This is a modified version of the Guyatone PS-021 Guitar Exciter and Compressor. Besides the compressor feature, this little secret weapon also allows for enhancement of odd or even harmonics. "So?", you may say. Well, if you're playing through a tube amp, yet you're looking for a slightly more solid state sound, you can dial up the odd harmonics to get that feel. If you're plugged into a solid state amp, and are looking for a more tubish feel, you can dial it the other way for more even harmonics. Don't get any wrong ideas here... it won't make your Plexi sound like an Ampeg G-212, or vice versa, but it most certainly will add or subtract a certain edge to your tone. A very useful tool that few know about. We've done away with the flip-flop bypass, and we retained the final buffer at the output. The final buffer may be switched in or out via a toggle switch, which may help with where in the chain you decide to place this little jewel.