Project: Pioneer SX-626

[Super Noob]

Decided to finish the unit tonight.... final parts came in today.

C3 3300 uF 63v Electro Power 4700 uF 63v (Kemet)
(bypass) Polypropylene 1 uF 450v ECW-FD2W105J

C13 2200 uF 35v Electro (ACH) 2200 uF 35v UKA1V222MHD UKA - Audio Premium 105 C
C14 2200 uF 35v Electro (ACH) 2200 uF 35v UKA1V222MHD UKA - Audio Premium 105 C
(be sure to jumper the negative pads)

Bought the 25K VRs for the setting the collect current... should have went with 50K (FYI)
(had to add 10K ohm resistor in series)

 

[Super Noob]

@larryderouin

The string was corrected along the way.... but thanks for the close eye. Tuner works great on this rig.

 

[Super Noob]

Final / Completion Shots.... after a few weeks of burn in, it will be headed to Micah.

This thing is a lower rated WPC unit; however, it sure sounds sweet on the OLAs.

 

[MIJ_Pioneer]

That is a beefy receiver for just 20wpc! Jeeze just took a second look. That tuner board is as big as the 1250 and tuning gang looks bigger than any 80 series. Am I seeing things?

I mistakenly passed up a 1010 for $500 locally. Sat for sale for a while. Someone had been in it before and recapped some portion of it, but said it was working. After it sold the next week I see a "restored" 1010 for sale for $1,600 locally! So yeah, I'm keeping an eye out now

 

[Super Noob]

Little listen...

https://photos.google.com/share/AF1...?key=U3FySDZmREduckxSZ3RlMzJrdXRpTVV2Nmt4Z25R

 

[EC1]

Really detailed documented, excellent job you do here. Thank you. 626 is always on my list to get. What and how you remove the glue as you shown in post no. 4, may I ask?

 

[Super Noob]

What and how you remove the glue as you shown in post no. 4, may I ask?

You can use isopropyl alcohol... I used acetone carefully on the stubborn glue, then scrap away with a thin flat blade screwdriver.

 

[EC1]

, thanks.

 

[satellite65]

Control Amp (AWG-008-A)

Capacitors:
C1 0.1 uF 50v Mylar Film 0.1 uF 450v ECW-FE2W104JA
C2 0.1 uF 50v Mylar Film 0.1 uF 450v ECW-FE2W104JA
C3 47 uF 50v CEA 47 uF 50v UPW1H470MED
C4 47 uF 50v CEA 47 uF 50v UPW1H470MED
C7 47 uF 6v CEA 47 uF 16v UPW1C470MDD
C8 47 uF 6v CEA 47 uF 16v UPW1C470MDD
C11 4.7 uF 25v CEA 4.7 uF 63v MKS2C044701M00JO00
C12 4.7 uF 25v CEA 4.7 uF 63v MKS2C044701M00JO00
C19 10 uF 25v CEA 10 uF 25v UKL1E100MDDANA
C20 10 uF 25v CEA 10 uF 25v UKL1E100MDDANA
C23 100 uF 6v Electro (CEA) 100 uF 16v UPW1C101MED
C24 100 uF 6v Electro (CEA) 100 uF 16v UPW1C101MED
C25 47 uF 50v CEA 47 uF 50v UPW1H470MED
C26 47 uF 50v CEA 47 uF 50v UPW1H470MED

Transistors:
Q1 2SA725 KSA992F
Q2 2SA725 KSA992F
Q3 2SC1312 KSC1845F
Q4 2SC1312 KSC1845F

Before:

After:

Typo, should be Q3-6 not 1-4...
Also, I'm confused because my manual shows 2SA572 for Q3,4 and 2SC1000 for Q5,6 on AWG-008A.
Also, you didn't list C27,28 which my manual shows as 2.2uF 25V CSSA.

I really appreciate your thread as I'm getting ready to recap the 626 that I bought used in 1974. Very helpful.

Edit: I opened my 626 and the transistors on my AWG-008A are A725 and C1312, same as listed by Super Noob...

 

[larryderouin]

SATELLITE65. Check here for BOTH versions of the SX-626 manual. Your's may be a 1971 version (early manual) vs. a 1973 version (late manual). Check in the Late manual for the serial number start for each sub type of the 626. PIONEER redesigned the 626 mid model.

 

[satellite65]

SATELLITE65. Check here for BOTH versions of the SX-626 manual. Your's may be a 1971 version (early manual) vs. a 1973 version (late manual). Check in the Late manual for the serial number start for each sub type of the 626. PIONEER redesigned the 626 mid model.

