEU-FM1E101 100uF 25v
AWG-027-0: C47: 2.2uF 25v CSSA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-027-0: C48: 2.2uF 25v CSSA: 647-UKL1H2R2KDDANA 2.2uF 50v
AWG-027-0: C49: 47uF 16v CEA or 100uF 16v CEA: 667-EEU-FM1E101 100uF 25v or 667-EEU-FM1E470 47uF 25v
AWG-027-0: C50: 47uF 16v CEA or 100uF 16v CEA: 667-EEU-FM1E101 100uF 25v or 667-EEU-FM1E470 47uF 25v
AWG-027-0: C51: 47uF 16v CEA or 100uF 16v CEA: 667-EEU-FM1E101 100uF 25v or 667-EEU-FM1E470 47uF 25v
AWG-027-0: C52: 47uF 16v CEA or 100uF 16v CEA: 667-EEU-FM1E101 100uF 25v or 667-EEU-FM1E470 47uF 25v

Q1: 2SA725: 512-KSA992FBU
Q2: 2SA725: 512-KSA992FBU
Q3: 2SC1313: 512-KSC1845FTA
Q4: 2SC1313: 512-KSC1845FTA
Q5: 2SC1313: 512-KSC1845FTA
Q6: 2SC1313: 512-KSC1845FTA
Q7: 2SC1313: 512-KSC1845FTA
Q8: 2SC1313: 512-KSC1845FTA

Power Amp Assembly (AWH-032-0) (Times two) (Check board number, the D version does not have the 1.5uF cap.) (Q1 and Q2 should ideally be gain matched, this is optional though)

AWH-032-0: C1: .68uF 25v CSSA: 505-MKS20.68/63/5 .68uF 50v
AWH-032-0: C2: 1.5uF 25v CSSA: 647-UKL1H1R5MDD1TA 1.5uF 50v (CHECK FOR THIS BEFORE ORDERING!!)
AWH-032-0: C4: 10uF 16v CEA: 647-UPW1E100MDD 10uF 25v
AWH-032-0: C8: 330uF 6.3v CEA: 647-UPW1A331MPD 330uF 10v

Q1: 2SA726: 512-KSA992FBU
Q2: 2SA726: 512-KSA992FBU
Q3: 2SA726: 512-KSA992FBU
Q5: 2SC1451: 512-KSC3503DSTU
Q6: 2SC1451: 512-KSC3503DSTU

VR1: 2.2K ohm multi offset: 652-3296P-1-202LF 2K ohm 25 turn
VR2: 470 ohm single bias: 652-3386H-1-501LF 500 ohm single turn

Protection Assembly (AWM-062-0)

AWM-062-0: C1: .22uF 10v CSSA: 505-MKS20.22/63/5 .22uF 63v
AWM-062-0: C2: .22uF 10v CSSA: 505-MKS20.22/63/5 .22uF 63v
AWM-062-0: C3: 330uF 6.3v CEA: 647-UPW1A331MPD 330uF 10v
AWM-062-0: C4: 330uF 6.3v CEA: 647-UPW1A331MPD 330uF 10v
AWM-062-0: C5: 4.7uF 25v CEA: 647-UPW1V4R7MDD 4.7uF 35v
AWM-062-0: C6: 100uF 16v CEA: 647-UPW1E101MED 100uF 25v

Q1: 2SC869: 512-KSC1845FTA
Q2: 2SC869: 512-KSC1845FTA
Q6: 2SC945: 512-KSC2383YTA
Q7: 2SC1384: 512-KSC2690AYS
1N4004 flyback diode is added between pins 9 (anode +) and 10 (cathode -)

Power Supply Assembly (AWR-054-0) (Stand the new resistors up off the board about a half inch)

