SX-880 restoration project

Went ahead this evening and replaced a bunch of transistors. Didn't want to touch anything in the power amp circuit since I assume they are matched pairs. Didn't touch Q21, Q22, Q24, or Q25, markthefixer had said they are pretty robust and don't need replacement.

Replaced Q23, Q27, Q28, Q29, Q30, Q31, Q32, Q33, Q34, Q36, & Q37 per the transistor list a few posts back. Added Wavefield-Vette 274-3AB heatsink to Q27 & Q30 in a similar vain to what I did with Q26... they won't do anything, but I had them on hand. Maybe a -1AB or -2AB in the same family would do more. Unfortunately the clearance behind these two are a little more tight than I felt comfortable dealing with.

Pulled the protection relay, so tomorrow I can drop it in. Then I'll look at dc bias and idle current one more time before I call the functional part of this project complete (outside a tuner alignment, which I dont have the equipment for, will probably go to a local shop and have them do it someday).

Took the cabinet (freshly stripped of all vinyl veneer) and squeeze some glue into the corner braces where most had broken free on one side or the other. Tomorrow I hope to do a once-over sanding and smother the damaged spots with putty. I hope I can rebuild the corners sufficiently to handle the veneer and look solid. Unfortunately I have a wedding to go to this weekend, so I might get to work some more on it Sunday, otherwise it'll be middle of the week before I'm finish.
 
Got new relay in the mail, bent the back pins to fatigue them off, installed and soldered. That finalized the electronics replacements/changed I'm making. I wiped down the front panel and knobs of gunk with some dawn and a chamois cloth and reassembled the case (minus cabinet). Damn is she pretty!

Not sure why I thought wood putty took hours to dry, which would have delayed me a couple days. Turns out it's 15-20 minutes, so I puttied up the corners sanded them down and started on veneer. I had sticky-backed Oak veneer. Super easy to install, I definitely learned a hell of a lot when I used it for my previous SX-650 project, so this went a lot more smoothly. The hardest part BY FAR was cutting out the vent opening. If it was just an edge trim, it wouldn't have been so bad, but since there is a recessed lip for the vent, had to kind of work blind. Didn't turn out too poorly, with some sand paper to smooth the edges, and the dark-ish stain, the mistakes are pretty well hidden. Used some Red Oak stain I had left over from a speaker project, same stuff I used on the SX-650. It's stained and drying over night.

Sanded down the vent grill with some 120 grit sandpaper using my ROS. Two coats of matte (or it might be semi-gloss?) black spray paint. I'll flip it over in the morning before work and spray it with a couple coats on the back as well. I think my plan will be to come home from work and use some Titebond II to glue it into the cabinet and clamp it over the weekend while I'm out of town.

I'm going to do a little electronics technician shopping tomorrow at work and see if anyone can do a tuner alignment fairly quickly. Luckily KC has several repair shops.

I think this project will be done much more quickly than I expected... unfortunately that means I'm going to end up obsessed with another project sooner rather than later. I think I decided this SX-880 will probably take over primary duty and I'm thinking I'll build my old man a set of speakers and gift him the SX-650 for Christmas. He was in high school when these Pioneers were released, so I'm thinking it would be a cool throw back.
 
One fault I'm finding.....

I put my cell phone into the phono in (lowest volume setting, sink the bass knob and crank the trebel to accomodate for RIAA filter), it played well for a bit, turned it up a bit, then POP on the speaker and protection relay kicked in. Turned it down and to zero and unplugged.

With no input, if I turn it up a bit, it started popping intermittently on the left channel, which I think is ****ed. The right channel is clean and rock solid. My best guess is the left channel's HA1457 that I kind of neglected the last several days.

Anyone have a preferred source for HA1457s? Is a HA1457W a reasonable replacement? I'm hesitant to order ebay junk, but that might be the best option.
 
DerekR said:
One fault I'm finding.....

I put my cell phone into the phono in (lowest volume setting, sink the bass knob and crank the trebel to accomodate for RIAA filter), it played well for a bit, turned it up a bit, then POP on the speaker and protection relay kicked in. Turned it down and to zero and unplugged.

With no input, if I turn it up a bit, it started popping intermittently on the left channel, which I think is ****ed. The right channel is clean and rock solid. My best guess is the left channel's HA1457 that I kind of neglected the last several days.

Anyone have a preferred source for HA1457s? Is a HA1457W a reasonable replacement? I'm hesitant to order ebay junk, but that might be the best option.
Click to expand...

Some of these and some modern op amps for the win, http://cimarrontechnology.com/ha1457adapter.aspx

Why would you plug in your cell phone into the phono jack???
 
fernarias said:
Some of these and some modern op amps for the win, http://cimarrontechnology.com/ha1457adapter.aspx

Why would you plug in your cell phone into the phono jack???
Click to expand...

To test it? Set the volume to the lowest setting shouldn't over drive the input and although freqs will be off, it'll be functional. A lot easier than dragging a turntable into the work bench.

I found those adapters but I couldn't find any reference to a recommended modern amp to use. Someone recommended an OPA604, but it has a Max supply of 24v (25v absolute Max), whole the sx-880 hovers right in that range.
 
about a year ago i bought one from an ebay seller from ireland. i had well tarnished silver contacts and although i didnt ask i believe it was nos. at any rate it worked just fine and still does, next time use auto body filler instead of wood filler its very hard doesnt shrink and cures really fast and adheres like mad. the ebay seller was "sparepartsforcomputers"
 
john stumpf said:
about a year ago i bought one from an ebay seller from ireland. i had well tarnished silver contacts and although i didnt ask i believe it was nos. at any rate it worked just fine and still does, next time use auto body filler instead of wood filler its very hard doesnt shrink and cures really fast and adheres like mad. the ebay seller was "sparepartsforcomputers"
Click to expand...
Thanks for the recommendation. I ended up buying one from littlediode from the UK, which will probably take a week or more to arrive, that'll be my back up.

If neither work, then I'll start experimenting with the adapter.

Wood putty worked really well, plus I already had it on hand. I'll post some pictures when I get home tomorrow!
 
when i was searching for ha1457 i got involved on this forum and it seemed that all the possible sub's operated at to low a voltage and in the end there was "no drop in" answer for the 880 or 890.perhaps i was misled or just didnt find the right thread. mine got hosed when i lent it out and someone plugged a microphone into the phono input. in the process i started to check resistors and found at least four way out. in the end i changed all those resistors that arent mounted flush to the board. seems theres about a half dozen of them. some were ok but figured there was a reason they were up in the air!
 
Rebuild album here: http://imgur.com/a/vmn2q

Got home and installed the cabinet, still have some clean-up to do, and holding the HA1457 comes in soon to get the phono cleaned up. Until then she'll sit on my office desk. Will probably take it to a local shop for realignment soon. Considering trying to buy the gear to do it myself in the future, I'm enjoying this hobby for sure.
 
Last edited:
i would recommend you brush some clear polyurethane on the INSIDE and edges of the sides use flat finish and no one will know its there. as you know that particle board doesnt like humidity or any water and absorbs it like a sponge.i did the same thing to my cs99a speakers when i recapped them a bit of cheap "insurance" if you will.
 
john stumpf said:
i would recommend you brush some clear polyurethane on the INSIDE and edges of the sides use flat finish and no one will know its there. as you know that particle board doesnt like humidity or any water and absorbs it like a sponge.i did the same thing to my cs99a speakers when i recapped them a bit of cheap "insurance" if you will.
Click to expand...

Particle board where? The cabinet is plywood.
 
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