Check out what I'm building today

[LesStrat]

[NevermindUs]

Yes that's essentially it. I have never come across a pedal that can't be modded to true bypass.

One thing to be aware of with true bypass is sometimes you can get a pop through your amp the first few times you turn the pedal on/off this can be reduced and in some cases eliminated with a pull down resistor.

Thanks a lot of the info and tips!

[ratherdashing]

From this thread you should be able to build one just from copying the pictures alone.

I always thought stuff like this would be really difficult until I actually tried it and did some further reading then I realised that it's really not that tough at all.

That was my idea. I wanted to make this thread to help de-mystify the looper boxes.

In the schematic/wiring layout, i didn't see a dropping resistor for the LEDs. ?

You are correct - yet another omission from the crappy schematic (to be honest, I drew it while watching TV). I will be putting a 1k resistor between the DC jack and the power rail.

Nice to see you building again, Matt. My Raptor is still one of my favorite (and most versatile) pedals.

Thanks! I love that people are still enjoying my pedals. I use my Raptor a lot too.

[ratherdashing]

Added a ground rail (grey wires) to all the switches:




Switches wired up to each other. The tuner switch is the first in line, and its output (the purple wire) goes all the way back to the main switch on the opposite end of the board. I wanted those two on opposite ends with the loops themselves in the middle.




All switches are now wired to each other. The switch panel is now complete.




Next up: the jacks!

[ratherdashing]

For those who would like to do a build like this, my big piece of advice is test your connections with a meter as you go. After each stage of wiring I always meter my connections, and make sure the signal gets routed how I expect it would be when I hit the switches. It's way easier to troubleshoot problems at this stage than when the whole thing is assembled and hooked up.

More to come today!

[JOLLY]

Nice job!!

[SrDeMaFp]

'll post a revised schematic later if someone wants to build one of these for themselves.

Yes, please do!

[Mr 9finger]

Yes, please do!

I second this! I was messing around today had a semi brilliant idea (for me anyway) that this could come in real handy! Great job man!

[ratherdashing]

Got it hooked up today, but there was a minor problem. Here's the pics to help explain.

I decided to put a 1k resistor right on the power jack for all the LED's. This turned out to be a mistake (explanation later), but I did to a good job of it at least.




Added some heat shrink to prevent it from shorting out on the enclosure or anything.




Mounted to the panel with the input jack. The panel provides a common ground for all jacks, so I wired the DC ground to the jack's ring.




Bottom row jacks mounted with leads:




Top row jacks mounted with leads:




Both sides all hooked up:




Case re-assembled (not screwed back together yet):




So, after I put it together and gave it some power, I noticed a problem with the LED's.

Let's test your knowledge of electronics! See if you can figure out: a. what the problem is, b. why the problem occurred, and c. what I should do to fix it.

I already know the answer, and I'll reveal it soon.

[everdrone]

u gonna make teh best pedalz evah!!!

[CTN]

shouldn't you have had a different resistor for each LED?

[ratherdashing]

shouldn't you have had a different resistor for each LED?

Correct! You've identified the cause of the problem. But why do I need a different resistor for each LED?

[Mr 9finger]

Each color of LED runs at a different voltage!

[ratherdashing]

Each color of LED runs at a different voltage!

Nope!

Here's a hint: it's only a problem when more than one LED is on at the same time.

[misterwhizzy]

Correct! You've identified the cause of the problem. But why do I need a different resistor for each LED?

Each one is going to draw current, so if you only have one resistor, it's going to divide the current among the LEDs. I think once you put more than one on, each one will be a bit dimmer, since it doesn't have an individual resistor to set the current.

[That90'sGuy]

Isn't 1k kinda high for resistance for something like this? I mean at 9vdc with 1kOhms we're talking amperage of only 9mA and doesn't each LED draw about 20mA? My math may be way off here, but it just doesn't add up to me. Of course, I don't claim to be an electrical engineer.


If there's a resistor at just one and the rest don't have any, wouldn't that one LED with the resistor be pretty dim and the others would be brighter because there's no resistance on the others so more current will flow through those other LEDs?

[misterwhizzy]

I took it to mean there was one node connecting all the positive terminals of the LEDs to the negative node of the draw-down resistor. That way, each would draw current proportional to its drop-down voltage or whatever it's called in those things (typically about 0.7 V, if I remember right).

[Nightburst]

I'm not sure what would happen when you just use one 1K resistor for that many LED's, I guess either they will be way too bright or burn out. For ultra bright LED's (which I assume you are using) I prefer a 10 or 12 K resistor in front so my eyes won't get blasted when I look over the pedal. I hate too bright LED's!

Anyway, nice build! Are you going to give the pedal some colour or artwork? I'd love to see it get powder coated and maybe some printing.
I know it's all about true bypass here but I think a small buffer would benefit the circuit to prevent it from popping? A good buffer is mandatory to have either in front or back of the pedal chain to keep the signal juicy. A quality buffer will not degrade or color your tone a lot!

[ratherdashing]

Each one is going to draw current, so if you only have one resistor, it's going to divide the current among the LEDs. I think once you put more than one on, each one will be a bit dimmer, since it doesn't have an individual resistor to set the current.

Ding ding ding!

Each LED draws a certain amount of current. With two LED's on at the same time the circuit should be drawing twice as much current (assuming LED's of different colours draw the same current, which they don't), but since voltage and resistance stay constant each LED gets half the current. It gets even worse the more LED's you turn on.

The solution is to give each LED its own 1k resistor. That's what I did! I'll post some photos tomorrow.

I'm not sure what would happen when you just use one 1K resistor for that many LED's, I guess either they will be way too bright or burn out. For ultra bright LED's (which I assume you are using) I prefer a 10 or 12 K resistor in front so my eyes won't get blasted when I look over the pedal. I hate too bright LED's!

Anyway, nice build! Are you going to give the pedal some colour or artwork? I'd love to see it get powder coated and maybe some printing.
I know it's all about true bypass here but I think a small buffer would benefit the circuit to prevent it from popping? A good buffer is mandatory to have either in front or back of the pedal chain to keep the signal juicy. A quality buffer will not degrade or color your tone a lot!

The LED's look fine to me with 1k.

I have no intention of painting this thing. I would have done that first. I'm just going to label it. To me, this is a workhorse pedal.

The buffer is taken care of in another box.

[ratherdashing]

I was in the Seattle area on training this week, but I'm back at the looper stuff now!

As I said there was a problem with each LED needing its own resistor. I fixed that.

First step was to remove the resistor from the DC jack. I still used heat shrink to prevent shorts.




Next I replaced the orange wires between the LED's and the switches with resistors. It doesn't matter what side of the LED the resistor is on - as long as it's in series. I used heat shrink on each one to keep things clean. Here's the tuner switch:




Other switches with the resistor in:






That did the trick. All LED's now illuminate clearly:




Brightness is the same with some off too.