Sansui au-919 redo.

anderslober

Yikes...not again!
Hello Forum.......this unit is part of my plunder from the US of A. While I wait for some parts to arrive for some other units, I will start the redo on this 'famous' amp.
It seems in pretty good condition. The PS has been recapped by someone else. Good quality caps have been used. Everything else seems completely original. I changed the voltage to 240v operation. I then dbt'ed the unit....bright then dim......relays clicked. A good sign. Hopefully the speedy outputs are ok!

Black flag caps will go. The usual supect tr's/diodes will also go.

On top of the EQ board there is a connector.....what does this connector connect to? I couldn't find any loose connectors inside the unit.......

I will post pics soon..........
 
Hello Forum.......this unit is part of my plunder from the US of A. While I wait for some parts to arrive for some other units, I will start the redo on this 'famous' amp.
It seems in pretty good condition. The PS has been recapped by someone else. Good quality caps have been used. Everything else seems completely original. I changed the voltage to 240v operation. I then dbt'ed the unit....bright then dim......relays clicked. A good sign. Hopefully the speedy outputs are ok!

Black flag caps will go. The usual supect tr's/diodes will also go.

On top of the EQ board there is a connector.....what does this connector connect to? I couldn't find any loose connectors inside the unit.......

I will post pics soon..........

You must mean the Flat Amp - if this is the case - nothing, it is a test connector for measuring DC offset from the Flat Amp.

Anders, please read some of the restoration threads about this amp - there are one or two "gotcha's" to be aware of...
 
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Hey John.....I have been reading all the threads that I could find. Interesting stuff!

What are the 'gotcha's'? I didn't find anything really critical in the threads...............please let me know.....

Reg. the connector......ok......yes, true, it is on the flat amp.........I initially thought something was missing.
 
There is a back to front capacitor in the PSU, I can't remember what the precise issue is at the moment, (silk screening error? or factory incorrect fit?) there is some discussion about it, with PSU 'before' and 'after' pictures compared.

Another issue is components on the driver board factory fitted, but missing on the schematic - power line filtering capacitors IIRC.
 
There is a back to front capacitor in the PSU, I can't remember what the precise issue is at the moment, (silk screening error? or factory incorrect fit?) there is some discussion about it, with PSU 'before' and 'after' pictures compared.

On the preamplifier power supply board, the orientation of capacitors C07 and C08 (light blue sleeve) is opposite that which is silk screened.

 
Leestereo.....awesome...thanks for posting that picture. If anybody can think of any other 'gotcha's'....please post.

I did take a closer look at the main outputs. One side has definitely been changed. :-(
I intend to put in the best possible sub for the NMA/NMC devices. Even subs are getting hard to find now........:-(
 
just to repeat, repeat, take zillions of pictures, even if you have a perfect memory. I forgot about this during the cleaning of NMA/NMA 1012 trannies and spent 15minutes tracing the schematic to the wiring. Not good.
 
Those larger 1000 uF caps have 3 legs. The third leg is only for support. I used panasonic FC in it's place. It doesn't have (or need) the 3rd leg because it's smaller and lighter.;)
 
Great info guys! Keep it comin', so I dont mess up:thmbsp:

Some pics...........cant wait to hear it:thmbsp:









 
'Done right' the AU-919 sounds amazing, with a good quality source it will take your breath away. :yes:

(Just a bit of motivational hype there, while you contemplate how much love and attention you are going to lavish on it :))
 
Got the amp section out. One side is original NMC/NMA....the other side is 2sa909/2sc1586........a pretty good choice, except for the low 10hz rating.
 

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I think they'll be fine Anders - I wouldn't normally say that for a two channel amp with different output transistors on each side - but the replacements here are so good that reservations about this can be cast aside.

The replacements you have are the same transistors that are used in the BA-5000 (among others).
 
Yeah...thats what I thought too...........I totally disassembled the amp section, cleaned it, tested all outputs, regreased them.........I went over the driver section too.....all caps changed, black flags gone.....
I put it all back together and dbt'ed........all good......on dbt, I connected meters to speaker outs and bias connection points......all numbers dialled in easily. I then tested on normal power.......all good too.
 
I recapped the EQ board......a bit of a hassle......many caps, a couple of diodes and a ton of black flags were changed.
The preamp board was also recapped and done over.
While I was in there, I deoxited all switches and pots.
Now to put everything back together....dbt test......and the AUDIO TEST!
 
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