Pre-gain high cut to the Informant overdrive

[Fama]

Hello!

I built the Informant Overdrive a while back, but I'm not in love with it. At least with my Strat that I normally use, which is obviously pretty bright sounding, it's not a great match. If I turn down the tone control on the guitar I can get a really nice, smooth, distortion with a lot of clarity on tap with the Cut control. But with the tone control down, it sounds more gritty and a bit grating, even with the Cut control at full.

The thing is, I don't want to always roll down my tone control to use that one pedal. So I'd like to implement a similar (?) low pass filter in the pedal itself - not sure if being before the clipping stage is important or not, but it might be, so preferably before that.

Here's the schematic https://docs.pedalpcb.com/project/PedalPCB-Informant.pdf

My thinking was that I would snip the leg from R6 that goes to R7, and add a 5k trimmer and a (for example) 10nF cap going to ground. That should give me a 1k 10nF to 6k 10nF RC filter, which should give me 16kHz with the trimmer at zero and 2.65kHz with the trimmer at full - plenty of range to work with I think.

The issue is that I'm not sure if C4 or R7 interfere with this at all? I'm not that good at electronics so I have no idea about that.

(I also had some comments last time about "Just build a RAT", but I've got this done already, I like it otherwise, and I love how it looks, so I'd like to use this one if possible)

 

[Cvoxdog]

I'm in the same boat. I always think it sounds too bright.

 

[jesuscrisp]

Yeah the DRV is a weird one. It manages to be pretty smooth in the treble but also harsh in the high mids... Less fizzy than a Rat but somehow more grating to me at least.

TBH I'd just try to put a cap in parallel with R7, you can basically solder it to the resistor legs. That will form a filter with R6. You can also replace R6 with a trim pot.

However, cutting a lot of treble pre-gain will emphasise the mids even more and might result in a rather honky sound. What I would rather do is put a cap in parallel with the clipping diodes, which tames the actual treble by forming a second order filter in conjunction with the cut control.

 

[music6000]

Hello!

I built the Informant Overdrive a while back, but I'm not in love with it. At least with my Strat that I normally use, which is obviously pretty bright sounding, it's not a great match. If I turn down the tone control on the guitar I can get a really nice, smooth, distortion with a lot of clarity on tap with the Cut control. But with the tone control down, it sounds more gritty and a bit grating, even with the Cut control at full.

The thing is, I don't want to always roll down my tone control to use that one pedal. So I'd like to implement a similar (?) low pass filter in the pedal itself - not sure if being before the clipping stage is important or not, but it might be, so preferably before that.

Here's the schematic https://docs.pedalpcb.com/project/PedalPCB-Informant.pdf

My thinking was that I would snip the leg from R6 that goes to R7, and add a 5k trimmer and a (for example) 10nF cap going to ground. That should give me a 1k 10nF to 6k 10nF RC filter, which should give me 16kHz with the trimmer at zero and 2.65kHz with the trimmer at full - plenty of range to work with I think.

The issue is that I'm not sure if C4 or R7 interfere with this at all? I'm not that good at electronics so I have no idea about that.

(I also had some comments last time about "Just build a RAT", but I've got this done already, I like it otherwise, and I love how it looks, so I'd like to use this one if possible)

This was a topic when it was first released:

Informant Filter mods, less highs?

what can be done to get the high roll-off to happen somewhere about noon? right now I have the filter cranked to the right to get a minimal amount of high roll-off but I find that many amps need it to happen sooner, or to get a bit more roll-off than is available. in short: it's a bright...

forum.pedalpcb.com

 

[finebyfine]

Changing R11 to 3K (from 1.5K) is the equivalent of what I do for an, IMO, more usable sweep on the tone knob on Rats - Chuck talks about it in the thread linked above. Might not be exactly what you want but an easy starting point

 

[jesuscrisp]

Changing R11 to 3K (from 1.5K) is the equivalent of what I do for an, IMO, more usable sweep on the tone knob on Rats - Chuck talks about it in the thread linked above. Might not be exactly what you want but an easy starting point

That would mostly just change the cut control so it's mellower early on but won't do what OP wants:

But with the tone control down, it sounds more gritty and a bit grating, even with the Cut control at full.

With the cut maxed it doesn't really matter if the filter has 101.5k or 103k + 3n3 cap for the frequency cutoff. OP wants to cut treble in a different way than the cut can achieve.

 

[phi1]

The circuit has a low cut filter (R8&C5) at 1.5kHz, which is pretty high. This might contribute to the harsh high mids people are describing. You could try increasing C5 (or running another cap in parallel) and see if that helps balance it out.

 

[finebyfine]

That would mostly just change the cut control so it's mellower early on but won't do what OP wants:

With the cut maxed it doesn't really matter if the filter has 101.5k or 103k + 3n3 cap for the frequency cutoff. OP wants to cut treble in a different way than the cut can achieve.

I misread the pot direction going on here you're right, good catch

 

[DGWVI]

Pull C3, and audition higher values starting at 10n. Adjust up or down as necessary