[Scottdazzle]

My RM-10 just arrived and I am excited and eager to start listening. Unfortunately for me it arrived without a manual (the seller promised to send one in a separate package). I am going to install the tubes and hope for the best but would feel better if I knew the bias was correct.  Anyway, can someone tell me how to check and/or adjust the bias?

[Nilanjan]

Bias for the output tubes is set for one channel at a time instead of for individual tubes. The driver tubes don't need to be biased.

You will see two small jacks in front of each pair of output tubes. The jacks for the right channel are on each side of the on/off switch. The jacks for the left channel are over the "MUSIC REFERENCE" caption.

Bias is adjusted by turning the potentiometers called "BIAS ADJUST" behind the output tubes.

Insert the two leads of your multimeter into the jacks for one channel. The left jack is negative and the right positive. The designer advises that if you are starting with tubes of unknown bias, turn the pots all the way down (counter-clockwise), then raise the bias to 250 mV. Let the tubes warm up, but keep the bias below 300 mV.

The amp should be warmed up for 20-30 minutes before making final adjustments. The final bias should be set at 300 mV or 30 mA.

[Scottdazzle]

Nilanjan,
thank you.

[Nilanjan]

You are welcome. It was late at night and I did my best to get it right. I hope it worked out well.