Recent content by Rpschultz13

Here is a *terrible* demo. I thought my iphone would do better, but it doesn't capture what I was hearing at all. When I was demonstrating the notch, it was really feeding back hard, but you don't get that in the video. You can kinda hear the variation in the low end, but the variation in the...

Pricey as hell is right, that's why I started this whole thing. Felix is amazing, but wow, not worth that price. After years of experimenting with dual-source, I have moved away from that and simply use IR on my piezo pickups. Sounds better, simpler, no feedback issues, etc. Back then I always...

Sure I could do a simple walk through video, in True Bypass to hear with it on/off (should sound the same), play with some of the knobs, etc. Maybe later this week.

Theoretically, sure. But it wouldn't be simple. The set HPF could easily be removed to allow full range into the first gain stage. But most/all the EQ stages would need to have the frequency range adjusted. At the very least, the HPF/Notch range would obviously need to be lowered since right now...

Boards came in a few days ago, assembled one and it tested as expected. Web site as a LOT of details and documentation to dig through. I'm happy to answer any questions here, or hit the contact button. I started this project in fall of 2023... because I was annoyed at how expensive a Grace...

I finally got REW, and realized that my very old Presonus Audiobox kinda sucks from a noise (THD) perspective. So I upgraded to a Motu M4, much lower THD. Then I measured my Gamma Acoustic Preamp, it has a THD of 0.013%. I need to borrow some other acoustic preamps to compare. Grace Designs...

I asked this over on AllAboutCircuits. Great thread, especially the Cyril Bateman articles. Also the TI article in post #2 is fantastic. https://forum.allaboutcircuits.com/threads/film-capacitors-for-audio-in-smd.208074/

I love these things, made by Daier: Tayda has 6-7 different options (red, blue, green, purple, red/green, blue/red, momentary, etc) for $3.49. Amplified Parts has something similar with a bigger knob for $8.45. I don't like the big knob or the price. Aliexpress has a 10 pack for $45 shipped...

Tayda Yesterday - DHL: Not terrible, but a far cry from what used to be $20-25 to ship a larger order like this.

Cool. Here's the BOM and cost estimate (minus boards). The part costs don't include shipping (mouser, stompboxparts, Tayda, etc), so factor that in. It's not a cheap build. I could sell the 2 PCB's only or do the whole kit (except enclosure at this point). Google Sheets BOM

Ah, I’ve wondered about THD, I’ll look into REW!

I settled on this for the power section. It seems fine. And using the 2W version has plenty of current capacity, I don't think the 3W is even remotely necessary for my application, about 200mA at 9v. Currently mouser has the 2W for $11 and the 3W for $15 (+tariffs), but the 3W is often out of...

A few years ago I bought a good scope for troubleshooting, a Siglent SDS 804X HD, which is a pretty nice beginner scope for $350-450 (2 vs 4 channels). Probably way more features than I'll ever figure out, but I'm learning. One of the reasons I needed a scope, I'm designing an acoustic preamp &...

A recent picture of this project, a Bode plot of the parametric mid. This version of the PCB is a 4-layer I designed in EasyEDA, much improved over previous version. I made mistakes converting the schematic from Eagle to EasyEDA, fixed them. Now re-printing. Should have the final version here...