Want a very smooth and rich tone with less grit? This is the Gold Pin Option Retube Kit for the Engl Special Edition E670 and the Special Edition E670 EL34 Amps. The preamp section uses five ECC83S's with one balanced for the phase inverter in V9. The default power tubes are a matched quad of the JJ Electronic 6L6GC's but you can configure this kit to use the JJ 5881's, EL34II's, E34L's, EL34’s, KT77’s or the Big Bottle 6CA7’s by clicking on the "Customize" button.
These are adjustable bias amps and the biasing can be done without any equipment following the instructions in your manual. We included a small copy under the "Tube Info" tab.