Gemini PMX-20 Digital Performance Mixer

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Safety Instructions

WARNING

To reduce the risk of electric shock, do not remove cover (or back). There are no user serviceable parts inside. Maintenance and repairs should be exclusively carried out by qualified service personnel.

CAUTION

To reduce the risk of electric shock, do not remove cover. No user serviceable parts inside. Refer servicing to qualified service personnel only.

• Read these Instructions.
• Keep these Instructions.
• Heed all Warnings.
• Follow all Instructions.
• Do not use this apparatus near water.
• Clean only with dry cloth.
• Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
• Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
• Do not defeat the safety purpose of the polarized plug. A polarized plug has two blades with one wider than the other. The wide blade is provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.
• Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
• Only use attachments/accessories specified by the manufacturer.
• Use only with the cart, stand, tripod, bracket, or table specified by the manufacturer or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.
• Unplug this apparatus during lightning storms or when unused for long periods of time.
• Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.
• WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture.
• Since the device's power cable is used as the primary disconnection device, the power cable should remain readily operable at all times.
• The ventilation should not be impeded by covering the ventilation openings with items, such as newspapers, table-cloths, curtains, etc.
• No naked flame sources, such as lighted candles, should be placed on the apparatus.
• The apparatus should be used in moderate climate.
• The apparatus shall not be exposed to dripping or splashing and no objects filled with liquids (such as drinks) shall be placed on the apparatus.

! The warning triangle with exclamation mark indicates important operating and maintenance instructions.

⚡ The warning triangle with lightning symbol indicates dangerous uninsulated voltage inside the unit, which may cause an electrical shock.

To prevent electric shock, do not use this Polarized Plug with an extension cord, receptacle or other outlet unless the blades can be fully insert to prevent blade exposure.

RoHS CE

Function - Top View

• 1. Effect 1 Button ON/OFF: Turns Effect 1 ON or OFF.
• 2. Effect 1 Knob: Controls value of Effect 1.
• 3. Effect Button 2 ON/OFF: Turns Effect 2 ON or OFF.
• 4. Effect Knob 2: Controls value of Effect 2.
• 5. Loop Size Encoder: Turn to increase or decrease loop size.
• 6. Loop Button ON/OFF: Turns looping for associated deck ON or OFF.
• 7. Hotcues Mode Button: Switches buttons 1-8 to HOTCUE mode.
• 8. Samples Mode Button: Switches buttons 1-8 into SAMPLES mode.
• 9. Hotcue Buttons: Triggers or sets Hotcues.
• 10. USB Button: Switches channel source from external to USB audio interface.
• 11. Channel Gain Knob: Turn to change input gain of channel.
• 12. High Frequency EQ Knob: Turn to adjust the High EQ value.
• 13. Mid Frequency EQ Knob: Turn to adjust the Mid EQ value.
• 14. Low Frequency EQ Knob: Turn to adjust the Low EQ value.
• 15. Dual Pole (HP/LP) Filter Knob: Turn to adjust filter for selected channel. Center: No Filter Effect. Clockwise from center: High-pass Filter. Counter-Clockwise from center: Low-pass filter.
• 16. FX Send Button: Press to send channel audio to effects loop.
• 17. CUE/PFL Button: Press to insert channel into Cue (PFL) bus.
• 18. 45mm Channel Fader: Move to increase or decrease volume for selected channel.
• 19. Channel LED Meter: Shows pre-fader level of selected channel.
• 20. Load Deck 1/3 Buttons: Loads selected track into the Deck 1 or Deck 3 Player.
• 21. Load Deck 2/4 Buttons: Loads selected track into Deck 2 or Deck 4 Player.
• 22. Track Search Encoder: Turn to scroll through library/Press to enter a directory.
• 23. Back Button: Press to go back one directory.
• 24. Forward Button: Press to go into the highlighted directory.
• 25. Master Volume Knob: Turn to increase Master Output Volume.
• 26. Booth Volume Knob: Turns to increase Booth Output Volume.
• 27. FX Return Knob: Adds FX return signal back to Master Bus.
• 28. Talkover Button: Lowers the volume of the non-microphone channels.
• 29. Mic On/Off Button: Turns the mic channel on or off.
• 30. Mic Level Knob: Turn to increase volume of attached Microphone.
• 31. Cue Split Knob: Splits cue between Cue bus and Program bus.
• 32. Cue Level Knob: Turn to increase or decrease volume of Cue bus.
• 33. Master Bus LED Meter: Shows level of Master bus.
• 34. 45mm Crossfader: Move to select channel audio sent to Master bus.

