EL509S

The JJ EL509S is a modern octal based “non plate-cap” version of the classic EL509. This is a powerhouse of a tube with a 42 watt Screen+Plate rating and 500mA peak cathode current capability. This makes it ideal for “Output-Transformerless” designs, but they can also be used in traditional Single Ended or Push/Pull topologies.

The JJ EL509S utilizes pin #3 for the plate connection. Because of this tubes high cathode current capability they’re ideal in OTL applications or anywhere large peak current swings desired.

We’ve seen/heard amazing results with these tubes in the classic Futterman circuit/topology. If you’re into Electrostatic or planar style transducers this is the ultimate pairing.

Please contact us if you have special matching or grade requirements. Full curve matching is possible at an additional cost.

After a 24 hour burn in all power tubes are tested for noise and matched at multiple operating points for plate current (± one milliamp) and transconductance. Please leave us a note in the comments section as to what amp they’re going into and or if you’re looking for a specific grade.