Mine is a 1971 version based on KUW S/N SK3724438 and lack of "IC" sticker above power cord exit, and I'm looking at the 1971 version of the manual. Thanks for posting.

Mine was built in Nov 1972. Seeming like some of it is per 1971 manual and some is per 1973 manual.

 

[RICK KING]

I know this was about a year ago. Great job!

I intend to rebuild my SX-626 but need to finish my SA-9500 rebuild. Using the 626 now. However, I can only use headphones. The left channel has noise when using the speakers only. The headphones are fine. Is there a quick fix for this? I can't do anything major until the 9500 is done.

Thanks!

 

[markthefixer]

Dirty speaker selector switch. research the schematic to find which wafer, look to see if with the bonnet off it is accessible.
Use a q-tip to get deoxit on both sides of the contacts and twist away!!!

 

[RICK KING]

Dirty speaker selector switch. research the schematic to find which wafer, look to see if with the bonnet off it is accessible.
Use a q-tip to get deoxit on both sides of the contacts and twist away!!!

@markthefixer Thanks for your reply

I have the original OI & SM. Serial No. 3747275. I tried D5 then L5. It does not occur with headphone. I will try again. Only in left channel. Tried A,B,C speaker connections.

EDIT & P.S.: My Service Manual is <ART-027-0> not on hifiengine.

 

[RICK KING]

So the headphones come directly from AWH-002. The speakers go through AWS-013? I'm just an novice. Or does that matter?

 

[larryderouin]

Your headphones tap off the Amp(AWH-002) output's (to the speakers). The leads for the speakers continue to the SPKR Selector (Rotary switch with OFF/ON, Spkr "A", "B", & "C" selections), get folded, spindled and mutilated and sent to the individual spkr connections on the back.

 

[Csaba Vari]

Hi.
Nice job! I wanna do the same recap project but first of all I have an importat question. How can I set the bias of the main amp? Unfortunately the schematic doesn't contain any measurement value and instruction.
By the way I haven't got oscilloscope, signal generator neither a distorsion meter. Only have basic intstuments.
Thanks

 

[Super Noob]

Set the bias to 17mv measured from exposed lead taped on each coupling cap to ground. Set the lesser output collector to (50% of main voltage measured on main output). For this unit = 55.5V / 27.75V. Make some pre-amp jumpers and take a listen.

Tip = the T03 case is the collector.... so you can just clip on the exposed threaded post holding the main output to the heat sink.

 

[Csaba Vari]

Thank you for your answer. The bias setting was succesful. There is only one issue left. Hearing some distortion from the tuner section in stereo mode since I've replaced the parts of the pwr supply unit. There is12VDC on the pin 4 of the tuner PCB. The capacitors haven't been replaced yet in tuner section.

 

[HWKI]

Control Amp (AWG-008-A)

Capacitors:
C1 0.1 uF 50v Mylar Film 0.1 uF 450v ECW-FE2W104JA
C2 0.1 uF 50v Mylar Film 0.1 uF 450v ECW-FE2W104JA
C3 47 uF 50v CEA 47 uF 50v UPW1H470MED
C4 47 uF 50v CEA 47 uF 50v UPW1H470MED
C7 47 uF 6v CEA 47 uF 16v UPW1C470MDD
C8 47 uF 6v CEA 47 uF 16v UPW1C470MDD
C11 4.7 uF 25v CEA 4.7 uF 63v MKS2C044701M00JO00
C12 4.7 uF 25v CEA 4.7 uF 63v MKS2C044701M00JO00
C19 10 uF 25v CEA 10 uF 25v UKL1E100MDDANA
C20 10 uF 25v CEA 10 uF 25v UKL1E100MDDANA
C23 100 uF 6v Electro (CEA) 100 uF 16v UPW1C101MED
C24 100 uF 6v Electro (CEA) 100 uF 16v UPW1C101MED
C25 47 uF 50v CEA 47 uF 50v UPW1H470MED
C26 47 uF 50v CEA 47 uF 50v UPW1H470MED

Transistors:
Q3 2SA725 KSA992F
Q4 2SA725 KSA992F
Q5 2SC1312 KSC1845F
Q6 2SC1312 KSC1845F

Before:

After:

The 2sc725 have a BCE orientation. From the looks of this edited control board the ksa992’s ECB are in backwards. Possible that i am not seeing this correctly. Sorry for being late to the party.


This is a pic of a different ctrl board using 992’s with ECB orientation .