This is one of those good news, bad news moments.
First, the good news: the pedal sounds like a tube screamer. No weird noises, bypass works, all knobs do what they should (and in the right direction - not making that mistake twice!). With the gain rolled all the way down it works as a very nice cleanish boost. With the gain rolled all the way up it's not as saturated as my OD-2 which is mostly a tube screamer. I might try a couple of op amps and see if that changes things. It probably won't, but I did have a dodgy opamp last week so worth testing a couple.
The slightly disappointing news: the clipping diode selector switch works, but the effect is not nearly as audible as the same diode combos on my OD-2. I might solder up an asymmetric diode pair to test. I was hoping for a larger sonic difference in the two diode positions.
The bad news: the flat EQ mod sounds bad, at least with my amp. Makes the pedal sound kind of farty. I think it's letting way too much bass through. The mod is a switch that shorts out a 47nF capacitor in a high pass filter that dumps frequencies below 720Hz to ground (or to Vr actually), helping give the circuit its famous mid-hump. Jack's analysis gives a table showing the corner frequency for different cap values. He also suggests a mod that shorts the cap completely, allowing the full frequency range. That's what I have done, but it doesn't sound good in the shorted position.
But wait, there's more good news!
I used a DPDT on-on switch because that's all I had, which means I can mod the mod. Instead of the stock cap and a shorted cap, I can change it so the switch selects between the stock cap and a different cap value. Maybe the same socket idea I used on the diodes will allow swappable caps to tune the bass response of the modded position (with the stock value hard-wired in).
But I am tired now, and I have some Coopers Extra Stout to finish, so modding the mod can wait until tomorrow.
Almost forgot, the disemboweled but fully functional FS-808:
Reply With Quote
