AU-11000A all out...

[Meteli]

I took it open for you. I did not take too many pictures at the time:

there are few parts I did not touch, one is headphone related things, not really nessesary and bit sceary thing to put your headphones anyway.
Other parts are polystyrene capacitors, those clear plastic caps, they are ok in my opinion.


F2661 is easy to take out so here it for you.
I did not swap all the part, I accidently ordered too low voltage value caps for those 104/100v caps on board, all 10 of them.
Also in last order I got MJE15031G / MJE15030G, they were out of stock for while.
Also, signal path cap Elna Silmic with polypropelene bypas it, my plan is to change that one out after next order. Did try to fit Panasonic ECW to replace both of them, but did not fit.



I did thought this can be considered as heretic to make so big clear out, but positive responce from you is surprising.
How I see this; these were not really presision gear from factory, they did not match resistors or capacitors together or anything, so in that sense it is better. Would Sansui used metal film resistors if they had a change? propably, least on more expensive gear. I would really like to know what kind of THD% this amp got now, but I do not know anyone who got the gear to test it or any place were I could actually had this type of work done.
For those who would like to do something like this; take your time, double check. I used 18€ solder station for this build and 5€ solder pump, it is not about the tools.

 

[Davron94]

Great work on this unit, Meteli! I'm working on another 717 currently and with the bad shape that it is in, I will probably go the same route, if not very close!

 

[Meteli]

Great work on this unit, Meteli! I'm working on another 717 currently and with the bad shape that it is in, I will probably go the same route, if not very close!

Thank you
As it hapend I also do have AU-717 and that with "Leestereo" modification and A/B switch.
Before, 11000A was like sound coming behind fog, sound was old, I would believe you all know what that mean.

btw. I do have TU-717, but is is under the knife right now, as both TU's are modified, but I am changing amp section resistors after I did it to TU-9900.

After, right now as I am writing this:
They do sound very similar, but there are very small differences. 11000A sounds heavier more weight in sound, modified 717 got faster punch strike, but 11000A got more base after that initial slam, kind of like base note got structure. This could be from transformer difference, 11000A got heavier one and 717 suffers bit about having two smaler ones. It is like where 717 stops with base note, 11000A got more after this.

Yes, 717 got clearer note, little bit more space in soundstage and you can hear how two seperate mono's.
But 717 vocal sound "S" sounds more like "Szz" if you compare them dirrectly together and I belive that is because resistors, sound is somewhat fuzzy, non natural, like high notes got artificial robot like sound behind them.
11000A got more natural sound.

What I have A/B amps, usually they are very difficult to seperate and if you hear them alone, you could not tell the difference, only with switch and I got serius speakers.

btw.
I did same resistor change to Pioneer M-90a and now I find that Pioneer C-90a is the weak link.

M

Thread 'Pioneer M-90a hit the floor!'

Jun 25, 2026

No, seriously it did...
Let's start from the begining.... These are original sale pictures from eBay, all the best amps comes from Italy sold literally on the street, with power cord cut and legs missing.
Oh this is going to be fun, only thing I hoped was, no-one have try to fix it. It was an auction and got it for fair price.

I have zero idea what have hapend, is a earthquake or Donna had enaugh? Bad furniture or move damage, No idea.



(To be continued...)

• Meteli
• Replies: 10
• Forum: Pioneer Audio

 

[TouchSpark]

Beautiful work and certainly a keeper!
to me these units are like some of the last of the very hi-end Sansui AU-series.

Just curious do you happen to have a parts list for the transistors, caps & fusible resistors, I have one and you got me inspired to go for it.
I would even buy a Full Parts kit (caps, fuse resistors, small signal transistors) if one exists.

 

[Meteli]

Beautiful work and certainly a keeper!
to me these units are like some of the last of the very hi-end Sansui AU-series.

Just curious do you happen to have a parts list for the transistors, caps & fusible resistors, I have one and you got me inspired to go for it.
I would even buy a Full Parts kit (caps, fuse resistors, small signal transistors) if one exists.

Thanks!

Sorry, I do not have any list record what I used as I have most of the parts already in stock.
What I do is to follow the schematics change what I have and order what I don't have.

Few things to hint for those who will do this;
I use cheap TC1 - multi tester for transistors and lcr-st1 tweeters to check resistors. Check colors on resistors and measure each one to be double sure. Also remember to change pair of component with similar resistance, specs.

Some Sansui boards can be delicate and copper might come loose, so cutting legs is safe way to de-solder. Also some workers at the factory bended legs more then others so one board might be easy and some difficult.

