hifi engine

Sansui AU-4400 left channel distoted at volume level 3 and above

Left channel distorted fuses OK
This amp is very clean. There are no shorted transistors and the sound with the headphones is good. Voltage measurements on driver transistors and outputs seem normal. Has anyone had this problem?



Re: Sansui AU-4400 left channel distoted at volume level 3 ...

Might be dirty switches; try moving your monitor switch several times.
The headphone signal is basically the same as that going to the speakers, only through a couple of resistors first; if the headphone audio is good then you must have a speaker or speaker cable problem.

Re: Sansui AU-4400 left channel distoted at volume level 3 ...

I have deoxed the switches and controls. It did not fix it. I think that it is breaking into distortion because of the higher volume as the headphones are at an extremely small signal.
Thank you for your reply and if resolved I will let you know the resolution.

Re: Sansui AU-4400 left channel distoted at volume level 3 ...

The additional loading of the speakers may have an effect. One of the output transistors may have an open emitter.

Re: Sansui AU-4400 left channel distoted at volume level 3 ...

Hi Johnsan I found the problem TR09 (2SC1211) shorted
Thanks for your help