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  1. JTEX

    Hissing noise goes away when pad is touched

    Does it do the same thing with the input shorted or with a mic plugged in?
  2. JTEX

    Op amp buffered power supply?

    ^ This. Sometimes you just need a low impedance Vref. This means that it's able to supply (or sink) significant current without moving up or down with the load. A simple resistive divider made with sensible values, such as 100k or 10k, can't do this.
  3. JTEX

    Recommendations for Rockman X100 Stereo output mixed to mono conversion?

    It's safe to use the low level 1/4" output with a simple mono cable and just call it a day. Shorting the unused Channel to ground in this fashion does not harm the unit at all. Don't do this with the 1/8" headphone output though. There is a subtle difference between the L and R outputs: one...
  4. JTEX

    I’m trying to understand the cut off frequency of this tone control… but need help!

    ^ there's a weird path to ground from the emitter of T1 which might explain why it works:
  5. JTEX

    I’m trying to understand the cut off frequency of this tone control… but need help!

    Well, I'll be damned. It seems to work in Tina! You should have taken the bet, you'd be up $20 :) The only way I can imagine it working is if the PNP transistor is simply used as a passive clipping device. Maybe someone more knoweledgeable could explain how the darn thing actually works??
  6. JTEX

    I’m trying to understand the cut off frequency of this tone control… but need help!

    Ok, now I'll really put it into Tina if I find some time. As drawn, it really looks to me like it shouldn't work. Will let you know.
  7. JTEX

    I’m trying to understand the cut off frequency of this tone control… but need help!

    Easy. Put the whole thing in Tina-ti and see if it works. I have $20 that says it doesn't. But what if I'm cheating and I've already done that? 😁 (I haven't)
  8. JTEX

    Random pix

    Like cheap beer. Headache included.
  9. JTEX

    Random pix

    My GF bought me a whole case of these beers. What in the world? Where do you even buy this? AliExpress? Tayda? No label at all. Not even "No Name" . Just says Beer/Bière.
  10. JTEX

    I’m trying to understand the cut off frequency of this tone control… but need help!

    What I don't get is how the two transistors work, seeing that they don't have a DC path from their emitters to ground. Also, the PNP seems to go between... GND and GND at both ends??? Makes no sense. It's not powered in any way.
  11. JTEX

    I’m trying to understand the cut off frequency of this tone control… but need help!

    I haven't tried this myelf, but apparently there's a way to run Tina-TI on a Mac using Wine: https://www.diyaudio.com/community/threads/how-to-run-tina-ti-on-your-mac-for-free.409104/
  12. JTEX

    I’m trying to understand the cut off frequency of this tone control… but need help!

    You can download Tina-Ti and open the txt file I attached (change its extension from .txt to .tsc). Then press CTRL-A and you'll get a frequency response plot for different pot settings. Something like this:
  13. JTEX

    Stuff you wanted to know but were afraid to ask

    To prove you're not a bot 😁
  14. JTEX

    Component value and frequency response

    There's this too. Possibly the easiest to get started with, but I have barely touched it myself: https://www.circuitlab.com/
  15. JTEX

    Component value and frequency response

    ^ I second that motion. It may be a bit hard to get started with a circuit simulator, but if you get the hang of it, it will have been time well spent. Having said this. I tried LTspice and there was absolutely no way in hell I was going to deal with that. I absolutely hate the user interface...
  16. JTEX

    Can someone demystify “type 1” versus “type 2” DPDT switches for me?

    I can confirm that Dailywell are very good. Nothing wrong with them.
  17. JTEX

    op amp bias voltage divider - resistor values?

    Yes, but I believe @thunderaxe is planning to use that extra opamp for something else eventually. And in this particular, simple circuit, there's no real benefit from an opamp-buffered VREF, since nothing draws or sinks significant current to/from it.
  18. JTEX

    op amp bias voltage divider - resistor values?

    C2 in Sour Grape will help reduce ripple to some degree, depending on the output impedance of the power supply. The "stiffer" (lower impedance) the power supply, the less effective is C2 at filtering. If you look at R17 in Dream Fuzz, its main purpose is to help with PSU filtering when combined...
  19. JTEX

    op amp bias voltage divider - resistor values?

    That's on the Dream Fuzz. I was talking about Sour Grape. My bad, I forgot to mention it.
  20. JTEX

    op amp bias voltage divider - resistor values?

    Just wanted to point out that the R7/R8 divider will dump whatever noise/ripple there is in the AC power supply straight into the op amp input. Why not simply tie pin 5 to Vref through a resistor?
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