The Vanderveen MCML05 Vanderveen valve pre amplifier
 
 

The MCML05 is the new all valve pre amplifier DIY kit, designed by Vanderveen and manufactured by Amplimo. Two goals are met in this design: uptime sound quality and very simple easy construction. We made many prototypes, tested them in every technical aspect, and of coarse they were profoundly evaluated in many listening tests. We paid attention to the smallest details and now finally the design is approved for production. The kit is for sale now and here we give a small introduction to the concepts used. A profound and complete description of all schematics is given in the Dutch language book by Menno van der Veen "High End Buizenversterkers 2", available at Segment bv. We hope that an English translation of this book will be available soon, the German translation is already available. The Dutch Language construction manual gives even more precise details and literature. We now are spending much attention to the translation of this manual to the German and English languages. Stay in close contact with Amplimo for availability.


Above picture clearly shows the many in and outputs of this pre amplifier. The schematics below gives more insight.



Two turntable inputs are present: for MC and MM. The special MC-10 step up transformer is applied. You find a complete description of this transformer on this site, section transformers. The MM pre amp uses 4 triodes per channel with passive RIAA correction in-between. The switch S-2 on the back side selects between MC or MM.




The schematics of the MM pre amp section is shown follwoing.

The input selector switch S-3 selects between the available inputs and is followed by the balance and volume controls.



The selected and controlled audio signal is amplified about 5 times in the line-stage.




At the output of the line amplifier a relays selects between main output and headphone. This relay is activated by the headphone plug.

The power supply of the MCML05 is very special. The filament supply starts at zero Volt and slowly increases in about 15 seconds to the final stabilized supply voltage. The high voltage supply uses 30 seconds to get to its final value. The start up procedure is fully automatic and prevents damage to the precious pre amplifier valves. There is no need now for a separate stand by switch. The supply itself fully protects and gives the best start up procedure ever thinkable.


The next photo gives a complete overview of all sections and PCB boards.

The pre amplifier is designed for the UL40-S2 and the UL40-S2p. However, every other good power amplifier can be used, like the PR20HE-S2 (see the description on this site). The pictures following give two examples how the pre and power amps can be combined.



The MCML05 DIY kit can be ordered at Amplimo (www.amplimo.com) or at Vanderveen (this site www.mennovanderveen.nl, go to "order"). All internal audio wiring is high quality special silver wire. We think that this pre amp needs no further modifications, but time will teach us. Maybe Menno van der Veen finds some nice improvements, which will immediately be published on this site.

SPECIFICATIONS MCML05 VALVE PRE AMP

MCML05

Valve pre amp

Design

Menno van der Veen

Manufacturing

Amplimo b.v.

Inputs

4 x line;

phono: MM-MC selectable

Line-input

100 kOhm; 250 mVrms nominal; 10Vrms maximal

MM-input

47 kOhm; 4,7 mVrms

RIAA within 0,1 dB

MM-headroom

+ 45 dB @ 20 Hz

+ 47 dB @ 1 kHz

+ 33 dB @ 20 kHz

MC-input

470 Ohm (selectable)

0,47 mVrms

-3dB Frequency range

1,6 Hz to 71 kHz(min)

to 360 kHz (max);

depends on volume setting

Output

3,5 kOhm; 1 Vrms nominal

11,3 Vrms max in 100 kOhm

6 Vrms max in 10 kOhm

Output record

250 mVrms nominal

or selected source level

Hum-Noise

-128 dBV (C-curve)

Headphone

100 mW in 30 Ohm

Valves

4 x ECC82; 2 x ECC81

Mains

180-240 V @50/60 Hz

90-120 V @ 50/60 Hz

Power unit

Automatic start filament in 15 s

Automatic high voltage supply in 30 s

Stand-by

Not needed for, automatic start up procedure

Dimensions

30 x 30 x 9 cm

DIY-manual

Very complete; 64 pages with many figures, extra literature