Available Now at Northeast Music Center!
Give your MESA/Boogie 2:Fifty the fresh tube complement it deserves. This complete OEM replacement set includes four MESA 6L6 power tubes and three MESA 12AX7 preamp/driver tubes—the full seven-tube complement required to restore the 2:Fifty's punch, clarity, dynamics, and unmistakable all-tube stereo response.
The MESA/Boogie Stereo 2:Fifty has long been a favorite among players who want genuine tube power and MESA character in a compact two-rack-space stereo power amplifier.
Delivering 50 watts per channel, the 2:Fifty uses four 6L6 power tubes—two per channel—along with three 12AX7 tubes in its front end. MESA's official specifications confirm this 4 × 6L6 / 3 × 12AX7 configuration.
This complete replacement set provides all seven tubes required to refresh the amplifier in one convenient package.
Available from Northeast Music Center, this is the straightforward choice for 2:Fifty owners who want the proper MESA tube complement without piecing together an individual replacement set.
• Designed specifically for the MESA/Boogie Stereo 2:Fifty Power Amplifier
• 4 × MESA 6L6 power tubes
• 3 × MESA 12AX7 preamp/driver tubes
• Complete 7-tube replacement set
• Replaces both power and preamp/driver tube complements
• Correct tube configuration for the 50-watt-per-channel 2:Fifty
• Genuine MESA/Boogie replacement tubes
• Ideal for a complete amplifier re-tube
• Designed for MESA's fixed-bias amplifier architecture
The existing Northeast Music Center product record also confirms that this OEM replacement set contains four 6L6 power tubes and three 12AX7 preamp tubes.
The Stereo 2:Fifty is a genuine Class A/B all-tube stereo power amplifier delivering:
50 watts per channel.
Each side uses:
2 × 6L6 power tubes
for a total of:
4 × 6L6 power tubes.
This architecture gives the 2:Fifty the punch, harmonic character, dynamics, and power-tube response that made it such a natural partner for MESA tube preamps and professional rack systems.
As power tubes age, the change isn't always dramatic.
It can happen gradually.
Punch begins to soften.
High-frequency detail can diminish.
Clarity may decrease.
The amplifier simply doesn't seem to respond with the authority you remember.
MESA's original 2:Fifty manual specifically notes that worn power tubes can produce a flatter sound with reduced punch, clarity, and high end.
Fresh power tubes can bring that authority back.
The 2:Fifty also uses:
3 × MESA 12AX7 tubes.
MESA describes these as part of the amplifier's three-tube front end, which works with the active Presence circuitry to give the 2:Fifty the harmonic character and response of a genuine guitar amplifier rather than a neutral "hi-fi" style power amp.
That's an important part of what makes the 2:Fifty special.
This isn't simply a device designed to make a preamp louder.
The power amplifier itself contributes to the final guitar sound.
Tubes are wear components.
And because their performance can deteriorate gradually, it's easy to become accustomed to an amplifier that's no longer performing exactly as it did with a healthy tube complement.
A complete replacement set gives you:
Fresh power tubes
Fresh preamp/driver tubes
and:
A known starting point for the entire amplifier.
For an older professional rack amplifier, that can be particularly valuable.
Instead of wondering which tubes have been replaced, how old they are, or whether the tubes in Channel A are aging differently than those in Channel B, a complete set allows you to refresh the entire complement.
The MESA Stereo 2:Fifty was designed as a compact but serious professional power amplifier.
Its specifications include:
50 watts per channel
Class A/B power
Four 6L6 power tubes
Three 12AX7 tubes
Independent Volume controls
Independent Presence controls
Fan cooling
and:
Two rack-space construction.
At only 23 pounds, the original 2:Fifty offered genuine stereo tube amplification without requiring the enormous rack systems traditionally associated with high-powered tube rigs.
That's exactly why so many of these amplifiers are still worth maintaining today.
The 2:Fifty also includes a Bias Select switch allowing operation with either 6L6 or EL34 power tubes when the amplifier is properly configured. MESA's specifications confirm the selectable 6L6/EL34 architecture.
This particular replacement set is the 6L6 configuration.
For players who want the traditional 2:Fifty setup, that's exactly where we'd start.
The 2:Fifty uses MESA's maintenance-free fixed-bias design.
That's one of the advantages of using properly selected MESA replacement tubes.
The amplifier and tubes are intended to work as a system, eliminating the need for the typical user-adjustable bias procedure associated with many other tube amplifiers.
For the owner, that means less guesswork and a straightforward path toward getting the amplifier back into service.
The Stereo 2:Fifty may no longer be part of MESA's current amplifier lineup, but that doesn't make a good one any less useful.
In fact, with modern rack preamps, modelers, effects processors, and traditional MESA tube preamps, a genuine stereo tube power amplifier can still form the heart of an exceptional guitar rig.
That's why Northeast Music Center continues to offer proper replacement tube sets for these amplifiers.
A good 2:Fifty deserves to keep making music.
And when the existing tubes have reached the end of their useful life, this complete replacement set gives you everything required to refresh the amplifier's seven-tube complement.
4 × MESA 6L6.
3 × MESA 12AX7.
One complete 2:Fifty replacement set.
