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AU-9900 replacement parts recommendations?

Hyperion said:
Just enter the type number into the AK 'search' box - I just tried this and got 96 hits where people have encountered 2SC1364 and done something about it. ;)
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I did do a search in the Sansui forum, and one turned up with a PS application in an 881.

https://audiokarma.org/forums/index.php?threads/2sc1364-crossover.641424/

Recommended replacement was KSC1845FTA. I thought someone who had restored an AU-9900 might be able to say what they used for TR10 on the PS. Will keep digging.
 
AnalogueBen said:
Have you viewed the specs on the original transistor? I just looked and saw that the 2690 will better suit.
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Thanks Ben, I did look at the data sheets, but I'm never sure what the critical values are that need to match vs. those that are less important. I'm sure it depends on the application, which is why I was asking. I'll take a closer look at the 2690 as compared to the 1364.

sanjib said:
What about this one? Base at center
https://www.mouser.com/datasheet/2/308/2N3904-D-1801586.pdf
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I don't have the 2N3904 on hand, and the pinouts are different from the 1364, so the legs would have to be twisted to fit it in.
 
Here are the transistor comparisons:

Screen Shot 2021-01-05 at 5.01.53 PM.png

Looks like 2383 might be better because of the Max Veb matching that of the 1364?
 
TR10 is in the protection circuit I believe KSC945 work fine although rated 150mA. To be on the safe side I think KSC2383YTA is better suited here. hFE of YTA suffix is 160-320.
 
sanjib said:
TR10 is in the protection circuit I believe KSC945 work fine although rated 150mA. To be on the safe side I think KSC2383YTA is better suited here. hFE of YTA suffix is 160-320.
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Actually, I have KSC945CGTA on hand with an hFE range of 200-400 according to the data sheet.
 
Narrowing down the filter caps to get. Here are three options I came up with for screw terminal caps. The current filter caps are 51 mm wide by 72 mm high. Total clearance is about 82 mm, so given variations in the height of the terminals, I believe I need to stay at or below 80 mm total height. blhagstrom used United Chemicon as described in his thread on replacing the filter caps. Looked like a tight fit. I'm intrigued by the Kemet caps. Size would be good. Any thoughts on which to pick? If all equal, I'll get the Kemets.

Screen Shot 2021-01-12 at 4.39.15 PM.png
 
KeithD said:
Narrowing down the filter caps to get. Here are three options I came up with for screw terminal caps. The current filter caps are 51 mm wide by 72 mm high. Total clearance is about 82 mm, so given variations in the height of the terminals, I believe I need to stay at or below 80 mm total height. blhagstrom used United Chemicon as described in his thread on replacing the filter caps. Looked like a tight fit. I'm intrigued by the Kemet caps. Size would be good. Any thoughts on which to pick? If all equal, I'll get the Kemets.

View attachment 2095233
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I've used Kemet caps before and have had great results......
 
kevzep said:
I've used Kemet caps before and have had great results......
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Thanks Kev. I think I'll be ordering those. I have a few other parts I somehow forgot to get on the first order. Recapped the two PS boards and all went well.
 
Put the filter caps in. Here is what the originals look like on the terminal side with the board removed.

IMG_2500.JPG

As @blhagstrom showed in this thread, new caps have the terminals further apart, so some adjustment to the center connecting bracket is needed. Pretty easy to do I found.

IMG_2501.JPG

I chose Kemet caps as given in post #52 above. Same diameter as original caps, but a bit shorter. I did not want to worry about the larger ones (higher voltage) being a tight fit. Here's a picture of the original caps in.

IMG_2477.JPG

And then the replacement Kemets.

IMG_2502.JPG

Plenty of room, and great fit!
 
MacMillan said:
Hi KeithD
...Is it complete?....will you be posting more pics ?....and of course...how does it sound now?
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Sound is excellent. I've been working on this part time the last month, so I kind of forget what it sounded like, but it's certainly as good or better to my ears than pre-restoration work. There is a low level hiss in the tone control circuit. I'm convinced that it is likely a bad KSA992 I used replacing the 2SA798 ICs. Barely noticeable, so I'm not going to track that down just yet. Need to enjoy this one for a while. I've got to replace a few diodes on the PS of my TU-9900 to finish that project as well.

For pics, here's the driver board pre and post. New caps and trimmers. I also replaced D05 and D06 at @Hyperion's direction, but did not get a picture of that fix.

E512789F-C34B-4EA9-BF78-D5FD905897D4.jpeg

E8AB6166-9B4D-4070-B844-84FA21B64366.jpeg

Here's the F-2570 equalizer circuit board. I used WIMA film caps for C03/05 and C15/16. There was enough room to get the big 10 µF Wima's in.

00AA3BF4-DDE4-4216-9973-B541700D64A5.jpeg

012400F4-AAC1-4D13-B3C0-8873409D189B.jpeg

I've got other pics if there is anything you want to see.
 
thanks for the update and pics KeithD...!
....great job on the filter caps with the Kemets..
...still waiting on my backorder for transistors, UPW caps, Wima and a few other items...a lot of components still not available..
..I do have a lot of Nichicon FG caps ...but now not sure if I should use them or not...with UPW caps being recommended....who uses FG and for what?
 
[QUOTE="
..I do have a lot of Nichicon FG caps ...but now not sure if I should use them or not...with UPW caps being recommended....who uses FG and for what?[/QUOTE]

Not sure, I feel that each person seems to have his/her own preferences. When I had more Pioneer gear, the recommendations over in that forum seemed to be only UPW and UKL depending on what was being replaced. But I've read people recommending FG and Elna Silmic II along with UPW. What seems universal is PS applications call for UPW. Beyond that in each application there seem to be more than one choice.

When I recapped my Eight the opinions I received were to use FG or Silmic II, or whatever I liked. I'm not an electrical engineer, so I don't have the knowledge to pick specific caps for specific locations from the wide array that is available. You can probably spend endless hours on this looking at all the specs. On my Eight I used UPW for the PS, WIMA MKS2 films for all of the caps below 10 µF, and FG for the rest. I've read people say the specific line of caps will make no difference in what you hear. Maybe some are longer lived than others? Possibly, but again, this is beyond my ability to decide. I have no complains about how my Eight sounds or performs after re-capping. It's my favorite single unit.

I believe a lot of techs will use what they have in stock that works for the application whether that be FG, UPW, Panasonic, Elna, etc. So, if I were you, I would not worry about it. I had about half the parts on hand and the rest I ordered from Mouser. I did not have any out of stock issues. If a cap was not in stock, I just went up one level in voltage at the same capacitance and bought that.
 
If it is of interest I mostly use Panasonic FM or FR, Nichicon HE, PM or PW - in other words low, or very low ESR capacitors, with 105°C rating, and highest possible ripple current rating for all PSU and local filtering positions. I seldom use audio grade capacitors in PSU's, because A). they aren't necessarily low ESR etc, and B). they are seldom rated for 105°C - being commonly 85°C rated. I do use audio grade capacitors in what I consider to be the signal path, and FG's would be one of those I use.
 
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