New JTM45 Build

[heba]

Hi,
I just finished my Metroamp JTM45. Most parts i got from Valvestorm. Iron is from IGMP.
After power up i got the standby switch squeal. But after changing the primary OT leads it's gone.
It works fine now and sounds great in my opinion.
I only have two little issues:
When i patch the two input channels together there is a little hum. Not too loud but bugging.
With my SG the amp begins to distort with the volume at 2. The pot is nearly a switch. Is there a way to make it more sensitive?
Any help would be great...
Sorry for my english, thanks!

Some Pics:
JTM45 Inside
JTM45 front
JTM45 back
JTM45 cabinet