I don't have the 102 but I'm pretty sure the left switch is mute, and right shifts between class A and class AB (not sure which is up/down). You can download the manual at www.pliniusaudio.com, or just see which gets hottest/sounds best.
Hello Elboroth2/ in response to your question yes that switch is for your class A biasing. The other switch to the left is for muting the inputs on the back when changing cables, respect these as i was recently changing xlr interconnects in a sa 102 dual mono setup and didnt have the switch engaged and a thump went through my system and I believe I burnt one of the ;hot; legs either positive or negative theres also the ground in xlr[three pins] but half my volume is missing in xlr. These amps are well made and its my fault but I purhased all plinius electronics in my home theatre since they come with a seven year warrenty repair is being taken care of, and I also have an sa100 mk 3 for my surrouds in a 5.1 setup.Your sa 102 in class A will generally take about 45 minutes and will get quite hot but my feeling in listening in this configuration the amp tends to produce smoother harmonic tones, cymbles decay a little longer as the stage becomes more dimensional,bass control is steller in both settings, most frequency change is on top regions, great amp in both configurations and as i also bought theyre m-8 preamp and theyre p-8 amp for my center channel. Theyre class A amps are all very musical with great dynamics and harmonic tones.Again this description of sound is a subtle change and I generally listen with no distractions to audibly account for the change, so for me; class A for contemporary Jazz or Classical and class AB for rock ect... Love theyre gear so I just wanted to share my own personal thoughts . Happy listening,Tim W....
timothywas1 -> thanks for the warning. fortunately for me, I noticed the rotary switch at the back and set it to XLR stereo before switching on the amp.
I have also notced thet the amp reverts to class A/B operation after 30 minutes (or so) when there is no signal. Nice touch, helps to save on electric bill.
Your welcome Elboroth2 and yes they now have microcessors inside the 102s that allow the user to change the brightness of the L.E.Ds as well as adjust the class A settings for 15,30 or 60 minutes when leaving the amp unattended for a period of time they will auto engage setting the amp back to class AB, saving on electricity.This and the spring loaded front switches are just a few of the changes incorporated in the new model over the plinius sa 100mk3,its predecessor that also a very refined amplifier as I own both.Should you need any further info. you can download theyre manual at www.pliniusaudio.com/good luck with your dedicated room it looks great. Regards Tim W...