This summer, Maxon released the latest in a line of great overdrive pedals, the RTO700. The “RTO” stands for real tube overdrive, and indeed houses a tiny dual triode preamp tube instead of the usual clipping diode. Maxon certainly isn’t the first manufacturer to use real tubes in its overdrive pedals, but the RTO700 is the best I’ve heard.

I AB’d the RTO700 against the Maxon OD820, effectively a really good Tube Screamer that beats the bar set by the Ibanez original decades ago by increasing headroom and transparency. The RTO700 does the same to the OD820—and more.

Tested through tube-driven Fender Pro Jr. and a Bassman, plus a solid state Sidekick 25, the RTO700 achieved several remarkable feats—it fixed the Pro Jr.’s flubbery distortion, it boosted the Bassman’s midrange and it transformed the Sidekick’s clean channel into a roaring high-gain tube dragon.

What makes the RTO700 so special is its awesome clarity of tone—while all overdrive pedals compress the signal as they distort it, the RTO700 retains each string’s voice in the chord while enhancing it with true grit. The RTO700 is versatile, too. While it excels at classic rock tones, dial down the mids and jack the gain and you’re in metal territory, albeit with a muscular grind, not the antiseptic buzz sound some prefer. An added bonus, the RTO700 also features a switchable noise gate to keep unwanted feedback at bay.

The one downside is the price. This pedal retails at a hefty $389, a fistful of dollars that would put you well on your way to buying an actual amp. But if you’ve already got an amp you love — tube or solid state — the RTO700 is going to make you want to marry it. — Howard J. Stock