Looking for more warmth and definition? This is the Standard Retube Kit for the Ampeg VL-501 Amps. The preamp section uses five ECC83S's with one balanced for the phase inverter in V5. The default power tubes are a matched pair of the JJ Electronic E34L’s but you can configure this kit to use the JJ EL34II's, EL34’s, KT77’s, Big Bottle 6CA7’s or 6550's by clicking on the "Customize" button.