Nikko STA-5010 - please help identify bias/dc-offset trimmer pots

[P. S.]

Hi,

I bought a Nikko STA-5010 and need to adjust DC offset. I see 2 pairs of trimmer pots on the amp board but cannot really tell which ones adjust bias and which ones do DC-offset. I would like to avoid mistakenly touch the bias pots as I usually have problems readjusting them later on.

I could only find schematic for this receiver but it contains no clear mark which pot pair is responsible for dc offset adjustment. I am also not knowledgeable enough to figure it out based on reading the amp schematics.

I am looking for an advice from somebody who knows the amp board designs and take a look at the attached photo and schematics and help me out identify DC offset trimmers. (I marked the location of trimmers on the schematics with red rectangles).

Help would be greatly appreciated.
-Peter

 

[Ylli]

Hard to read the designators (R661, R662?), but the 500 ohm pots between the emitters of the input pair are the offset adjust.

 

[P. S.]

Hard to read the designators (R661, R662?), but the 500 ohm pots between the emitters of the input pair are the offset adjust.

Thank you @Ylli - much appreciated!

 

[sregor]

Your red rectangles are slightly off. I did a quick redo with orange circles.

The the 500 is Offset, the 1K is Bias. I always replace the trimmer pots because they get intermittent (often the rivets, sometimes the wiper), which can cause some problems.
If the offset is hard to adjust, recommend changing the input pair with matched transistors.