The Maxon RTO700 Real Tube Overdrive is a tube overdrive pedal from Maxon, built around a real dual triode preamp tube instead of the clipping diodes most overdrive pedals use. Maxon describes it as a tube preamp circuit in a stand-alone stompbox format, with three cascading gain stages and no clipping diodes at all1. The pedal is discontinued, so it is now a used-market item.
The RTO700 is listed as a discontinued item on Maxon's product page, so it is no longer in production1.
Where most overdrives generate their grit by pushing a signal into diodes, the RTO700 gets its sound from the tube itself. Maxon says the RTO is "an amazingly amp-like overdrive" and that while many companies claim to offer "amp in a box" pedals, the RTO is in actuality a tube preamp circuit in a stand-alone stompbox format1. When Premier Guitar covered the pedal's release, the magazine said the design made it suited to clean and semi-clean amps, effectively adding a second or third "channel" of tube tone2.
A tube overdrive with no clipping diodes
The RTO700's circuit is its defining feature. Instead of the diode clipping that shapes most overdrive pedals, it runs three cascading gain stages into a real dual triode preamp tube1. Once the pedal is engaged, 12.6 VDC is applied to the tube heater4. Performer Magazine's reviewer, Chris Devine, noted that the dual triode preamp tube doesn't require any warm-up time between switching it on or off3.
The gain on tap is substantial. Devine found it had "MUCH more gain than your average overdrive pedal," with a wide range running from slight clipping to full-on old school metal punch, and note clarity holding up across the gain range3. He summed it up as a great pedal for dialing in overdrive or distortion3.
"It has MUCH more gain than your average overdrive pedal. The gain has a very wide range, from slight clipping to a full-on old school metal punch."
The controls and noise suppressor
The RTO700 carries a three-band tone circuit with Bass, Midrange and Treble controls1. Premier Guitar highlighted these as three completely independent tone controls with no frequency overlap, providing what the magazine called an unprecedented degree of tonal options2.
| Control | What it does |
|---|---|
| BASS | Controls low frequency range3 |
| MID | Controls middle frequency range3 |
| TREBLE | Controls high frequency range3 |
| NR On/Off | Turns Noise Reduction on/off3 |
| NR | Controls amount of Noise Reduction when NR is switched on3 |
The noise suppressor is a switchable Noise Suppressor with a variable threshold1. It has its own footswitch, an NR ON/OFF switch, alongside the main BYPASS/EFFECT footswitch, and its own GATE LED indicator next to the BYPASS/EFFECT LED4. For a high-gain tube pedal, the built-in gate is a practical feature: the equivalent input noise is rated at -102dBu or less with the input shorted, IHF-A weighted4.
Power and specifications
The RTO700 runs on 9V DC and draws 400mA4. It ships with the Maxon AC2009 power supply, an auto-sensing digital supply usable anywhere in the world4. A DC-to-DC converter inside the pedal steps the circuit up to 12.6 VDC to feed the tube4.
At 400mA, the RTO700 draws far more current than a typical 9V pedal, so it needs its own supply rather than a shared daisy chain, and a battery is not an option.
| Specification | Value |
|---|---|
| Max gain | 72dB (at 1.8 kHz)4 |
| Input impedance | 500K Ohms4 |
| Output impedance | 10K Ohms4 |
| Equivalent input noise | -102dBu or less (input shorted, IHF-A weighted)4 |
| Dimensions | 121 (W) x 152 (D) x 60 (H) mm / 4.8" x 6" x 2.4"4 |
| Weight | Approx. 600g / 1.3 lbs (without power supply)4 |
Where it sits among Maxon's tube overdrives
The RTO700 is not Maxon's only tube-based overdrive. Players comparing tube circuits may also want to look at the Maxon ROD880 Real Tube Overdrive and the Maxon TOD-9 True Tube Overdrive. For diode-based Maxon overdrives in the 9 series, the Maxon OD-9 and the Maxon OD808 Overdrive take a different approach to the same job.
Videos
Godlyke Inc.
Brett Kingman
gearmanndude
Questions
Is the Maxon RTO700 discontinued?
Yes. Maxon's distributor page marks the RTO700 as a discontinued item, so it is no longer in production. It was priced at $449 when Performer Magazine reviewed it in December 2011, and finding one now means searching the used market.
Does the Maxon RTO700 have a real tube?
Yes. The RTO700 is an overdrive built around a real dual triode preamp tube, and Maxon describes it as a tube preamp circuit in a stompbox format rather than a diode-clipping overdrive. Once the pedal is engaged, 12.6 VDC is applied to the tube heater.
Is the Maxon RTO700 true bypass?
Yes. The RTO700 uses mechanical true bypass switching built on a 3PDT footswitch, which Maxon says gives the cleanest bypass tone possible. A BYPASS/EFFECT LED shows the pedal's status.
What power supply does the Maxon RTO700 need?
It runs on 9V DC at 400mA and ships with the Maxon AC2009 auto-sensing power supply, usable anywhere in the world. A DC-to-DC converter steps the internal circuit voltage up to 12.6 VDC for the tube. The high current draw rules out a standard battery.
Sources (4)
- REAL TUBE OVERDRIVE (RTO700), Godlyke Distributing, Inc.
- Maxon Unveils Real Tube II Compressors & Overdrives, Premier Guitar, 2011-08-23
- GEAR REVIEW: Maxon RTO700 Tube Overdrive (w/Video), Performer Mag, 2011-12-09
- REAL TUBE OVERDRIVE (RTO700), Maxon (maxonfx.com, Godlyke, Inc.)
