Sansui AU-G33X amplifier

 

General:

Around 1985 Sansui company came with its AU-G33X amplifier. It was a competitor to the L200 series of Luxman.

 

Owners manual:

 

 

special futures:

The amplifier is a relatively cheap and good performance amplifier.

 

Schematic:

Click here to download the service manual of the AU-G33X/55X

Modifications:

The mechanical build of this amp is not to Luxman standards, problems will occur like the ones below.
This amplifier suffers from defective balance and tone potentiometers, they are small and cheap, not well fixed to the front and have
no protection against force from the front, they should be replaced by better ones.
Although the power amp module is well made its connectors are made awkward.
The power amplifier module can be taken out the cabinet by unscrewing 6 screws and taking off 2 connectors.
Sansui applied some type of glue to secure the main ps. capacitors and that glue makes the pcb and parts corroding,
this glue should be taken off the pcb and non coroding paint should be applied to stop corrosion,
the copper side can be protected by flux spray.

The power amp has a tripple-stage output with discrete bipolar transistors and is well compensated.
The pre-amp has some IC's, and few discrete active parts.
The power supply is simple but ok, the protection circuit works well.

 

Sound:

The sound is good. The mechanical build quality of the Luxman L200 series is better and the sound is also better,
as Luxman used fewer IC's and mainly discrete parts and no tripple-stage in the power amp.

 

© Hans Hilberink - PE1MMK ® 2003 - Last update: 09-04-2012.