Beyond the list of standard restoration steps detailed on the main page, here are some added notes for this unit :

I acquired this receiver from a local collector who saved it from being recycled.  Cosmetics were very good, but it produced no sound.

The 881 was Sansui’s top-of-the-line receiver in 1974 so includes features like midrange tone control, -20dB muting, preamp out/amp in and 2 Aux inputs.  With 2 tape ports, it can handle 4 “aux level” inputs.

side note : With this series, Sansui began omitting things from their service manuals.  Specifically, they stopped providing complete lists of components for each board.  They also started using fuse resistors (and did not document where these were vs normal resistors).  This only got worse in later years.

Initial visual inspection and power up was uneventful.  The lack of sound from either channel was confirmed despite previously cleaning the switches and pots.  Both channels being dead almost always points to a shared infrastructure issue as the odds of 2 separate issues in each channel is highly unlikely. 

Using the scope, I could see that the preamp was not functioning.  Sure enough, the undocumented fuse resistor in line with the power supply was open.  I replaced this and the unit sprang to life.  I could hear that the tuner was not putting out FM stereo (made a quick tweak to fix that) and had to replace the FM stereo bulb along with all the dial and meter lights.

The recap went fine, but I noted that the FM section had a flaky channel.  I traced that to the dual amp IC Sansui used in the final stage of the tuner path.  These 50-year old ICs can be tricky to source, but I have a reliable vendor in Ohio for NOS parts like this.  Swapping in the new part resolved the issue and the tuner now works quite well.

I decided to “up-cap” the main amplifier supply caps from 10,000uF nominal to new caps at 14,000uF (measured).  This modest bump helps bass performance a bit without risking damage to the transformer or rectifier due to higher power-on in-rush currents.

Hours of final testing show that this is a solid performer with typical Sansui sound.

The unit cleaned up nicely.  The only cosmetic issue is some of the silver coating rubbing off of the plastic tuner bezel (see photos).  This is very common for this series, and I have seen much worse.