From Analogman :The Boss BD-2 is quite an excellent pedal but has some drawbacks in it's stock form. Through a Fender amp with Fender guitars it is quite the icepick in the ear... and the TONE knob does not really roll off the high end. It is not a normal TONE circuit, even all the way down it is still quite bright.They do not have the midrange vocal quality that a tube screamer has - which is a good thing to some people. The sound is less "effected" - more transparent than a tube screamer. I like the TS-808 sound a lot myself but I see where sometimes it is great to use a BD-2 instead. The BD-2 does not have the low-end loss that a tube screamer has so it stays nice and thick on the lows without getting flabby.My collaborator in Japan (Ohbayashi san), and I came up with this mod as we knew there was real promise in the BD-2 pedal. This BD-2 mod does not drastically change the circuit, but replaces many cheap, poor sounding components that Boss used. This is similar to what the high-end home audio guys routinely do when they buy a piece of equipment - they spend a few hundred dollars putting in the EXPENSIVE capacitors which lets the true sound come through. We are also changing circuit values in several places to make the tone control more useable and less shrill high end.I think the mod came out great but the caps are VERY expensive so the mod is best for professional guitarists or the type of people who go for the absolute best in their tone. You should use good patch cords like George L's or Lava (which we carry) to allow the full sound to come through. Ohbayashi san is sending me these high grade capacitors from Japan as they are not available in the USA.NOTE : The BD-2/SUPER can get squeal if you turn all 3 knobs up all the way. But our customers are normally not going for that loud, bright, and distorted of a tone so I have not heard any complaints yet. And the tone knob should never be run up that high with any decent amp.The difference in sound with our BD2 mod is easily heard at medium settings, and especially with your guitar volume rolled back a bit. There is not as much difference in sound when played through an already distorted amp. But if you crank the gain knob and turn down the TONE knob on the BD2, and play leads with the neck pickup, with the tone knob turned down on the guitar too, there is a huge difference. It changes a ratty sounding near-fuzz into a sweet woman tone, smooth and CREAMy.The BD-2/Super can get a VERY pure clean boost sound after our mod, more transparent than a tube screamer due to less midrange boost, compression, and distortion. We tuned this mod so that when you put the gain knob all the way down, and the volume and tone knobs at 12:00, you cannot tell if the pedal is on or off. Then you can just turn up the volume knob for your amount of CLEAN BOOST. On the other end, the BD-2/Super has more available distortion than a Tube screamer. It really has a wide range of excellent tones. If the gain knob is up, you can get cleaner sounds as you turn your guitar down, like our Sunface fuzz pedal.You can use the BD-2/Super along with the TS9/808/Silver for a great combination! I set them with the TS9 for rhythm and kick on the BD2 for leads or heavy rhythm. Both on together make my silverface Twin Reverb sound like a VOX AC-30 on 11! These setting are from 1-10, not o'clock settings. TS-9/808/Silver DRIVE:7, TONE:5, LEVEL:5-7 BD-2/Super LEVEL:5, TONE:4, GAIN:3-5The BD-2/Super also works well with our Sunface pedal. Put the BD-2 after the sunface and it can thicken it up well if you are running into a clean amp. I really like the sound with the sunface with the volume knob backed down for a clean fuzz, then into the BD2 at a medium setting for a very dynamic crunchy sound.