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.
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)?
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.
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?
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.
OK. Maybe ill use a 2k2 or something. my buddy plays a lot of outdoor gigs and wants his "as bright as possible"
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.
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.
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.
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?
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.
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?
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.
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.
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
To add to Jacobs post
This is a build that a lot of people power at 18v . 35V would be a safe bet for this. I always use caps rated double what I'm going to run the pedal at. It's usually only an issue with electrolytic caps, film caps are usually rated higher than we ever need, same with most ceramics.
Welcome to the forum. ;D
Josh
Hello it's me again. ;D
I've run in another problem, in new EgoDriver board there are two (+/-)9V "holes". So it confuses me where to solder them? I've checked the standard wiring diagram and all the projects if there is the solution and I didn't find it...
http://www.madbeanpedals.com/projects/EgoDriver/docs/EgoDriver.pdf (http://www.madbeanpedals.com/projects/EgoDriver/docs/EgoDriver.pdf)
Thanks for your help!
Nejc
Square pad is +9v the circle next to it is ground. The two circle ground pads are connected via the PCB. This can make wiring easier; for example the one ground pad can go be wired to the power jack and the other ground pad wired to the 3pdt etc.
Josh
I finally just got back onto my builds. I just got married, so I decided it was safe to move all my stuff onto my kitchen table again. At least until I get my soldering station built in my office (a desk with my old bathroom exhaust fan inside my closet).
But I finished one OCD, but am still having some issues with the other. I'm getting correct voltage readings, but my Tone and Drive pots don't do anything as much as i work them. I etched my own boards and at this point I'm tempted to just order a new board. I still need to build my testing probe, although I don't really see it helping in this situation.
Any ideas? probably some bridges somewhere. I couldnt find any. But it was my first etched board and pretty poor at that...
I might give this a shot.... http://www.madbeanpedals.com/forum/index.php?topic=368.0
On a sidenote, looking at some other pictures I realized I used a 1n4148 in place of the 1n34a. Will this make a big difference? It sounds fine to me. Maybe a bit gritty, but still has good clarity. I guess my question being that I've never used a real OCD, is this diode a must have feature? If so I feel like i should open my working one and replace it as well.
Diodes are like flavours of ice cream. Some like their strawberry, some won't have anything but chocolate.
When used for clipping, Diodes sort of different basic characteristics. While this is a general rule, you can find exceptions.
Soft clipping = Ge (1n34a, 1n60, 1n270)
Hard clipping = LED/MOSFET
Medium clipping = Silicon.
Now, you can also make things harder or softer depending on where you use them.
Really soft clipping = Ge in a feedback loop
Soft clipping = Silicon in a feedback loop
Medium clipping = LED/MOSFET in a feedback loop, Silicon on signal path to ground
Hard clipping = LED/MOSFET on signal path to ground.
Again, you can make things sound different depending on what you use too. An LED in the feedback path will not sound the same as a Silicon on the path to ground, even though they may give you 'similar' clipping patterns. Nor will two diodes neccessarily sound identically alike even if they are from the same 'family.'
Complicated I know. The real answer is that if it sounds good to you, use it. If you wanna change it and experiment, use sockets.
jacob
turns out I did use a 1n34a. they look a lot like a 4148...
Er....
Mine don't. Did you get some workalikes?
Jacob
i dont know. i think i got them from pedal parts plus or smallbear last winter. i saw someone elses build and they looked like they used a germanium, thats when i second guessed it, but my short little orange ones, a bit stubbier than the 4148 say 1n34a on them.
I had some 1n34a a while back that looked like 1n4148s... from futurlec IIRC
Hellooo everyone!
I've run into some problem with my Egodriver all built but when I'm playing it suddenly after approx. 5 seconds it starts losing volume and it come to "zero" sound, I can't get no sound out of it.
What could go wrong through my building process?
Thanks
Nejc
There are a large number of potential issues you could be experiencing. My advice is for you to go and check out the "rules for getting Tech help" thread and then starting your own thread for getting your pedal working. We'll be happy to help you out!
jacob
I'm so far behind on these damn things... I started playing again.
Voltage in = 9.16, pins 123567 = 4.29V pin4=0V, pin8=8.59V. q1 I have 4.29 on all legs, and q2 is 4.29 on cb and 4.19 on the emitter.
I've got some output, but it sounds like a fuzz, super bassy. I used my probe for the first time and it seems to happen right after R11, the 33k. I get full kinda tinny sound on the c7 side, and then it sounds like someone covers it with a blanket on the other side of the resistor going into the vol pot. I tried replacing C8 and r11, didn't make a difference.
I'm gonna go through and quadruple check all the resistor values.
Any suggestions?
If I have the volume pot turned all the way up, it seems to send it to ground? Does this mean I have it wired backwards??
Pics....
Yellow section is going to ground when volume is cranked all the way.
(https://lh3.googleusercontent.com/-ZVfBXyhsahU/ULGimunL6TI/AAAAAAAAFJQ/gkhUp0dgZw8/s640/2012-11-24_20-44-51_487.jpg)
Here is top of my build showing pot wiring
(https://lh5.googleusercontent.com/-hfbwQYZf6bk/ULGiiFR3apI/AAAAAAAAFIM/380TGAjD1mI/s640/2012-11-24_20-44-38_280.jpg)
Sitting here at work, I'm starting to suspect a bad volume pot. I'm going to replace it when I get home.
In the mean time, I've decided to order an egodriver board and a fatpants to do a dual pedal, single box build with a->b and b->a switch as well, so I can run off of 18V also.
But I'm really banking on the pot being the culprit. It needs to be cranked just to get a little signal, then it shuts off right quick.
Pot didn't seem to make a difference. I did notice that pin3 was actually slightly lower, 4.11 while all the others were 4.30V so i need to trace that back. It really seems like that 33k is where its completely dying. Anyone think of anything why that might happen? No pots seem to work except for the volume but the usable sweep is only about 20 degrees at the upper end, then the output completely disappears.