The genesis of the Diamond line grew out of Diamant’s longstanding friendship with rig guru Bob Bradshaw and circuit designer Martin Golub. Drawing on what they liked and didn’t like about their collection of classic amps, which includes Marshall plexis and JCM 800s, Bogners, and Soldanos, Diamant and Golub set about creating their own designs, all based around the venerable EL34 power tube. Their latest offering is the badass Nitrox head and accompanying 4x12 cab you see here. This is every bit the raging beast it appears to be, but we found a lot more depth and subtlety during the discovery phase. The Nitrox features more gain than any amp in the Diamond line, but it’s flexible enough to find its way onto classic rock and blues stages as well.
Co-designed by Diamant and Golub, the Nitrox looks like pure metal with its zinc nameplate and hexagonal steel grille on the head and cab. Switching it on elicited a chorus of “oohs,” “whoas,” and impressive expletives because the Nitrox lights up the whole room with a bitchin’ array of red LEDs inside the head. The rest of the visuals point to a two-channel amp, with Volume, Gain, 3-band EQ, and Presence on each channel. While not untrue, this doesn’t tell the whole truth. Thanks to additional Volume and Gain knobs on the dirty channel, The Nitrox is actually a 2.5-channel amp. More on this smart, useful feature in a bit, but we will prove to the jury that it provides a lot of gain and level options without cluttering the front panel. The last knob is labeled E. Return, and it governs the level of the effects return. This will also prove important as our trial progresses.
We cross-examined the Nitrox with a Gibson Les Paul, Fender Strat, Schecter Blackjack ATX, and a PRS SC 245. With the Les Paul, Channel 1 delivered a huge, full-bodied clean tone when the Gain control was at 3 or below. At those settings, there is an amazing amount of headroom on this channel, making it suitable for funk, country, jazz, or JC-120-style Metallica arpeggios. Channel 1 is capable of decent grind at higher Gain settings. The breakup sounds more Fender than Marshall to my ears, and works great for ZZ Top raunch or SRV sting. If I run the Gain higher than about 5, however, I need this channel to be loud, as the distortion is more pleasing at higher volume settings than lower ones. Thankfully, Channel 1 can get loud. Like, so loud your neighbors might just slap an injunction on you (although the company president might be able to help out if they do). The EQ is very responsive and, like all the controls on the Nitrox, has more range than you really need. The very well written manual cautions against turning any of the knobs up all the way and that holds true for the EQ. I set every knob at 5 and then made subtle tweaks to taste.
I kicked on Channel 2 and was instantly reminded of the advice in the manual—don’t crank any knob, least of all the Gain knob, to 10. This channel is guilty of reckless distortion and felony sustain. There is so much grind on tap that you can get a killer old-school AC/DC rhythm tone with the Gain on 1! Turning the Gain up poured on the saturation and the compression and, thanks to a capacitor on the pot, the tone goes from brighter and punchier at 5 and below to darker and creamier at higher settings. All the test guitars sounded great through this channel, but the Schecter (loaded with active Seymour Duncan Blackouts) smoked them all. This combination gave me the best Hetfield-on-’roids tone that I’ve heard in a long time.
Channel 2’s EQ does a great job of sculpting the tone and it can definitely get into the scooped-mid death zone. Again, here’s where the excellent Nitrox manual comes in handy. In what should be required reading for every rock dude (and every employee in a music store), Diamant makes a brilliant case for the power and the glory of midrange: “Note to us metal guys: Don’t be afraid of your mids. All the crunch in the world is fine, so long as the audience can hear us. Take out too many mids and you’ll get lost in the mix.” The defense rests. With the Mid control on 3 and the Bass and Treble at 6, I got vicious crunch that was definitely metal but still had body. Settings at 6 or above brought out great classic metal and rock tones à la Priest, Maiden, and UFO.
Channel 2 sports an additional, switchable set of Gain and Volume controls. This is a great way to preset a rhythm tone and a louder, more distorted lead sound. Or two different levels of the exact same tone. It’s intuitive and musical, and sharing EQ between the two sounds—something that made me nervous at first—was no problem whatsoever.
One more trick up the Nitrox’s sleeve is the E. Return knob on the front panel. Here’s how it works: If you have an effect in the loop (or you simply connect a jumper cable between the send and return jacks), the E. Return knob becomes a global master volume. This allows you to run the preamp hotter while maintaining a reasonable volume in the room. It’s also a great way to set relative levels between the channels and then adjust your overall level on a gig when the soundman inevitably tells you to turn down.
Diamond Amplification is definitely making a strong case in the high-gain tube amp world. Everything about the Nitrox reeks of quality and durability (and we didn’t even talk about the cab, which is totally hand built, loaded with Celestion Vintage 30s, and wired with 12-gauge Monster Cable), so I’ll be surprised if we don’t see lots of Diamond amps on the scene in the near future. Give one a fair trial and judge for yourself.