Pinnacle/Sovereign - to much sag

[maoriente]

As I understand it, high output pickups can cause to much sag with the Pinnacle and/or Sovereign.

Brian's suggestion (a few years ago) was to lower that guitar's pickup height.

What would be the best approach to simulating lowering the pickup height, by limiting the input signal without killing the pedal's response?

Would any of these "mods" accomplish this? (using a switch)
Lower the impedance to the 1st jfet? (R28)
Increase the 470R input resistor value? (R2) Maybe with a treble bypass cap paralleled?

Any other way(s) to do it?
Previously Posted Schematic

[Satch12879]

Increase the supply voltage.

[maoriente]

Thanks Satch, sorry I should have mentioned I already tried a charge pump 9v/18v "sag" switch, did not resolve the low end clipping.

[brejna]

Few years ago I had same problem with the pinnacle build, so so I increased input resistor. In your case R2, if I remember correctly I changed it with the 33k

[maoriente]

Cool, thanks brejna, will try that next.

I'll switch in a 33k between the 470R and 22n cap.

BTW, the low end "splat" only happens when attacking the strings hard.

[phatt]

You can halve the value of C4 for less bass and lower values of C3 may also be needed.
Lower values of both might be needed. Higher values of R3 and R9 will back off the gain.
Phil.

[maoriente]

Thanks Phatt!

Had tried 10n for C4 and removing C3 all together. Neither helped with the "splat" itself.

And it happens in the lower gain switch setting too, when R3 and R9 are not engaged.

I've also swapped jfets, socketed and tried other values for every coupling cap. Nothing helped with the low end "extra" sag. (again, only happens when digging in on the low strings)

After all I have tried and read, I'm pretty much convinced the issue is with the input signal level.

Just don't know the best way to tame the input strength (when using high output pickups) without effecting the pedal's tone or response.

per brenja's suggestion, I'm going to put in a temporary pot (wired as an adjustable resistor) between the 470R and 22n input cap to see if I can dial out the splat without killing the response or tone. I'll also try a treble "bleed" resistor across the two lugs if needed.

Also, I forgot I had already tried lowering the input impedance on another build, which killed the pedal's response.

Hoping someone else has had this same issue and found a fix other than lowering the pickup height. (And maybe brenja already has the answer)

[phatt]

OK then try lower values for C5.
I did build a similar circuit long ago and I do recall C5 was lowered to wipe off bass.
You can do same at C9 if needed.
You can also try half values for R5 & R6,,
C6 is another place you can lower to wipe off even more low end.
Like a lot of these circuits you really have to fine tune the response to the rig you have.
Phil.

[bmxguitarsbmx]

Drop C6 to 2.2nF. Or even 1nF. That's what I would do.

C5 can give you weird transient response. I would be tempted to just put that at 1uF and not use it to limit low end. While C5 does limit low end, it also creates transient instability the lower the value is. I.e. it's not simply a first order filter. YMMV

[maoriente]

Thanks BMX, will give that a try. And thanks for correcting the too too :0)

[phatt]

Drop C6 to 2.2nF. Or even 1nF. That's what I would do.

C5 can give you weird transient response. I would be tempted to just put that at 1uF and not use it to limit low end. While C5 does limit low end, it also creates transient instability the lower the value is. I.e. it's not simply a first order filter. YMMV

Ta mate,, good catch. Now that you mention it, I recall weird thing happening with small values for C5 but long time ago so all a bit vague now.
Phil.