Classique – Phono Valve Preamp Amplifier With Passive RIAA Using 12AX7 / 12AU7 – DIY Kit


Checkout the WHITE PAPER for the Classique – 12AU7 12AX7 Phono Valve Preamp Amplifier With Passive RIAA – DIY Kit.

We Love Vinyl Too…

Let It Spin!!!!!

And we hope all vinyl lovers will be excited about this new kit.

This is an all-valve DIY 12AX7 and 12AU7 phono amplifier kit that enables you to use your moving magnet record player with your integrated amplifier.

Similar concept to all designs in our Classique range, this DIY phono amplifier uses traditional design and topology which have been used and tested for many decades. It is powered by two 12AX7 valves for passive RIAA equalization and a single 12AU7 valve as the buffer stage. You will only need one phono PCB per amplifier to power both left and right channel.

The complete phono preamp amplifier kit includes (optional) an aluminium mounting plate which has the same dimension with other kits in the Classique range and this makes it compatible with the same wooden enclosure.


SKU: KIT2 Category: Tags: , , , ,



  • Common cathode class-A gain stage with no feedback, passive RIAA equalization and cathode follower buffer stage
  • 2 x 12AX7 for RIAA correction and 1 x 12AU7 for buffer stage
  • Cartridge Compatibility: Moving Magnet
  • Input Impedance: 47k ohms
  • Output Impedance: 322 ohms
  • Gain: 39 dB gain @ 1kHz
  • Distortion: <0.05% @1kHz
  • Equalization: RIAA +/- 0.5 dB, 40Hz to 30kHz (measured)
  • Regulated 12VDC heater power supply elevated to 90V
  • Current draw: 24mAmp at 300VDC
  • Classic Dale grid resistor
  • Reverse-able main Phono amp PCB. Components can be soldered on the same side as the valves OR on the opposite of the valves. This feature enables builder to mount the board with valves outside chassis OR valves being inside of the chassis.

Documentations / Downloads

The Components

Please note the list below is the complete list for the kit. What you get will depend on the kit ordered.

  • 1 x main power transformer – locally made
  • 1 x integrated power supply PCB and components (for B+ and heater filament)
  • 1 x phono amplifier PCB and components (only one piece is needed for stereo channel)
  • 1 x mounting plate (3mm aluminium)
  • All screws / nuts / bolts / spacers
  • Carling Technologies double pole switch
  • RCA input/output terminals
  • IEC power socket with with internal fuse slot

The Kit

There is a number of different kits that can be purchased here, depending on your requirements. The simplest kit, Kit A is the PCB and components only, where you will have to purchase everything else.

Please also note that valves (tubes) are NOT included in any of the kits. You will have to source 2 x 12AX7 and 1 x 12AU7. These valves can be purchase from our shop too.

  • Kit A = Phono PCB + Components – main phono amplifier PCB and all electronic parts and components (you supply transformers and power supply boards)
  • Kit B = Kit A + Integrated Power Supply PCB (includes all electronic parts and components – you supply 2 transformers)
  • Kit C = Kit B + 2 transformers
  • Kit D = Kit C + mounting plate + wooden enclosure + switches + RCA terminals + IEC power socket + nuts/bolts/stands/washers (this is the complete kit)

Audio Analysis

Graph below shows the measured frequency response tested using 2 x Electro Harmonix 12AX7 and 1 x Electro Harmonix 12AU7:

Measured frequency response of the RIAA correction.
Measured frequency response of the RIAA correction.


This product is sold as a kit, which means that buyer would have to assemble all parts. Printed circuit boards (PCB) are not populated so all parts will have to be soldered onto the PCBs.

It is assumed that buyers would have the knowledge of:

  • soldering
  • assembling screws/nuts/bolts
  • highly skilled and knowledge of high voltage electric circuits and parts
CALEDONIAN AUDIO will take no responsibility on any injury or death as a result of the work conducted to assemble this kit. Please make sure that you know what you are buying and handling. If you have never done any electric and electronic work before we would strongly suggest that you consult us before buying this kit.

Additional information

Weight 0.2 kg
Dimensions 20 × 20 × 5 cm
Classique Phono Options


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