Re: THD Flexi-50 and UniValve 15W
I've owned both a Univalve and Bivalve and have played through a flexi for a couple of hours. They are all a little different, for my tastes I liked the Univlave with a mullard EL34 best, it had wonderful overtones and crunch. The bivalve was very articulate as was the flexi - the flexi was more in your face kind of crunch but from what I've read swapping tubes can offer up some different tones. I loved the univalve and bivalve and wish I would have kept the Uni - even at 15 watts it had more than enough output into a 2x12 cabinet for me to gig with (I play mostly small clubs), the bivalve had a little more clean headroom and definitely more punch but it wasn't as sweet sounding to me. The flexi would be great for if I were in a drving rock band, unfortunately I play a variety of different types of songs so none of amps has the versatility I needed. One day I'll get another Univalve though - the uni and a Les Paul was the best tone I've had to date (but I'm always working on that).