Egodriver tech help

[mandrewbot3k]

Is there a reason Why I still have to run a third wire to the gain pot when its not connected to anything on the board? Just an isolated hole in the pad? The reason I ask is because I etched my own board and the pad got screwed up so its essentially missing, but I don't really see any value in it.

[mandrewbot3k]

Also, if not using onboard LED and switch, should i take out R12 (4k7) or just leave it open? or ground out the end of it? I guess if anything it just pulls a little more current (negligible)?

[madbean]

You don't have to connect the wire. I usually do because the parallel wires give it a bit more tensile strength, but it's not necessary.

You can clip out that resistor or just leave it open. Without it connected to anything, there's nothing to draw current through.

[mandrewbot3k]

fantastic. thanks for the quick reply. I'll just leave it in. i have a bag of 100 4k7s so its not an issue or reserving one. itll be more of a hassle to get it out then anything. I use a guitarpcb 3pdt board so I just use their wiring scheme.

What's the brightest I could probably use without blowing the LED, like a 1k?

[madbean]

I've used 1k on a water clear high brightness LED before. It'll light up the room. You can use up to 22k or so and keep it relatively bright.

Only thing to remember is that smaller value also equals shorter lifespan for the LED.

[mandrewbot3k]

OK. Maybe ill use a 2k2 or something. my buddy plays a lot of outdoor gigs and wants his "as bright as possible"

[mandrewbot3k]

So apparently I wired 1 and 3 reversed because my controls are working backwards. wooops. Now I am having issues with my second build. here are the voltages from both of my builds, the first one not working, the second one is, do they look right? i was getting a bit of noise on the working one (probably the TL082), but no signal at all on the second one

1: 4.37
2: 4.37
3: 4.11
4: 0
5: 4.36
6: 4.38
7: 4.38
8: 8.73

1: 6.92
2: 0
3: 0.59
4: 0
5: 0.15
6: 7.86
7: 7.97
8: 8.51

Obviously something is wrong. I've traced everything. all my values are good. i resoldered a couple connections I was unsure about.

[madbean]

You may have incorrect values for R14 and R15. Check that junction to see if you are getting 4.5v. I think you probably are not.

[mandrewbot3k]

OK. Ill recheck those ones. I build both of the pedals side by side, doing one r11, then the ohters r11, etc... Maybe they shorted or something.

I also have a little bit of a paste buildup on the boards from my rosin flux. I'm going to try to clean that up tonight with some alcohol to see if maybe that is causing some unwanted conductance in the circuit.

[mandrewbot3k]

i have 10k readings for both r14 and r15, but im getting 0.62v on the junction. the interesting part is that i get around 8.8 from r15 on the working board from ground. could a pot be affecting that value for any reason?

[mandrewbot3k]

alright well i gave up and i swapped the reversed controls. and then after i did that i got proper readings. still doesnt work though. i left the transistors in and when i was resoldering so i think i fried em, or they have been my problem the whole time. not sure. i have them socketed but i wasnt thinking when i soldered em.

im getting very low output. i swapped the IC for a working one, but it didnt do anything.

[mandrewbot3k]

Compared voltages to the working OCD and I'm just slightly low now. Instead of 4.37, i'm getting 4.30. I assume this is fine as the tolerance is quite low there. When testing, I noticed that really what didnt seem to be working was the Drive control. The level, although a little low, was at least controllable. The tone seemed to work as well as the HP switch. But the drive didnt change a thing, so i assume this is my problem. the pot tested to about 900K, not ideal, but close enough i suppose.

I was also thinking it may be R13 as the voltage coming in was like 8.51, just slightly lower than the working one. Will the voltage on pin8 greatly affect the output if its just slightly off?

i  checked all the transistors and they seem fine. getting the same 4.30v on all the legs. i pulled em out and tested em and they seemed fine. trimmed em down a little more, and then reseated them and still nothing.

is there something quite obvious that im missing here?

[mandrewbot3k]

So I'm assuming I'm just gonna have to make an audio probe to figure this out? I unfortunately just moved and have been having to do all this stuff on my kitchen table which my fiancée does not appreciate. So i'll have ot make my testing rig another day :-/

But i'd appreciate it if anyone had any ideas as to why my drive pot seems to have no affect on the output. pot was tested and working fine. i get variable voltage coming through it as its turned and i get about 900k on my DMM for its resistance. so I know it works.

[metfreak]

Hello every one! I have a question about Egodriver pedal I'm working on and I won't write this in new topic since there are a lot of them already, I hope that's fine.

So as I said I'm working on my MBP Egodriver and I got a problem with capacitors. I'm noob but I want to learn some new stuff

What should be rated voltage (VDC) for those caps, since I've mentioned I'm noob in this and I don't want anything go wrong.

Thanks for your help.

[jkokura]

Welcome to the forum!

It's alright to start a new one, it's actually more helpful because it then becomes a searchable question that's found more easily.

It should be listed in your documentation actually, so double check that. We recommend a voltage of 25 or higher on caps, but as long as they are higher than the voltage you are using (9v, 12v 15v or 18v are common) you will be fine.

Jacob