Musical Surroundings SuperNova II Phono Preamp

The SuperNova is a three input phono preamp intended for use with more than one turntable or a turntable with more than one tonearm. There is user adjustable loading and gain for each of the inputs. The loading and gain is set via switches and is accessible from the rear of the chassis.

The SuperNova switching between the inputs does not actually switch the inputs and loading. Instead, it has three independent front ends--the current source is switched to the one that will be active. The outputs are summed into the backend circuitry. In this way no switching occurs in the signal path when not using the switched attenuator.

The SuperNova is fully dual mono and is powered from a remote dual mono power supply. The remote power supply supports NiMH rechargeable batteries but is designed to work perfectly without the batteries.

The batteries will allow the SuperNova to run completely isolated from the wall power for a period of 3 hours. There are 4 independent charging circuits for the 4 battery packs.

The SuperNova has an 11 position variable output switched attenuator that allows direct connection to a power amplifier.

• Handles 3 Phono Inputs.
• Gain user adjustable from 40 to 60 dB.
• Loading is user adjustable from 30 Ohms to 100kOhms.
• Independent Gain and Loading settings for each of the 3 Phono Inputs.
• There are no “signal path” switches except for switched attenuator if used.
• Normal “Line Out", and “Variable” outputs.
• The variable output Switched Attenuator can drive a power amp directly.
• Uses Large Area Monolithic Super Matched Pairs for lowest noise performance.

Remote Power Supply (not pictured) features:

• Rechargeable batteries.
• The charging circuits completely disconnect from the batteries when in battery mode.
• Optically coupled voltage monitors will wake up the processor to engage the charging of the batteries if the batteries are discharged enough.
• Four, seven cell NiMH “AA” packs, one for each positive and negative power supply, and each channel.
• Four separate charging circuits.
• Positive and Negative battery packs are charged separately in case there is different current usage between positive and negative power supplies. This prevents repeated overcharging one battery pack while undercharging the other.
• The batteries will be “topped off” by putting the unit into charge mode if there is no activity for a week.
• Fully Dual Mono even when not in Battery Mode.
• The power supply has been designed to sound excellent even without the batteries installed.

How the Limited Attenuator Works:

Gain in a typical system:

Moving Coil Phono Stage 60dB
Line Amp 18dB
Power Amp 30dB
Total Gain 108dB
Required Attenuation -30dB

Gain with the SuperNova Limited Attenuator:

Moving Coil Phono Stage 40dB
Power Amp 30dB
Total Gain 70dB
Required Attenuation -5dB

Most audio systems have far too much gain. The excess gain needs to reduced by setting an attenuator by a typical –30dB. By fine tuning the SuperNova gain switches and using the Limited Attenuator, typical listening can be done with little or no excess gain. By reducing unneeded gain, the system does not need to work as hard, thereby achieving a more natural sound. The extra 25dB gain equates to about 20 times more work, imagine working 20 times harder than you need to.

The Limited Attenuator has a major advantage over a standard passive attenuator. A passive attenuator typically has significant output impedance creating sensitivity to the particular type of output cable. The SuperNova Attenuator has much lower output impedance.