I just purchased an SVT II and a QuatraValve. Neither have arrived yet, and my main amp has been a TwinValve for the past 9 months. I LOVE my TwinValve, it just didn't get loud enough. At about 2:30PM on the master, you will get some power tube grind with a TwinValve, and it does have a pre-amp tube or 2. I looked for a reasonably-priced Quatra/Hexa valve for almost 6 months, but the only ones I saw were on e-bay and too pricey. So, I ended up getting an SVT II, which was more easily available. And, after reading up on these, it sounded like what I was after...mostly. Fast forward a bit...had a gig last weekend and the band before us had an SVT-CL set up with an 8x10 Ampeg Fridge. He insisted I use his head/cab, so I tried it for one set. Now, I admit 1) the head was the CL which is very different from the SVT II, from what I've heard, 2) I didn't mess with the settings much because I didn't want to throw his settings out of whack, and 3) it was loud. The SVT-CL was very "farty" sounding with my active 5-string (my main bass). I backed off the volume, backed off the lows on the bass, and I still couldn't get a decent sound. After the first set, I set up my TwinValve and my 2 12" Genz cabs (into the mic the sound guy originally had on the Ampeg), and I realized how much I like that TwinValve sound. It's crisp, but I still get the tubey grind I love. Here's my dilemma: the SVT II is at the shop and needs some repairs and I spent my whole "gear fund" on the SVT II and I had to charge the Quatra Valve. Not my preferred way of doing things, but they are hard to come by. What should I do at this point? 1) Sell the SVT-II. That would leave me the QuatraValve as my main amp, and the Twin as a back-up or for smaller gigs/venues. That would mean less tweaking if I go between amps. 2) Sell the QuatraValve. I haven't heard it yet and I know that I like my TwinValve. That would leave me the TwinValve for small gigs and the SVTII for larger ones. 3) Sell the TwinValve & keep the other two (higher-powered) amps, which will give me more tonal options. Who knows, I may end up loving the SVT-II sound. I play in a 90's band right now, but have done a fair number of musicals and recitals (for which the Quatra and the SVT II would both be overkill). I do some slap & pop stuff and like a lot more high-mids/highs in my sound than most rock players that I listen to. My other bass is a 4 string MusicMan Sub4 Active, which did sound pretty good into the SVT-CL last weekend. But, I only play that bass for about 4 songs, and rarely use it for non-rock gigs. Additionally, I stopped using my 4x10 and 1x15 cabs because they're so d@mn heavy. I already lug around all the PA gear for my band, and didn't want any other heavy gear. I'm only 165 and 5'8", so the idea of lugging the SVT II around is another reason I jumped on that QuatraValve.