The Svetlana EL34 is very dependable and our recommended choice for combos. It has little less power, but therefor a nicely balanced tone with fine heights, very detailed and musical mids and just the right amount of bass. This tube is another example where our TAD burn-in and matching processes optimize the sound potential of any tube: the clear and lively tone and its three-dimensional character that can be achieved with matched TAD tubes speaks for itself. The TAD EL34-SVT is identical to the stock tube used by Marshall for the JCM2000 TSL/DSL series. It is the only EL34 version that we do recommend for these amp models.