The shop I bought my new bass (F Bass BNF w/high C) had a couple of Aguilar 359 all tube heads. I thought it would be kind of interesting to A/B it with my existing head. For the last 9 years I've been playing with the same SWR Bassic350 head. It's been mounted in a soft rack case. I've changed the preamp tube once. And the pots are getting a little scratchy; it's time to clean them. I tell you this because the amp has required absolutely zero maintenance! I use the head with a 9 year old Goliath II Jr. Going into the comparison, I'll admit that I'm biased towards tubes. When I play guitar, my guitar amp is all tube. I think it sound unquestionably better. Therefore, I figured that this would be my excuse to have to dig up $1,300 for a new head. I played both heads through an Aguilar 4x10 cabinet. First was the SWR. I like to get good sounds quickly without a lot of fiddling. I kept the EQ flat and the Aural Enhancer at about 1:00 o'clock. The sound was great. Similar to what I'm familiar with but slightly more full range (my 2x10 seems to have more pronounced mids). Very detailed and modern. Next, I tried the Aguilar (in the same cabinet) with the EQ flat. At first, it sounded very midrangy. But the longer I played with the head, I felt it was the warmth of the tubes. I went back and forth between the two amps for about 30 minutes trying different styles and settings. The two amps sound much more different than I though they would. Both have very useable, viable sounds. It's just that they're different. I think the EQ section of the Aguilar is much better. I have to play with SWR for a while to find a good tone other than flat (with the EQ; I can some good tones with the Aural Enhancer). The Aguilar seemed like where ever I put the EQ, the sound was good. I'm guessing, but I'd figure the DI and effects loop of the Aguilar is probably better also. On the other hand, the SWR is much lighter, will need much less maintance, is cheaper and I can get a few good, usable tones with just the Aural Enhance knob. So what did I conclude? I'm amazed at the professional sounds that come out of the SWR. For about $450 used, it generates legitimate professional tone. I'm also amazed at how different the two heads sound. Both very, very good but very different. The SWR has a very dynamic, modern, in your face kind of sound. The Aguilar is very glowing, warm, comfortable sound. The differences are hard to describe but very easy to hear. All that said, I did like the Aguilar very much. Before trying them, I was scheming on selling the SWR and how to come up with the difference. At this point, I would not sell the SWR. Actually, my next amp purchase will be a 1x15 cabinet to add to my 2x10 (I got to try an Epifani 1x15 with tweeter but that's another post). But I can definitely see an all tube amp in the future to add to the SWR.