Description: Sweet 16 + Combo Amp
Designed & handbuilt by Doug Sewell & the "CAD" amp shop at PRS Guitars
40 watts, 6L6 (Output Tubes), 12AX7 (Preamp Tubes), Custom 12" Speaker
Front Controls: Vol,Reverb, Treble, Middle, Bass, Vol
Rear Controls: 4,8,16 Ohms, Extension jack, Bias jack
From Doug Sewell...
The circuitry was tweaked towards AC30 tones, which seems to be the optimum arrangement to allow somewhat Fenderish crisp cleans AND throaty, non-flubby/farty distortion with the use of the guitar volume knob. It's seems to have the best ability to do that-- not *perfect* Fender® cleans, but those will sound less perfect when distorted, etc. and not perfect Marshall distortion that won't clean up...
The specifics involve "wide open" cathode bypass caps on the tubes, with smaller coupling caps to keep the lows tighter. The tone stack nearly matches an AC30, but it's located in the circuit more like a Fender® (also used by Ken Fischer in his Trainwreck Liverpool and Express amps). The phase inverter is more SLO with a fixed "depth" control to bring in strong tight power amp lows, and makes the amp "fuller" sounding as a combo. The plate voltage is upped to the mid-400V range, the power tubes are fixed bias like a big amp, and a 4,8,10 ohm output tapped Pro Reverb/Vibroverb output transformer is used. This OPT is smaller, and smooths the edges off the high and low frequency range with a bit of sweet compression. The power tubes used are TAD 6L6- "short bottles", which excel in clarity, sweet compression, and warm overdrive. I chose these and the OPT to nudge the *feel* towards a cathode-biased amp, like the AC30.