The BYOC FET PreAmp kit is an almost exact replica of the legendary and discontinued BOSS FA-1 FET AMP. We say "an almost exact replica" because the only difference is that we've added a true bypass footswitch so that you can turn it on and off just like a real stompbox. The BYOC FET PreAmp kit comes with Hitachi HA1457W OpAmps and an NOS Toshiba 2SK246 JFET which are the exact same semiconductors used in the original FA-1. The BYOC FET PreAmp also adds a few upgrades by using higher quality components than the original such as 1% metal film resistors and higher quality film capacitors anywhere it was possible.