Audio equipment
Application of mica capacitor

Acoustic MICA Geometry

The application example of Marantz Model 7c
(SOUNDARIES)

The model 7c PHONE jack RIAA equalizer uses the following two capacitors. 5600pF and 1600pF (red part in right figure). The original capacitors used in the Marantz7c use film-type capacitors with very high immunity. This part uses Matsuzaki Electric's acoustic capacitors that use ruby ​​mica, which is considered to be higher quality in terms of tone and transparency than conventional silver mica capacitors.

Acoustic MICA Geometry
Acoustic MICA Geometry

The orange capacitor is for 5600pF.

Acoustic MICA Geometry

Two brown capacitors near the 560k resistor are 1600pF (1500pF).

Acoustic MICA Geometry

After replacing the capacitor.

Acoustic MICA Geometry

Two replacements of 1600pF.

Acoustic MICA Geometry

Replace 4 Ruby Mica inside.

<References>

SOUNDARIES ( Last viewed date : 12/7,2019)
http://soundaries.com/2016/06/spec-ruby-mica-in-model7.html/

The application example of replica of Marantz Model 7(Jeff's Place)

A modified Marantz Model 7 replica. When the Marantz Model 7 appeared in 1958, the main playback sound source was analog LP and FM broadcasting, so the tone amplifier receiving the Phono EQ output did not need to extend the bass range.

Acoustic MICA Geometry
Acoustic MICA Geometry

In order for the bass to be expressed naturally, a new capacitor must be installed. Our Ruby Mica is a breakthrough in sound quality thanks to its outstanding characteristics.

Acoustic MICA Geometry

Jeff's article shows an expanded schematic of this part of Marantz Model 7.

Acoustic MICA Geometry

The sound quality has been greatly improved as a result of changing from 0.01 MFD to 0.016 MFD. By simply replacing a few parts, the sound quality was greatly improved, and the sound was closer to realistic sound. Jeff also mentioned in the article that he strongly recommends his comrades who are Marantz Model 7 enthusiasts.