Hello out there... I just acquired a 1966 Ampeg B-18N. It's in extremely good condition. I rehearsed with it last night, but I was somewhat disappointed with the tone. It didn't have the low, bottom end that I thought it would/should have. I actually rolled off all the treble and turned the bass all the way up, but it just didn't have the low freq response. Especially with an 18" speaker....(I think it's the original Cleveland) Anyone familiar with this amp have/had same issues?