Luxman L-10 integrated amplifier

General: 

This Luxman L10 amplifier was produced around 1980, its a great amplifier with outstanding specs.
The L10 gives unprecedented fine sound. Luxman L10 is an excellent product.

 

Photos:

Front ^

 

 

Interior view ^

 

Special futures:

This amplifier has 2 really separated amps and completely separated power supplies.
The L10 fits perfectly in the Luxman amp building tradition of ie. the 5C50/5M20 and C12/M12.
It has tape dubbing facility with rec-off and a double tone compensator.
It has no conventional tone amp with usual +/- 10dB tone-control, the tone amp is omitted.
It has a 2 way subsonic switch. And pre-out / main-in sockets.
Also an excellent High Quality RIAA-phono amp inside with outstanding specs.
This is one of the best amplifier Luxman ever produced. Many companies used this L10 amp as reference.
It is a myth that this amp could not drive big speakers: it drives 15" speakers perfectly.
The L10 electronic design is exactly done the way an amplifier should be designed.
The practical setup and construction is outstanding. Serviceability is good but not uncomplicated.
The total tape facilities are Japan tape-deck compatible only.

 

 

Schematic:

Click here to download the Luxman L10 service manual in PDF format

 

Modifications:

SERVICE WARNING:
When you service the Luxman L10 amp you should be aware of the fact that:
the power supply capacitors of the L10 keep the full +/- 45V = 90 V supply voltage on them when the amp is switched off,
even when completely taken off the mains supply and even after being weeks out of use !!!
These caps should be discharged by qualified service personel the proper and safe way with 100 Ohms resistors.
If you fail to respect the full & correct manual discharge of the power supply caps,
you will almost certainly damage the power amplifiers and possibly all output transistors,
improper discharge of these caps may be dangerous for your health.
The Sanken output transistors of the L10 are out of production and not sold anymore and
there is NO replacement transistor that is suitable and gives the same exceptional
performance of the Luxman L10 amplifier. Only original Sanken transistors are giving the exceptional specs.
All Luxman L10 amplifier models with different output transistors may sound well,
however do not meet the original Luxman L10 specs of Luxman.
(NOS L10 power transistors Sanken 2SC1445/2SA765 are in limited quantities available here: LTS click or mail me).

Some parts should be upgraded after many years of service:

The R417 - 10K Ohms resistor in the main amps should be replaced by a at least 1 Watt type.

Almost all electrolytic capacitors in this amp may be subject to replacement, except for the main power caps, these may be ok.
The Rifa mains caps should also be replaced. The output relays can get worn out after many years of service.

This L10 amp is worth repairing and updating. (There are many tricks that the electronics expert knows to get the most out of an L10).

Below the power supply board of a very heavely used L10, the board has suffered from heat of the power transistors on the board.
The glue that should keep the capacitors in place damaged the board at some places.
Also the acid leaking out of the old caps helped to the degradation of this board.
After the update, this board can function well again for many years to come.

If you do the restore of a vintage L10 right, you will get a unprecedented fine sounding amp, with outstanding specs.

 

DML modification:

The DML's of this amp should be replaced by discrete parts or a replacement unit as discribed on this website.
Take a look below and at the DML-page of this website and the Luxman C12/M12 page on this website for more DML-01 and DML-02 info.

 

Old broken DML-01 on the pcb of a L10 main amp.^

How the DML unit is integrated into the schematic^

the internal schematic diagram of a DML-01 looks like this:

  

DML-01 version 2 ^

A original DML-01 opened ^

 is this the way to do the replacement of a DML? No not really ^

Or this, this is the ultimate solution:

This new DML version is now available on this website ^

 

Older obsolete replacement DML-01 version 2:

Photos of the old DML-01 units replacement designed by Luxman and installed by the former Dutch distributor Audioscript in the late 1980's.
As you can see they are a little coarsely made, but they do their job fine and do not break down like the original black box original DML's.
The above units are not available anymore, there are however modern DML replacement units available, you can order them at this website!

Order the new DMLs here < click here.

 

Wrong power transistors:

On the picture above: The wrong power transistors, not meeting the specs, found in a L10 after a repair, this will sooner or later result in a breakdown of the amp.^

New LED V

New Led ^

 

Other Modifications:

Remove possible upgrade impedance amplifier boards out of the circuit, situated between RIAA- and power- amp.
Audioscript, the former distributor in the Netherlands, inserted such impedance amps equipped with two common-grade opamps,
remove this pcb in all but one situation:
Leave these boards in the amp ONLY when you use a European make tape-deck with
high impedance DIN in- & outputs, like a Tandberg or Revox, etc.

Below photos of such additional pcb, this one from Audioscript Netherlands. As you can see one of the
capacitors has exploded and spread some of its contents over the pcb and so corroding components,
requiring a repair some years later, the left IC has been exchanged, its a common grade op-amp.
PCBs like these do not meet the quality standard of the L10 amplifier at all, so take them out of your L10.
Or seriously upgrade these amps, but only when you really need them. V

 
Bad pcb boards ^

 

Luxman:

^ Bi-amping with a electronic x-over using L10 + C12/M12 and on top the T12 tuner: Luxman walhalla ;-)

 

 

Sound:

These series of Luxman audio components soon got legendary by their outstanding build quality and exceptional good quality sound, even after decades of service.

© Hans Hilberink - ON9MMK/PE1MMK ® - Last update: 25-10-2019.