Mark Levinson No.38 preamplifier

High-end audio companies take different approaches to staying successful. One way to maintain a market position is to continue improving fundamental designs, offering a little higher sonic performance with each model. The latest products from a company employing this approach will look and operate very much like their first products.

Another approach is to completely rethink the role of an audio component, significantly changing its design in response to the evolving way products are used. This company's recent products will be radically different from their lineup of just a few years ago.

The changing role of audio components is best exemplified by the preamplifier. Once needed to provide high gain and equalization for phono playback, the preamplifier has increasingly become merely a control center rather than a pre-amplifier before the main amplifier. Today's digital source components provide plenty of output level to drive any power amplifier; we now use a preamplifier for volume control (attenuation) and source selection. And if we want to play records, we can still use an outboard phono stage.

This introduction brings us to a remarkable new product from Madrigal Audio Laboratories—the Mark Levinson No.38 preamplifier. The No.38 represents a revolution in preamplifier design and function, and is so far removed from traditional preamplifiers that it makes the term "preamplifier" itself seem archaic.

How the No.38 operates in a system
The first thing I noticed about the No.38 is its similar appearance to other Mark Levinson 30-series products, particularly the No.30 Reference Digital Processor. The curved front panel, machined-aluminum buttons, and large alphanumeric display are a significant cosmetic departure from older Mark Levinson preamplifiers.

The display shows which input is selected, along with a numerical readout of the volume setting. Each input can be assigned one of 22 "aliases" that identify the source connected to it. For example, input #1 can be called "No.30" if you have a No.30 processor; if you have a CD player, it can be called "CD." With 22 aliases, the No.38 should accommodate any system configuration. By displaying the name of the selected input, there's no confusion about which source is active.

The volume-control readout shows the volume setting with 0.1dB resolution through most of the usable range; resetting the same volume position is easy and precise. Moreover, the large volume-control knob functions like no other. Instead of turning a potentiometer, the volume knob sends a signal to a switched resistor network. The volume setting determines which resistor is in the signal path, and therefore how much attenuation is provided.

A software-driven microprocessor controls the knob's action. When the knob is moved slowly, the volume changes slowly to allow fine setting; when the knob is moved quickly, the volume changes quickly to instantly get you to the volume you want. As you approach the desired volume, your hand naturally slows down; simultaneously, the volume control becomes more sensitive—it's almost as if the volume control is reading your mind and responding exactly the way you want it to. (I'll talk about how this is accomplished in "Technical Description.") This is an extraordinary feature—one that you must experience firsthand to appreciate.

In addition to assigning a name to the inputs, the No.38 can gain-match each source to the highest-level source in your system. For example, if your tuner puts out a level 10dB lower than that of your digital source, selecting the tuner input will automatically invoke an additional 10dB of gain. Consequently, you can switch between sources without adjusting the volume. In addition, you won't be surprised by a very loud level when high-output sources are selected with the volume control set for a low-output source.

The front-panel display also shows which source is routed to which tape output. In a nice touch, it's impossible to create a record loop that would generate feedback with the No.38—the device knows which inputs and outputs are connected, and simply won't make an improper connection. Moreover, only the selected input is connected to the internal circuitry—all other inputs are completely disconnected (both signal and ground conductors) for maximum sonic purity while eliminating the potential for ground loops.

Another refinement is the user-selectable mute level. You can program the No.38 to provide from 1 to 60dB of muting when the Mute button is pressed.

The No.38 solves a problem of integrating a surround-sound processor into an audio system. When in the "SSP" mode, the volume control is no longer active, and the No.38 locks into unity gain. This ensures that the surround-sound processor driven by the No.38 will maintain perfect output-level calibration at all times, and that the music system won't be compromised by the surround-sound processor.

As with all Mark Levinson 30-series components, the No.38 has a communications link for connection to the No.30 or 35 digital processor, the No.31 transport, and all future 30-series products. With the link in place, pressing Play on the No.31 causes the No.30 processor to select the digital input from the No.31, and the No.38 to select the input fed by the No.30's analog output. If you hit the Standby button on the No.38, all 30-series components linked to the No.38 will also go into standby. The alias displayed in the No.38's front panel, of course, will show the name of the 30-series source component. These are just a few examples of how the communication link integrates various functions.

Mark Levinson division of the Harman Consumer Group
1718 W. Mishawaka Road
Elkhart, IN 46517
(516) 594-0300