Mesa/Boogie Rectifier: every version
Every version, how to tell them apart, how to date one, and what to check before you buy. 7 versions, 1992–present.
The Rectifier is Mesa's high-gain line, introduced in 1992 with the Dual Rectifier: diamond-plate faceplate, four 6L6s, and a choice of valve (5U4) or silicon-diode rectification that gives the series its name. The two-channel amps of the 1990s went through revisions C to G, the 2000 redesign added a dedicated clean channel and three channels, and the Multi-Watt heads of 2010 added a power choice per channel. Channel count, rear-panel switches and the model name on the faceplate sort out most Rectifiers.
The versions, in order
Dual Rectifier, two channels (revisions C–G) (1992–2000)
Two-channel
The original Dual Rectifier: two channels and three voices, four 6L6s, and valve or diode rectification.
How to spot one
- Two channels and three voices: Clean and the Orange (vintage high gain) voice on channel 1, the Red high-gain voice on channel 2.
- Diamond-plate faceplate.
- A rear switch chooses the two 5U4 rectifier valves or silicon diodes.
- Five 12AX7 preamp valves and four 6L6 output valves, for 100 watts.
- Amps built until 1994 have a series effects loop; Revision G (1994 on) has a parallel loop.
Specs
| Power tubes | 4 × 6L6 |
|---|---|
| Rectifier | 2 × 5U4 tube or silicon diodes (switchable) |
| Phase inverter | Long-tail pair |
| Preamp tubes | 5 × 12AX7 |
| Channels | 2 |
Triple Rectifier, two channels (c. 1993/94–2000)
Two-channel
The two-channel Rectifier at 150 watts, with six 6L6s and three 5U4 rectifier valves.
What changed from the Dual Rectifier, two channels (revisions C–G)
- Power tubes: 4 × 6L6 → 6 × 6L6
- Two more 6L6s and a third 5U4 for 150 watts.
How to spot one
- Six 6L6 output valves for 150 watts.
- Three 5U4 rectifier valves; the name refers to them, not to three rectifier modes.
- The same two-channel, three-voice preamp as the Dual Rectifier.
Specs
| Power tubes | 6 × 6L6 |
|---|---|
| Rated power | 150 W |
Dual and Triple Rectifier, three channels (2000–2010)
Three-channel
A redesign with a dedicated clean Green channel plus Orange and Red channels, each with its own modes.
What changed from the Dual Rectifier, two channels (revisions C–G)
- A dedicated clean channel (Green) was added, and the gain channels got Raw, Vintage and Modern modes with their own controls.
How to spot one
- Three channels: Green (Clean or Pushed), Orange and Red (each Raw, Vintage or Modern).
- Each channel has its own controls and EQ.
- Rear switches choose valve (5U4) or silicon rectification and Bold or Spongy power, and a bias switch allows 6L6 or EL34 output valves.
- Dual Rectifier: four 6L6s, 100 watts. Triple Rectifier: six 6L6s, 150 watts.
Specs
| Power tubes | 4 × 6L6 (Dual) |
|---|---|
| Phase inverter | Long-tail pair |
| Preamp tubes | 5 × 12AX7 |
| Channels | 3 |
Multi-Watt Dual and Triple Rectifier (2010 on)
Multi-Watt
The three-channel Rectifier with a per-channel choice of full power or 50 watts.
What changed from the Dual and Triple Rectifier, three channels
- Each channel can now run at full power or 50 watts.
How to spot one
- Three channels, as on the 2000–2010 amps.
- Each channel can be set to run at full power or at 50 watts.
- Diamond-plate faceplate and valve/diode rectifier choice as before.
Specs
| Channels | 3 |
|---|
Single Rectifier Solo 50 and Recto-Verb (1998–2011)
50-watt
50-watt, two-channel Rectifiers with two 6L6s; the Recto-Verb adds spring reverb, and Series 2 revised both.
What changed from the Dual Rectifier, two channels (revisions C–G)
- Power tubes: 4 × 6L6 → 2 × 6L6
- Half the power (two 6L6s, 50 W) in a two-channel head; the Recto-Verb adds spring reverb.
How to spot one
- 50 watts from two 6L6 output valves.
- Two channels; the Recto-Verb adds spring reverb.
- Series 2 versions have independent controls per channel and a bias switch for 6L6 or EL34 output valves.
- The Single Rectifier Solo 50 uses diode rectification only.
Specs
| Power tubes | 2 × 6L6 |
|---|---|
| Rectifier | Solid-state (silicon diodes) |
| Phase inverter | Long-tail pair |
| Rated power | 50 W |
| Channels | 2 |
Road King and Road King II (2002–2017)
Road King
Four channels, six output valves in selectable combinations, and rectifier choice per channel.
What changed from the Dual and Triple Rectifier, three channels
- Four channels, six output valves (four 6L6, two EL34) and per-channel rectifier choice.
How to spot one
- Four channels.
- Six output valves, four 6L6s and two EL34s, which can be used in different combinations.
- Valve or silicon rectification can be chosen per channel.
- The Road King was built from 2002 to 2005; the Road King II replaced it from 2005 to 2017.
Specs
| Power tubes | 4 × 6L6 + 2 × EL34 |
|---|---|
| Rectifier | Solid-state (silicon diodes) |
| Phase inverter | Long-tail pair |
| Rated power | 120 W |
| Channels | 4 |
Mini Rectifier Twenty-Five (2011–2023)
Mini
A compact two-channel head running 25 watts, or 10 watts in triode.
How to spot one
- A very small head, about 12½ inches wide and 12 pounds.
- Two channels.
- Two output valves running 25 watts, or 10 watts in triode.
Specs
| Rectifier | Solid-state (silicon diodes) |
|---|---|
| Phase inverter | Long-tail pair |
| Rated power | 25 W / 10 W |
| Channels | 2 |
Rectifier buying checklist
Date it
- Channel count dates a Dual or Triple Rectifier: two channels means 1992–2000, three channels means 2000 on.
- On two-channel amps, a series effects loop points to 1992–94 and a parallel loop to Revision G (1994–2000).
- Mesa keeps factory records and can confirm an amp's build date and original spec from its serial number.
- A per-channel power switch means a Multi-Watt amp from 2010 or later.
Check it’s original
- The 5U4 rectifier valves are part of the design; check both sockets are filled on Dual and Triple Rectifiers.
- EL34s in a three-channel Rectifier are allowed by its bias switch, so they don't mean a modification.
- Two-channel Rectifiers have been modded toward Revision G voicing; ask for the revision and check the loop type.
What usually needs work
- Weak or mismatched 5U4s make the valve-rectifier setting sag more and lose power; try the diode setting to compare.
- Most noise and gain-loss faults come down to preamp valves; swap V1 first.
- Rectifiers run hot and have many switches; check the rear-panel switches and footswitch connections when channels misbehave.
Questions buyers ask
Why is it called a Rectifier?
The amp lets you choose valve (5U4) or silicon-diode rectification. The Dual has two 5U4s, the Triple three.
Two-channel or three-channel: how do I tell?
The three-channel amps (2000 on) have a separate Green clean channel and Raw/Vintage/Modern switches; the two-channel amps have two channels and three voices.
What was Revision G?
The 1994 revision of the two-channel Dual Rectifier, with a parallel effects loop; earlier amps have a series loop.
Is a Triple Rectifier three times the rectifier?
It has three 5U4 rectifier valves and six 6L6s for 150 watts, not three rectifier modes.
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