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What do those 10 Ohms extra resistance across the frequency spectrum matter if all the surrounding circuitry has impedances hundreds or thousands of times higher? A 100K 1% resistor alone is going to be +/- 1000 Ohms. There's a point of diminishing returns (for audio signals at least) even if...

In your example I'm guessing PWR_GND is a separate ground pour around the charge pump to help isolate the switching noise and prevent it from coupling into the audio signal. Power ground and signal ground then likely meet only at a single point somewhere around the main filtering capacitors...

Anybody got experience with Vishay DG469 analog switches? Link to datasheet below. Just need a second set of eyes to confirm I got the switching logic right (or not). So, with the IN pin floating, the n/c pin connects to common and the n/o pin is essentially left floating. And when the IN pin is...

These are available at Tayda. It's the matte black sand finish. I don't know exactly how the effect is achieved.

Correct.

Thanks, man. It's a cool pedal and very fun to play. Interesting circuit as well with those zeners in the clipping stages. A little on the dark side but R19 or C15 can be lowered to up the presence.

Thanks for checking out the video! I designed the enclosure in Illustrator from scratch, taking heavy inspiration from the original amps (fonts, knob scale markings, etc.). UV print job was done by Tayda. I overhauled the design a while ago, here's one I recently built: I'm running the pedal...

Common to circuit ground is correct, but is there continuity between common and the ground terminal of the DC jack? If there isn't, maybe the converter references the wrong voltage which causes the offset of the +/- outputs in relation to chassis ground. A fix would be to run a wire from the...

Can you share your vero layout and wiring from/to the DC jack? Kind of peculiar that the converter output is offset by 9V.

Power transistors in general seem to be lower gain, just mind the pinout and the package size. I found some of them also have higher parasitic capacitances than regular transistors, which may or may not matter and may or may not be a good thing as it can lead to high-end roll-off due to the...

Cool idea. I'd like to check out that schematic. Currently planning to build it stock with a DC-DC converter for +/-15V, then see what I do and don't like about the circuit and go on from there. Simulations in LTSpice seem to suggest a bit of a lack in bass content, but it's hard to hear with...

I suspected as much. Some of those older Randalls look intriguing for sure, but I'm adapting the boost channel of the Marshall Valvestate 8100 with (probably) FETs for tubes. Uses TL072 and obsolete M5201 switching op amps throughout, which seem to be very similar in specs to plain old 4558s...

I'm working on pedal recreation of the preamp section of a solid state guitar amp. I want to stay true to the original and use the same or similarly spec'd op amps throughout. Due to the circuit design, I could either use two separate single op amps for the input and output sections, or use one...

Double check where the pins are connected on your pots. Your mids and presence pots for example seem to be reversed, so they're going to function backwards. C107/C106/D2 aren't connected to ground, so they won't do anything. Q4 is not going to work as intended. This is a source follower stage...

It's worth experimenting at least. I currently have a silicon treble booster on the breadboard and transistor choice has a pretty big effect on how compressed the signal sounds, even when biased to the same voltages. High frequency response is also affected quite a bit depending on the...

We'll see :D Wiring this up was a real turn-off. Need to get more into DipTrace so I can create a PCB with board-mounted pots and switches. Yeah, it works really well here. Overall, I prefer the sound of this DIY buffer/boost over my PedalPCB Transcendence Boost with an OPA2134. That...

I'm located in Germany. The handful of JLCPCB orders I've placed so far were with the "HASL (with lead)" option and I haven't had any issues. I use "Global Standard Direct Line" shipping with duties pre-paid to JLCPCB. Packages have been delivered directly to my door without further actions...

Maybe I should share some of the actual circuitry. This is the buffer/boost stage: C1 = 470n film C4 = 100n X7R C7 = 10u electrolytic R12 = 100K R13 = 51R "Boost" is an A10K pot with pins 1 and 2 bridged. A 1.1K resistor (R7) goes from pin 2 to 0V. The impedance selector switch simply has a...

I nicknamed this build the BSMSB – Buffer-Splitter-Mixer-Switcher-Boost. It does pretty much what the name suggests, although the splitter-mixer part doesn't really work particularly well. More on that later. A simple non-inverting op amp circuit provides adjustable gain from unity to +20 dB...

Getting slightly off-topic, but couldn't you just reference the transistor to the negative voltage instead of ground in a common emitter amplifier for example? If not, why not? I don't think this case was covered in your BJT biasing series, Chuck.