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Pre phono 1 - Marantz 7
May 13 st , 2008 

 
INTRODUCTION

Searching on eBay I have found this interesting project of phono preamplifier kits by JLWtools so I will start to test this before design a my circuit also to get a first reference.

DESIGN LS37

This kit is based on the original schematic of the Marantz 7, a real classic in audio history.

KIT PARTS

  

The LS37 Phono pre-amplifier kits, the complete system included a main photo board, a power regulator board and a power supply transformer.

The unit is capable to take the MM and MC phono input the 4 stage design ( cathode follower-  gain 1st, gain 2nd  and final cathode follower). Design employ 4 pc of 12AX7.
 

Selective high grade Dale/AB resistor and the polypropylene capacitor, large size filter capacitor, Round core transformer etc, all the part are design and made to meet high end audio standard with fraction of the price.

All you need is a chassis to assemble the kits, or your can even mount on bear board.

SCHEMATIC

Some measurement with the Clio system by Audiomatica with 9.5mV input.