disassembly for restoration

The Sansui AU-11000 is part of what Sansui called the “Professional Series”. The Au-11000 has side connected inputs and outputs.  There are outputs for 2 sets of speakers selectable by Off, A, B or A & B.  There are 2 phono inputs with load and sensitivity adjustments. 2 tape connections for playing and dubbing. A Tuner input and 2 Aux. inputs. The AU-11000 has a 3 position volume attentuator. Sansui is famous for their quality transformer and the 11000 has a large toroidial transformer.  The knobs are machined solid aluminum.

110 watts per channel.

A damping factor of 80 @ 8 ohm load.

The following restoration has been done to ensure the Sansui AU-11000’s reliability and doesn’t effect the intended “sound” of the amplifier.  The Sansui sound is in the circuit design but the new components  may improve the perceived sound quality. This is a  sweet, smooth sounding amplifier that reveals all the detail.

The unit was completely disassembled and cleaned.

All the electrolytics on all boards have been replaced and all the boards have been cleaned and defluxed.

The bi-polar electrolytics in the preamp have been replaced with polypropolene film capacitors.

The 4, 10000uf power supply filter capacitors have been rebuilt using Chemi-Con KMH capacitors.

The motorola “Uni-Watt” pre-driver transistors have proven to be unreliable in this and other Sansui amps, especially at this age,  so they have been replaced with OnSemi MJE350 and MJE340. A direct cross from OnSemi.

The 2 VD1212 diodes were replaced with modern substitutes.

The protection relay has been replaced with a new Omron relay.

The output transistors have been removed cleaned and replaced with new heat sink compound and are original.

All the controls have been cleaned and operate noise free.

Bias has been set after a 30 minute warm up with the covers in place and checked again after 60 minutes.

The spring type speaker terminals have been replaced with insulated binding posts that accept bare wire, spades and banana plugs.  It is a tight area so large WBT type spades won’t fit.

The hard wired power cord has been replaced with an IEC jack so other power cords may be used. Since there was no ground connection on the original cord the ground was left unconnected.

7 Responses to AU-11000

  1. j-p says:

    i need a toroid transformer to repair a sansui au-11000a amp. were can i find that ? it seem to be hard to find , any clue !

  2. mike says:

    I have the same amp that was pass down to me and i love the sound and detail it produce. You did a very nice rehab job on that sansui au-11000, one of these days i will like to do the same to my au-11000, enjoy

  3. Connor G says:

    Hello! I just bought an AU-11000 and was wondering what steps you took to replace the terminals with binding posts… Did you have to cut and fabricate a plate to mount the binding posts to? Any information is appreciated

    Nice resto work by the way 🙂

    • admin says:

      Hi and thanks for the comments and stopping by. I can’t remember specifically what I did on this amp but I often use a piece of lean cut to fit the opening, dill the new holes and spray the back side black. Good luck with yours they are beautiful amps.

  4. O.R.Pollard says:

    How timely to find this greatly useful page..I have an AU 11000 that should be here in a day or so that im sure will deserve rehabilitating…Thanks for the numbers on the replacement parts ! That is the least enjoyable part for me is researching modern replacements! Speaking of which i would really like to know what Omron relays you used so i can get them on the way.. Thanks and thanks for the info!!

  5. Ross Dalrymple says:

    I used MJE15030 & MJE15031 instead of the MJE340/350s on my driver board. They work great as well. I used the more robust MJ21193/94 on the outputs, they dont affect the sound at all, regardless of what some (Purists) would say. I believe my ears before anything else. There is a list of modern transistors to substitute on Plus, there is a dedicated Sansui forum there. Dont forget the mute behind the volume control, its a bit hard to see in some circumstances, dark room, etc…I used the Nichicon Superthrough 10,000 uf electro capacitors in the filter power supply and Cerafine Audio caps in the other power supplies and driver board. Panasonic FM electro caps are supposed to be good too and cheaper. I wish I had of known that beforehand. lol

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