Switching to the neck pickup produced a predictable boost in the amp’s low mids, which the Positron handled beautifully, retaining a fully dynamic clean tone that didn’t break up too easily at low volume. The amp is really expressive and present in clean mode, and plenty loud too. But the amp does not stay clean for long. Bringing the Volume up to just 10 o’clock produced a fantastic, bluesy breakup that responds, like any good tube amp, to even the most delicate fingering. And what I quickly discovered was that this amp could have easily included just a single volume knob. With most amps, I find myself searching for a slightly brighter sound, but from sparkling clean to raunchy overdrive, the folks at Diamond Amplification have obviously taken the time to make sure this amp is voiced perfectly right at noon. The Tone knob is still useful and enables subtle brightening or darkening effects, but it does not deviate much from what Diamond deemed the ideal tone.

With my Fender Stratocaster and the Positron wired to the Emperor 4x12, I rolled the Volume up to noon and let the Strat’s bridge single-coil kick out the twang with a startling volume and dynamic punch. Because of the non-Master volume architecture, I was also to dictate an array of responses quite readily by using the guitar’s Volume knob. For kicks, I dimed the amp’s Volume and strummed power chords, which filled the room with thunderous rock ’n’ roll tones that were similar to an AC30’s, but with a bottom end more like an early Marshall (a quality that was no doubt enhanced by the 4x12 cabinet). Switching to the Strat’s neck pickup kicked up the low-end content yet again, and the amp responded with a smooth, creamy overdrive.

In search of more classic rock tones, I routed the Positron to the Celestion Vintage 30-loaded 2x12 and plugged in my Gibson SG again. The hotter output from the humbuckers drove the Positron into overdrive land, with the preamp emitting traces of sizzling distortion. This is as close to a Marshall sound as I’ve ever heard from a class A amp. Sustained lead notes rang out with musical feedback. Throughout all settings, the amp’s dynamics remained intact, and I had to think that the Positron would be an invaluable amp in the studio.

The Verdict
Tone that hearkens to ’60s, class A, non- Master-volume British amps has been a sound ideal among amp freaks for years. Now, Diamond Amplification’s Positron allows you to access those beautiful vintage Vox and Marshall tones in a moderately powered, portable package that sacrifices nothing but the heft of those icons. The two-knob control setup makes it quick and easy to tap in to the tonal magic, and the compact package means you can take it anywhere, provided there’s a cab waiting for you at your end destination. For class A fans on the run, the Positron is an ingenious little amp of surprising capability.

Buy if...
you crave a handwired, compact, no-nonsense class A tube head that’s loud.
Skip if...
one channel isn’t enough.

Street $1499 - Diamond Amplification - diamondamplification.com