-the crack plays music
but the voltage check gave me really different results from the ones in the pdf
Please do not use/listen to an amplifier that isn't working. It hasn't passed its voltage checks! This is not safe.
1 90V
2 0V
3 170V
4 0V
5 90V
6 170V
7 65V
8 170V
9 65V
10 170V
should I be concerned?
and do I need to fix this?
Considering terminal 3 is the chassis and you have +170V there, yes, you should be concerned. Terminals 6 and 10 are also grounded and show this high voltage.
Generally I find that weird readings like this come from the junction of the black wires on the headphone jack not being all the way soldered together, but it's odd that your high voltage terminals are reading 0V. This I suppose could also happen if you had the ground probe of your meter connected to the wrong terminal and all your readings are negative voltages.
Again, please
do not use/listen to this amp until these issues are resolved.
-PB