It’s worth knowing that in the early days of modular synthesizer development, there were different and to some extent competing approaches based on different philosophies of electronic music production.
These two different approaches to modular design stem from Bob Moog (East Coast, NY) and Don Buchla (West Coast, CA) in the 1960s and are important to synthesizer design due to their philosophical and technical approaches. As summarized in this Nerd Audio post:
West Coast Synthesis revolves around the idea of Additive Synthesis, Wave Shaping and Dynamic Depth FM (Frequency Modulation) Synthesis.
• Features Low Pass Gate (LPG)
• Essentially a Voltage Controlled Filter Amplifier (VCFA)
• AD/AR (Attack-Decay/Attack-Release)
• Unique Touch Based Sequencer
• Experimental Sequencing Capabilities
East Coast Synthesis revolves around the idea of Subtractive Synthesis oriented around a filter that removes specific frequencies to get the desired result.
• VCO-VCF-VCA with ADSR Envelope Generators.
• Simple Waveforms such as Sawtooth, Sine or Square
• Designed to be utilized by a black/white keyboard
• Classic Step Sequencer
More historical background can be found in The Basics of East Coast and West Coast Synthesis (Reverb.com).
For a more scholarly discussion, check out The Social Construction of the Early Electronic Music Synthesizer by Pinch and Trocco (1998).
Finally, here are some videos which offer listening opportunities along with further explanation of these different approaches.