Hi all,
Let me first explain what I am trying to achieve. I would like to combine 2 variants of the Big Muff. I want to use a potentiometer to dial in the effect BM1 vs BM2. Therefore, I use the JMK paralizer schematic. I also want to dial in the original guitar sound vs paralizer effect sound. Therefore, I use the JMK panner schematic.
So in summary:
(https://i.postimg.cc/nXY6DVhM/schematic.png) (https://postimg.cc/nXY6DVhM)
JMK panner schematic: http://jmkpcbs.com/wp-content/uploads/2014/03/Panner.pdf
JMK paralizer schematic: http://jmkpcbs.com/wp-content/uploads/2014/10/Paralyzer.pdf
My question is: Can I just combine these schematics or do I need to adjust something to it? Both BM circuits starts with a diode (1n4001), a large capacitor and a R=1M. The Paralizer and Panner also have an 1n4001 and a capacitor in front. Are these still needed in the BM schematic?
(https://i.postimg.cc/bDhrR9Xp/Basic-BMP-schem.png) (https://postimg.cc/bDhrR9Xp)
Thanks!
Sofia :)
Quote from: Sophia2001 on December 31, 2023, 09:21:09 AMBoth BM circuits starts with a diode (1n4001), a large capacitor
No, those are not in the signal path, they're for polarity protection and filtering, respectively.
Quote from: Sophia2001 on December 31, 2023, 09:21:09 AMI also want to dial in the original guitar sound vs paralizer effect sound. Therefore, I use the JMK panner schematic.
The JMK panner has a 100K input impedance, which is a significant load for passive pickups. I would use a non-inverting buffer as the first stage instead of the inverting one.
Big Muffs have volume pots so you can just use a passive mixer (two resistors) and set their balance by turning one up and the other down. Does the convenience of having a single blend pot justify building an active circuit? You could also get away with a passive blend.
Thanks FiveseveN,
I realize that my questions are maybe a bit stupid...? My knowledge of schematics is limited. I do know how to read/breadboard them, but I do not really understand what is happening and what the function is of each component within the schematic.
Both JMK Panner and Paralizer start with this bit of schematic:
(https://i.postimg.cc/5H3z5s9V/jmk.jpg) (https://postimg.cc/5H3z5s9V)me
1) By using this schematic only for the panner (first in the row), it will be sufficient? I could remove this part of the Paralizer and the 1n4001/capacitor of the BM?
2) Could you explain what you mean with a non-inverting buffer instead of the 100K?
3) for the active vs passive blend: I would also like to experiment with an BM and OC2 combination. The OC2 does not have an volume pot so an active blend is needed, correct?
Sofia :)
1. That snippet is also for filtering, polarity protection, plus provides the mid-supply reference for op-amp biasing (https://eng.libretexts.org/Bookshelves/Electrical_Engineering/Electronics/Operational_Amplifiers_and_Linear_Integrated_Circuits_-_Theory_and_Application_(Fiore)/04%3A_Basic_Op_Amp_Circuits/4.03%3A_Single_Supply_Biasing). If you're going to build the Panner and Paralizer in a single box then you don't need to replicate it, one can power both circuits. I don't get what the Muffs have to do with it though, are they also going in this same box?
2. Voltage follower (unity buffer amplifier) (https://en.wikipedia.org/wiki/Operational_amplifier_applications#Voltage_follower_(unity_buffer_amplifier)). Compare with Inverting amplifier further up the page.
3. The OC2 doesn't have a volume pot, it has three: one for the dry signal, one for 1 octave down and one for 2 octaves down. Essentially the same approach to mixing as I suggested.