Project Description

Luna – Tube phono preamplifier

Luna tube phono preamplifier is top class product in Trafomatic Audio production .

The main advantage is that this preamplifier use very rare LCR method to apply the RIAA correction due to complexity and cost.

There are a total of only the finest components such as four C3g SE tubes connected in triode mode , two interstage and two line output transformers as well as LL1941 input MC step up .

This preamplifier also applies the separately executed power supply used low induction toroidal transformer as well as two high inductivity chokes and Mundorf MLytic HV electrolytic capacitors .


Luna features :

  • Built in step up transformers
  • Switches ground plane with input selection preventing ground loops
  • Balanced and unbalanced output
  • Separate low impedance CLC power supply

Luna uses two tube gain stages with zero feedback and passive LCR equalizer .

The input stage as well as output is low noise Siemens c3g German Post tubes used in triode connection. Every stage is loaded by transformers and this provide complete isolation of this sensitive circuit from the following components.

There are no capacitors in signal way except in RIAA correction where we used Silver mica ones.

Luna – Image gallery


Single-ended Class A
Separate power supply

Gain MM – 45 dB, MC – 70 dB using input transformers LL1941 (uncut amorphous cobalt core, Cardas high purity copper wire)

Noise and Hum -78 dB

Output voltage 1.0Vrms

MM (RCA) – 47k

Adjustable MC inputs 10ohms, 20 ohms, 50 ohms, 100 ohms

Output Impedance 660 Ohms, XLR and RCA

Frequency Response RIAA Curve +/- 0.4 dB

Vacuum Tube Complement 4 x C3g SE

Power supply: Low Induction toroid transformer by Trafomatic Audio, High Inductivity custom made chokes, Mundorf MLytic HV type

Requirements 100, 117 or 240 Volts / 50-60 Hz, 60 watts

Weight 10 kg

Dimensions 400x 310 x 85mm (two box)