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Messages - ddog

#1
I took a look back on my board C2/C7 are actually MLCC (makes a bit more sense than tantalum).

I've also noticed that the output jack isn't always outputting a voltage when bypassed. What tends to happen is I can use the pedal as normal (meaning the pedal won't cause the pedals in front to pop), then suddenly I will get a volume drop followed by a volume recovery and now all the pedals in front will start popping. If I take the pedal out of the chain and try again next day, the behaviour resets.

Quote from: Zerro on September 12, 2021, 01:46:08 PM
C2 would be wrong, it is second possibility. But try that hack with resistor at output bypass.

I've been playing around with this hack. Does the size of the resistor matter with respect to tone? Ie is there any auditory difference between 470k vs 22k?

I've managed to reduce the output voltage to 0  if I use a 270R resistor. Im sure I can achieve the same result if I use a 10R as well. Is there any advantages to using a lower value? (or higher value?)

Is there any benefit to achieving a 0.00V? I can achieve a 0.05 or a 0.2 voltage; will these also cause a large pop? Is there a risk to continuously output such voltages (via the output jack) to other pedals / amps?
#2
Thanks mauman. Yep looks, like it is C2. 5 and 6 are shorted during bypass.
#3
With the 9V plugged in:
-when bypassed, 5 and 6 are 'momentarily' grounding, that is when I set dmm for continuity measurement I get a short beep, (and the LED turns on). Sometimes I get chirping (ie multiple short beeps)
-when turned on 5 and 6 is continuous

Without the 9V:
-when bypassed, no ground connection between 5 and 6

I'll replace C2 and report back. It seems I used a tantalum capacitor for C2 (oops), Ill try to replace it with a metal film. I'll probably replace the C7 one as well, since I used the exact same type of capacitor for it as C2.
#4
I have a Fatpants (2013) that has recently started making pedals placed after it 'pop' when I hit their stomp switch. This only happens to the pedals placed after, not the ones before.

I checked the voltages - when the pedal is bypassed there is  3.5V - 4V on the tip of the output jack which drops to 0V when I turn on the pedal. Turning the knobs (FAT, LVL) or the switches (SOFT, BODY) has no effect on the voltage.

The pedal is currently wired in buffered mode (diagram). I was thinking of re-wiring it into true bypass to fix the problem.

Before I do that, is there a possibility that a component is faulty (C2?, C7?, other? and which one do I check) or maybe the switch became faulty (how would I check that?). I rather switch out a component than rewire the pedal into true bypass.

Here is the schematic:




Thanks for the help!
#5
Thanks everyone, I went with the 1n34 with the tl072. It is a sweet sounding circuit ;D
#6
General Questions / Cupcake Diode/Op-Amp Substitution
August 21, 2021, 09:46:50 PM
I'm building a Cupcake (2016 PCB, not the 2020 version) and I have a question about substituting the diodes. I currently have a 1N34 (not 1N34A) and a BAT41. Can I use either? Which one is more recommended? I read midwayfair's post that the diode just affects the compression (https://www.madbeanpedals.com/forum/index.php?topic=21345.0). Madbean recommends the BAT46.

As far as I know the approximate forward voltages are:
1n314a is around 0.21
1n314 is ?
BAT41 is around 0.36
BAT46 is around 0.25
1N60P is around 0.33

is there any significant "auditory" compression differences between them? Is it higher forward voltage = more compression?

With Op-Amps, I have both a 4558 and a TL072. Is there any advantages with sticking to the 4558?

Thanks for your help!


#7
I'm thinking of adding the 'Vibe Mod' to an old Galacticon Phase Shifter I have lying around. I'm planning on using a ON/ON 4PDT switch to do so. I've drawn a rough diagram to how I think the wiring should look like:



Can anyone verify that this is the correct wiring? This Post confirms that C2 and C3 are the right caps. Here is a blank drawing if the above wiring is incorrect. Cheers!
#8
Just discovered Kings of the City and I've been on a small binge. Enjoy:







Really excited for the one (and only  :() album coming this spring!
#9
Open Discussion / Re: PCB mounted pots/switches/LED's
January 08, 2015, 04:29:03 PM
16mm pots arent that hard to desolder if you are willing to clip the legs. I usually just clip right on top of the long legs and just remove each leg one by one. You could probably convert that pot to a solder lug pot, but I usually just stick a new one in just in case. Same thing probably works for 9mm pots, but I haven't tried it with those
#10
General Questions / Re: Sunking II - Sub for BS250?
December 22, 2014, 08:24:17 AM
Didn't really want to start a new thread, so Ill post in this one. Would this be a good substitute:

VP0808L
Datasheet: http://www.supertex.com/pdf/datasheets/VP0808.pdf

I just searched for a P channel Mosfet, from my local supplier
#11
Thank you!
I think this should do it:




Seems very fundamental, but just making sure
#12
Quote from: madbean on February 08, 2014, 02:22:27 AM

What I suggest here is using a DPDT or SPDT toggle and switch between the stock C8 and either no cap or something much smaller, say 10pF. That way you get essentially the same tones but a tiny bit of HF filtering at the same time.

Sorry for the old bump.

Im very dumb with switches, can someone draw this out for me on the sunking ii (presumingly c9)? Thank you!

EDIT: Don't even have to draw it out, let me know if there is a link to somebody else switching caps with a switch and Ill steal their idea
#13
Open Discussion / Re: Portable Recording Solution
December 14, 2014, 11:10:13 PM
I use the Zoom H2 for the above listed purposes. Very good, but the battery could be better (I use the eneloop rechargables so its not that bad). You also have to do research if you are interested in using an external mic. While the zoom h2's internal mic is good, external mic results in some hiss. I am not sure what the deal is with the h5.

I'd also check out the Sony PCM series. When I was researching they had better ratings then the zoom h2, but they were out of my budget
#14
Global Annoucements / Re: Holiday Sale and more
December 06, 2014, 04:26:21 PM
Quote from: jighead81 on December 06, 2014, 04:22:40 PM
dang, were the dirtbabys gone instantly?

Sale live at 10:15, sold out at 10:21 (when I checked). Really crossing my fingers for another run for those (with the critical mod already applied perhaps)
#15
Open Discussion / Re: Woohoo!
December 06, 2014, 05:10:01 AM
I'm still refreshing for that winter sale