The JJ 6SL7 is a High quality, low
noise replacement for any 6SL7 / 5691 type tube. These are also available Balanced and matched in pairs or multiples.
All our preamp tubes are stringently tested for noise and microphonics using Amplitrex testers driving an external amp. There is no extra charge for low noise and microphonics testing like with other tube vendors. If a tube does not pass our strict performance criteria it's tossed or sent back to JJ Electronic for evaluation.