Pioneer SA-8500 II - Bass Turnover Rotary Switch

[Krešo]

Hi fellow AKers!

Hope everyone is safe and well!

OK, so as the subject line says, I am looking for rotary switch (Bass Turnover Frequency 3-position switch for SA-8500 II). I am in position of buying that amplifier model which has broken switch and missing that knob as well. Switch has broken just the part sticking out from the faceplate. Probably in transport. Other than that amp is in almost pristine condition. The switch in question is top row, first from the left.

If any of you fine people has spare parts and happens to have that switch and the knob I would like to buy them.

Original part numbers as stated in the service manual for SA-8500 II is:
- ASD-057 (rotary switch, 3-positions)
- AAB-116 (knob)

If any of you have that switch and that knob feel free to PM me.

Thank you!

Stay safe everyone,

Krešo

 

[markthefixer]

brain fart, the OPPOSITE substitution would work bass (2 deck) for treble (1 deck).

shaft not long enough!!! sorry!!!

final word:

bass is TWO decks, treble is one deck

the shaft from the treble control will not be long enough to move the second deck in the bass switch

 

[Krešo]

Yes Mark, that is true. Finally Amp. has arrived. Now I am in real position of eyeballing the switch and getting into it. From what I can see, those switches were made in such a way that they are in fact easy to disassemble. I may be wrong but I took a magnifying glass and it looks to me it can be disassembled. Yes, there are a lot of parts, balls, layers and what not (sorry for the wrong terminology) but if I am correct replacing shaft from donor pot/switch or even getting a rod to CNC machine after detailed measurements and technical drawing is the way to go. If that turns out to be true (disassembly) then all BS like JB-Weld and such is the wrong way. I am hoping for the best. Amp is from a good, known source, 100% (well minus the switch, hehehe) working up to the specs., mint on the outside and in. A true bliss!

If only I would find somewhere one old, vintage ALPS rotary switch with shaft long enough... Oh well, other way to go would be CNC. Anyway, I am going to fix this switch (broken piece of shaft where the knob goes) and give this baby a new life it deserves. ;-)

If any of you fine readers have by any chance spare parts drop me a line!

Thanks in advance to everyone taking the time reding this Thread!

Stay safe everyone!!!

 

[markthefixer]

I should have directed you to read the terms of service and the forum rules. There is a real strong possibility that your post(s) or this whole thread can disappear as a violation. That is an advertisment for parts, and that is allowed free for subscribers ($25 per year) in the "bartertown" section.

everything else is ok.

 

[Krešo]

Hey Mark,

oh well, if it didappears, it disappears. I can't do thing about it. I, honest to God, didn't mean to break any rule. If any of Mods have issue with this post of mine, this Thread, if ir need s to go - it needs to go.

Sadly I am not paid member (subscriber) so I can't see nor participate in the Bartertown section.

OTOH, if somebody by accident sceeens this Thread and wants to help... ;-) PM is the way to go.

I can't understand why unpaid members can't at least see the posts/threads. But hey, I am not complaining. I really didn't think this post could possibly be violation. Enough said. Right?!

AK is an amazing place. I learned quite a few things I could never find in such compressed and detailed way like on AK. So kudos to AK for that!

I am leaving you with these thoughts for now. Again, I thank you for your suggestions and all your willingless to help!

Stay safe & take good care in these troblesome pandemic times!

 

[Krešo]

Hi everyone!

So, it's been a while but finally rotary switch has been dealt with. It's all working now and repair, as hard as it seemed in the beginning, was really easy. For all interested in similar situation (in case a piece of shaft that is protruding out from the faceplate anyway) I can tell you that there is no need of welding, dremmeling, filing off etc. as long as rotary switch is healthy, not bent or broken all the way to the end.