Most difficult part is to remove spring washer or clip behind potentiometers. I use very thin file (or lathe if you got one, don't try it for these pots, test somewhere else first)

I marked sockets with dots and colors, took pictures so I don't mess reassembly. Take pictures.

Take time and have fun!

 

[TouchSpark]

My AU-11000A has NO issues with it's stock 2SA798 transistors but i see people replace as a preventive task. My question is should i just leave my 2SA798's or replace though the originals are working fine (so far)?
Are those a Must Replace item?

 

[Hyperion]

Are those a Must Replace item?

While they might be functioning as transistors, what tends to happen (in my experience), is that their gain drifts - so the pair becomes unmatched. This can cause SQ problems in the pre-amp, and DC offset problems in the power amp. You can easily fabricate replacements with pairs of gain selected KSA992's, for a significant overall improvement. The more accurate the matching, the better the end result.

I recently restored a JDM AU-10000 (same model), and every one of the 2SA798's was out of spec.

A post, by me from the restore thread
"I have been checking the 2SA798's as I remove them, the worst Hfe imbalance was 210/394 ! - none of the rest were anything like close. I have also been fitting the replacement pairs of KSA992 'channel matched' (as well as gain matched)."

 

[TouchSpark]

So basically ksa992fata's one back one front tie the emitters together, try to match HFE and that's it?

 

[Meteli]

My AU-11000A has NO issues with it's stock 2SA798 transistors but i see people replace as a preventive task. My question is should i just leave my 2SA798's or replace though the originals are working fine (so far)?
Are those a Must Replace item?

I am probably wrong person to answer, as my AU-11000a don't have any of the original board transistors left.
Put it this way; as you are there, it's just worth it.

Pre amp is the problem with these, too much noise. You can check the difference if you run your amp separated from an other pre amp and hear yourself how good the amp is, without preamp noise.

 

[TouchSpark]

There seem to be 6 of these 798's in this unit 2 in the amp driver board and 4 in the preamp/phono stage.
So let me make sure i got this right 2 KSA992 (BCEECB) with the HFE as close as possible are ok to replace the 798?

 

[bhairavi]

Wow!

I would never tackle this.

On the other hand I wonder about doing this 're-res' to a 222..

Edit: I had an LLM do the legwork and it tabulated like a 100+ resistors. Not sure I have the patience for that

 

[KeithD]

If you replace the 798's use extreme caution. The solder pads are very small, close together, and delicate = easily damaged. I agree, the pre-amp in the 9900/11000 is noisier than you'd like. However, if you don't use tone controls and leave the switch in defeat, you won't hear that background noise. I set out to replace all the 798s in my 9900. Had success with the phono board, but less so with the tone control boards. I ended up damaging a few of the solder pads, and I couldn't make a satisfactory repair. Ended up having to buy a pair of tone control boards off e-bay. I left the 798s alone on the replacement boards, only re-cap.

If you are not in there already replacing parts, I'd leave the 798s alone unless/until you are having problems.

 

[Zekeman]

That is a tremendous amount of work, and very well done by you, if I may say so.

But the main thing is, it now sounds how you like it to sound, and really, how it 'should' sound. I found the same thing with my AU-D11 II, which like you, I gave it a nearly 100% resistor swapout. (all the standard ones, and many of the others).

Oh man, really? I love my D11ii and you’re saying it can sound better with a resistor swap? I’m not sure I am ready to tackle that. Actually I’m still trying to figure out why my alchemy phono won’t work after the ic swap.

 

[TouchSpark]

So did some work on the F-2661 board first. To replace the 798's I was able to match the new transistors within +-2 HFE.
I used thermal adhesive (WARNING! Use gloves with this product!) to make the transistors as one then wrapped in heat shrink.
This is better than just heatsink compound as it essentially makes the two transistors as one monolith for the best possible heat transfer between the transistors for stability.
No damage to pads thank goodness.

Have not tested the board yet as I am waiting on new resistors to replaced the old Fusible -Resistors.

It looks like it is suggested to replace the old 2SA818/2SC1628 pair but I cannot seem to find a currently available part from Digikey or Mouser?
What do people use these days?

 

[KeithD]

So did some work on the F-2661 board first. To replace the 798's I was able to match the new transistors within +-2 HFE.
I used thermal adhesive (WARNING! Use gloves with this product!) to make the transistors as one then wrapped in heat shrink.
This is better than just heatsink compound as it essentially makes the two transistors as one monolith for the best possible heat transfer between the transistors for stability.
No damage to pads thank goodness.

