General:

Generously build power amplifier with true 2x 100 Watts RMS of output power, issued in 1977.

5M20 with 5C50 ^

 

Special futures:

The 5M21 has power meters on the front panel.

The 5M20 & 5M21 are full completely separated 2x mono amplifiers, resulting in the unprecedented channel-separation.

5M21 ^

 

User Manual:

Click here to download the user manual in PDF format

 

 

Schematic:

Click here to download the service manual of the 5M20 in PDF format

 

Top 5M20 without cover ^

 

5M21 ^

 

Modifications:

The amplifier can be updated by checking all power rail- and protection-pcb's and all capacitors on these pcb-boards.
Many capacitors may be out of specs. Check if the DML units are the new units we provide on this website.

Attention: full 120 Volt and 140 Volt is on the power rails of the transistors, you can suffer electric shock,
Also be aware of the full supply voltage present on the power rails and main power capacitors:
even when the amp is switched off and even if the amp has been off for a longer period of time!
Discharge the caps as instructed on the page of the Luxman L10 amplifier on this website.

Old DML units that need to be replaced ^

 

The famous new DML-01 units in place, these 'Ultimate Quality DMLs' are only available here on this website. Order now to update your amplifier ^

 

Input amplifier update solderside ^

 

Updated protection circuit using Sanyo caps ^

 

Updated +/- 87 Volt power-rail section. ^

 

Input Capacitors replaced, taking away the tantal C's: the high grade red Wima polypropylene fit well: small and first quality. ^
 

Leaking 100V capacitor in the 87 Volt power supply of the 5M20, this cap should be replaced ^

 

Power supply big capacitors ^

 

Toshiba driver & Sanken power transistors, NEC drivers were also used in many 5M20's ^

 

Sound:

Exceptional, unprecedented and powerfull sound, one of the best amplifiers ever made.

I drive my updated 5M20 with my Luxman 5C50: a great couple.

 

Back top with typical heatsink ^

 

Power amp section with the Sanken power- and NEC driver- and Sony predriver- transistors and the big heatsinks ^