Does anyone know the procedure for adjusting bias,ect. on a TFM-45?The amp works well but has developed a slight muffle in the mids/lower highs that seems to disapear at higher volumes.At lower volume(just off zero)it is very noticeable.Only on the left channel.I've done all the trouble shooting to say that it is in fact in the amplifier.Dif. speakers,Preamps,amp ect..I'd like to make sure the amp is operating per specs before I look any further.Beings it seems to go away at higher output I suspect it may be a bad solder joint on the left PCB or related curcuit.I'll be Reflowing the solder joints regardless. Anyone had any experience with this problem?It doesn't seem to need a major repair as it has very stout output and doesn't fatigue in the least through amazing silvers at ungodly volumes.(Ribbons are perfect,it is NOT in the Amazings.problem reverses sides when outputs are reversed,and non existant with another amp)If anyone has a service manual for this that'd be awesome.I'd ask the powers that be but being a newbie to the forum,I'm not allowed yet,and I don't think I can wait that long to get this running 100%.I hope I'm not out of line asking this way either.I'd like to listen at a little lower volume before my nieghbors call the cops(again).but this little sizzle is gotta go.