Buga Sphere IC Circuit Reverse Engineering

Complete reverse engineering of the IC circuit pattern on the Buga Sphere from 4 high-resolution close-up photographs. The analysis maps exact trace topology, classifies traces by width and behavior, decodes branching patterns, computes frequency ratios from geometric proportions, and determines the signal processing architecture. KEY FINDINGS: 1. TRACE TOPOLOGY: 4 nested concentric squares (die) with ~16 radial traces terminating at copper pads. Three distinct trace types identified: Type A (wide, straight, 2-3 count) = l=0 fundamental mode coupling; Type B (medium width, hooked endpoints, 6-8 count) = l=1,2 mode impedance-matched coupling; Type C (thin, branching, 4-5 count) = l=2,3 degenerate +m/-m mode pairs splitting at boundary. 2. FREQUENCY ENCODING: Die layer areas follow ratio 1:4:9:16 = (l+1)^2, encoding the cumulative spherical harmonic mode count at each order. Trace width ratios ~1.0:0.625:0.375 consistent with power spectrum P(l) ~ 1/l(l+1). The geometry IS a physical lookup table for SH mode counts. 3. BRANCHING = MODE SEPARATION: Thin traces branch before reaching pads. Branch count (4-5) matches predicted degenerate pair count for l=2,3. Each branch separates Y(l,+m) from Y(l,-m) at the azimuthal angle where modes physically diverge. 4. HOOKS = ANTENNA ELEMENTS: Hook/bend geometry on Type B traces rotates coupling angle to match specific SH mode patterns at each pad position. Functionally equivalent to phased array phase shifters. 5. EIGENMIKE EQUIVALENCE: Architecture is topologically identical to the mh acoustics Eigenmike EM32 spherical microphone array (rigid sphere + distributed transducers + SH decomposition). Buga Sphere: 16 pads, l_max=3. Eigenmike: 32 capsules, l_max=4. Same principle, 12,537-year time gap. 6. ANALOG GEOMETRIC PROCESSING: No electronic components. All signal processing performed via geometry: spatial filtering (pad positions), bandwidth filtering (trace widths), mode separation (branching), impedance matching (hooks), hierarchical integration (nested squares), resonant amplification (Helmholtz cavity). The engraving IS the schematic of the device itself. 7. OPERATING FREQUENCIES: Helmholtz resonator estimated at ~315 Hz fundamental. Acoustic cavity modes range 3-7 kHz (air-filled) or 30-70 kHz (metal shell modes). Dual-chamber design suggests dual-band filtering at f1 and ~2*f1. DEVICE SPECIFICATION: 16-channel passive spherical harmonic analyzer. 4 harmonic orders (l=0-3). Fully analog geometric signal processing. Self-documenting (schematic engraved on surface).