Different Zombie chorus schematic

[Otsismi]

I recently built the zombie chorus from the pcb on solderman's site. I wired it all up and get sound but it doesn't sound like chorus. Starting over with another bigger thicker trace schematic.

On this one, where do the offboard components connect?

[merlinb]

#nolinktoschematic lol

[closetmonster.]

#dohashtagsevenworkinforums ?

guess we'll find out

[Mark Hammer]

Make sure that whatever layout you use employs one dual op-amp for the audio and a second one for the LFO.  This will provide more opportunity to prevent and reduce audible LFO "ticking".

[garcho]

it doesn't sound like chorus.

Does it sound like something? Or is it straight up clean? Or straight up zombie? I don't know what that means.

If you read this, you'll get it figured out.

#idontknowwhatthatmeans

[Otsismi]

Image upload failed.

When I say something I mean I'm getting output from the guitar but it is fuzzy and distorted and compressed.

[garcho]

That looks like one of Perrow's sexy layouts. Judging by the use of commas instead of decimal points, it's a European forum member, anyway. If it is Perrow's and it says verified, that's the case. So, chances are cold solder, miswiring, you're BBD is toast, misreading of those miniscule resistor color codes, static electricity destroyed your CMOS chip, etc. That's why I put that link to the troubleshooting guide. If you go through the steps earnestly, there's no way this won't get figured out. The folks on this forum could probably, collectively build a rocket ship. I'm not joking.

[garcho]

Here's the schematic from the guy who designed it.



He lists the op amp as a TL064. This is a quad op amp, or 4 op amps on one IC. It doesn't matter that you're using two dual op amps - a TL072 and a TL062 - they're basically compatible with the TL064. Either way, you have 4 FET op amps, that's what matters. So, that's not why you're having issues. It's something else. Do you have a voltmeter, or a digital multimeter (DMM)? Take some voltages at least and post them here.

You can figure out the off board wiring with this schematic. For instance, the signal input is what connects to the 1N capacitor and 10M resistor, on the bottom of the right side of your layout, when looking at the traces. This is the top left side of the schematic. The other lead of the capacitor is connected to the non-inverting (+, pin 3) input of the TL072. Or another example, the 'rate' potentiometer is connected to the 100K resistor and pin 3 of your TL062, the 4,7M resistor, and the 4,7K resistor (the 3 nodes on the top left, just to the right of the single node). They appear on the PCB left to right in the same order you wire them to the potentiometer when the shaft is facing away from you (3, 2, 1).

[Mark Hammer]

This is old history, but you will note the absence of a bias trimpot.  The BBD is biased through the first op-amp, but apparently this only happens if its a TL062.

The LFO will generate a tick, as a result of the square wave it starts out with.  The tick can be removed by using a low current opamp for the LFO, such as tl062 or 022, or lm358, and decoupling that chip with a 10-100ohm resistor to pin 8 (v+) and 10uf cap from pin 8 to gnd. You can't decouple the LFO from the restofthe circuit when using a quad opamp like a tl064.

[garcho]

It doesn't matter that you're using two dual op amps - a TL072 and a TL062 - they're basically compatible with the TL064.

You can't decouple the LFO from the restofthe circuit when using a quad opamp like a tl064.

I guess I was referring to this:

When I say something I mean I'm getting output from the guitar but it is fuzzy and distorted and compressed.

Either way, OP is referring to the layout with a TL072 and a TL062, so LFO ticking is probably not what's causing the "fuzzy and distorted and compressed" sound, no? Sorry if I implied there were no consequences to using a quad op amp, just trying to prevent a misunderstanding.

[Otsismi]

This is op. this is the circuit I built. The reason I asked about the other is because I'm worried about this ones validity for several reasons. This is the circuit I'm getting the distorted sound from

[closetmonster.]

Could just be a wrong resistor value somewhere in the circuit. When I was messing around inside my EHX Small Clone, I mistook a 100k resistor for a 10k and it worked, just came out garbled.

[Otsismi]

Well some of my traces have also started to lift off of the board which I think is a result of poor solder technique so I wouldn't be surprised if one is broken. I just want a simpler design. I'm a beginner and need more somple

[Otsismi]

Thinking the little angle might be better for me

[closetmonster.]

If this is one of your first builds, it may be a little advanced. I'd start off with a simpler Fuzz Face circuit or boost, then come back to this.

The problem with your build is most likely something basic.

Any way you can take a picture of the build? That might help.

[garcho]

little angle

Fantastic pedal, I use it frequently, but only marginally easier to build if at all. If you're new to this, find something else with less components and offboard wiring.