SA-9800 Re-Work Begins

Hi Brent,

I too am watching this thread with interest. I just acquired an SA-9800 in sorry state. Missing several knobs and the top cover and bottom plates, see pic below.

SA-9800-01.jpg


Since you have yours in bits, would you mind taking a picture of the bottom plate and the top cover, and maybe adding some measurements on them? I figure I could make something out of some sheet steel until a more suitable replacement comes along. I've have a posting on Barter Town and in this Pioneer Audio sub-forum for both knobs and covers, but nothing so far.

I just finished my SX-535 re-cap and also a JVC A-X1, so I'm itching to get my teeth into this Pioneer.

Lee.
 
leesonic said:
Hi Brent,

I too am watching this thread with interest. I just acquired an SA-9800 in sorry state. Missing several knobs and the top cover and bottom plates, see pic below.

SA-9800-01.jpg


Since you have yours in bits, would you mind taking a picture of the bottom plate and the top cover, and maybe adding some measurements on them? I figure I could make something out of some sheet steel until a more suitable replacement comes along. I've have a posting on Barter Town and in this Pioneer Audio sub-forum for both knobs and covers, but nothing so far.

I just finished my SX-535 re-cap and also a JVC A-X1, so I'm itching to get my teeth into this Pioneer.

Lee.
Click to expand...

Looks like there are a few sets of eyes on this thread. I hope in the end that it will be a beneficial thread and help others out. After having worked on a few of these older Pioneer units, it is important to note that not every SA-9800 will have the exact same components on every board. Nothing can replace actually looking at your specific amp to make your assessment and replacement lists.

And yes, I sure can take some photos for you, and measurements as well. If you plan on building a new wood case, which I will be doing, just know that it will require numerous measurements and intricate work for a proper fit and finish.

But first things first... I need to get the internals all doctored up and then focus on the aesthetics. Just gotta confirm the parts replacements and move forward to the "pretty" stuff.
 
I don't have one of these, but I am watching this with great interest because, if one ever shows up in my world, I will snag it.
 
Bottom Cover

Lee,

Here are 2 photos of the bottom metal cover. The dimensions are 15 5/8" wide (side to side) by 14" deep (front to back). It looks deeper than wide, but that is the camera eye fibbing.

As far as the wooden case goes, I think this thread http://www.audiokarma.org/forums/showthread.php?t=326991&highlight=sa-9800 would best help you, as I have not yet began work on my custom case, and why re-invent the wheel...

I am currently in a holding pattern awaiting part replacement confirmation/suggestions.
 

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Checking In...

It's been a bit, and was wondering if there was any confirmation on my parts selections. Any word? In a holding pattern before ordering parts, as I want to ensure that the right ones are chosen. Once again, as always, thanks so much for the help and guidance given. It is HIGHLY appreciated.
 
Can confirm that the cap list looks ok, still working on the transistors, including the power supply ones.
 
markthefixer said:
Can confirm that the cap list looks ok, still working on the transistors, including the power supply ones.
Click to expand...

Thanks much. I will mark those confirmed and await the transistor confirmations. And if it is not too much to ask, the other points inquired about on the thread (other cap types and trim pots, etc.) would be appreciated as well.:yes::yes:
 
Other cap types do not need replacement.

trim pots, sigh.... :sigh:

gwh-129 vr1 330k multi offset 652-3296P-1-204LF
gwh-129 vr3 100 single idle 70 652-3386H-1-101LF
gwh-129 vr5 47k single idle 56 652-3386H-1-503LF

gwh-130 vr2 330k multi offset 652-3296P-1-204LF
gwh-130 vr4 100 single idle 70 652-3386H-1-101LF
gwh-130 vr6 47k single idle 56 652-3386H-1-503LF
 
Last edited:
markthefixer said:
Other cap types do not need replacement.

trim pots, sigh.... :sigh:

gwh-129 vr1 330k multi offset 652-3296P-1-204LF
gwh-129 vr3 100 single idle 70 652-3386H-1-101LF
gwh-129 vr5 47k single idle 56 652-3386H-1-503LF

gwh-130 vr2 330k multi offset 652-3296P-1-204LF
gwh-130 vr4 100 single idle 70 652-3386H-1-101LF
gwh-130 vr6 47k single idle 56 652-3386H-1-503LF
Click to expand...