AWR-054-0: C8: 470uF 80v CEA: 647-UPW2A471MHD 470uF 100v
AWR-054-0: C9: 470uF 80v CEA: 647-UPW2A471MHD 470uF 100v
AWR-054-0: C10: 100uF 63v CEA: 647-UPW2A101MHD 100uF 100v
AWR-054-0: C11: 100uF 63v CEA: 647-UPW2A101MHD 100uF 100v
AWR-054-0: C12: 100uF 35v CEA: 647-UPW1H101MPD 100uF 50v
AWR-054-0: C13: 100uF 35v CEA: 647-UPW1H101MPD 100uF 50v
AWR-054-0: C14: 47uF 50v CEA: 647-UPW1J470MPD 47uF 63v
AWR-054-0: C18: 1000uF 35v CEA: 647-UPW1H102MHD 1000uF 50v
AWR-054-0: C19: 220uF 16v CEA: 647-UPW1V221MPD6 220uF 35v
AWR-054-0: C20: 2200uF 10v CEA: 647-UPW1C222MHD 2200uF 16v
AWR-054-0: C21: 2200uF 10v CEA: 647-UPW1C222MHD 2200uF 16v

R11: 10 Ohm 1/4 watt: 660-MFS1/2DCT52R10R0 10 Ohm 1/2 watt
R12: 10 Ohm 1/4 watt: 660-MFS1/2DCT52R10R0 10 Ohm 1/2 watt
R20: 3.3 Ohm 1/4 watt: 660-MF1/2DCT52R3R32F 3.32 Ohm 1/2 watt
R21: 10 Ohm 1/4 watt: 660-MFS1/2DCT52R10R0 10 Ohm 1/2 watt

Q1: 2SD313: 863-MJE15032G
Q2: 2SC869: 512-KSC2383YTA
Q3: 2SC869: 512-KSC2383YTA
Q4: 2SB507: 863-MJE15033G
Q5: 2SA628A: 512-KSA1013YBU
Q6: 2SA628A: 512-KSA1013YBU
Q7: 2SD313: 863-MJE15032G
Q8: 2SC1384: 512-KSC2690AYS

Main filter caps, 18000uF 63v, 50mm dia x 90mm high:

(Digi-Key) 565-3331-ND, 18000uF 75v screw terminal 50.80mm dia x 79.38mm high
(Mouser) 661-E36D750N183TC79M, 18000uF 75v screw terminal 50.80mm dia x 79.38mm high

BOM List (with 4 100uF 25v caps for the tone amp, does not include the filter caps or the 1.5uF cap, add if needed)

505-MKS2C034701CJSSD | 1
647-UPW1H470MED | 1
647-UPW2A471MHD | 2
647-UPW1H102MHD | 1
647-UPW1V221MPD6 | 1
647-UPW1C222MHD | 2
647-UPW1E101MED | 1
647-UPW1V4R7MDD | 1
647-UPW1A331MPD | 4
505-MKS20.22/63/5 | 2
647-UPW1E100MDD | 2
505-MKS20.68/63/5 | 2
647-UKL1H2R2KDDANA | 6
647-UKL1C471KPD | 2
647-UKL1E101KPDANA | 4
647-UKL1C221KPDANA | 1
647-UKL1C100MDDANA | 2
505-MKS20.33/63/5 | 2
647-UKL1H4R7KDDANA | 4
647-UPW2A101MHD | 2
647-UPW1J470MPD | 1
647-UPW1H101MPD | 2
667-EEU-FC1H4R7 | 4
667-EEU-FC1H100L | 4
667-EEU-FM1E101 | 10
512-KSC1845FTA | 12
512-KSA992FBU | 12
512-KSC3503DSTU | 4
512-KSA1220AYS | 4
512-KSC2690AYS | 4
512-KSA1013YBU | 2
512-KSC2383YTA | 3
863-MJE15032G | 2
863-MJE15033G | 1
660-MFS1/2DCT52R10R0 | 3
660-MF1/2DCT52R3R32F | 1
652-3296P-1-202LF | 2
652-3386H-1-501LF | 2
 
Thanks Bob. But it does not have the replacement of all transistors in Power amp. It has replacements for only Q1, Q2. Q3, Q5 and Q6.
 
