To be honest, I don't know yet. Since it got back, it was just "plug and play" and I haven't bothered evening looking inside. With the preamp tubes being covered, it is difficult to see too. Rick, being the obscure one, didn't say. The conversation went something like this:
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Rick: Steve, your amp is ready. Where do you want it sent?
Steve: Send it direct to me overseas. What did you do to it?
Rick: What you needed to have done to it. Trust me, you will like it.