Analog Gear News

Marchand LN112 MM & MC Tube Phono Preamp

Mike Mettler  |  Apr 3, 2023

I don’t know about you, but I still quite enjoy seeing tubes on full display when it comes to the design philosophy behind certain types of analog gear. Case in point: the simply tube-ariffic look of Marchand’s LN112 tube phono preamp.

According to Marchand company president Phil Marchand, the LN112 tube phono preamp is available in two versions: the LN112-AA (for MM) and the LN112MC-AA (for MC). The LN112 provides precision amplification and RIAA correction, and the standard input load is 47kohm and 120pF for MM (and, as Marchand adds, others are available). The preamp uses four 12AX7WA dual triode tubes. The RIAA network uses a passive configuration, and the power for the filaments is regulated at 12VDC, using an internal voltage regulator. A DC/DC converter steps the 12V to 240VDC plate voltage.

Other LN112 features include one pair of heavy-duty gold RCA connectors each for both input and output, and a binding post near the input connectors for grounding. The LN112 can be powered directly from a 12V lead-acid battery, or from AV with the included adapter.

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Meanwhile, the MC version sports a set of high-performance Jensen MC transformers built into the unit, and are said to give an additional 20dB of gain.

A full array of specs for the MarchandLN112 phono preamp appears below, following pricing and contact information.

The MM version, the Marchand LN112-AA, has an SRP of $1,100. The MC version, the LN112MC-AA, has an SRP of $1,400.

For more about Marchand, go here.
To find out how and where to buy Marchand products, go here.

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MARCHAND LN112 TUBE PHONO PREAMP
(LN112-AA version [MM], $1,100; LN112MC-AA version [MC], $1,400)

Specs
Frequency response: 20Hz-20KHz ±0.25dB
Input impedance: MM: 47kohm + 120pF (others on request); MC: 10ohm
Output Impedance: 500ohm
Gain: MM: 40dB at 1kHz; MC: 60dB at 1kHz
Signal-to-Noise ratio: MM: 82dB ref. 5mV input at 1kHz, A-weighted; MC: 82dB ref. 0.5mV input at 1KHz, A-weighted
Input noise voltage: 0.04uVRMS, A-weighted
Output load: 10kohm (or higher)
Max output voltage: 7VRMS
Dimensions (w/h/d): 4 x 5 x 8in

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COMMENTS
JACK L's picture
Submitted by JACK L on Wed, 2023-04-05 19:46

Hi

$1,100 to buy a MM phonostage is heck a good deal, even if it were made off shore.

But this tube phonostage employs switch mode power supply (SMPS)!!

Why? To save cost apparently ?

A typical SMPS for audio use switching frequency up to 2MHz with EMI noise about 10KHz - within the audio frequency.

Looking at the shielding layout of the switching power supply inside the box, I am not that impressed at all !

If it were a phonostage using only solidstate devices in the audio circuitry, e.g. FETs, transistors or op-amps, it is still logical to a SMPS - 100% solidstate pre-Amp !

But this is ALL-tube phonostage but with a HF SMPS - a hybrid design with a EMI noisy power supply !!!!! Hopefully, its built-in EMI noise suppression is effective enough !

But as a die-hard analogue handyman, it is not my cup of tea !

JACK L

Jim Hagerman's picture
Submitted by Jim Hagerman on Thu, 2023-04-13 00:39

Keep in mind that traditional (large and expensive) B+ power supplies that convert AC line voltage to DC are switching types as well!!!

They switch at double the line frequency, or 120Hz in North America. Yeah, right there in the middle of the audible spectrum. You hear this as hum or buzz.

A high frequency switcher (on the other hand) switches at an ultrasonic frequency, typically around 100kHz. This is much easier to filter out and is inaudible at the same time!

Which would you actually prefer?

No, high frequency switchers do NOT introduce 10kHz noise. And yes, this is all about reducing size and cost. Is that really a bad thing?

I was probably the first to introduce this technology to tube phonostages with my Cornet3 design roughly ten years ago. Today I am shipping the Trumpet MC as well, kindly reviewed right here in the AP pages by MF himself...

phil marchand's picture
Submitted by phil marchand on Mon, 2023-04-17 09:13

The reason for the switch-mode power supply is that I wanted to fit it into the small base. Indeed, the supply runs at 100KHz so any harmonics cannot be heard. Also, having a 60Hz transformer in the base might cause hum. We can supply an external linear supply on a custom basis. There is also a MC version available with Jensen transformers. Phil Marchand, President, Marchand Electronics Inc.

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