Tonepad MXR EF volume drop

[Govmnt_Lacky]

I searched the forum and build reports and found that a possible solution to the volume drop in the Tonepad MXR Envelope Filter is to change the value of C4 on the layout/schematic. It is set as .1uF on the site however, I have read  that people have used different values ranging from .01 to .001uF to boost the volume. Has anyone tried this cap change mod yet? Also, what value did you use to best "fix" the volume drop?

http://www.tonepad.com/getFile.asp?id=113

Thanks all...

[Mark Hammer]

C4 rolls off treble at the output.  Insomuch as there is a HF clock in the circuit, this is a safety precaution against clock noise.  Making its value smaller will allow more treble out, and the greater brightness will make it sound a bit louder.  Don't go crazy with it though because you still have that HF clock to contend with.

R1/R2 at the output provide some attenuation.  If R1 is on the high side of 3k6 via its 5% tolerance, and R2 is on the low side of its 200k +/-10k tolerance, then there may be a bit more attenuation than intended (e.g., 3k7/192k).  Worst case scenario, measure a 220k resistor, verify it is at least 220k and stick it in place of R2.

Try those fixes and you should probably get the desired level balance.  Let us know if that doesn't do it.

[Govmnt_Lacky]

Thanks Mark. I am pretty sure I used some good resistors in those spots.... in all spots actually. I usually use 1% resistors in my builds however, I may have used some 10-20% resistors in some spots where I did not have those values in 1%. I will have to verify.

I did use a .047uF cap in C2 instead of the "called for" .05uF. Would that have any effect on the output volume? I figured it was in the +/-10% threshold so it would not be a concern.