MUSEATEX MELIOR PHONO CENTER

OWNER'S MANUAL

Features | Unpacking | Connections | Panel Controls | User Adjustments | Modifications | Specifications

Overview

The Melior phono Center is designed to work with the Melior Control Center, Melior A/V Center, or as a stand-alone unit. In the latter case, the Museatex Floating Charge power supply (PP-100) will have to be purchased separately.
Whether used independently or in tandem with Melior Control Center, the Melior Phono Center offers one of the best phono preamplifiers in the market today.
The Meitner PA6i is heralded as one of the best preamplifiers in the market today and the phono stage of the PA6i is one of the contributing factors to this high rating among audiophiles. The Melior Phono Center, designed and manufactured by Museatex takes the performance a step further.
Please take the time to read this owner's manual so that you can optimize the performance of your phono playback system.

Features

Universal Phono Stage. The user adjustable, infinitely variable gain control accommodates both moving coil and moving magnet cartridges.
User Adjustable Gain. Balanced line Trans -impedance Input allows for DC controlled gain setting., The 20 dB gain adjustment allows you to match your phono input to that of your other line inputs.
Comprehensive Load Network. The user can adjust the loading of the phono center to match any cartridge.
High Pass Rumble Filter. This is user switchable and is automatically selected for a few seconds when the gain control is activated.
Class A Output Stage. Up to 10 feet of interconnect can be driven by the phono center. This allows you to place the phono center where it belongs - close to the phono center.
Balanced or Regular Input. If your turntable has been custom wired for balanced line output, the phono center can also be wired for balanced line input. This arrangement will improve performance and your present Melior Phono Center can be modified at a nominal cost to accommodate balanced line input.

Unpacking

When you first unpack the Melior Phono Center confirm that the following are included:

The Phono Center
Warranty Registration Card
Quality Control Sheet

Contact your dealer or Museatex directly if any of these are missing.

In handling the Melior Phono Center, take care not to scratch or damage the wood side panels. Keep the packing. The Melior Phono Center cannot be safely shipped without the packing. It is important that the unit is examined carefully for any shipping damage. If there is any damage, please contact your dealer. The original packing showing the damage must be retained to institute any claim against the carrier.

Connecting the Melior Phono Center

place the Melior Phono Center as close to the turntable as possible.
Ensure that the Melior Control Center (or Power Supply) is turned off prior to making any connections.
Connect output terminals of your turntable to the input RCA jacks of the Melior Phono center taking care to match the channels. The bottom jack marked "R" with the red color code is the right channel and the top jack marked "L" with the white color code is the left channel.
Connect the ground wire from the turntable to the ground post on the Melior Phono Center. Make sure this connection is tight as this is one of the most common causes for hum originating with the turntable.
Now connect the power cable to the Melior Control Center (or supply). The Melior Phono Center has a cable with a male DIN plug at the back and this should be connected to ;the DIN power out of the Melior Control Center. In the case of the Museatex Independent Power Supply, the DIN input is located at the end of the cable.
Turn the Gain Control knob at the back of Melior phono Center to its lowest setting by turning it counter-clockwise. Switch the Rumble Filter to the "on" position.
Turn the Melior Control Center (or supply) on.
Ensure that the connections from the control center to the amplifier are made in accordance with the instructions supplied.
Select the appropriate line input on your control center or preamplifier. If you are using another preamplifier, make sure that you use on of the line inputs rather than the "phono" inputs. The Melior Phono Center is an RIAA equalized phono pre-amplifier and if you connect the output from the Melior Phono Center to the "phono" input of another pre-amplifier, you will hear severe distortion caused by "double equalization".
You are now ready to make the gain adjustments to match your cartridge.

Rear Panel Controls

Adjusting Input Gain:
Select your normal listening level by using another source, say the tuner, and switch the input back to the phono section on your control center. Now gradually turn the knob clockwise until the sound level is approximately at the level of your other inputs. Your phono cartridge is now adjusted for playback in your system.
High Pass Rumble Filter:
The Melior Phono Center has a 2 pole high pass rumble filter to eliminate infrasonic frequencies below 10 Hz which can cause speaker damage at high volumes. This filter is "automatically" activated for a few seconds when the gain switch is used. This is to prevent any unpleasant thumps when gain adjustments are being made.
The toggle switch at the rear of the Melior Phono Center allows the user to leave the filter permanently activated. We recommend that you activate the filter when playing warped records.

User Adjustments Inside the Melior Phono Center

The Melior Phono Center is factory adjusted for 51 Kohms input impedance and 50pF input capacitance. In some cases, it may be desirable to vary these settings to suit your cartridge. In most cases, the cartridge manufacturers suggest ideal settings and we would recommend that your use the recommended settings as a starting point. In our experience, however, the optimum settings are often obtained by trial and error as factors like cable impedance, length of cable used, tone arm wiring etc. affect performance.

Our customer service department may be able to help you in many instances as we have experimented with many of the high quality cartridges in the market.

To gain access to the adjustment pins, it is necessary to open the Melior Phono Center. The loading adjustments are directly in the signal path, and any rotary type pots accessible from the outside would contaminate the signal path. Please ensure when making the adjustments, to use a clean pair of tweezers. Opening the control center is a simple process and requires a small Phillips screw driver. Please follow these steps:

Unplug the Melior Control Center from your Melior Control Center (or Power Supply).
Using a clean surface to work on (preferably felt or cloth covered to prevent damage to the cosmetics of the unit), place the Melior Phono Center upside down and remove the four Phillips screws at the bottom. Now remove the two screws at the rear of the unit. These groups (from front to back) are:
Input Capacitance Adjustments. You will see a white sticker showing the values for each set of pins with a black jumper factory set at the 50 pF marking. There are five pairs of settings from 50 to 250 pF.
Input Impedance Adjustments: The white stickers show values from 100 ohms to 51 Kohms. The factory setting is at 51 Kohms.
Jumpers for converting to balanced line inputs: These require some rewiring and a change of the rear panel. We recommend that you have this change done at the factory.
With tweezers, remove the black jumpers and position them in the appropriate pins ensuring that the same values are used for each channel.
If you do not wish to experiment any further, close the unit by placing the cover back and inserting all 6 screws and tightening them. Follow installation procedures as already explained. Remember not to turn the power on until all the connections are made.
If you wish to experiment and optimize the settings, leave the cover off and try different combinations. Careful listening with different types of music is recommended prior to selecting the optimum settings. Whenever accessing the adjustment jumpers, the power, inputs and outputs must be disconnected. Failure to follow this precaution could result in damage to this unit, the preamplifier or the speakers.

Special Factory Modifications

In addition to the user adjustments described above, the Melior Phono Center has provisions for special factory modifications. The two adjustments offered are:

Balanced line input.
Increasing gain by an additional 10 dB to accommodate a few moving coil cartridges that have very low output.

Please contact your dealer for the cost of these modifications.

Specifications

Construction: Pure copper printed circuit board - no tin plating.
Power Supply: External. Either in tandem with Melior Control Center, A/V Center, or Museatex PP-100 Power Supply.
Inputs: One Phono Input. Variable gain. MM or MC.
Outputs: One stereo line-level output.
Output Impedance: 300 ohms.
Signal to Noise Ratio: MC: Typically 80 to 90 dB (A WTD), MM: Typically 85 to 100 dB (A WTD).
RIAA Accuracy: 0.2 dB - RIAA timing capacitors are charge-biased. Left/Right match: 1%.
Gain: 20 dB from +30 dB to +50 dB.
Filter: 2 Pole High Pass Rumble Filter at 10 Hz.