Pioneer SX-650 Receiver - In-Depth Discussion

One of my KZbin subscribers asked if I could post a more detailed video of the Pioneer SX-650 receiver. He’s new to this sort of thing and just wants to know more about how things work, I have a strong appreciation for anybody who wants to work with vintage audio. It’s becoming a lost art and I like to share and inform - that’s my way of giving back.
That said I ramble on and talk about the 650 from a number of different dynamics. And please chime in with any comments or things that you have to add.
Warning: this is an 18 minute video. Please give me your feedback as it is valuable to me. I learn from all of you!

[@marianavelino6081]

Same with my Father's Pioneer SX-650, Relay s not working. FM is in stereo mode but no output / sound at all. I remember, when you switch-on, after second you hear 'CLICK". This time, I can't hear the sound click

[@jamiewykes8585]

that shelf paper turned out nice

[@blackswann9]

It really did!

[@a.f.1587]

Just out of curiosity, what do you mean under this receiver doesn't have STK modules? It uses amplifier modules from Sanken, the SP-40W, yes they are not STK but they are just as rare amp modules, and they are almost impossible to find, just as the STK modules. I would avoid the SX-650 just because of that. The 550 and the 750 are using transistors in the power stage, much more repair friendly...

[@davismv]

Hi, thanks for your comment. You are correct that the Sanken’s are very difficult to find. I have a couple receivers that have them, and I’ve never had a problem, and everything I have read has pointed towards those being much more reliable than STK packs. I have over 40 receivers from various vintages and brands. I have blown up STK chips just when units have been powered on and not stressed, I find them to be very unreliable, but they work good when they are functioning. In general, most I’ve been able to source NOS or used STK’s from different places, including eBay. But there are a lot of fakes. That said, most folks will say the SX-650 is preferred over the SX-680 which has STK chips. But everything as a matter of opinion - getting a unit that has more readily available replacement parts might be a better option depending on your preference.

[@blackswann9]

Thank you so much. I am picking up the SX-650 tomorrow and this is exactly what I needed to make my decision firm.

[@blackswann9]

Got it, followed your instructions and it looks fantastic after i cleaned it up inside and out. I even changed the contact paper. Again, it looked fantastic- brand new even, but it was in good shape save the veneer. Thank you so much for this video.

[@xruraldustx]

I can't thank you enough, Mark. This is very appreciated. I'm learning a little more as time goes on about this unit and receivers in general. This makes a great overall refresher video to have about the SX-650. 🙂

[@davismv]

Glad you liked it, I enjoyed making it.

[@AstroHunter5280]

@@davismv So, you spray the deoxit from the front side? Meaning you take the knobs off, spray, put them back on, and then turn 20 times?