Absolutely perfect! Thanks so much. Once I get the transistors all confirmed I am set to place the order.
 
SolutionRoom said:
Please see if my replacement suggestions are solid. They are all in BOLD. Are these good replacements?

1. The power supply board has a total of 12 transistors:

Q1 & Q2 2SC1735 Replace with 512-KSC2383YTA
Q3 & Q10 2SA733A Replace with 512-KSA1013YBU
Q4 & Q8 2SA904A Replace with 512-KSA992FBU
Q5 & Q6 2SK34 Replace with Sk34 (I currently have from Ampslab)
Q7 2SC1914A Replace with 512-KSC1845FTA
Q9 2SC945A - Replace with 512-KSC2383OTA
Q11 2SD712 (TO-92) Replace with 512-KSC2073TU
Q12 2SB682 (TO-92) Replace with 512-KSA940TU
Click to expand...

pretty good for a first try... (but a few changes)
awr-194 q1 2sc1735 pwr pass + 100v .5a .8w 512-KSC2690AYS to-126
awr-194 q2 2sc1735 pwr pass - 100v .5a .8w 512-KSC2690AYS to-126
awr-194 q3 2sa733 pwr darl + 50v 0.15a 0.25w 512-KSA1013YBU to-92L
awr-194 q4 2sa904 pwr darl - 90v 0.05a 0.2w 512-KSA1013YBU to-92L
awr-194 q5 2sk34
awr-194 q6 2sk34
awr-194 q7 2sc1914 fb ampl + 90v 0.05a 0.2w 512-KSC1845FTA (ln)to-92
awr-194 q8 2sa904 fb ampl - 90v 0.05a 0.2w 512-KSA992FBU (ln)to-92
awr-194 q9 2sc945 lv err amp + 50v 0.1a 0.25w 512-KSC2383YBU to-92L
awr-194 q10 2sa733 lv err amp - 50v 0.15a 0.25w 512-KSA1013YBU to-92L
awr-194 q11 2sd712 lv pass + 100 4a 30w 863-MJE15032G npn to-220 (c2073 was ok, this takes heat better) ** corrected **
awr-194 q12 2sb682 lv pass - 100 4a 30w 863-MJE15033G pnp to-220 (a940 was ok, this takes heat better) ** corrected **
awr-194 d5 xz-060 main zener 512-1n5233b
awr-194 d10 mz-177 512-1N5247B


SolutionRoom said:
2. Protection board has a total of 3 transistors.

Q1 & Q2 2SC945A Replace with 512-KSC2383OTA
Q3 2SC1885 Replace with 512-KSC2310YBU
Click to expand...

just
Q3 2SC1885 Replace with 512-KSC2690AYS to-126

SolutionRoom said:
3. We determined the following on the amp boards get replaced. Any others need replacing?

Q7 & Q8 2SA912 TO-92L Replace with 512-KSA1220AYS TO-126
Q9 & Q10 2SA726S Replace with 512-KSA992FBU
Q11 & Q12 2SC1885 TO-92L Replace with 512-KSC2690AYS TO-126
Click to expand...
For now, no

SolutionRoom said:
4. Phono transistors??? I scoured AK for 7800 posts and those that reference them and found no definitive info. Can you clarify please?
Click to expand...

The phono final stages are different and run at a lower current, so we leave them alone for now.
 
Last edited:
markthefixer said:
awr-194 q11 2sd712 lv pass + 100 4a 30w 863-MJE15032G pnp to-220 (940 ok, this better)
awr-194 q12 2sb682 lv pass - 100 4a 30w 863-MJE15033G pnp to-220 (2073 ok, this better)
Click to expand...

