LN112 Tube Phono Preamp

Precise RIAA correction.
8Hz subsonic filter.
MM version 40dB gain
MC version 60dB gain
Low noise: 82dB SNR.
Battery or AC operation.
Digital interface (sp/diff) available.

The LN112 tube phono preamp provides precision amplification and RIAA correction for MovingMagnet or MovingCoil cartridges. Standard input load is 47K and 120pF for MM; others are available. A 8Hz subsonic filter suppresses all frequencies below 8 Hz while keeping the in-band sound signals unaffected.

The subsonic filter greatly reduces unwanted cone movements due to record warp, etc.
Power is provided using a 15VDC external power supply.
The LN112 is available in two versions: Moving Coil and Moving Magnet. The special version for Moving Coil (MC) has as set of high performance Jensen MC transformers built into the unit. This gives the additional 20dB of gain required for the MC cartridge.
We use the highest quality parts, precision metal film resistors and precision polypropylene capacitors for superior sound. The preamp uses 4 12AX7WA dual triode  tubes. We normally use Sovtek, but can also supply other brands. Each channel uses three triodes for voltage amplification and one triode as a cathode follower. The RIAA network uses a passive configuration. The power for the filaments is regulated 12VDC, using an internal voltage regulator. A DC/DC converter steps the 12V to 240VDC plate voltage.
The LN112 can be powered directly from a 12V battery (lead-acid battery) or from AV with adapet included.

Inputs: 1 pair of heavy duty gold RCA connectors.
Output: 1 pair of heavy duty gold RCA connectors.
Grounding: Binding post near input connectors.
Power: 2.1mm power jack for 15VDC power supply.

Specifications (MM):
Frequency response: 20Hz - 20KHz +/- 0.25dB
Input impedance: MM: 47 KOhm + 120pF (other on request)
MC: 10 Ohm
Output Impedance: 500 Ohm.
Gain: MM:40dB @ 1KHz.
 MC:60dB @ 1KHz.
Signal to noise ratio: MM:82dB ref. 5mV input@1KHz, A weighted.
MC:82dB ref. 0.5mV input@1KHz, A weighted.
Equ. input noise voltage: 0.04uVRMS, A weighted
Output load: 10KOhm or higher.
Max. output voltage: 7 VRMS.
Dimensions: 4" x 8" x 5"

Ordering Information:

LN112-AA   Phono Preamp, Moving Magnet version
LN112MC-AA Phono Preamp, Moving Coil version

Optional DIN connectors instead of RCA
 DAC SP/DIFF digital interface


UHF Magazine 79 www.uhfmag.com/Issue79/UHF79.pdf