Need help understanding circuit

[caspercody]

Hello

I want to make a pedal out of the Nobel's Sound Studio (none of the modulations) and I am having trouble determining where the clean, compressor, and outputs are coming from the circuit. I have attached some cleaned up schematics, hoping they will help someone show me where the outputs connect to the eq sections. I can see how the (2) eq sections are connected, I am having issues seeing where the normal guitar tone would come from, compressor output is, and the overdrive section. Here is how I think the rotary switch works for selecting the mode:

S1-F - 440 HZ
S1-E - normal
S1-D - clean A
S1-C - clean B
S1-B - overdrive
S1-A - distortion

Here is description from Nobel of the sounds from each mode:

[garcho]

Signal input is IC101A, compressor output is IC101B, clipping is 102A.

[caspercody]

Thanks!!

Is the compressor output from C508 (150nf)?

Do you know what Q102 does, with diode D108? Is it sending a clean signal back from R103? If you look at the rotary switch and at S1-B, and S1-E contacts, there are (3) positions that are connected together that get a signal from R102, and R103. This section of the schematic is confusing to me??

[garcho]

Do you know what Q102 does, with diode D108?

Are you familiar with how a CD4066 works? Follow the all the connections from the cathode of the diode throughout the circuit, where do they lead? What do they all have in common? Hope you don't mind working with clues

[garcho]

Is the compressor output from C508 (150nf)?

There are two outputs from the compressor block - one goes to the clipping stage, one goes to output, what they're calling clean modes. Sometimes it's more helpful to follow the signal backwards from the output. Compressors can be a bit odd looking at first because they come in two main flavors - feed forward and feed backward. It has to do with the point at which you tap the audio signal for the control signal.

This section of the schematic is confusing to me??

These type of schematics - wiring diagrams - are a bit confusing for everyone! They're made with the intent to show every single component and connection, more about making a PCB and a serviceable product than clearly and quickly understanding how it works.

The switching and CD4066 are what make this circuitry look so confusing, try redrawing the schematic in only one mode.

[Vivek]

I'm working with a bunch of good folk

Last month, we breadboarded and then made SMD modules/PCB of ROCKMAN X100's

A) Compressor, Gain Stage, EQ1 and EQ2
B) Chorus
C) Mixer and LM386

Since Nobel and Rockman are very close, it appears we are both doing similar projects !

[caspercody]

I have the X100 done and working on my breadboard. I need to create a vero board next, but I am just doing the compressor, gain stage, and Eq sections.

They both use the same EQ sections. The X100 uses a hard clipping gain circuit, and the Nobel uses a soft clipping gain stage. I am just going to breadboard the compressor, and gain stage of the Nobel.

I am just scratching my head on the switching to get where the different modes (normal, cleans, overdrive, distortion) outputs come from. The only outputs I see are from S1-A, and S1-D. There is a output from IC105 (see original schematic), but I think this is the 440hz signal. I just do not see the difference in signal for the normal mode and clean 1, and the distortion mode and overdrive?

I added a schematic that I highlighted (3) signals that I am not sure of. The yellow is a switching circuit, i believe. The green only happens in the clean 1, clean 2, and distortion modes. Blue i have no idea.