All other layouts, pcbs and schematics should be considered as unverified. Most of the discussion about debugging was on the basis of boards or layouts made ELSEWHERE! This was moved to the debuggin thread...
modman, 10.ii.2015
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Could this be a Marshall Bluesbreaker/KOT? Is this picture enough to go on?
I'll take it apart and photograph the other side if you need me to. Or has this
already been discussed. I searched and found nothing.
"super ecstasy is a basic opamp clipper with bass boosts, from there go to a cap, diodes to ground on a switch, tone control is basically what people call the stupid wonderful tone control (IIRC - I don't remember the exact schem of mark's but it's basically the same thing). From there into a jfet gain stage and then into the volume control."
culturejam wrote: We are equal opportunity exposure artists.
"super ecstasy is a basic opamp clipper with bass boosts, from there go to a cap, diodes to ground on a switch, tone control is basically what people call the stupid wonderful tone control (IIRC - I don't remember the exact schem of mark's but it's basically the same thing). From there into a jfet gain stage and then into the volume control."
I don't see a jfet in the above picture. Interesting.
ugh, I have a habit of hitting submit too quickly.
Here's the thinking along the design of the ecstasy. The idea was to boost the bass to fuzz up the bottom end a bit, yet retain soft clipping. So there's a pot to a big cap (nfb to ground), variable low pass filter as a tone control, simple gain boost opamp stage after this.
switch adds in diodes to 4.5v ref (IIRC!), soft clipping only, or no diodes which is all opamp clipping. Simple design, but works and sounds great.
Somehow I can't edit my posts (feature deactivated not enough posts maybe?) so here is a new one. If its possible I would be happy to know.
It is way harder to reverse engineer from pictures than the actual unit. In the attachments are the parts were I am sure. Hope that helps somehow. Red lines are connections were I can't be 100% sure, but everything else wouldnt make much sense.
Usually the gain is in series with a res(10k?)and in parallel with the diodes on op1,which is referenced to Vref with the other 470k.
also the 2 diodes after the 47k are on Vref
i guess tone goes to ground (or Vref)with a cap,then vol to output
ok
i should have figured it out,what about cap values missing?
,c7 is 1uF,tone cap could be 22 or 47nF,wiper to ground,then vol out.
ceramic? 100,220p?
I just traced it yesterday from the gut-shots. The only critical component that I don't know the value of is C3. It looks like 22n or 47n from the size of the cap on the gut-shots, but it makes no sense to me.
220n makes the bass control much more effective. Maybe it should be socketed on builds.
Where I put "switch", it goes to the on-off-on switch to select the clipping fashion.
It is from LTspice schematic capture module so I separated the tone control in half for simulation purpose, but it is a 25k pot in a Stupidly Wonderful Tone Control configuration.
Then we have a potentially fully working schematic since the other caps are not too critical and are not expected to modify the response curve in any noticeable fashion.
I won't build it, but I am impatient to see it verified
Hey jymaze, thanks for the schematic. Am I interpreting this correctly, is the tone control:
Lug 3 to 1K
Lug 2 to 22n to ground
Lug 1 to volume 3
and is the 100K shown at the output the volume pot or is there a resistor to ground before the pot?
Cheers
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP
