Help with a simple circuit please!

Can someone help me please. I have modded a 202 like this.

I’m trying to make mini mixer to run waveforms out of the 202 and back into the filter.
I wired up 1 socket to a pot then another socket. I checked this and it worked as a volume for a pot for one wave form.
I wired another socket to a pot then the pot to the output socket of the first part. Non of it works now. What am I doing wrong?

Like this

  • Ground the sleeve of the output jack.
  • If point A is at 5V and point B is at 3V, connecting them won’t make 4V. It will create a short. The simplest thing you can do is connect 10k resistors from the wiper of each pot to the same point on the output jack. Now, some summing is happening… with some attenuation too!

Found on the web:


Can you recommend anywhere to learn about this kind of stuff. I really enjoy building kits/modifying equipment from instructions but I have no understanding of how it works. Just how to check for connectivity/resistance/voltage

There are quite some tutorials and online classes out there. Try understanding other circuits while troubleshooting - personally i learned a lot today while searching for an error in this thingie and i finally found that i had accidentially ordered 330K instead of 330R 1x8 Resistor networks…

Matt from just wrote a blog that may help. It led me to a lot of great info. iTunes U is great as well.

Cheers! :slight_smile:

Thanks alot guys, got hold of the Art Of Electronics book. Looks pretty in depth and heavy but I’ll give it a good stab.

I don’t recommend you to start with this book - even I haven’t finished digesting it. I must have read some chapters 3 or 4 times and I still have “ah-ah” moments at each read. It’s that dense. It is a good book, but is not intended to be a tutorial teaching things form scratch. It is organized by topics rather than according to a progressive learning curve.

A book I can recommend is “Operational Amplifiers with Linear Integrated Circuits” by Stanley. It is very “textbook-ish”, in the sense that it has a gentle gradual curve. It has maths inside - mostly high-school level things - but you can’t avoid it anyway. Don’t get fooled by the people who use AoE as an example showing that you can do electronics without maths. AoE is mostly about the practical details - everything else you need to know once you have figured out the theory and you want to get things to work. It is not a substitute for the theory.

Nice one. Ordered off Amazon £3.50 :slight_smile:

Got it… just had a quick look. Im going to give it a go but then I think Ill have to be demoted to “Electronics For Dummies”