Mullard

1966 Mullard EL37 Matched Pair - Made in Great Britain

Mullard EL37 Matched Pair – Made in Great Britain – Rare 6L6GC Substitute

The Altitude Summary

Here’s a true gem for the tone chasers: a matched pair of vintage Mullard EL37 power "Coke Bottle" tubes, made in Great Britain and known for their rich harmonic depth, warm mids, and legendary clarity. These rare glass giants have been fully tested and both come in excellent working condition. They test strong to factory spec on a calibrated tube tester—no gas, no shorts, and balanced output across the pair. The glass is clean, the pins are solid, and the only markings are "EL37", "Made in Great Britain", and the etched code “R61 B8 H.” Perfect for audiophiles or vintage amp restoration.

These tubes carry the etched production code R61 B8 H, which dates them to the 8th week of February, produced at Mullard’s famed Mitcham Works in the UK— in 1966. That detail alone will spark joy in any collector or tone purist looking for true British pedigree.

British Power, Cult Tone

The EL37 isn’t just a tube—it’s a tone signature. Designed as a high-grade alternative to the 6L6GC, the Mullard EL37 offers a smoother response curve, tighter low-end, and a sweeter top-end breakup. Whether you’re chasing hi-fi richness or classic guitar amp warmth, this pair brings unmistakable British mojo to your rig.

Matched and Ready

This is a genuine matched pair—tested and verified for consistent performance. Expect smooth symmetry in push-pull circuits and zero guesswork during install. They're ready to drop into your next hi-fi project or classic tube amp build.

Rare Find for the Right Ears

Tubes like these don’t surface often, and when they do, they don’t stick around. These are true Mullard builds—no rebrands or relabels—just pure British engineering from one of the most revered names in tube history. A must-have for serious tone aficionados or restoration purists.

Key Features

Matched pair of vintage Mullard EL37 tubes
Made in Great Britain in 1966 (etched “R61 B8 H”)
Power pentode design – 6L6GC-compatible
Balanced output – both tubes test to factory spec
Excellent condition with clean pins and markings
Highly sought after by audiophiles and amp builders

$1,000.00 USD

PRODUCT SPECS

Condition:Excellent
Brand:Mullard
Model:EL37
Year:1966
Made In:Great Britain
Serial Number:R61B81
Product Weight:1.0lb

Condition	Excellent
Brand	Mullard
Model	EL37
Year	1966
Made In	Great Britain
Serial Number	R61B81
Product Weight	1.0lb

Mullard EL37 Matched Pair – Made in Great Britain – Rare 6L6GC Substitute

The Altitude Summary

Here’s a true gem for the tone chasers: a matched pair of vintage Mullard EL37 power "Coke Bottle" tubes, made in Great Britain and known for their rich harmonic depth, warm mids, and legendary clarity. These rare glass giants have been fully tested and both come in excellent working condition. They test strong to factory spec on a calibrated tube tester—no gas, no shorts, and balanced output across the pair. The glass is clean, the pins are solid, and the only markings are "EL37", "Made in Great Britain", and the etched code “R61 B8 H.” Perfect for audiophiles or vintage amp restoration.

These tubes carry the etched production code R61 B8 H, which dates them to the 8th week of February, produced at Mullard’s famed Mitcham Works in the UK— in 1966. That detail alone will spark joy in any collector or tone purist looking for true British pedigree.

British Power, Cult Tone

The EL37 isn’t just a tube—it’s a tone signature. Designed as a high-grade alternative to the 6L6GC, the Mullard EL37 offers a smoother response curve, tighter low-end, and a sweeter top-end breakup. Whether you’re chasing hi-fi richness or classic guitar amp warmth, this pair brings unmistakable British mojo to your rig.

Matched and Ready

This is a genuine matched pair—tested and verified for consistent performance. Expect smooth symmetry in push-pull circuits and zero guesswork during install. They're ready to drop into your next hi-fi project or classic tube amp build.

Rare Find for the Right Ears

Tubes like these don’t surface often, and when they do, they don’t stick around. These are true Mullard builds—no rebrands or relabels—just pure British engineering from one of the most revered names in tube history. A must-have for serious tone aficionados or restoration purists.

Key Features

Matched pair of vintage Mullard EL37 tubes
Made in Great Britain in 1966 (etched “R61 B8 H”)
Power pentode design – 6L6GC-compatible
Balanced output – both tubes test to factory spec
Excellent condition with clean pins and markings
Highly sought after by audiophiles and amp builders

At Altitude Guitar, our collection of vintage electric guitars includes instruments that stand the test of time, prized for their history, craftsmanship, and unique characteristics. Vintage guitars are typically defined by their age, often being 30 years or older, with many models becoming increasingly rare electric guitars due to limited production runs, discontinued designs, or iconic status in music history. A rare guitar is one that has distinctive features—whether it's a limited edition, a unique model, or one with significant cultural impact. Our selection includes old electric guitars with vintage appointments, offering a rich tone and unparalleled playability that modern guitars often struggle to replicate. From vintage guitar brands known for their legendary quality to retro electric guitars that offer a classic sound and aesthetic, each instrument in our collection tells a story of musical evolution. Whether you're searching for vintage electric guitars for sale or simply seeking a rare electric guitar to add to your collection, our guitars provide a unique playing experience that celebrates the rich history of electric guitar craftsmanship. Explore our full collection of high-end electric guitars for more premium instruments designed to elevate your sound.