UNI-QUAD UQ-1A

QUADRAPHONIC DECODER

The page author took the idea for the Dynaquad device, and expanded it into an adjustable decoder. It can decode any of the regular matrix formats. The following are instructions on how to build and use this decoder. The instructions for use are placed first.

UQ-1A front panel
SAMPLE FRONT PANEL OF UQ-1A
 


USING THE DECODER

Calibration

Before the UQ-1A decoder can be used, it must be calibrated. To calibrate the decoder, follow the following steps:

  1. Choose a monaural audio source (or select MONO on the amplifier, if possible).
  2. Turn down (counterclockwise) the FRONT LEVEL, CENTER, and SUBWOOFER controls.
  3. Play the source.
  4. Move the NULL switch to the NULL position.
  5. Adjust the amplifier's BALANCE control.
  6. Move the NULL switch away from the NULL position. The NULL position is used only for calibration.

Using the Decoder

Use the following table to adjust the decoder.

MATRIXWIDTHDEPTHFILTERAUTOVARYOTHER INSTRUCTIONS
Sansui QS60 %60 %OFFAs desired-
Dynaquad100 %40 %OFFAs desired-
EV Stereo-480 %90 %OFFAs desired-
Dolby Surround90 %100 %ONAs desired Back speakers farther away, louder than front
Synthesized Quad70 %60 %OFFAs desired-
Concert Hall60 %90 %Try eachAs desired-
Stage Surround60 %30 %OFF0 %-
Noisy Lateral Records0 %Turn downON0 %-
Vertical RecordingsTurn down100 %ON0 % Turn down center and subwoofer

Using Autovary

The decoder is equipped with Autovary separation enhancement logic. Autovary must be adjusted for each matrix according to the following instructions:

  1. Play the program source.
  2. Turn the Autovary control to 0 %.
  3. Adjust the Depth control to the widest the back channel separation desired.
  4. Adjust the Autovary control so the light is on when front-center program material is present.
  5. If more enhancement is desired, increase the Autovary setting.
  6. If the image seems to shift abruptly, reduce the Autovary control setting.
  7. To turn off Autovary separation enhancement, turn the control to 0 %.
     

TECHNICAL DETAILS

How the decoder works

The decoder works in the following way:

How the matrix systems work

The matrix systems are designed in the following ways:

Building the decoder:

Use the schematic diagram to wire the decoder.

UQ-1A schematic Parts list:

*These parts need to be higher wattages, amperages, and voltages for higher power systems.

**Double the capacitances and halve the inductances if the speakers are 4 ohm.

***Connect multiple #49 lamps in series-parallel for higher wattages. Only one lamp needs to be on the front panel.

Construction:

  1. Make sure there is room between the front and back panels for the stereo L-pads, the terminal strips, and the resistors.
  2. Drill the holes and mount the parts on the front and back panels.
  3. Mount the terminal strips and connect the resistors, coils, and capacitor to them. Parts that are connected together can share the same terminal.
  4. Wire the decoder according to the circuit diagram at right.
  5. If high amplifier power is used, provide enough ventilation for cooling.
     

Connections:

  1. Connect the amplifier to the input terminals as indicated. Be sure to observe polarity.
  2. The speakers used should be nominally 8 ohms.
  3. Connect the left and right front speakers to the indicated terminals. Be sure to observe polarity.
  4. Connect the left and right back speakers to the indicated terminals. Be sure to observe polarity.
  5. If a center speaker is used, connect it to the center speaker terminals.
  6. If no center speaker is used, turn the center speaker control to 100 %.
  7. If a subwoofer is used, connect it to the subwoofer speaker terminals.
  8. If no subwoofer is used, turn the subwoofer control to 100 %.
     


LINKS: