Sansui AU-222 restoration

[VA50]

I picked this little sansui up at a garage sale a couple of months ago in a very sad state, now that i have restored it i thought i might post a thread showing the whole process. This is the first full restoration I've done and also my first sansui. I'd like to thank Skippy124, he's helped me out a few times over the years starting back when i first got into the hobby 3-4 years ago. He gave me a few pointers on this one that help save me a fair amount of time.

 

I will be breaking this up into several post just to make it easier on myself uploading the photos while keeping things in order.

 

First couple of photo's from the day i found it, nothing broken or missing except for the odd screw but in very rough cosmetic condition, upon powering up it presented lots of cracks and pops, a blown power indicator bulb and the sound of an air conditioner in the speakers

Edited November 23, 2015 by VA50

[VA50]

First step was to give the unit a good clean in preparation for a recap and replacement of other faulty components. This unit was full of corrosion leaving all the screws covered in rust and the internal casing in pretty bad shape.

 

 

 

 

Holes drilled for the narrower pin spacing on modern capacitors

 

 

 

 

 

I found the best way to tackle the corrosion on the casing was with a kitchen scourer and a ton of elbow grease.

[VA50]

Next step was the recap, i used elna silmic II's throughout the unit and Nichicon kg/ fg for the power supply filtering capacitor and output coupling capacitors.

 

Main amplifier board completed

 

Here's a shot of the tone control board, The AU-222 along with other sansui's have 2SC871 transistors in them, these are renowned for getting noisy and causing crackles as they age, there are 6 in total in the AU-222, some of which have been replaced with mismatched items in the past as seen in the photo. All of these were replaced with bc550's as suggest by skippy124.

 

Capacitor nasties

 

reccap complete

 

Edited November 23, 2015 by VA50

[VA50]

After the reccap was completed i gave the unit a power on, tested bias current. Right channel was sitting fine but the left channel was sitting up at 240ma when in should be around 16-20ma. Adjusted that back to spec and gave it a try, the right channel now worked perfectly but the left channel was distorted and would crackle then jump up in volume. A quick test showed bursts of dc on the output when the crackles would happen. 24v and 5v was found on the coupling caps which immediately caught my attention, after attacking skippys inbox again i was told that it should be 24v and that the 5v is where to start looking. I eventually narrowed it down to a single 100pf mica capacitor.

 

 

The 100pf mica cap replaced with like value in a polyfilm cap from wima along with all the other mica caps in the unit just to be on the safe side. 200k ohm pots replaced with multi turn sealed units while i was at it.

 

 

Next up i decided to replace the output transistors. Although the originals tested ok i decided to replace them mostly for cosmetic reasons but also due to concerns one of them was starting to potentially fail. These where replaced with MJ5003 made by on-semi

 

[VA50]

After all this, output adjustments were set and i could finally give the unit a listen. Finally all working well. Now just cosmetics and loose odds and ends to deal with to complete the restoration. While i was ordering parts the one thing i forgot to get was a power indicator bulb, these are a weird voltage used in the au-222 at 8v. I thought i would be able to get away with using a 12v in its place. I went to my local jaycar store assuming i would be able to get such a thing however all they stock now is led conversions, i could not find any for sale locally leaving me with the option to order one online and wait a week or make my own. I opted for the later option, i found a standard wedge type bulb from a car. Next i smashed the original bulb and gutted it leaving only the shell, then the wedge bulb was soldered in and finally held in place with resin.

 

 

Would never tell the difference and works a charm.

Edited November 23, 2015 by VA50

[VA50]

All the black screws from the rear panel where resprayed, i also resprayed the top cover however i forgot to take photos of this step. I struggled to find any suitable places around to colour match and pack into a rattle can for me so i gave grey a try. It looks alright but i would have preferred the original sansui colour.

Lastly the finished result. Also not mentioned earlier i repainted the transformer, this was done using a brush and some white knight satin black from a spray can available at most hardware stores. It blended in very well and gave a better result then i expected.

This is the first sansui i've ever listened too, my initial plan with this one was to restore it then sell it but now i am big time questioning the idea. It has a very unique sound that I quiet enjoy.

Edited November 25, 2015 by VA50

[oldrose]

Well done. I love reading these posts, especially how the cosmetic side of things is tackled.

[VA50]

Thanks! Glad you enjoy them. Suprised there isn't more interest in this thread to be honest ¯\_(ツ)_/¯

Edited November 25, 2015 by VA50

[elcamry]

Have been reading as well, very interesting.

[Cloth Ears]

This is the first sansui i've ever listened too, my initial plan with this one was to restore it then sell it but now i am big time questioning the idea. It has a very unique sound that I quiet enjoy.

Do you have the service manual? I can let you have one if you need it. I ended up selling mine when I accidentally transported it badly and bent the knobs (somehow). I was in the process of moving to the AU-X1 anyway and had sold the AU-417. But it was sweet, especially playing through some Peak coaxials I had at the time.

[VA50]

Do you have the service manual? I can let you have one if you need it. I ended up selling mine when I accidentally transported it badly and bent the knobs (somehow). I was in the process of moving to the AU-X1 anyway and had sold the AU-417. But it was sweet, especially playing through some Peak coaxials I had at the time.

 

That would have been a painful day when you found that out! I actually just printed out the service manual today and had it bound in a plastic folder. If its an original copy though it would defiantly go nicely with the unit. PM sent

Edited November 27, 2015 by VA50

[zenikoy]

Thanks! Glad you enjoy them. Suprised there isn't more interest in this thread to be honest ¯\_(ツ)_/¯

Loving what you have revived here, not much else to add. OK that emoticon (?) is killa.

[BLAH BLAH]

Love your work...full credit to you...

[garm1520]

Interesting reading and very good pictures. What's next?

[VA50]

Interesting reading and very good pictures. What's next?

 

Not quiet sure whats next, i have a few ideas. Perhaps a bigger sansui if i find one. I also have my eye on an luxman l510 which could be interesting, its still in working condition and reasonable cosmetic condition unlike the sansui when i got it. Other then that i have plans to do a diy direct drive tt sometime after Christmas using the tone arm off my project essential II, still debating what timber i am going to use on the plinth for now.

Edited November 30, 2015 by VA50

[olegau]

I bought one faulty. The defect was a micro crack located on the copper path to the base of the output transistor that did not allow me to adjust correctly the bios of the left channel. Then I Replaced some caps that did not meet requirements. That is all.

I do not know what means very unique sound. I would say this is very well balanced amp. The sound is perfect, natural, huge sound stage, 3-D dimension (you can localize any instrument location) with my Focal's 1007.  I really enjoy it.   

 

[sloper]

Goodaye all

 

l did one of these 6 months ago, wasnt working at the time.

Really great sound out of a small amp.

 

Young kid bought it, loves it.

Should have kept it as it sounded better than the AU555 l have here.

 

regards Bruce

[Gilbert151]

Looks like this was a great thread - any way to get the photos back?