You have 863-MJE15032G pnp for q11 (should be NPN, no?)

Are these correct, or swapped? I had 940 on q12 and 2073 on q11

Just wanted to verify.

Thanks SO MUCH for this work! HIGHLY APPRECIATED.

Once I get this final confirmation, the order is in.
 
Last edited:
SolutionRoom said:
You have 863-MJE15032G pnp for q11 (should be NPN, no?)

Are these correct, or swapped? I had 940 on q12 and 2073 on q11

Just wanted to verify.

Thanks SO MUCH for this work! HIGHLY APPRECIATED.

Once I get this final confirmation, the order is in.
Click to expand...

863-MJE15033G pnp to-220 bce 250v 8a 50w 30mhz 70hfe $1.30
863-MJE15032G npn to-220 bce 250v 8a 50w 30mhz 70hfe $1.30

awr-194 q11 2sd712 lv pass + 100 4a 30w 863-MJE15032G npn to-220 (c2073 was ok, this takes heat better) ** corrected **
awr-194 q12 2sb682 lv pass - 100 4a 30w 863-MJE15033G pnp to-220 (a940 was ok, this takes heat better) ** corrected **
 
Last edited:
markthefixer said:
863-MJE15033G pnp to-220 bce 250v 8a 50w 30mhz 70hfe $1.30
863-MJE15032G npn to-220 bce 250v 8a 50w 30mhz 70hfe $1.30

awr-194 q11 2sd712 lv pass + 100 4a 30w 863-MJE15032G npn to-220 (c2073 was ok, this takes heat better) ** corrected **
awr-194 q12 2sb682 lv pass - 100 4a 30w 863-MJE15033G pnp to-220 (a940 was ok, this takes heat better) ** corrected **
Click to expand...

Thanks Mark for double checking (or triple or quadruple).
I know your time is valuable and limited.
 
Resistor heat

When I was recapping/rebuilding power board on A-88x I was worried about those dark heat spots around resistors. After those years of constant heat soldering/desoldering those resistors became somewhat an issue. First tried replacing with Vishay/Dale yellow power resistors with more power rating. Some were sufficient. Then with black silicone coated wirewound. Those worked good, and rated to 350 Deg C, if I am not mistaken. But one resistor was still running severely hot. So I took a Dale aluminum housed one, glued to a metal surface with Arctic Silver epoxy, and connected to the board with wires. Might be drastic and not elegant, but problem was solved. In case of future dis-assembly just disconnect the wires at the resistor and that's it. Mouser has them all. When replacing hot running resistor you may leave some space between its body and the board. If wishing to isolate the legs, thin wall teflon tubing works great.
 
hennessy said:
When I was recapping/rebuilding power board on A-88x I was worried about those dark heat spots around resistors. After those years of constant heat soldering/desoldering those resistors became somewhat an issue. First tried replacing with Vishay/Dale yellow power resistors with more power rating. Some were sufficient. Then with black silicone coated wirewound. Those worked good, and rated to 350 Deg C, if I am not mistaken. But one resistor was still running severely hot. So I took a Dale aluminum housed one, glued to a metal surface with Arctic Silver epoxy, and connected to the board with wires. Might be drastic and not elegant, but problem was solved. In case of future dis-assembly just disconnect the wires at the resistor and that's it. Mouser has them all. When replacing hot running resistor you may leave some space between its body and the board. If wishing to isolate the legs, thin wall teflon tubing works great.
Click to expand...

Good points. I think however, that on this board on my SA-9800, that the heat coloration is primarily due to that transistor next to the resistor and diode. Replacing this transistor and ensuring that the heat sink has fresh thermal paste on it and is snug to the sink, will likely allow it to dissipate the heat more efficiently. I hope...
 
I hate to sound really lazy, but do you have a complete list of the parts that you ordered. I know I could go through this thread (and others) and see what's needed, but some of us are also on limited posting time as well.

It would really be a great help.

Lee.
 
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