Function - Rear View

• 35. Power Button: Turns mixer on or off.
• 36. Master XLR (Balanced) Outputs: Professional-grade stereo outputs.
• 37. Master RCA (Unbalanced) Outputs: Consumer quality Stereo outputs.
• 38. Booth Output: Output for monitoring speakers.
• 39. Record Output: Output for recording devices.
• 40. USB Type-B Connector: To connect PMX-20 to a computer.
• 41. CH4 Line/Phono Switch: Switch to control level of CH4 input.
• 42. CH4 RCA Inputs: Input for CH4 Source.
• 43. CH3 RCA Inputs: Input for CH3 Source.
• 44. CH3 Line/Phono Switch: Switch to control level of CH3 input.
• 45. CH2 Line/Phono Switch: Switch to control level of CH2 input.
• 46. CH2 RCA Inputs: Input for CH2 Source.
• 47. CH1 RCA Inputs: Input for CH1 Source.
• 48. CH1 Line/Phono Switch: Switch to control level of CH1 input.
• 49. Microphone Input Combo Jack: Connect XLR or 1/4" TRS Dynamic Microphone.
• 50. FX Send Output: RCA Output for FX Send Loop.
• 51. FX Return Input: RCA Input for FX Send Loop.
• 52. IEC 3-Prong Mains Power connector: Mains AC Power connector.
• 53. Ground for use with TT sources.
• 54. Kensington Lock Connection: Connect Kensington Lock to secure mixer.

Connection Diagram

A diagram shows the PMX-20 mixer connected to turntables/media players and a PA system. The rear panel connections are illustrated, showing inputs and outputs for Master, Booth, Record, USB, CH1-CH4, FX Send/Return, and Mic In.

Computer Connection

Ensure the PMX-20 is connected to your computer via the included USB cable. The PMX-20 Mixer is a Class Compliant multi-channel audio and MIDI interface with low latency. No additional drivers are needed for OSX. For Windows, it is recommended to download and install the Gemini ASIO drivers from the PMX-20 product page on www.geminisound.com for optimal performance. This page also provides additional information and downloads (e.g., MIDI configuration files). Firmware updates are available via the Gemini Updater software, also downloadable from the product page. Regularly running the updater is advised to ensure you have the latest device firmware.

Operational Modes

Mixer Mode

The unit functions as a normal mixer (default mode). No computer is required; external devices are processed by the PMX-20's internal CPU. When connected via USB to an external computer, MIDI for most controls can be sent and received. Pressing the USB buttons above each channel switches that channel to the internal soundcard instead of the external source.

DVS Mode

Enter this mode by pressing and holding the USB button on CH1 for approximately 10 seconds. Lights will blink to indicate a mode change. In this mode, Channels 1 and 2 are the DVS channels, the audio interface is reconfigured as a 4-in/4-out interface, and Channels 3 and 4 function as pure MIDI controls. Any open DVS software (like Virtual DJ) will recognize and use the onboard audio interface. Additional DVS functionality may need to be purchased from the software developer.

Full MIDI Mode

Enter this mode by pressing and holding the USB button on CH2 for 10 seconds. Lights will blink to indicate a mode change. The PMX-20 acts as a pure controller. The built-in audio interface is reconfigured as an 8-out (4 stereo) interface. Channel and Master peak metering is driven by the audio interface. If mapping the PMX-20 to custom software, set the operational mode BEFORE opening the software.

Using the FX Loop

The FX Loop allows the use of external hardware effects with a stereo send and return.

Send

Sends are activated by the FX SEND buttons above the CUE buttons on each channel strip. Pressing an FX SEND button sends channel audio to the FX SEND output RCA jacks on the rear of the PMX-20. The send behavior can be switched from PRE-FADER to POST FADER using the switch below the TRACK SEARCH knob. PRE-FADER sends audio after the GAIN knob but before the channel fader. POST FADER sends audio after the GAIN, channel fader, and crossfader.

