New OD based on the Sparkle Boost

[oliphaunt]

I thought I would share this idea I had for an overdrive and see what you folks can do to improve it.  It is based on Andrew's Sparkle Boost, and is basically three of them running into each other.  It is a fairly smooth low to medium gain OD with very little compression until you really crank it up.

The original Sparkle Boost:


I replaced the original gain control on each stage with fixed resistors and am using the output of the first stage as a gain control.  I found that the original 1M resistor to ground on the Sparkle Boost is resposible for it's "sparkle" so I lowered that value to tame the high end.  Still, they combine to have an outrageous amount of high end so I added cap in the feedback of the last JFET.  I like the sound of an MPF102 in the last position better than a J201, it seems to breaks up more smoothly.  The 680R resistor to ground after the output cap is there to bleed off the outrageous amount of volume boost this thing has.  Even with that much going to ground there is still a ton of boost available.  

The big thig I am hoping to improve upon is the overall frequency response.  It has a bit of a low mid hump, and gets kind of mushy, especially in the neck pickup.  I have been tweaking the input and output caps but there is still some low mids that are a bit much I think.  

Also, by accident I came a cross a solution to tame the high end that I like but am not sure is a good idea.  I accidently strapped a cap across the Drain and the Scource of Q1 and Q2 rather than the Drain and Gate.  It works well and sounds good, though this has no effect on Q3.  In general Q3 acts differently than the other 2.  it takes a much higher value cap there to have any influence on the high end.  Q1 and 2 react to as low as 200p.  The overall frequency response is a little different, maybe even better with this configuratrion but I don't know if it's a good idea or not.

I would love to know what you think about this, and please point out anything ridiculous I am doing!

[oliphaunt]

Here is the Sparkly Overdrive: