Want all the growl and gain you can get? This is our High Gain Option Retube Kit for the Orange AD200B and AD200B MKIII Bass amps. For the front end this kit contains two Handpicked High Gain ECC83S's and one current balanced ECC81 for the phase inverter. The default power tubes are a matched quad of the JJ Electronic 6550's however you can configure this kit to use a quad of the JJ KT88's for a little more power and depth by clicking on the "Customize" button!
These are all adjustable bias amps and all you need to check and adjust the bias is a bias probe and a Multimeter, or our all-in-one Eurotubes "Pro One" bias probe that reads both the plate current and the plate voltage simultaneously. You can find all these under the Related Products Tab. The KT88's and 6550's bias the same.