Project: Pioneer SX-850

[PTL-Pioneer]

Amazing stuff Super Noob! Fine song selection also!! Your level of work is what i aspire to

 

[ageis1]

What a tremendous job Super Noob! How much did all of the parts set you back?

 

[Super Noob]

What a tremendous job Super Noob! How much did all of the parts set you back?

Most of the parts were in stock minus the filters... would guess somewhere around $150.

 

[Vince1966]

im building a BOM list off your rebuild and was wondering if you know a good alternate part number for the Q5 and Q6 transistors on the protection board. mouser is showing them available by the reel only. Q5 / 2SA733 / KSA922FBU
Q6 / 2SC945 / KSC2383YTA is what you have listed. thanks.

 

[Super Noob]

Search KSA992FB in mouser... either bulk or tape roll works. I buy 100 at a time. FB has the higher HFE and that is what you want.

KSC2383YTA... buy the ammo packing here too. No minimum - you just pull off the tape. No worries. Y had the higher HFE verses the O.

 

[Vince1966]

got it, just placed the order. thanks again

 

[ConchBoy66]

greetings from bokeelia! love your build notes!! very helpful for my sx-950 and sx-850 refurb. just an fyi....C1 / 2.2 uF 25v Electro (CSSA) / 2.2 uF 450v EECW-FD2W684KB..once i deleted one of the e's in the part number with mouser i was good to go! thank you so much for sharing, i only hope to get near the wonderful job you did with this one...very inspiring..

 

[ConchBoy66]

would you happen to have a recommendation for the 22000 filter caps for an sx-950? would i still use the same 2.2 uf 450v Polypropylene Bypass Caps / ECW-FE2W225J for it as well? did you reuse the micas when you did the output transistors or did you replace them? thanks again

would these work? 661-E36D800N223MC92M

 

[gtx580]

Great "deep dive" on the SX850. I did a rebuild on the power board and protection board of an SX850 I picked up last year that was DOA. As a true "noob" I found the Pioneer to be challenging to get to some of the caps and such to de-solder and solder,but it was worth the work! Great sounding receiver that will be in my collection for many years.

 

[Super Noob]

would you happen to have a recommendation for the 22000 filter caps for an sx-950? would i still use the same 2.2 uf 450v Polypropylene Bypass Caps / ECW-FE2W225J for it as well? did you reuse the micas when you did the output transistors or did you replace them? thanks again
would these work? 661-E36D800N223MC92M

https://audiokarma.org/forums/index.php?threads/project-sx-950.850960/

Recommend the Polypropylene... bypass caps in this thread (same ones 2.2uf).
661-E36D800N223MC92M (2" diameter) = Believe those are the ones I used on the SX-950.

Have spare micas...if the old ones are fine, I retain; however, you should plan on new ones. It is not the cost of the micas, it is the cost of not having them when you need them.

Pine Island is the best... as matter of fact we just bought a weekend get away place at flamingo bay so we can enjoy some boating.

Pull the marantz stuff out... for a change from the steady diet of pioneer sx.

 

[ConchBoy66]

Hi again..may i ask where you sourced the veneer? i have more than a few cases that i would like to fix. it's an art form in of itself for sure, also what did you use to adhere it to the case? thanks alot for your reply

 

[Super Noob]

African Mahogany Wood Veneer Plain Sliced PSA Backer 2' ... https://www.amazon.com/dp/B00AYF045W/ref=cm_sw_r_sms_api_glc_fabc_xRs3FbY7TCTD2?_encoding=UTF8&psc=1

PSA...

https://audiokarma.org/forums/index.php?threads/project-pioneer-sx-1010.907688/page-2

 

[ConchBoy66]

Thanks for the info...you did a beautiful job! I just hope mine comes out half as good..

 

[Megalomani]

THIS is the definitive SX-850 rebuild thread! Well done, and I very much appreciate the time and posts to document every step! Thank you!!

 

[mustang1102]

@Super Noob....... You have done some fabulous restoration work, thanks for such detailed info and great pictures of the work in progress. I did not see this when first posted, so I'm glad to see it came up again.

Since this post of yours has been revived, I would be interested in a little more detail how your repaired the broken shaft off the bass pot. From the pictures, it appears you drilled a hole in the center of what shaft was left in the broken pot, tapped in for a certain size screw and put the screw in ???

Where it got fuzzy for me was when you put the screw in the hole you drilled....did you cut the head of the screw off, and then tap threads into the new shaft, and screwed the new shaft onto the screw ??? If so, how did you secure the two once screwed together to ensure they do not come apart in use ??? Thanks in advance.

 

[Super Noob]

It is aluminum... I just drilled hole with hand drill. Small bolt from my misc hardware bin, then cut the head off with a dremel. They lock together plenty tight... you can add thread lock if you like.

 

[DAY4201]

Protection board up next...

Protection Assembly (AWH-062-0)
Capacitors:
C1 / 0.22 uF 10v Electro (CSSA) / 0.22 uF 100v MKS2D032201C00KI00
C2 / 0.22 uF 10v Electro (CSSA) / 0.22 uF 100v MKS2D032201C00KI00
C3 / 330 uF 6.3v Electro (CEA) / 330 uF 16v UPW1C331MPD
C4 / 330 uF 6.3v Electro (CEA) / 330 uF 16v UPW1C331MPD
C5 / 4.7 uF 25v Electro (CEA) / 4.7 uF 63v MKS2C044701M00JO00
C6 / 100 uF 16v Electro (CEA) / 100 uF 25v UPW1E101MED
Transistors:
Q1 / 2SC869 / KSC1845
Q2 / 2SC869 / KSC1845
Q3 / 2SC945 / KSC1845
Q4 / 2SC945 / KSC1845
Q5 / 2SA733 / KSA922FBU
Q6 / 2SC945 / KSC2383YTA
Q7 / 2SC1384 / KSC2690AYS
Diodes
D1 / 1S2472 1N4148
D2 / 1S2472 1N4148
D3 / 1S2472 1N4148
D4 / 1S2472 1N4148
D5 / 1S2472 / 1N4148
D7 / 1S2473 / 1N4148
D8 / 1S2473 / 1N4004


+ 1N4004 fly-back diode is added between pins 9 (anode +) and 10 (cathode -)

Before:

After:

Thanks for posting all the info on your restoration. Great photos! I am considering doing some "upgrading" of what I would consider a partial restoration of my SX-850 I did a few years ago. I am curious why you replaced D8 (1S2473) on the Protection Bd. with a 1N4004 instead of what appears to be the usual replacement the 1N4148? I am going to replace the diodes on this board but would like to hear your reasoning for that particular replacement. Thanks!

 

[Super Noob]

https://audiokarma.org/forums/index.php?threads/pioneer-sx-1050.425303/page-4

 

[DAY4201]

https://audiokarma.org/forums/index.php?threads/pioneer-sx-1050.425303/page-4

Thanks for that!

 

[markthefixer]

Yup, it is directly exposed to the outside world and all the smutz that can come in over the power line and make it through the transformer..

I've only seen a few failures over the years of that diode, but the factory bean counters no longer hold sway here. Especially for those with oodles of 1n4004's in a parts bin.