GML 8304 4-Channel Microphone Preamp with 8355 Power Supply – Alto Music
GML 8300 Mic Preamp - YouTube
Model 8304 – George Massenburg Labs
GML 8302 Two-Channel Mic Preamp w/ PSU #M0047 (Used) - Vintage King
Spheremusic - Bargain or auction detail
Spheremusic - Bargain or auction detail
GML 8302 2-channel Microphone Preamp | Sweetwater
GML 8302 Two-Channel Mic Preamp w/PSU #M0988 (Used) - Vintage King
GML 2032 Mic Preamp / EQ | Funky Junk
GML 8300 2ch Transformerless Mic Preamp w/PSU Massenburg Labs  | eBay
GML 2020 Mic Pre / Compressor / EQ / Channel Strip Massenburg Serial 118 | Reverb
Preamplifier | R-Amps
GML 8302 2-channel Microphone Preamp | Sweetwater
GML 8302 2-channel Microphone Preamp | Sweetwater
Model 2020 – George Massenburg Labs
GML 8304 4 Channel Mic Preamp including 8355 Power Supply | Reverb
GML 8304 Series II Four-Channel Microphone Preamp - Vintage King
GML 8304 Series II – Sonic Circus
GML 2032 - Model 2032 - George Massenburg Labs 2032 - Vintage King
GML 8304 | Studio Economik | Pro-Audio Recording Equipment | Montreal, Canada
8304 - GML 8304 - Audiofanzine
