DIY - Look McIntosh for Passive Preamplifier on vintageshifi.com

The outline of this DIY.

Creating of a passive preamplifier on the basis of the previous attenuator but with an addition of two vu-meters and a McIntosh look. This a esthetic favours the production of a silkscreen on front side with a professional side. Admire this look, it's DIY! No breath, no noise disturbs listening to the QUAD 405. Plan a neat wiring of the masses. The potentiometer is in the middle of the cabinet to avoid disturbances of the power supply.

1

Addition and Creating a 12 volt regulated power supply with a LM338K. This 12 volt power supply supplies all relays, backlight and vu-meter lighting and circuitry. Wiring the preamplifier with a switch to be able to select the mode with or without attenuator.

2

Making a loudspeaker connection between the preamplifier and the QUAD 405 power amplifier. Cable Connection and Brand cards: NEUTRIK NL4MP. This cable is necessary for the operation of the vu-meters and the delay of the loudspeakers.

3

Creating a 12 volt backlight as well as a timer for the speakers. (aliexpress.com)

Plug Speakon NEUTRIK Female NL-4FX

amplifier Quad 405

Speakon chassis socket NEUTRIK Male

Speakon plugs for professional HP connections. 4 poles.

amplifier Quad 405

The special ELEPHANT SPM4025 combi cable is one of the outstanding models designed specifically for the woofer and surround systems. The SPM4025 consists of a total of 4 conductors with a section of 2.5 mm. Due to its wiring mode similar to that of hi-fi drivers, the SPM4025 reproduces absolutely pure highs and faithful and dynamic bass.

ADVANTAGES:

Transmission of signals without losses, thanks to special constitution souls Very flexible, suitable for stage installations (PVC version only), easy to roll up Compatible with current Neutrik-Speakon connectors Easy transformation thanks to the excellent insulation and the numbering of the souls

USE:

Professional acoustic equipment / output amplifier Surround and woofer systems Fixed installations for buildings.