Are you using the supplied factory power adapter? If so, I'd suggest changing to a 12 vac @ 4.5 amp adapter (part # 56-821) from www.hosfelt.com for $7.95! After removing the factory power supply and using the hosfelt power supply in its place, I was impressed with a much fuller sound, more dynamics, and a cleaner sound. Another tweak you might want to consider would be Herbie's tube dampeners for your tubes.