Recent content by BigBottom49

Success! I put the components in the board and it fired right up! I built out the three boards I got from OSH Park. I installed one in an enclosure I found in a drawer and it's already at home in my pedalboard. The s/n is excellent. An instrument into the pedal and then out to an...

Thanks so much for doing that analysis. Which resistors did you change to get the difference in response? I think overall which is better is a matter of taste, but it might be interesting to listen to some options to find out what sounds best. Great News! I managed to design a PCB for this...

Oh, it's been a while since I was deep diving on this, but I believe the slope is set by the topology, which should be first order if I'm not mistaken. The actual shape of the curve is altered by the resonance tuning of the 133k resistor. I've been using the prototype and it's really working...

I am attempting to have a PCB made of this project. As part of that I am updating the schematics. If anyone happens to see obvious errors please let me know. One is in KiCad an the other is in TinyCad.

I'd like to post a correction for anyone who stumbles across this later on. It seems that the order of HPF>LPF vs. LPF>HPF for these two stacked filters has to be looked at more closely. Turns out I have it backwards and the High pass should go first followed by the low pass. The reason is...

I have acquired a new and powerful weapon in the fight against unreasonable frequencies.... I have somehow managed to make a working simulation of this circuit in LTspice. I have tried to do this kind of thing once or twice before but could never make it work. But somehow I got all the pieces...

Good eye, although at first I couldn't tell which filter your were referring to, HPF or LPF, but after looking at it a little closer there are actually different reasons why both the HPF and LPF response for the widget I've made differ from the Broughton HPF+LPF. I know I make stupid long posts...

Second prototype fired up on the first try! Which is semi-amazing when you see the back side of this one.... This second version, also built very compact on a 0.1" spacing perf board, features some proper 100kC reverse log pots that are mounted to the board itself, a OPA1644 opamp, a header for...

the spec sheets indicate that the OPA1644 (stock available) can be substituted for the unavailable OPA1654 so I'll order a couple of those and some dip adapters and see what happens.

Success! This is the prototype (I won't show the nasty underside where I did the connections): Surprisingly it came on and passes clean signal. I used a 9v battery to test and I didn't notice any noise issues. It's unity gain. I did some basic frequency response plots and it gives me what I...

You have a good set of pedals that covers a lot of ground, nicely done. For compressor location I think there are two things that are worth considering, one is subjective/empirical but one is more analytical/testable. The analytical issue is a basic pragmatic assessment of signal to noise...

Great! I'll put a prototype together on a piece of perf board and see if I can get some signal through it. I'll put the opamp on a socket so I could look into choosing a different one later if there is a need to optimize based on noise, signal level (instrument or line level for example) and...

I'm going to throw this out there. I was blessed with a '73 P bass 35 years ago that came from a pawn shop in a burlap bag for $50. The P bass sound is all I know and love. But last year I got the itch to upgrade. I wanted to retain the traditional P-bass sound but add some variation. I...

Looking at the wiring diagram for that preamp, it has the input from the pickup(s) going through the volume and tone and then to the switch to put the preamp in/active or out/passive. Hopefully I've got that right. That would suggest to me that you should be fine to take the output of the bass...

Sure, the ABC or a passive 25k would be wired exactly the same (input 1, input 2, blended output, common ground) except the ABC would have a power input and the passive won't.