There aren't a lot of AC15C1 to AC4HW1 comparisons out there, even though it seems like an obvious step for home players who realize the AC15 is too loud. Most times people are comparing the other AC4 models... or posters in the thread start getting HW1 confused with AC4TV, AC4-BL, and AC4C1-12. I thought I'd post one that compares the AC4HW1 and AC15C1 based on my recent experience. I have an AC15C1 that I really love on days when I can get the master up to about 4. But often that's still too loud if I'm pushing the gain to breakup. Being a forum lurker, I know I'm not alone in this. The AC15C1 has a great master volume. But it's just not enough sometimes. So I've been curious about the AC4HW1 for a while. So yesterday I found one for a decent price and went for it. Turns out the AC4HW1 is a completely different amp. The seller warned me of this, but I was not prepared when I put them both on an A/B box and spent some time experimenting. I was really hating the AC4HW1 for a while. It's extremely honky, muddy and thin at the same time, with no clarity compared to the AC15C1. With the treble and bass at noon it sounded more like the little 8" Orange PPC108 cab that I sold recently (a beer-box sized cabinet). I could boost the bass and get some more boom - but all the other frequencies quickly got undefined and smothered sounding. The only thing it had going for it was the top end chime. Above all the muddy/honkiness, there's a beautiful chime to it - moreso than my AC15C1. I tried scooping the mids on the AC4HW1 (i.e. crank treble and bass and adjust volume). It moved things in the right direction a bit, but didn't even get me close to where I wanted to be. Honk/honk/honk. My Rat sounds nasty in a good way in the AC15C1, and then nasty in a terrible way on the AC4HW1. Is it the speaker? No. Both identical greenbacks. Is it the cab? No. I swapped wiring and played each amp through hte other cab/speaker. The sound quality follows the amp itself - at least 99% of the sound quality to my ears. Is it the tubes? No. I swapped V1 and V2 and it did help marginally, but only marginally. I couldn't exactly swap the EL84s, so I put a new JJ in the AC4HW1 - still no improvement. Then I tried an GE7 EQ. Bingo! I put the EQ on the AC4HW1 only, then I notched out 400, 800, and 1.6k - I probably took about 8-10dB off each one. Both amps are now very close in every way - bass is there, honk is gone, fullness is there, amp takes the rat like a champ. They're not identical, but are now well within the tolerance I was willing to accept while going to a smaller amp. But I'm disappointed that this isn't a grab and go amp now. That's one thing I really liked about the AC15C1. I just needed the amp and enough energy to move it. With the AC4HW1 it's now amp+pedal+extra cable+power supply.... I know, I now... first world problems. So I'm already thinking about modding the thing. I think if I do a treble bypass it'll get me closer to my beloved AC15C1. THink I'm going to draw out the circuit this weekend and start thinking about how I could change the tone circuit. If I come up with anything useful I'll post back here.