MoonWatcher wrote:The tightness control does appear to be similar to what Amptweaker is doing - a highpass filter that's also a gain dump. Corner frequency goes up as gain goes down.
it's not a gain dump. The Op amp has zero output impedance, so the "tight control" has no resistance to divide the signal with. Tight control only divides the signal with the complex impedance of the capacitor. If it was a stage with output impedance, you would be correct.
MoonWatcher wrote:U2A looks to be a variation of IC1B in a Marshall Bluesbreaker - inverting input means more like hard clipping, but R15 basically serves the same function as the 6K8 in the Bluesbreaker. Even the highpass filter at U2A's input is the same corner frequency as a Bluesbreaker (or Guv'nor).
MoonWatcher wrote:The bass control is an adjustable bridged-T. It actually does look to be like a cousin of the Shredmaster's contour control. The Amptweaker pedals also use a bridged-T variation at the thrash switch.
The contour is a passive midscoop. In the feedback loop, it is a active midboost. I did scale the 3.3k values to 33k to get them into the bass region.
MoonWatcher wrote:I'm wondering if the presence and treble are possibly closer to how it's done with runoffgroove's Thunderbird? The treble control in the BE-OD is actually 100k-linear, right?
Great catch on the 100k! Thanks. That makes more sense now. I did the presence and treble like the presence and tone from the MI crunchbox. Maybe someone could comment if it appears they react similar.
MoonWatcher wrote:I'm not familiar with the BAT54, but it looks to have similar characteristics to other Schottky-types, and the forward voltage looks similar to some germanium-types.
I just threw the bat54 in there because I didn't feeling drafting the BAV?? part Jok3rx put in.
You do not have the required permissions to view the files attached to this post.