This is the transistors list posted by "Mattsd" in one thread (https://audiokarma.org/forums/index.php?threads/latest-recap-list-for-sx-1010.636587/). The replacement of Q8 2SB528 is KSA1220 but it is not available in mouser or digikey. Also my board is version D so there is no didoe D1 instead there is a resistor.

awh-032 Q1 2SA726 512-KSA992FBU
awh-032 Q2 2SA726 512-KSA992FBU
awh-032 Q3 2SA726 512-KSA992FBU
awh-032 q4 2sb528 ksa1220 / ksa1381
awh-032 Q5 2SC1451 512-KSC3503DSTU / KSC2690?
awh-032 Q6 2SC1451 512-KSC3503DSTU
awh-032 q7 2sd358 ksc2690
awh-032 q8 2sb528 ksa1220
awh-032 q9 2sc1448 ksc2073
awh-032 q10 2sa740 ksa940
awh-032 q11 2sc945 512-KSC1845FTA
awh-032 q12 2sa733 512-KSA992FBU

awh-032 D1 1S2473 512-IN4148
awh-032 D2 1S2473 512-IN4148
awh-032 D3 1S2472 512-UF4004
awh-032 D4 1S2472 512-UF4004
awh-032 D5 STV-3H X
awh-032 D6 STV-3H X
awh-032 D7 1S1885 512-UF4004
awh-032 D8 1S1885 512-UF4004
 
I have that list too. Forgot about it.
I can send a couple 1220's first class.
 
Last edited:
some of the wires in the pins at the top of the board are broken and is very hard to resolder with wrapped wire in pins. I took out those pins and thinking of soldering the wire directly to the board. Is that ok to do?
 
You can, but I'd rather remove the old wire wrap from the pin (needle nose come in handy for this), then wrap a turn or two of the wire on the post and Solder.
 
zebulon1 said:
Is the PS up to speed?
Click to expand...
UPDATE
While waiting for transistors I though I might check the PS is good or not. Thinking about Bob's question "Is the PS upto speed". So, I disconnected both amp by taking out Pins 3,7 and 4 from both amp insulate them. Powered on through DBT, passed DBT but relay did not click. I check the Pin voltages and Pin 10 is still amiss at positive voltage. All other pins are fine. I checked R12 on PS board and it is tested open. I replace it with 10 ohm 1/2 watt. After powering on DBT, negative rail back! BUT relay is not clicking. In the present state both amps are disconnected from PS below are the voltage readings from PS and protection board. Burned R12 can damage any other component?

Power Supply
Pin 6 = 6.4 V
Pin 8 = 13.3 V
Pin 9 = -11.1 V
Pin 10 = -55.1 V
Pin 11 = -22.7 V
Pin 12 = 0 V
Pin 13 = 34.8 V
Pin 14 = 55.0 V
Pin 15 = 25 V

Protection Board
Pin 2 = -10.9 V
Pin 9 = 34.2 V
Pin 10 = 34.4 V
Pin 11 = 34.4 V
Almost all looks perfect. Is Pin 9 and 11 on protection board should be at same voltage? Now question is why relay is not clicking??
 
Relay solved

Replacing Q5 and Q6 in protection board solved the relay problem and it is now clicking voltage at Pin 9 is 8.5V.
 
Bob is it safe to check sound through headphones? Or with amp disconnected can I get any sound with headphones?
 
So, your PS is back on line and up to specs?
The amps are back together and double checked for correctness?
The protection is working.
DBT is dim?
Did you check the DC Balance and idle adjustments using the DBT? Is the DC Balance and idles stable?
Remember you can't operate the receiver on the DBT but you can set the balance and check the idles for adjustment.
Once the idles are checked on the DBT, run the trimmers back for a minimum reading and reset them to specs when on house power. 25mV's is the correct setting.
If you have any questions ask now.
If all the above has a yes answer you can try it.
Maybe give us another rundown on the days work.
 
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