Don,
I can't speak to your particular unit since you built it yourself and I have no idea how it's set. That's too bad it gives a sound you don't like. Properly set up, treble boosters can be very useful specifically with Rectifier series amps, and especially for lead playing, because they replace some of the missing mids and harmonic overtones that Rectos are known for lacking, as well as provide deep saturation of high notes without the corresponding mud that usually comes with it, especially on a Recto. Rectos are so naturally bass-heavy that it is easy to dial back in the appropriate amount of bass that the treble booster reduced, and yet still have clarity and articulation in the bass notes, something usually difficult to achieve on a Recto without help.