IMHO, dynaco amps, are useful if you are looking for using with speakers with normal efficiencies (85-89 db) if you have efficient speakers (90 db +) then there are plenty of other choices....for examle the stoekit from heart audio, that i am currently reviewing, that sound pretty good. If you do buy a dynaco,spend the $600 and buy one that has been done up completely, otherwise you may be entering a never ending cycle of buzz and hum...... just my 2 cents -akhilesh