Available Now at Northeast Music Center!

MESA/Boogie Replacement Tube Set for Express Plus 5:50

Restore the performance, response, and reliability of your MESA/Boogie Express Plus 5:50 with a properly matched replacement tube set built around the amplifier’s original tube complement. This complete retube configuration includes two MESA 6L6 power tubes and five MESA 12AX7 preamp tubes—the correct layout for the Express Plus 5:50.

The MESA/Boogie Express Plus 5:50 is a remarkably versatile amplifier, combining Clean, Crunch, Blues, and Burn modes with Multi-Watt™ power switching and MESA’s classic 5-band graphic EQ.

Like any all-tube amplifier, its feel and tone are directly influenced by the condition of the tubes inside it.

A fresh, properly matched tube set can help restore:

Clarity.

Punch.

Dynamic response.

Gain structure.

Low-end authority.

And overall reliability.

Available from Northeast Music Center, this replacement tube set gives Express Plus 5:50 owners a straightforward way to refresh the complete tube complement using the correct MESA tube types.

COMPLETE REPLACEMENT TUBE SET

This set includes:

• 2 × MESA 6L6 Power Tubes
• 5 × MESA 12AX7 Preamp Tubes

That matches the factory tube complement specified by MESA for the Express Plus 5:50 Head and Combo.

DESIGNED FOR THE EXPRESS PLUS 5:50

The Express Plus 5:50 uses:

2 × 6L6 power tubes

and:

5 × 12AX7 preamp tubes.

Its Multi-Watt™ power section operates the 6L6s differently depending on the selected wattage mode, giving the amplifier:

5 Watts

25 Watts

or:

50 Watts.

Because the power section is central to the way these modes feel and respond, healthy, properly matched 6L6 tubes are especially important.

MESA 6L6 POWER TUBES

The power section of the Express Plus 5:50 is built around:

2 × MESA 6L6 tubes.

6L6s are known for:

Strong clean headroom.

Full low end.

Defined mids.

Open high-frequency response.

And a broad dynamic range.

MESA’s current 6L6 STR-448 matched pairs are designed for consistency, reliability, punch, and tonal balance, making them a natural choice for compatible MESA amplifiers.

FIVE 12AX7 PREAMP TUBES

The Express Plus 5:50 also uses:

5 × MESA 12AX7 preamp tubes.

These tubes play a major role in:

Input gain.

Channel voicing.

Overdrive character.

Effects-loop operation.

Phase-inverter duties.

And the overall feel of the amplifier.

When preamp tubes begin to wear, players may notice increased noise, reduced clarity, microphonics, inconsistent gain, or a general loss of immediacy.

Replacing the full preamp complement can help bring the amplifier back toward its intended operating character.

WHY RETUBE AN EXPRESS PLUS 5:50?

Tube wear doesn't always happen suddenly.

It often happens gradually.

An amplifier may begin to feel:

Less lively.

Less punchy.

Noisier.

Softer in the low end.

More compressed than usual.

Or less consistent from one playing session to the next.

Because those changes happen over time, many players don't realize how much performance has been lost until fresh tubes are installed.

A complete retube can be one of the most effective maintenance upgrades for a well-used tube amplifier.

FIXED-BIAS MESA DESIGN

The Express Plus 5:50 uses MESA’s:

Maintenance-Free Fixed Bias

design.

That means the amplifier is designed around properly selected MESA power tubes operating within the intended bias range.

For many players, that simplifies routine tube replacement compared with amplifiers that require manual rebiasing every time power tubes are changed.

RESTORE CLEAN HEADROOM

One of the first areas players may notice power-tube wear is clean performance.

A tired set of power tubes can begin to sound softer or more compressed than expected.

Fresh 6L6s can help restore:

Clean headroom.

Low-frequency control.

Transient attack.

And overall authority.

That matters especially in the Express Plus 5:50, where the Clean and Blues modes depend heavily on dynamic response.

RESTORE DRIVE & BURN RESPONSE

The same applies to the amplifier’s higher-gain voices.

The Express Plus platform includes:

CRUNCH

BLUES

and:

BURN

alongside its Clean mode.

Healthy preamp tubes help preserve the gain structure, harmonic detail, and articulation that allow those modes to remain musical rather than muddy or undefined.

For players who use the entire range of the amplifier, retubing is about much more than simply replacing worn components.

It is about restoring the full voice of the amp.

IDEAL FOR PREVENTIVE MAINTENANCE

Not every tube replacement has to begin with a failure.

For working players, studios, churches, touring musicians, and anyone who depends on their amplifier regularly, a complete retube can also be part of preventive maintenance.

Having a fresh set available means you're prepared before a tube becomes noisy, microphonic, or fails at an inconvenient time.

At Northeast Music Center, we consider that especially worthwhile for older discontinued MESA amplifiers that players intend to keep in service for many years.

KEEPING A GREAT MESA IN SERVICE

The Express Plus 5:50 may no longer be in production, but that does not make it any less capable.

Its combination of:

Clean / Crunch

Blues / Burn

5 / 25 / 50-watt Multi-Watt™ operation

5-band graphic EQ

Reverb

FX loop

and:

Solo control

still makes it an extremely versatile professional amplifier.

A fresh tube set helps protect the investment already made in that amplifier.

THE RIGHT TUBES FOR THE RIGHT MESA

For us at Northeast Music Center, tube replacement should be straightforward.

The goal isn't to guess.

It's to install the tube complement the amplifier was actually designed around.

For the Express Plus 5:50, that means:

2 × MESA 6L6

and:

5 × MESA 12AX7.

Simple.

Correct.

And ready to put a great MESA back to work.

Northeast Music Center is a full line Music retailer located in Northeast Pennsylvania- We are an Authorized Mesa Boogie Dealer and purchase these products direct from MESA HEADQUARTERS IN PETALUMA CALIFORNIA. We do not obtain our MESA AMPLIFIERS or other MESA products from "jobbers" or other dealers. Our MESA AMPLIFIERS AND CABINETS come to you in the factory boxes with factory packing material. We will, upon request, and also randomly, open the box prior to shipping to check that all contents are included and that no damage has been found in shipping from MESA to our Store location. Northeast Music Center does reserve the right to sell these products in our store to daily walk in customers. It is our goal to always have this product in stock and if for any reason we sell out, we will reorder immediately as long as this MESA AMPLIFIER is currently produced for resale by the company. We will order the amplifier in a ample quantity to fill your order. It is our goal to make your experience a good one; We invite you to ask any and all questions about this product.  Please do not purchase this item if you can not pay. This is a new Mesa with full 5 Year factory warranty to the Original Owner. 3 Year Warranty on Speakers.