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SX 1250 FROM SCRATCH

View attachment 2070282 I'm going to be cleaning up all the ground connections, especially on the filter bonding straps but I have to get a more powerful soldering iron. Anyone have suggestions for that? My Rat Shack iron just can't cut it.

I really like the Weller station that I've been using for the last several years without issue. It looks like this is the modern version of what I have. That's where I'd start looking... https://www.amazon.com/Weller-WE101...9Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
 
After ya' wire up about a hundred of 'em, ya' probably don't even have to look at the print any more. :D

As to soldering irons, I've been using the same Weller TC-201 for nearly 20 years. With heavy use, I have to replace the (temp control) switch and heater about every seven or eight years. I have been kicking around the idea of buying a Hakko FX888D.
 
^^^ Ha! Me too! Just had to replace the whole iron end of it as a new heater didn't correct the low heat issue. Thankfully where I used to work replaced the ones used in the assembly department when the whole lead free soldering process took over so we could meet the modern standards. I got several used bases and parts and a couple new heaters. SCORE!!

We used Hakko dual irons, the $500 plus models up in the Engineering lab and I liked those very much. The smaller irons were nicer for longer sessions like hand building surface mount prototype boards. They heat up quickly on power up too. You'll like it if you get one. I was recently looking at them and settled on the FX-951-66 model if I were to get one right now.

Edit: Just read through the thread and you have my admiration. I did a similar project on a Marantz 2385 a couple of years back that a fella had gathered up many parts for me but it wasn't this torn apart! It's very satisfying. For more heating power I use a good old Weller gun, model 8200 that is 100 watts, 140 watts on demand for short "turbo" bursts. It wasn't all that expensive at my local hardware store.
 
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After ya' wire up about a hundred of 'em, ya' probably don't even have to look at the print any more. :D

As to soldering irons, I've been using the same Weller TC-201 for nearly 20 years. With heavy use, I have to replace the (temp control) switch and heater about every seven or eight years. I have been kicking around the idea of buying a Hakko FX888D.
Haha! That would be about a quarter of a million dollars worth of 1250s at current rate.
 
If you find a solder station that lasts 20 years, you might want to consider staying with that.
 
Haha! That would be about a quarter of a million dollars worth of 1250s at current rate.
No kiddin'. I bought mine about 12 years ago for $200, and almost passed on it then. Good thing I went ahead and bought it.
As for wiring up a hundred, I was thinking about the people assembling them. After a while, they would have it memorized and could probably whip them out relatively quickly. Still a very expensive unit to manufacture though.
 
If you find a solder station that lasts 20 years, you might want to consider staying with that.
It was used when I bought it. Weller used to make seriously high quality products. And yeah, I really don't have any good reason to replace it. I keep a spare heater and switch on hand, along with a few tips. It will probably still be working long after I'm not.
 
No kiddin'. I bought mine about 12 years ago for $200, and almost passed on it then. Good thing I went ahead and bought it.
As for wiring up a hundred, I was thinking about the people assembling them. After a while, they would have it memorized and could probably whip them out relatively quickly. Still a very expensive unit to manufacture though.
I get it. I've done repetitive electrical jobs, chain outlet stores, restaurants, etc., that were basically all the same except for site work and the plans were around just for verification after awhile.
 
I worked on a 2385, it fell in the moving truck, damaged a few boards mounted to the front panel. A real mess of connectors. What a royal PITA to service. I’ll take a 1250 any day. Keep up the good work :)
 
I keep hoping I find one of those that is cracked up so I can scam the power amp out of it.
 
2385. IMO, the best amplifier section ever put into a receiver.
I'd build it into some kind of enclosure and use it for a standalone power amp.
 
2385. IMO, the best amplifier section ever put into a receiver.
I'd build it into some kind of enclosure and use it for a standalone power amp.

That's the kind of stuff I like. There is an AK member who once pondered the marriage of a Marantz (2325 IIRC) and an SX1250 amp section. I don't know if he ever attempted it but it sounded intriguing. As far as a standalone amp, I considered that option for this 1250 but realized I had accumulated nearly enough parts for a complete unit.
 
I have gone over these models pretty well, to the point of finding all the faults.
As good as they were, at the time they were designed, there can be a number of, lets say, modern day refinements, in materials and design :)

Please elaborate. I'm here to learn...
 
In many cases you are improving on the original by using new parts. The connectors and switches are silver plated which we all know is a Achilles heel but if you polish them up they are good for years. It is kind of nit picking because even the speaker terminals are kind of a joke for a serious power amplifier but where do you start and where do you end in this journey or $ sink hole :)
 
Please elaborate. I'm here to learn...
The number one thing I've noticed with Pioneer is hot running power supplies, some worse than others, and sometimes running semiconductors right on the edge of their SAO, also in the regulated power supplies. Often giving a bad name to good transistors. Pioneer, and other brands, also used some semis that were state of the art or close to it at the time, but it turned out that they weren't so great, i.e., 2SA725/726/750 and what not.
 
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