Jeff Rowland Model 1

I am looking for the schematic diagram of the front end module with socket pins.
Who can upload this? I need the schematic because a friend of me have a device of this model sporadic error (crackling, shoot noise) is occurs, particularly before a warm up phase.

image of these module is here:
Jeff Rowland Model 1 adjustment

some additional URLs from this power amp model:
Jeff Rowland :: Model 1 Owner's Manual
L'Audiotecnico - Jeff Rowland - Model 1
Jeff Rowland Design Group Model 1 power amplifier Measurements |
JRDG Company Special – Model 1 | HFA - The Independent Source for Audio Equipment Reviews
Jeff Rowland Model One amplifier Photo #1443513 - US Audio Mart
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Hi all,
I have some questions regarding this amplifier if anyone can answer;
I cannot find any service manual online regarding this power amp for this reason I would like to know if anyone knows the value of the bias current as what I have is slightly warm after hours from switching on, I have read from some owners that usually the heatsinks get quite hot.

Furthermore, the right channel in unbalanced mode is mute while in "inverting unbalanced" mode it works well; in balanced mode, however, the right channel always plays at a lower volume than the left channel.
Any solution?