I am selling Sansui top model amplifier from 1980, model AU-D11.
Another Sansui item from my collection, which now I am reducing….
The amplifier still has all original components, except for a few, which I replaced to make the amplifier technically stabile on high power levels….
In fact, after my stress test I found that on just about 30 watts of output power, the negative period of test signal gone to the clipping, and I found that one pair of transistors in the power supply for driver stage lost gain factor (HFE were under 10 on the both transistors), and after I changed them by much more powerful ON Semi transistors (it's power supply board) everything worked properly.
I would say one thing here; the amplifier worked perfectly with these old transistors in the power supply at low level power, but only when amplifier was loaded at high power levels, this clipping come out… which... once again confirms my rule how important it is to do a stress test on vintage amplifier to see if everything is really ok and how it is risky to buy a vintage amplifier only by doing a low power level listening test….
As a precaution, in the power supplies 4 pieces of zener diodes were changed and both bias trimmers (for adjusting the bias current). The thermal compound on the output stage was changed too (on the output transistors, on the driver transistors and on the bias transistors).
I also totally disassembled the two most important potentiometers on the signal path (volume and balance) and cleaned them from corrosion and dirt (a very sensitive process of disassembly and assembly and especially very sensitive process of cleaning).
The amplifier is adjusted by the service manual, I did again stress test to the maximum (with 8 ohm dummy resistors connected to the speaker connectors, and the amplifier driven to clipping) and here you can see the results of clipping for test signals of 100Hz, 1kHz and 10kHz on youtube video (link given below).
The amplifier is tested and it is in working condition, but because it is more than 40 years old, I can't offer any kind of warranty, I hope that you can understand me….
It is not "like a new" unit, so if you are searching a visual MINT unit, please skip this auction...
The amplifier is already packed, and ready for delivery!
Please look at my you-tube very good video about that amplifier (just copy that link and paste it into your web browser):
Feel free to email if any questions and please check mine other listing. I will ship that amplifier to EU countries only.
Versand Deutschland und EU!
Please look carefully at high resolution pictures, because they are part of description.
Please note, I cannot accept return or refund for this item once when that item will be shipped to you.