I have a '67 Bandmaster amp head with 4 ohm output. I believe the original Bandmaster cabinet had (2) 8 ohm speakers, making it 4 ohm. I am now outputting to a single 8 ohm speaker. Is this going to do any damage to the amp head? Does it have any serious affect on the sound? I just spent $150.00 getting the amp fixed and I don't want to do anything to screw it up.