The Maxon Real Tube Compressor RTC600 is a tube compressor and preamp built into a compact stompbox, offered as the newest member of Maxon's Real Tube line1. It provides up to +30 dB of gain for maximum headroom1, and it replaced the earlier RCP660 model21. Maxon describes the result as "a warm yet bold compression sound with an ultra-low noise floor"1. It carried a street price of $3893.
The pedal is housed in a cast zinc enclosure and carries a variable Threshold control, a Ratio control, variable Attack and Release controls, and up to +30 dB of clean gain21. Its US street price at launch was $3893.
The maker's product page lists the RTC600 as sold out, and the page shows a price of £230.00 GBP rather than a US dollar figure2. The $389 figure above is the US street price from the 2011 launch coverage3.
What it is and what it does
The RTC600 is a compressor pedal with a real vacuum tube in the signal path. Maxon places the tube before the compression stage, and says this "pre-compression tube placement adds classic valve warmth without increasing noise level"3. The compression itself comes from a precision RMS level detection circuit and a high-performance VCA (voltage-controlled amplifier), the parts a studio compressor uses to measure and control level3.
The pedal is capable of both "Brick Wall" and "Soft Knee" compression2. In practical terms, soft knee eases into compression gradually as the input level rises, while brick wall limiting clamps harder at the threshold, which suits taming peaks on loud passages.
Because it is a preamp as well as a compressor, with up to +30 dB of gain on tap21, the RTC600 can also serve as a level booster. Maxon says it can be used at the amp's front end, placed in an effects loop, or used as an outboard processor for home recordings3, so it is not limited to a guitar pedalboard role.
The controls: Threshold, Ratio, Attack, Release
The RTC600 gives the player the four controls of a studio compressor, each doing the job it does on a rack unit:
| Control | What it does |
|---|---|
| Threshold | Variable from 0 to 40 dBu; sets the level at which compression begins31 |
| Ratio | Variable from 1:1 up to 1:∞; sets how hard the signal is squeezed once past the threshold21 |
| Attack | Variable; sets how quickly compression engages21 |
| Release | Variable; sets how quickly the signal recovers after compression21 |
Alongside these, the pedal has a Gain control offering up to +30 dB of clean gain21, and an In-Rush Current control that heats the tube at low voltage as soon as power is applied to the circuit1.
That full set of controls is where the RTC600 differs from simpler compressor pedals. The CP-9 Pro+, whose circuit it shares, offers Threshold, Ratio, and Gain controls but no separate Attack and Release knobs42, so the RTC600 adds the time constants a player needs to shape how the compression behaves, from fast country-style squashing to slow, transparent leveling.
Power and switching
The RTC600 runs from the included Maxon AC2009 9-volt power supply, an auto-sensing digital supply that can be used anywhere in the world2. Inside the pedal, a charge pump raises the circuit's operating voltage to 25 volts, which Maxon credits with "massive headroom and full-range frequency response"3. The higher internal voltage means the compressor can handle hot input signals without the circuit itself overloading.
Bypass is True Mechanical Bypass switching using a 3PDT switch2, so with the pedal off the signal passes through without buffering or coloration.
From the CP-9 Pro+ circuit to the Real Tube II Series
The RTC600 starts out with the same patented DBX compression circuit used in Maxon's CP-9 Pro+ pedal2. The CP-9 Pro+ was itself a new design rather than a reissue of the original CP-9, built around patented low-noise DBX compression technology4. Maxon says that circuit provides "a very smooth, transparent, almost 'glassy' compression with very low noise floor, even at maximum settings"2.
OvniLab's reviewer, reviewing the CP-9 Pro+, found it "more effective, with fewer artifacts, than most of the competition" as a clean utility compressor52.
The RTC600 is a new device that replaced Maxon's RCP660 model as the company's tube compressor offering1. Its compression approach has a lineage in Maxon's CP-9 Pro+, a compressor pedal featuring patented low-noise DBX compression technology built on a completely new circuit rather than a reissue of the original CP-94.
Videos
Brett Kingman
Godlyke Inc.
funkishness
Questions
Does the Maxon RTC600 use a real vacuum tube?
Yes. Maxon describes the RTC600 as a studio-grade compressor with a real vacuum tube, and the tube sits before the compression stage. The maker says this pre-compression placement adds classic valve warmth without raising the noise level.
Is the Maxon RTC600 true bypass?
Yes. The RTC600 uses True Mechanical Bypass switching with a 3PDT switch, so the signal passes straight through when the pedal is off.
What power supply does the Maxon RTC600 come with?
It ships with the Maxon AC2009 9-volt power supply, an auto-sensing digital supply that can be used anywhere in the world. Internally, a charge pump runs the circuit at 25 volts, which Maxon credits with large headroom and full-range frequency response.
What circuit is the Maxon RTC600 based on?
It starts with the same patented DBX compression circuit used in the Maxon CP-9 Pro+, which Maxon says gives smooth, transparent, almost glassy compression with a very low noise floor even at maximum settings. It adds a precision RMS level detection circuit and a high-performance VCA.
Which Maxon compressor did the RTC600 replace?
The RTC600 replaced the RCP660 when Maxon retired the original Real Tube Series and launched the Real Tube II Series in August 2011. The new line also included the RTO700 overdrive and RTD800 overdrive/distortion.
Can the RTC600 go in an effects loop or be used for recording?
Yes. Maxon says it can be used at the amp's front end, placed in an effects loop, or used as an outboard processor for home recordings.
Sources (5)
- Maxon Introduces RTC600 Real Tube Compressor Pedal, No Treble, 2011-08-20
- REAL TUBE COMPRESSOR (RTC600), Godlyke Distributing, Inc.
- Maxon Unveils Real Tube II Compressors & Overdrives, Premier Guitar, 2011-08-23
- COMPRESSOR/LIMITER (CP9Pro+), Godlyke Distributing, Inc.
- Maxon CP9 Pro+, OvniLab
