Recent content by lowpitch

  1. L

    Please help me mod my Lead Solder OD

    Are you happy with how the pedal "feels" and just want to increase the overall level of brightness? Or do you find the response, on the initial pick attack for example, too muddy and lacking definition? That will determine where in the circuit we need to let more high frequencies through, post...
  2. L

    Valhalla Distortion

    Increase R24 to 1M-1.2M and decrease C19 to 1nF. That will give you about twice the output volume while retaining the cut-off frequency.
  3. L

    Acoustic Preamp Design - Preamp & EQ

    The question is whether it could hurt to put those LC filters there. Wish those tech notes weren't as bare bones and had some real life measurements. I came across some notes by Texas Instruments on filtering DC-DC converters today but haven't had a chance to check it out yet.
  4. L

    Acoustic Preamp Design - Preamp & EQ

    Curious about this. I'm currently working on a preamp design and will be using a Traco Tec series converter because I've had good experience with them in a couple of Aion FX PCBs. I would have just copied the Aion FX pi filter on the input, which uses a 100uF, 10uH and 47uF. Always open to...
  5. L

    Jlcpcb and tariffs

    Doesn't Mouser ship from the US?
  6. L

    Power Supply Questions - Reverse Voltage Over Voltage

    That will depend on the effect circuit. If it draws only 5 mA, then Ohm's law tells us there will be a 0.5V drop across the resistor. That's not too bad. If your circuit draws 50 mA, that resistor is now dropping 5V. No bueno.
  7. L

    Power Supply Questions - Reverse Voltage Over Voltage

    Check out this thread for some inspiration: https://forum.pedalpcb.com/threads/9v-protections-for-projects-with-a-voltage-doubler-muzzle-klon.22033/ You can also go very simple and use a zener reverse biased to ground. It will shunt any voltage exceeding the zener voltage directly to ground...
  8. L

    Power Supply Questions - Reverse Voltage Over Voltage

    If you're using the zener like above, it's not going to provide overvoltage protection for anything down the line. D1 is only there to protect the MOSFET by limiting Vgs to 9V.
  9. L

    Jlcpcb and tariffs

    Will likely become more common for German online stores at least. DHL Germany suspended shipping to the US for all commercial shipments as well as private gift shipments if they're worth over 100 USD.
  10. L

    HF noise with Duo-Phase (SOLVED)

    TC1044SCPA is rated for 12V maximum input voltage. I would advise against running it that close to max specs continuously. Also, not all power supplies are created equal. If the external power supply isn't filtered well, that noise can get into the pedal circuit. Also, running the charge pump...
  11. L

    General capacitor questions

    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...
  12. L

    Lt1054 negative voltage grounds

    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...
  13. L

    Stuff you wanted to know but were afraid to ask

    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...
  14. L

    DEMO Sunn Beta Bass (Aion FX Beta Preamp)

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

    jfet j309 by Interfet

    Correct.
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