SX-737 Project

Nice. Thats the combo I have basically. Check out my thread on my EPIs: http://audiokarma.org/forums/index.php?threads/cal-epi-score.700637/

I have them mated with my 737 and its a perfect match. You are probably going to want a nice turntable to go with the combo. I opted for the Dual 1229. I managed to find one locally and re-worked it. It's much less about electronics and a lot more about mechanics. Fun project. I managed to get it working perfectly along with a 1229Q that is with my SX-1010. CD will be good. Hell I even use an Amazon bluetooth receiver for convenience. But, the turntable is magical for some reason.
 
I have the last board all done now.

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The final step is to replace the two filter caps, C2 and C3.

The pieces that I have on hand to use are mouser 647-LLS1J682MELB, 6800uF, 63V. Are these acceptable to use as replacememts?

They are smaller in diameter, but I have some rubber sheets that I could cut strips from to wrap around the caps. It looks like the rubber will take up the difference between the caps and the brackets nicely. I plan to cut the strips a little wider than the brackets so that the rubber squeezes out a bit both above and below the bracket once the clamp is tightened up around the cap. Is this the best plan of action here, or is their another capacitor that would be a better choice for this?

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Motnick said:
Are these acceptable to use as replacememts
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Yes they are completely acceptable. I normally pick a cap that is the original diameter to keep things looking right but if you have those already and want to save a bit of cash they will work absolutely fine. I have used the Nichicon LS caps before and had no probs with them at all.

I assume the originals are either 35mm or 40mm?
 
Oldsansui441 said:
I normally pick a cap that is the original diameter to keep things looking right but if you have those already and want to save a bit of cash they will work absolutely fine.

I assume the originals are either 35mm or 40mm?
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I can see the value in seeking out replacement caps that will fit the original brackets correctly. For my SX-1010 I will be sure to find replacements with the same diameter as the originals.

The original caps in this receiver are 40mm.

I cut some strips that are .75" wide and 4.75" long. I had to straighten the bracket tabs to get a bit more pinch on the replacement caps and spacers. They seemed to tighten up snug.

I think this will work out ok, but I can order another set of caps if you guys think I will be better off.

Here is what it looks like with the first cap installed. Please let me know what you guys think of this solution.

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Motnick said:
I can see the value in seeking out replacement caps that will fit the original brackets correctly. For my SX-1010 I will be sure to find replacements with the same diameter as the originals.

The original caps in this receiver are 40mm.
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I can see why you have gone the way you have, a 6800uF or even a 8200uF cap in 40mm is not that easy to come by at all. l could only find United Chemicon KLH's that aren't stocked anywhere and Nichicon KG super throughs that are 19-20 USD each. Your work there with the clamp spacer looks very neat to me and far better than some l have seen. I think it will be fine.
 
Oldsansui441 said:
I can see why you have gone the way you have, a 6800uF or even a 8200uF cap in 40mm is not that easy to come by at all. l could only find United Chemicon KLH's that aren't stocked anywhere and Nichicon KG super throughs that are 19-20 USD each. Your work there with the clamp spacer looks very neat to me and far better than some l have seen. I think it will be fine.
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I don't know how I didn't find those Nichicon caps. I tried searching by cap diameter on Mousers site before I placed my order.

I think what I have done here will work fine, and it doesn't look to sloppy. The only concern that I have is that the heat inside may cause the spacers to loosen up and let the caps droop over time. I think I'll keep an eye on it for awhile to make sure that doesn't happen. I can always go back and replace these with the Nichicons later on if I need to.
 
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Thanks to everyone here for all of the help and support. It feels really good to have completed this project myself.

I also have the parts to rebuild the tuner board, but since it is working fine I think my best bet is to leave it alone. Please let me know if their is anything critical on the tuner board that should be replaced.

It is sounding wonderful now. The bias and DC offset seem rock solid once the unit has been allowed to warm up fully. This was certainly not the case when I started this project!

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Looking very nice, great work.

Motnick said:
I think what I have done here will work fine, and it doesn't look to sloppy. The only concern that I have is that the heat inside may cause the spacers to loosen up and let the caps droop over time. I think I'll keep an eye on it for awhile to make sure that doesn't happen
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No they don't look sloppy at all and they will barely get warm where they are, they will stay tight.

Motnick said:
I also have the parts to rebuild the tuner board, but since it is working fine I think my best bet is to leave it alone. Please let me know if their is anything critical on the tuner board that should be replaced.
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It's entirely up to you, l have replaced tuner caps on a few units and it will not affect the alignment, just don't replace any transistors on the tuner and you will be fine.
 
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Motnick said:
By the way, I just picked up my next project last Saturday. It looks like it will be a bigger challenge, but I am looking forward to it.
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Ahh the big brother, yes a much bigger job but it will be well worth it. Sounds like you are hooked on this series of receivers, l have a soft spot for them also.
 
Just checking back in to provide an update on the sx-737. I have been listening to the sx-737 every chance that I can since completing it. So far it hasn’t missed a beat. It seems to grow better the more that I listen to it, and I am really enjoying it.

I’ve recently added a Technics SL-D2 turntable and a box of albums which I have really been enjoying. The turntable really makes the sx-737 shine. This is what the sx-737 was meant to do well!

Unfortunately my dad had sold off most of his record collection before now, but he did drop off the few remaining albums that he had including a Steely Dan and a live Humble Pie.

Listening to the Humble Pie album really took me back to being a little kid and listening to the same album through his sx-980 while growing up. My childhood memories of listening to his sx-980 are what inspired me to find a vintage Pioneer receiver after all. The album jacket has lots of wear, but it’s priceless to me having been his since new.

I’ve always been a Steely Dan fan, but they really sound wonderful on vinyl through this receiver! I have definitely been missing out before now.

Thanks again to everyone here for all of the help and support.
 
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I do exactly that with all my PIONEER gear, IF I don't Stuff the CAN's. If you make the cut 1/8 to 1/4" from the bottom, some heavy duty heatshrink will cover up the seam, keep it intact(jb weld it 1st, let dry then cover it with the heatshrink) and you won't see it as the clamp covers it up. What you have is perfectly acceptable. You can go up to 10K 80V and find one that fits both the diam and the length, but the cost starts getting prohibitive.

Parts on the Tuner board (and I'm going off memory here so double check me). There's a couple of 2sa725 or 726's should be replaced. And the Sky blue (or baby blue) SANYO ALUMINUM Electrolytics smaller than 4.7uf in variuos values, all get replaced. (think there are 5 to 7 or so). The caps are notorious for eventually turning into resistors (Fred Longworth coined the term Capsistors for these!) They aren't critical as they would be in the amp or preamp boards but still should be replaced at your convenience.
 
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Motnick said:
Just checking back in to provide an update on the sx-737. I have been listening to the sx-737 every chance that I can since completing it. So far it hasn’t missed a beat. It seems to grow better the more that I listen to it, and I am really enjoying it.
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Glad to hear you are enjoying your SX-737 :thumbsup:.
 
Looks good man! I am excited that I just finished the board work on my SA-7800. Need to get my 737 back in rotation soon.
 
I just got some LED's for my FUSE lamps for the 939 and 737. Got the Warm White. WJOE.com They do make the dial a lot easier to read at distance and close up now, when I don't have my 3rd and 4th eye's on. :)
 
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