The tank for this amp should be 8 ohms in, 2250 ohms out. My reverb circuit has a bad hum and takes in to sqealing feedback at 7 on the volume. I took out the ruby tank and measured 1.5 ohms in and only 209 ohms out. I ordered a new MOD tank, just wondering if I measured the ohms right and if you think the Ruby tank is the cause of the problem? I changed v2 and v3, no help, changed cables no help. Hope this sorta made sense.