Return

Processed audio from external effects returns via the FX RETURN RCA jacks on the rear of the PMX-20 and is mixed into the master audio bus. The RETURN knob on the center channel strip controls the amount of audio added to the master output.

Crossfader Curve Control

A recessed knob labeled CURVE CONTROL in the bottom right corner adjusts the crossfader response, allowing for slow mixes to sharp transitions. Push the knob down to extend it, then turn to adjust. Full counterclockwise provides the sharpest curve; full clockwise provides the smoothest mix.

Crossfader Replacement

To replace the crossfader, disconnect all power and signal cables. Follow these steps:

• Remove all knob and fader caps (38 pieces total).
• Remove the 12 faceplate screws with a small Phillips screwdriver.
• Pull the faceplate straight up to expose the sub-chassis and access the crossfader.
• Carefully disconnect the standard molex-style connector from the installed crossfader.
• If installing a crossfader with adjustable parameters, make all necessary adjustments BEFORE reassembling.

Note: Replacing the crossfader may alter the performance of the crossfader curve controls. Take time to familiarize yourself with any changes.

Troubleshooting

Unit Will Not Power On

• Check that the power cord is securely connected to the mains and the mixer.

Audio Is Distorted (General)

• Ensure channel GAIN is set correctly.
• If connected to a computer, verify GAIN and LEVEL are set correctly in software.
• Check that mixer channel and master levels are not in the red.
• Ensure computer resources (CPU, memory) are not maxed out.

Analog Source Audio Is Distorted

• Ensure the correct input level (LINE or PHONO) is selected.

Microphone Is Not Audible

• Raise MIC LEVEL until the microphone is audible.
• Verify the connected microphone is a dynamic microphone.

Audio Interface Is Not Visible in Software

• Ensure the USB cable is connected to the mixer and computer.
• Re-install the Gemini ASIO driver.
• Ensure the PMX-20 audio interface is selected in software.

No MIDI Devices Available

• Verify the USB cable is connected to the mixer and computer.
• Ensure no other application is controlling the MIDI interface.

For other issues, contact Gemini support at 1-844-GEMINI9.

MIDI Specification

A table details the MIDI control names, data types, MIDI Out, and MIDI In values for various functions of the PMX-20.

Audio Specification

Inputs

• Line: 150mV, 27 KOhm
• Phono: 3mV, 47 KOhm
• Microphone: 1.5mV, 1 KOhm Balanced

Outputs

• Max: 20V Peak to Peak
• Record: 225mV, 5 KOhm

General

• Frequency Response: 20Hz – 20KHz +/-2dB
• Distortion: <0.02%
• S/N Ratio: Better than 85dB
• Headphone Impedance: 16 Ohm
• Power: 100-240 VAC 50~60Hz

Specifications are subject to change without notification for improvement.

RGB Color Chart (MIDI)

Warranty and Repair

Limited Warranty

Gemini guarantees products to be free from defects in materials and workmanship for one (1) year from the original purchase date. Exceptions apply for laser assemblies, cartridges, and crossfaders (90 days). This warranty does not cover damage from abuse, misuse, faulty installation, improper maintenance, or unauthorized repairs. Gemini is not liable for consequential damages. Implied warranties are limited to one (1) year from the original purchase date.

Return/Repair

In the USA, contact Customer Service at (732) 346-0061 for a Return Authorization Number (RA#) and service center address. Include a copy of the original sales receipt and a description of the defect with the returned product, sent by insured freight. Write the RA# on the outside of the package. Service covered under warranty is paid for by Gemini. Non-warrantied repairs will be done after payment is received. Shipping costs to Gemini are paid by the customer; return shipping within the continental US is paid by Gemini. Allow 2-3 weeks for product return.

In the USA

For problems, call 732-346-0061 for Gemini customer service. Do not return equipment to your dealer. Parts of the product may be protected by patents. Information is subject to change without notice. Gemini is not liable for loss or damage arising from the use of this manual. Maintenance and service should be performed by Gemini or authorized agents.

Gemini Worldwide Headquarters: 107 Trumbull Street, Building F8, Elizabeth, NJ 07206 USA. Tel: (732)346-0061.

Register your product online at WWW.GEMINISOUND.COM.