I have the tube rectified Welborne 45 and 300b DRD amps. I have a much different experience with 45 tubes. The bass is really fast on my 45 mono blocks. I used them for months to drive my 2-way speakers. The bass bins are jbl twin 15" wofers and 100 dB efficient. The bass is not muddy. These little 1.8 wpc mono blocks sounded great. They are driving my HF horns in my biamplified horn speaker set up. John C.