Pioneer sx-850 bias adjust

[Chriswashere]

I noticed the manual for this model did not show how to adjust the bias.

Does anyone know the proper procedure? I assume it is the same as the sa-9500 since both models have a fairly similar output board.

Any help would be great.

 

[zebulon1]

Use the sx-950 instructions. They are the same and work great. The 5.1 ohm Shorting plugs are not needed. No input, no volume.

 

[Chriswashere]

Thank you!!

I wasn't able to get the bias below 100mv which is odd... Anyways while adjusting the bias a transistor in the powersupply decided to die. I replaced it so it seems like maybe bias isn't the only problem .

 

[elnaldo]

I had problem with bias and protection issues in a sx850, the problem was the differential pair transistors. Replaced them with matched 2sa992. It's working ok now.

You can search a thread about a pioneer sx850 started by me some months ago.

 

[Chriswashere]

I had problem with bias and protection issues in a sx850, the problem was the differential pair transistors. Replaced them with matched 2sa992. It's working ok now.

You can search a thread about a pioneer sx850 started by me some months ago.

Would the bad transistors happen to be the d313 transistors? The ones in this one look sketchy.

At least it is turning on though.

Do you have to use equivilent transistors or can the d313 model still be used? I'll read your thread on it.

Thanks!