madbeanpedals::forum

Projects => VFE Projects => Topic started by: Aentons on April 30, 2018, 06:58:26 PM

Title: Blueprint high pass filter on repeats
Post by: Aentons on April 30, 2018, 06:58:26 PM
So when I get around to building the Blueprint, I want to try and figure out how add few options that I mentioned in previous posts like tap tempo and trails. I'm in the collecting ideas and research phase right now but... two other options I've thought of are, an effects loop using a stereo jack, and a variable high pass filter on repeats. Any pointers or knowledgeable insights are most welcome.

I have a EH Deluxe Memory Boy that I like sometimes and it has a semi-secret knob mode that does a HPF which is where I got the idea. It really takes the muddyness out and let's you play over the delay in a unique way which is something I haven't experienced in any other delay.

I'm only beginning to learn how to modify circuits and I learn best by example. I understand most components and mostly how they work llike opamps and filters and whatnot. So I'm at the point where I can understand the gist of what's going on in most effects circuits but this is my first time really looking at a delay in any detail and the vfe switch board confuses the hell out me.

I purchased the VFE schematics and board files from the website and I've been looking through them. It is fantastic of Peter to put it out there. In this instance, I'm not sure if they will provide anything beyond Brian's refined build doc schematic.

I know the PT2399 has a couple of low pass filters built in and I see a couple of others(r16+c4 and r31 and c11). Could the HPF thing be as easy as swapping cap and resistor positions and replacing resistor with a trimmer?





Title: Re: Blueprint high pass filter on repeats
Post by: Netnnk on April 30, 2018, 07:38:45 PM
*edit* sorry, I thought you meant low pass filter. I'd like an answer to your question too. C14 (1uf) , right before the tone section seems a good candidate for bass cut.
Title: Re: Blueprint high pass filter on repeats
Post by: Aentons on January 25, 2021, 08:35:44 AM
Quote from: Aentons on April 30, 2018, 06:58:26 PM
I know the PT2399 has a couple of low pass filters built in and I see a couple of others(r16+c4 and r31 and c11). Could the HPF thing be as easy as swapping cap and resistor positions and replacing resistor with a trimmer?

I finally ended up building a blueprint and this mod is confirmed and works well. It makes it much more usable(to me) to be able to dial out some of the low end on the repeats. You can now use the "tone" trimpot to blend the low cut to taste rather than to a (to me, basically unusable) darker setting. Same values work fine, just switch the positions of the resistors and caps. r16 <-->c4 and r31<-->c11

(https://lh3.googleusercontent.com/pw/ACtC-3d0sHz2OZDUlTz6qFCkWqR4dm6QOFjiTQ5CFDx2RFKvFvg60k2uwkVTYVsdnmg2z0mF5-k1jm6OGXpA9bQTDXUvRognehpe8PnbIHRfYqfxg_LAVzjbfMgGoBJaDEVP6XGhztC8lSR_EKzvbv5tTFg7YA=w723-h907-no)