This is the Standard Retube Kit for the Splawn Competition KT88 Model amps. The preamp section uses three ECC83S's with one balanced for the phase inverter in V3. The default power tubes are a matched pair of the JJ Electronic KT88's but you can configure this kit to use the JJ 6550's for a little earlier breakup 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. You can use the "Generic Bias Video" we made using a Marshall 800 for reference. The video below explains the difference between bias probe types.