AUX1 - from Japan to export model plus restoration

Phono Preamp

BTW Is that a scorch mark under one of the four bottom row of resistors (first picture of the Driver board on post #14) - If it is, looks like some serious heat(?)
Yes, I already noticed that, but that was something before I got it, and the new resistor is OK (I checked it).
Now I am going to restore phono preamps (MM and MC)...

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those pictures above are MC phono preamps-

Because those preamps can produce some problems, I made a special attention to restore them... first of all I replaced 2SB527 2SD357 with 2SB528 2SD529 (greater Vcbo)

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... then trimmers...

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... on the left side deadly glue removed...

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... again that glue... (on that picture you can see the new small signal transistors, there I have replaced them all)

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...VD1212 replaced ...

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Great photos and great restoration work. The AU-X1 is quite a challenge to work on, so anyone who can "tame" that particular amp, such as yourself, is to be congratulated.
 
Outstanding!
I will never be as skilled as fellows like yourself but I enjoy threads like these immensely.
 
I am restoring one as well

Very much enjoying this project. Thank you so much for posting this.

I am also restoring an AU-X1 and all this documentation is nothing short of tremendous.

A transistor replacement list would be a god send.

Moguće?:scratch2:

Also, where did you find the multi-voltage toroidal transformer?

Finally, my X1 is a later model with loads of factory modifications. It arrive to me actually functional, but desperately in need of service. When I started to do the re-cap component testing, I found that on both 2775 driver boards resistors 36 and 37
were crumbling to bits.

Did you need to replace those as well?
 
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Thank you guys for nice word about my job!

A transistor replacement list would be a god send.
There are no replacement list for AUX1, all small signal transistors are available today by Fairchild Semiconductor. For example 2SC1845 is KSC1845, or 2SA992 is KSA992... Now I am not at my home so I dont have documentation, but I know that all small signal transistors you can replace by direct today production from Fairchild Semiconductor.



Moguće?:scratch2:
How do you know Croatian?:scratch2:

Also, where did you find the multi-voltage toroidal transformer?

I was lucky, here in Croatia was one damaged AUX1, and that AUX1 was donor :)


Finally, my X1 is a later model with loads of factory modifications. It arrive to me actually functional, but desperately in need of service. When I started to do the re-cap component testing, I found that on both 2775 driver boards resistors 36 and 37
were crumbling to bits.

Did you need to replace those as well?
I replaced them because they change the value of resistance.
 
Motherboard for Phono Preamps

Now, the time has come to restore motherboard for phono preamp...

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New capacitors installed

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The Mute Board

Next was The Mute Board

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One interesting detail

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And now please take a look this picture

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Those 500mW zeners are very small, and it is really hard to read marks on them, but on schematic diagram it should be 24V zener?!?! I decided to put a new one the same as the old was.

Again glue :drool:

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... cleaned...

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... replaced semiconductors ...

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... the result is...

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Now the restoration work were moved at the front of the amplifier...

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There will be a lot of job....

First of all Flat Amp Board

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Subsonic and Jump filter switch

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... speakers selector switch...

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... cleaned ...

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...and replaced parts ...

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Volume pot

Volume potentiometer is made by Matsushita, and for export AUX1 volume pot is made by ALPS, but the both types are high quality pots.

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Tape selector

To dismount Tape Selector, first you must desolder all audio cables to get access to pins of selector.

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look how at factory soldered those audio wires to the boards

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really Sansui sometimes can make things on a bad way :no:
 
The good thing is that it will never leave your bench looking like that - (or mine :) ) :thmbsp:
 
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This restoration is putting others I've seen on line nearly to shame.

The work done by the guy who owns the amp8 website comes close.

Knowing Croatian- I grew up in Northwest Indiana and there is a rather sizable community of Croations and Serbians there. (Google translate was helpful as well.)

BTW did you change the 2sk97s?

Great work!

R6
 
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Outstanding Kale!!!!, How long has this project taken you so far? other then your time & labor what kind of cost have you put into this?
 
Great job. How does it perform? Have you listened yet?
My (April 1980) 919 didn't have any of that redish glue anywhere inside. A rare find. Anybody else out there without that glue?
 
BTW did you change the 2sk97s?


R6
No I didnt. Those IC are very rare today, and I have some NOS, but I replace them only if I cant adjust DC Offset or because some other problem which can be caused by that IC.
 
Outstanding Kale!!!!, How long has this project taken you so far? other then your time & labor what kind of cost have you put into this?

Really I dont know how much I have worked on it, and on second part of yours question I cant get you answer, but I know lot of money was gone on that amplifier. On the other hand, that amplifier is maybe only one Japan model amplifier with genuine Sansui multivoltage transformer, so I did restoration job as the best I can.
 
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Great job. How does it perform? Have you listened yet?
When I finished that amp, I have only couple of days to enjoy on them, because I sold it. When you change lot of capacitors during restoration job, you should be patience about character of sound, and after about 50 hours of work, it takes final character of the sound.
 
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