Have not tested the board yet as I am waiting on new resistors to replaced the old Fusible -Resistors.

It looks like it is suggested to replace the old 2SA818/2SC1628 pair but I cannot seem to find a currently available part from Digikey or Mouser?
What do people use these days?

Nice work, looks better than mine!

For transistors I used:

2SC1628 ➝ KSC3503
2SA818 ➝ KSA1381

That was 6 years ago, so don't know if those are still available.

 

[TupolevFan]

So did some work on the F-2661 board first. To replace the 798's I was able to match the new transistors within +-2 HFE.
I used thermal adhesive (WARNING! Use gloves with this product!) to make the transistors as one then wrapped in heat shrink.
This is better than just heatsink compound as it essentially makes the two transistors as one monolith for the best possible heat transfer between the transistors for stability.
No damage to pads thank goodness.

Have not tested the board yet as I am waiting on new resistors to replaced the old Fusible -Resistors.

It looks like it is suggested to replace the old 2SA818/2SC1628 pair but I cannot seem to find a currently available part from Digikey or Mouser?
What do people use these days?

for me the best way to unsolder trhose 2SA798 is to use solder wig soacked in flux. As to replacement you can use Toshiba chip installed on adapter.

 

[petesui]

Pre amp is the problem with these, too much noise. You can check the difference if you run your amp separated from an other pre amp and hear yourself how good the amp is, without preamp noise.

I agree, the pre-amp in the 9900/11000 is noisier than you'd like. However, if you don't use tone controls and leave the switch in defeat, you won't hear that background noise.

Very interesting observations. I use my 11000 to preamp my BA-2000, but I do tend to use the tone defeat. I haven't listened to the 11000's power amp stage in quite some time. You both have me questioning the 11000 preamp and wondering about future soundchecks. When I finish restoring my CA-F1, it has two outputs, I can A/B it to the BA-2000 and the 11000's power amp to see what I can hear.

 

[SaturationPt]

Since the AU-11000A is the BA-2000 and CA-2000 in one box minus the meters, do you use the BA-2000 with the AU-11000 just for the meters?

Thread 'Comparison of boards in Sansui Definition and Professional series'

Jun 5, 2026

A while back I looked at the service manuals to determine which boards were used in multiple units in Sansui's Definition series and Professional series: AU-9900, AU-11000, AU-20000, BA-3000, CA-3000 (did not look at the BA-5000). Also included the next generation of these units: AU-9900A, AU-11000A, BA-2000, CA-2000. I made the following comparison chart, with highlights for boards used in more than one unit. (I have posted this chart in a couple of other threads where the topic came up, but it's been suggested this information may be of interest in its own thread.)

...

• KeithD
• au-11000 au-20000 au-9900 au-9900a au11000a ba-2000 ba-3000 ca-2000 ca-3000
• Replies: 5
• Forum: Exclusively Sansui

• 
• 

 

[petesui]

Since the AU-11000A is the BA-2000 and CA-2000 in one box minus the meters, do you use the BA-2000 with the AU-11000 just for the meters?

Thread 'Comparison of boards in Sansui Definition and Professional series'

Jun 5, 2026

A while back I looked at the service manuals to determine which boards were used in multiple units in Sansui's Definition series and Professional series: AU-9900, AU-11000, AU-20000, BA-3000, CA-3000 (did not look at the BA-5000). Also included the next generation of these units: AU-9900A, AU-11000A, BA-2000, CA-2000. I made the following comparison chart, with highlights for boards used in more than one unit. (I have posted this chart in a couple of other threads where the topic came up, but it's been suggested this information may be of interest in its own thread.)

...

• KeithD
• au-11000 au-20000 au-9900 au-9900a au11000a ba-2000 ba-3000 ca-2000 ca-3000
• Replies: 5
• Forum: Exclusively Sansui

• 
• 

Yeah, I guess you could say that. I had the 11000 first and used it as an integrated. Then I came into the BA-2000 by itself (it's JDM). I didn't have a separate preamp to power it with. So, I thought I'd try the 11000. One of these days I'll pull the trigger on a CA-3000. Maybe. Now, I have a CA-F1 on the bench which I plan to give a spin on the BA-2000 when I finish it.

 

[SaturationPt]

I used to prefer integrated amps, made sense to me, but these days I’ll take separates every time.

I do love the 11000, but the BA/CA separates with the meters are tasty looking, everything I have these days has big blue meters so I do get it!