Same beginner, another 4 pedals

Started by ghiekorg, September 27, 2020, 04:48:19 PM

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11-90-an

Quote from: ghiekorg on October 22, 2020, 07:46:08 AM
what if i just add an A100k pot and i connect the CCW lug to ground, the CW to board-output and the middle to jack 3pdt-output? I could use a small pot on the side of the pedal or just use it as in internal trimmer, i set it properly and i leave it inside the enclosure

Yep this is a better idea. However, since you said the volume increases/decrease with different switching combinations, I'm thinking an external and proper pot
If you do this, I'm thinking you pull out R9 since it would mess with the taper and total resistance of the pot.
flip flop flip flop flip

ghiekorg

Isn't the R9 a pulldown resistor to avoid pops? Maybe it's a stupid question but i am starting to try to understand the various parts :D

duck_arse

R9 does pulldown, yes. take that out and fit a 100k pot - the pot will pulldown just the same. well, only now you can tap-off the volume level from that pullldown. a resistor is a resistor.
You hold the small basket while I strain the gnat.

antonis

And form a variable cut-off frequency HPF with C12 ..
(Volume set dependent..)
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

ghiekorg

#104
so... i added a 100k pot between out and 3pdt 7th lug. It worked fine. Then as EVERY freaking time, when i closed the pedal one switch was not working anymore. couldn't find a solution. Then out of the blue without any reason it started to work again.
question is: As i just read your messages, is it really necessary to remove R9? What would be the difference? i am just scare to touch it again :(

ok, i changed my mind. I wanna learn so i will do it no mater what

antonis

In a real world pedal, R9 is unnecessary..
(but for an effective simulation, some kind of load in needed..)

As Stephen said, it can be readily replaced by a 100k Volume/Level pot, also acting as pull-down resistor..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

ghiekorg

Everything good :D i think the R9 was taking off a bit of volume (was it or it's just my impression?) so removing it made it louder and made the volume knob even more meaningful.
Thank you guys :)


antonis

Quote from: ghiekorg on October 22, 2020, 03:36:15 PM
i think the R9 was taking off a bit of volume (was it or it's just my impression?) so removing it made it louder and made the volume knob even more meaningful.

It effectivelly made pot value 50k (set in parallel with it) and altered pot's taper (law)..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

ghiekorg

QuoteIt effectivelly made pot value 50k (set in parallel with it) and altered pot's taper (law)..

Ahhh now that you tell me so it made realize they were in parallel. I was just thinking "i wil just put it after the board, so it will be in series" (like everything that comes before the wire is another circuit) without thinking that the output wire is actually connected to a resistor, so adding a pot makes it in parallel and not in series.
Thank you

ghiekorg

Hi again guys...
I just made a DOD fx91 overdrive :D (this thread title has no sense anymore) but there is still a pop when i turn it on. If i understood correctly the connection between lug 1 and 6 of the 3pdt should avoid that. It's not super loud but it's there. What could it be? I wired everything like i always do... (apart from connecting the 2 jacks ground instead of using the enclosure as bridge because it is painted also inside)
Layout and schematics are here https://effectslayouts.blogspot.com/2019/09/dod-fx91-bass-overdrive.html
Thank you guys

antonis

As far as I can see, IN & OUT are grounded via 1M pull-down resistor and Level pot respectively..

You might need an LED anti-pop configuration, like the one below..

"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

11-90-an

QuoteI just made a DOD fx91 overdrive :D (this thread title has no sense anymore)

Not quite a beginner, another 4+1, 2, 3, 4... pedals  :icon_lol:

As for the problem, do what antonis suggested.
flip flop flip flop flip

ghiekorg

#112
Thank you Antonis. Next time i will have to solder something i wil give it a try. Can i ask why do you think this happens? I mean, it has to do with the input because when i have the pedal engaged every pedal before it pops if i turn it on, while this doesn't happen with the ones after it. I also don't get why the lug 3 of the driver pot goes nowhere (if you look at the layout the hole is not connected to anything)

@11-90-an: hahah yeah. It seems yesteraday i etched my first PCB and now i don't have space on my pedalboard nor on my desk. I have pedals everywhere literally.

11-90-an

As far as I read from other people, the LED's have a chance to make some sort of pop when turned on, (or something about voltage and stuff...) but I really don't know... :icon_redface: :P

Referring to schem:

http://www.sugardas.lt/~igoramps/article16/fx91.gif

The Drive pot is wired as a variable resistor... if your were to measure the resistance with your multimeter connected to lugs 1 and 2, it goes from 0 ohms to 100k (more or less, there are some tolerances) when you turn it...

Either when lug 2 and 3 are connected or when they aren't there really isn't much of a change in anything. Another example of "good practice", I guess...

not connecting them was probably for layout convenience...  :icon_lol:
flip flop flip flop flip

ghiekorg

#114
HI guys :)
this morning i decided i wasn't happy with the rebote so i decide to make another 1590A delay and i made the Dirty Punk Repeater  (https://effectslayouts.blogspot.com/2014/11/dirty-punk-repeater-delay.html)
It works, the repetitions are way cleaner then the rebote's but i have a big volume loss when it turn it on. I used everything as layered out, i just changed the Q2 (BC459b) for a 2N5089 and i used 2 resistors (1M+330k) instead of the 250k i didn't have. Is there some resistor i can change in order to have a proper volume?

I will try now the FX91 anti-pop. I tried to just cut the LED from the 3pdt but wasn't enough.
Nothing, the antipop wiring didn't solve the pop problem. I really see the LED go bright and dim when i turn it on, but i tried to disconnect it also from the 9v side  but the pop is still there. At least opening it made me notice i had place the 33uf in the wrong direction. It's getting frustrating again... i have no clue now how to fix this

ghiekorg

here is another problem occuring using the Punk Repeater: The time knob does a kinda weep sound

https://www.youtube.com/watch?v=UI5qxT5BFUo&ab_channel=ghiekorg

duck_arse

now I know you are all over this, but I'll ask anyway. what is the difference between a BC549 and a 2N5089 [that might affect your output level] ?
You hold the small basket while I strain the gnat.

ghiekorg

I don't have a BC549 to test, but looking at the schematic the first thing I thought about was this transistor.  I tried: 2N5088, 2N5089 (who  ci should have more gain), MPSA18, 2N3904. Maybe even something else, but I can't remember. They didn't make any difference in the output level :/

duck_arse

Quotei just changed the Q2 (BC459b)

I took this as a misstype. did you mean BC54xb? [sorry, it's not worth my time messing with my faulty "nine" key/s]. check your datasheet for pinout comparison!
You hold the small basket while I strain the gnat.

Marcos - Munky

The pinouts for the 2N5089 and BC549 are reversed. Did you rotated the transistor 180ยบ before soldering it?

For the delay, here your video have no sound. Don't know if it's an issue on my end. But if it's a weep sound that changes the pitch of the delay whey you rotate the pot while it's still playing a note, that's something that happens with all delays.

Just a suggestion. Your topic started as a "looking for 4 pedal suggestions", which was achieved. Then you used the same topic to ask for help with two more builds, but some people who can help you may not see your questions because they saw this topic earlier and think "well, he already picked the 4 pedals, so the new posts are just build reports or something like that". It's better to create one topic per build, so things keep organized and you get more visibility.