DIY - Look McIntosh for Preamplifier
Plug Speakon NEUTRIK Female NL-4FX
Speakon chassis socket NEUTRIK Male
Speakon plugs for professional HP connections. 4 poles.
Creating a 12 volts regulated power supply with a LM338K.
PCB Transformer 12 volts Gerth PT481201F.
Circuit of the attenuator for QUAD 405
Passive attenuator schematic for QUAD 405. (click)
Timers for the speakers in 12 volts. (aliexpress.com)
Speaker break with 12 volts relay. (aliexpress.com)
VU-meters Circuit in 12 volts