Now, the hardest part was to find exact same design of rotary switch that Pioneer outsourced (or they had their own mills, I don't know that detail) and installed in their units. Exact same part number I haven't been able to find but I did find one that had longer shaft. So, with a little bit of brainstorming and checking out donor switch (and contacting a few folks I know or found online - thanks Buddy) with my neighbour solution presented itself. No drilling, no disassembly (other than switches), no desoldering, nothing... Story is that all those switches (so far I know all ASD series) are the same but their length varies, depending on unit construction and utility of that switch. Shaft can be pulled out and switch left in place, all wafers and all soldered. Be gentle, be very careful and slowly pull out broken shaft. Now, my donor was longer. No big deal. All those switches comes with enough small parts (like those cilinders that goes on two long screws holding switch construction in place) and since my "new" shaft was longer I simply added those "elongaters (cylinders) and put all back together. Now, while I had Tone Control Board out I noticed a few Caps were higher and getting in the way of new, longer shaft. I replaced on that Board two Caps on the left and 2 on the right side (I had at home 4x100uF 25V electrolytics). Newly made Caps are twice smaller, both in heigth and diameter, so after they were replaced nothing else was in the way of newly placed shaft. Yes, it is 1-2 cm longer but it doesn't matter. It has no other function than rotating around it's axis. Right? So, initially I was pretty worried because I haven't ever disassemble old rotary switches. This ones, their construcion, is done in such a way that it is easy to work with.

In case any of you find yourself in similar situation you can go this way. Of course, issue must be as mine, partially broken shaft.

I just wanted to thank you all who participated and wrote back.

Stay safe!

 

[markthefixer]

A picture would be welcomed ( by me. at the very least).

Congratulations for solving the problem, and quickly too.

 

[Krešo]

Hi Mark!

OK, no problem. I have to get baggy with all small spare parts and leftovers of the donor and open top cover. At this very moment I am enjoying Supertramp - Child of Vision on vinyl, actually entire Album is spinning. What a superb soundstage! ;-)

Anyway, since there were no major things done, just the old shaft out - new in, I did not post any pics. I promise I will make them as repair was in steps and upload for all interested in this particular issue. Apparently, many people have problems with broken switches. Not exactly this model but I saw so many different approaches. That made me thinking, were all those approaches (gluing, welding, dremmeling, filing etc.) neccessary if switches can be disassembled in a gentleman's way. ;-)

Thanks for your support and as soon as I take a few pics and write down procedure I am posting new post here.

Stay safe!

 

[markthefixer]

Well, I was just looking for a picture of the final results, capacitors dodged and so forth.

This old one had a busted wafer. March 2007.

 

[Krešo]

If this is 8500II then yes, those 2 yellow-ish 100uF Caps were just a bit too high for newly insterted shaft. I will definitely snap few pics and post. Mine literally looks as if how it was intend to look. I guess it's because I got a hold of ASD type just a bit longer.

And I see in your case back wafer was in bananas! ;-) Uh, I see, shame... Your situation is somewhat different than mine. So, as far as I can see, you can't switch freq. center from the faceplate or what? I see toggle switch on your newly installed back "wafer". Or am I missing something here?

EDIT: Uh, sorry, I see it's 2007. Long time done...

 

[markthefixer]

Yes the turnover switching is unfortunately internal,
and if the correct switch wafer is ever procured, that it can be cleanly removed and the good switch installed.

The appearance was maintained for the panel. Correct steps and everything.

Back in 2007.

 

[Krešo]

@markthefixer (and anyone interested, really)

Hey, I found some spare time and took some new pics and took some old ones I sent around while searching for help, tips, guidance...

I tried to insert more than 10 photos but I am allowed to 10 max. per post so I am splitting this illustrated story in two parts.

I truly hope this will help some of you out there with same (or similar) problem!

Save these gems of audio engineering! They need to be on spec. and putting out music! ;-)





















...two more photos are in next post!

 

[Krešo]

...and two more photos.

Stay safe all!




That's it folks!

Bye ;-)