P h o n o   r i a a   p r e a m p l i f i e r   f o r   M M  c a r t r i d g e

model:  T h e   P h o no - M M P

 

Genuine all tube design

The Phono M M P   is a complete phono riaa all tubes preamplifier that operate on class A without any local or total feedback circuity.  This preamplifier provide the right amplification and equalization to standard riaa at the phono moving magnet cartridge signal. The circuity use three tubes, two ECC-81/12AT7 for moving magnet input (as passive riaa equalization) and one ECC-81/12AT7 for output as cathode follower adaptor, all tubes are accurate selected at very low noise operation . A innovative circuity designed from enginner of Lector make  the control of the bias by optical devices for clear sound and phase control. A solid shielded cabinet as hi-tickness off 1,5 mm reduce interference from emc field for a better signal to noise ratio.

For to built this riaa phono preamplifier we have design the circuit with minimun capacitors on signal path (only 2 as polypropilene grade) hi-reserved energy power supply with capacitors filter located near to active device.

 

C O N V E N I E N C E    and   O P T I O N A L

  • Cherry wood veenerede for lateral side panels (optional)

  • Low noise selected tubes as  12AT7 (3 unit as series)

  • Hi-shielded metal frame chassis

  • Hi-quality toroidal power supply transformer

  • Cathode opto circuit for 12AT7 riaa moving magnet

  • Black ash "piano finish" plexiglass front panel as 8 mm tickness

  • passive riaa equalization by precision components

 

S P E C I F I C A T I O N

(all measure by Audio Precision System One @ 230 V ac)

Type

 MM all tube step-up preamplifier by 12AT7

Input

MM at 47 Kohm  100 pF

Gain

47 db (Mm)

Frequency Response

20 - 50Khz      +/- 0.3 db

Noise ratio

69 db ( A )

Output Impedance

290 ohm

Voltage available

Power supply  @: 230-240 Vac / 110-120 Vac / 100V ac all voltage at 50 - 60 Hz

Overall Dimension and weight

400 x 85 x 300 (L x H x D mm) for main unit

weight  9 Kg  net

 
 
 

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