The GT EL34M is based on the original Mullard EL34 of the \'60s -the stock tube in most early Marshall and Hiwatt amps
Big, fat and well-defined tone and really "wakes up" reissue amps to perform like the originals

The Gold Series GT-E34L-S Matched Power Medium (4-7 GT Rating) Quartets are an exclusive GT design with special "heat wings" attached to the plate for more power, longer life, and better tone.

These Groove Tubes Gold Series GT-6L6-R Matched Power Tubes are Russian made, same as the 5881, but matched in the GT system.

ECC83S is 12AX7 high gain pre-amplifying double triode

Duet Matched Tubes JJ EL34 selected.

The Groove Tubes GT-12AT7 preamp tube is manufactured to the highest quality JAN spec. NOS

The Groove Tubes GT-12AX7-C preamp tube brings back the ever-popular and sorely missed Chinese 12AX7!

ECC83-Cz TAD Premium Selected

Groove Tubes GT-EL34-R Ratind Medium Matched Duet

Groove Tubes GT-EL-34M Matched Quartet Medium Rating