Here is what we did: Transistor Gain 1. Changed the 3 33k resistors in series connected to BBD output, to 7.5k each. Op Amp 2. Changed resistor from 47k to 120k at pin 1 output to inverting pin 2 3. Changed resistor from 47k to 91k at pin 1 output to inverting pin 6 I dont understand why we had to c...

...Its not working now, again... It is the above issue again? As a side note I can't get why drill a vintage enclosure when it's easier swap a connector on the cable... No, he had added some more resistors in parallel with the output from the sad, they show up as 3 33k resistors on the schematic wi...

update: We made a few mods to the pedal before my professor started playing with the input bias. He'd previous moved it and didn't put it back, so once the bias was set the pedal came to life. Here is a short video of me playing while the pedal was working. https://instagram.com/p/3SdCjXgWK-/?taken-...

What waveform are you feeding? It's easier to debug if you apply a sine waveform... if you did it already, then there's a huge distortion ratio... Waveform is clipped asymmetrically, it may be a bias issue, otherwise check signal (100mV must be enough) at 1st op amp output, and follow it throughout...

Here's another update I ran it threw the scopes again. I connected a tone generator and sent a steady tone to the pedal. I used an oscilloscope to monitor the signal. I am getting modulation on the tone and it seems to work properly, but only with the tone generator. soon as i plug in the guitar the...

To keep the same mix the equal increments part still applies, just a bit trickier to work out the values now. The schematic is close enough, unless you wanted to clone the pedal (and unless you happen to have a supply of SAD512D...) not much point in tracing it out that I can really see. Before you...

No, to increase the output level, decrease the values of the 2 x 47ks going in to the output opamp inverting pin in equal increments. Thank you Looking at the schematic I see where you mean, but when I look at the board the first 47k is actually 85k. Looking at other mini chorus pedals it is the sa...

Could the drop in volume be attributed to the voltage?
The SAD512d datasheet says that it requires 15v to operate?
I'm currently trying to bring one of these back to life. I'm building a power supply for it and fixed a capacitor that was on backwards.
I still have not been able to get it to work.

Thank you.

I am currently building an DC power supply for it. I just need to make sure its ok to build it for 12v.

Hello I'm currently trying to repair a DOD 460 Mini Chorus and in my research I noticed that the SAD512d requires 10 volts minimum to operate properly and a max of 15 volts. But the printed information on the pedal suggest it only requires 9v. Does anyone know how this is possible? I hooked up the p...