Front and rear panels¶
Front panel¶
Indicators¶
A matrix of indicators indicates the current status. Note that the LEDs, while shown as green circles on the front panel layout below, are not visible unless lit. The right-most column of LEDs has no labels – these indicate the output volume level.
- Source
-
Selects moving coil phono cartridge (MC), moving magnet phono cartridge (MM), RCA line-level input, or XLR line-level input.
- Preset
-
Selects one of the four presets. Each preset contains all the other front panel settings for easy recall.
- Equalization
-
If moving coil or moving magnet input is selected, selects the phono equalization curve. The most common is RIAA, which applies to all modern records. The Decca (DEC) and Columbia (COL) settings are useful for certain vintage records. The HPF setting is independently selected, and turns on a sub-sonic filter (20 Hz at 24 dB/octave).
- Gain
-
Selects the analog input gain. You will hear the relays switch when changing gain. The available gain values depend on the selected input – see Table 1 below.
- Resistance
-
Selects the input loading resistor. The values for L, M and H depend on the selected input – see Table 1 below. This has no effect if the XLR input is selected.
- Capacitance
-
Selects the input loading capacitance. The values for L, M and H depend on the selected input – see Table 1 below. This has no effect if the XLR input is selected.
- Clip
-
This LED flashes, together with the Gain or Volume LEDs, if analog or digital clipping is detected. For more information, see Fine-tuning gain structure.
- Volume control (no label)
-
This column of LEDs is not normally visible, but lights up when the output volume is changed with the remote control.
Changing settings¶
The rotary encoder can change all settings except output volume. To change a setting, press the encoder. The current input LED flashes. Rotate the encoder in either direction until the flashing LED is at the setting that you want to change, then press the encoder again.
Note that the flashing LED proceeds through all settings. That is, after the XLR input, continuing to rotate clockwise moves it to Preset 1, and so on. Similarly, rotating it counter-clockwise will switch to the capacitance row, then resistance and so on.
Using presets¶
Four presets are stored on the ADept. Each preset includes all of the front panel settings including input source and volume.
A preset is automatically saved. That is, when a preset is recalled, the settings will be set to the values shown on the front panel when that preset was last used.
To recall a preset, use the encoder knob as described above, or use the remote control.
Input gain, resistance and capacitance¶
Table 1. Values for the L, M and H settings (in that order)
Moving coil | Moving magnet | RCA line-level | XLR | |
---|---|---|---|---|
Gain | 4.2mV, 1.1mV, 0.6mV1 | 13mV, 6.5mV, 4.0mV1 | N/A, 2.2V, 1.1V2 | N/A, 4.4V, 2.2V2 |
Resistance | 50Ω, 100Ω, 1kΩ | 33kΩ, 50kΩ, 100kΩ | 33kΩ, 50kΩ, 100kΩ | 200kΩ3 |
Capacitance | 1nF, 3nF, 5nF | 50pF, 100pF, 500pF | 50pF, 100pF, 500pF | 100pF3 |
Notes:
- For phono input, the values provided are the highest recommended cartridge output voltage at a stylus velocity of 5 cm/second.
- For RCA and XLR line-level input, the values provided are the maximum RMS voltage that can be applied before clipping. Note that the RCA and XLR inputs do not have a Low gain option – when adjusting the settings using the front panel or remote control, the Low gain LED will simply be skipped over.
- The XLR input has fixed resistance and capacitance.
Rear panel¶
Warning
Apply power to the miniDSP ADept only after all input and output connections have been made.
-
Ground. Connect the turntable ground wire here. See also Grounding below.
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RCA/Phono. Connect an analog source here using RCA cables. This can be a connection from a turntable with moving coil cartridge, a turntable with moving magnet cartridge, or a line-level source.
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Analog Input (XLR). Connect a balanced line-level analog source here.
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Digital Out. Connect to a DAC, a home theater receiver, or active speakers with digital input. Both connections carry the same stereo signal. The sample rate on this output is set by the USB Audio connection.
-
USB Audio. Used for recording audio and to set the internal sample rate. Connect to an available USB port on your computer.
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DC 12V. The supplied 12 VDC power supply includes a set of interchangeable power pins for USA, UK, Europe and Australia. Fit the correct pins for your country. Connect the DC plug to the 12 VDC power socket.
Grounding¶
The miniDSP ADept does not have an earth ground through its power supply. In some cases, you may experience unwanted hum or buzz even though the turntable ground is connected to the ground terminal of the ADept.
If so, connect an additional wire from the ground terminal of the ADept to a piece of equipment that has an earth ground, such as an amplifier. Note however that there is no hard and fast rule – choose the grounding method that gives you the lowest noise.
Warning
Power off all equipment when making this type of connection.