I've had my Phil Jones D 600 for a while now, it is a 600Wrms @ 2ohms, and it can run safely there indefinitely. I use it mostly with a PJB C4 and/or C8, though I have also driven a Bergantino HS410 with it with very good results. In short, it is fantastic! EXTREMELY quiet, and plenty loud. There is a fan, but it's so quiet that I only hear it in a dead-quiet room. As for hiss and noise from the amp, even with the volume control cranked, it's nearly non-existent.
I have 100+ gigs on my Super Flightcase, but only a handful on the D600, so I'm still getting to know the D600. However, the gigs I've done with the it range from straight up rock to Americana to funk/jazz/R&B/fusion gigs around town. At one Eric McFadden show, a friend sat in on bass and the FOH bass tone, which was through the D600 DI, was absolutely bone-crushing (fretless G&L L2500). Huge, fat, but highly controlled lows, tons of definition on every note, plenty of bite on top, etc. All the PJB amps are very quick sounding, so each note just punches right through - perfect for really fast prog/metal lines that require a lot of articulation. The 5 bands of EQ work well for me, though I rarely make big changes to any single band. I do find myself often pushing the 2.5kHz up a bit with any of the PJB amps, but that's very dependent on the cab.
I also use mine with upright, which sounds fantastic through the PJB cabs, though I don't care for the upright through my Berg. I got it for doubling, because of the 2 channels, and I used it that way with Eric McFadden, which was rather loud and raucous with the upright, but sounded really good.
One thing that is different on the D600 from many other amps on the market is the way the gain control works. It is centered at 0dB of gain: CW adds up to 18dB, CCW subtracts up to 18dB. This is generally not a problem, but it takes a little getting used to. I generally like to run the master volume hot on the PJBs and then adjust the gain to give me the most headroom and still get the volume I need. This is a little different from most amps, where you turn up the gain knob till the input clips, then back it off a bit and turn up the master volume knob as needed. That's just what I've found to give me the best results with my PJB amps, vs. the other amps I still own and the many I have owned over the years.
Something else to consider is that the PJB cabs project a LONG way. In my case, a single C4 covers most upright gigs and lots of jazz/funk/fusion in small rooms. The C8 covers most bar gigs and stage situations with PA support, and the C4+C8 will handle everything else. Personally, I haven't had any need for more than 1 C4 and 1 C8 (12 drivers), which presents a 2.67ohm load to the amp and draws ~525Wrms at full power. Since I haven't had to run my master volume up more than about 1-2 O'clock, even on the loudest of gigs, it's probably not pushing more than about 350-400W at that volume. Certainly the cabs (one C4 and one C8) can handle more power than the D 600 can put out, so there's no danger of damaging the cabs with too much power. That said, I've also considered adding a second C8 to replace my Bergantino HS410 (which is a GREAT conventional cab). Not because I feel that I need the extra 4 drivers, but because it would be fun to have 2 C8s! I do love the portability of the C4 and I play PLENTY of gigs where that alone is all that is needed. I have to push the volume knob on the amp up higher, but it handles the power with ease and sounds fantastic, even with a drummer and guitars and horns.
Class D 600W @ 2 ohms / 450W @ 4 ohms / 300W @ 8 ohms.
2 inputs each with a 5-band EQ allowing you to plug in two different basses without being forced to touch the settings!
2 speakon outputs to connect cabs. 1 aux output to connect an MP3 player, a keyboard or even an e-drum kit! You can also plug in your headphones.
Dialing it is instinctive and the 5-band EQ is very effective. It's a true "Plug and Play" amp head.
I'm very satisfied with the multiple possibilities this quality amp head offers.
It's definitely a PJB, with a precise sound across the entire frequency spectrum, very faithful to the instrument's sound, and with a much higher output than what competing class D products usually offer. The sound is punchy for slap, and pure and extremely precise to play with your fingers.
I've had it for 3 months and I really believe I've found the amp head of my dreams: A precise and punchy sound, a great output power, a compact and lightweight amp head perfect to move it around. Excellent value for money. I really recommend this amp to anyone looking for a head with the characteristics I mentioned above.