SX-737 questions

[larryderouin]

Yeah, it's like waving chocolate in front of a woman's face. She can't get enough! Or even better showing her a walk-in closet in a new house with space for 400 pair of shoes. She's got to fill it up. (Emelda Marcos Syndrome)

 

[Motnick]

This was my first foray into the world of vintage audio repair. This has been such a fun project. This stuff is addictive, man!

I was happy to be nearing the finish line on my SX-737, but at the same time I was sad to not have anymore to do as I found it to be really enjoyable work. Then the SX-1010 fell into my lap!

I'm sure you will have another one to do before you know it.

 

[loweran]

Yup that's how it goes. I did a 737 first, then a 1010 then and 838 and I have an SA-7500 and an SX-1000tw on the way.

 

[loweran]

Just a note for future reference. Earlier you mentioned that you set the bias and offset. Then you mentioned you put it on line current. Be careful to dial back the the offset before moving from DBT to line power. As you mentioned, you will have more voltage when you move to the main line power. The idea is to trial set it, then dial it back, then set it properly with line power. Its a process called tickle the dragon.

 

[Syn_Error]

I made sure I adjusted appropriately before continuing when I made the discovery. Definitely don't need things over powered and blowing up in my face.

 

[Syn_Error]

I have yet to start the last few boards to complete the recap Motnick finished in his thread. I ran into a fun problem which I asked Loweran about. He suggested I post on the forum, which I should have in the first place. Here's what I have ran into. There are two capacitors on Mark's list that have a minimum of 200 and 2000 to make an order for the capacitor over at Mouser. Here are the capacitors

AWG-030 (Control Amplifier Assembly)
C1, C2 647-UKL1H010KDDANA

AWF-011 (Equalizer Amplifier Assembly)
C1, C2 647-UKL1H010MDD

Loweran suggested 647-UKW1H010MDD1TD as a replacement. Does anyone find anything wrong with this? I was actually reading the datasheet on this capacitor when Loweran came back and suggested the part and posting to the forum with this question for other opinions. Perhaps I'm learning a thing or two about this hobby.

 

[loweran]

Or maybe this is another option: 505-MKS2B041001C00KS

 

[larryderouin]

Go with the WIMA! It's a Film and at that value/voltage your grandkids won't have to replace them either.

 

[Syn_Error]

I'll try out those WIMA's when I put in an order to Mouser. I'll let you know how that works out. Really excited about getting back into the guts of this thing.

 

[larryderouin]

I've gotten to the point where with electrolytics, if the value is 4.7uf and SMALLER, and the overall size of the comparable film is the same or smaller, I bite the bullet for difference in cost and get the film in there. They tend to be more stable, don't dry out and again, your grandkids won't have to worry about changing them in 30 years from now. And I use them in all boards.

 

[Syn_Error]

is that 4.7uf and under or just under 4.7uf?

Edit: I guess looking at my BOM answers that question. lol.