The pre outs are nothing but the unamplified signals which are all used especially for the external amplifiers that have pre INs. Everyone can make use of it to feed the enough power amp input on some other amp. Pre-outs are used to connect an external amplifier to your receiver so they can power speakers in your Home Theater system. See it on Amazon. If there are black or red speaker jacks, they are especially for connecting the speakers to your audio system. Everyone can use pre out on receiver in order to get the best and significant benefits while enjoying the best sound quality of your audio receiver. The pre outs are nothing but the unamplified signals which are all used especially for the external amplifiers that have pre INs. The sub pre out is to make a connection to only the powered sub woofer. The individuals can also see the pre out even on the amplifier and it is also known as the power amp. Best Entry-level AV Receiver. Denon AVR-X3600H UHD AV Receiver (2019 Model) - 9.2 Channel, 105W Each | NEW Virtual Height El… You can also see the sub woofer pre out receiver which includes the RCA jacks on the back portion of the audio receiver only output the signals not the actual power. You can also see the sub woofer pre out receiver which includes the RCA jacks on the back portion of the audio receiver … Cambridge Audio AXR100 100-Watt Stereo Receiver with Bluetooth | Built-in Phono Stage, 3.5mm Inp… Synthesized Tuner, USB/SD Card MP3 Player & Subwoofer Control, A/B Speaker, iPod/MP3 Input w/ Karaoke, Cable & Remote Sensor - PyleHome PT270AIU, Yamaha TSR-7850R 7.2CH Dolby Atmos DTS Wi-Fi BT 4K Receiver, Black (Renewed), Rockville BluTube 70W Tube Amplifier/Home Theater Stereo Receiver with Bluetooth, Pyle Rack Mount Studio Pre-Amplifier - Audio Receiver System w/Digital LCD Display Bluetooth FM Radio Recording Mode Remote Control USB Flash or SD Card Reader Input and Output Jack - PPRE70BT, Rockville BluTube LED 70W Bluetooth Tube Amplifier/Home Stereo Receiver with Blue Illumination, Optical Input, Sub Output, Wireless Bluetooth Power Amplifier System - 420W 5.1 Channel Home Theater Surround Sound Audio Stereo Receiver Box w/ RCA, AUX, Mic w/ Echo, Remote - For Subwoofer Speaker - Pyle PT588AB, 500W Karaoke Wireless Bluetooth Amplifier - 4 Channel Stereo Audio Home Theater Speaker Sound Power Receiver w/ AUX IN, FM, RCA Subwoofer Speakers OUT, USB, Microphone IN w/ Echo - Pyle PTA44BT, Pioneer MVH-X390BT Digital Media Receiver with Pioneer ARC app, MIXTRAX, Built-in Bluetooth and USB Direct Control for iPod/iPhone and Android Phones & zonoz 3 in 1 Multi USB Charging Cable (Bundle), Car Stereo 2 din car Radio 7" HD Player MP5 Touch Screen Digital Display Bluetooth Multimedia USB 2din Autoradio Mobile Phone interconnetion with 12 LED Car Backup Camera, AMPrime Single Din Car Stereo Radio 4.1” Touch Screen AM/FM Bluetooth Car Player Support Voice Control/RDS/USB Input/Mirror Link for Phone/External Microphone + Backup Camera/Steering Wheel Control, gofanco Prophecy 4-Port DisplayPort Monitor 1.2 USB KVM Switch (4x1) – 4K @60Hz 4:4:4, 21.6Gbps, HDCP 1.3, USB Keyboard/Mouse, USB 3.0 Hub, MIC in, Stereo Out, Hotkeys, Firmware Upgradable, Sony STRDH130 2 Channel Stereo Receiver (Black), 1000W Bluetooth Home Theater Receiver - 5.2-Ch Surround Sound Stereo Amplifier System with 4K Ultra HD, 3D Video & Blu-Ray Video Pass-Through Supports, MP3/USB/AM/FM Radio - Pyle PT696BT, Kenwood DDX26BT Double DIN SiriusXM Ready Bluetooth In-Dash DVD/CD/AM/FM Car Stereo Receiver w/ 6.2" Touchscreen, Denon AVR-X4700H 8K Ultra HD 9.2 Channel (125 Watt X 9) AV Receiver 2020 Model - 3D Audio & Video with IMAX Enhanced, Built for Gaming, Music Streaming, Alexa + HEOS, NAKAMICHI NA300IR CD MP3 WMA SD USB iPOD iPHONE RDS AUX IN Car Stereo Player 32K variable color display & illumination 5V Front & rear pre- out / 5V sub-wout, Wireless Home Audio Amplifier System - Bluetooth Compatible Sound Stereo Receiver Amp - 6 Channel 600Watt Power, Digital LCD, Headphone Jack, 1/4'' Microphone IN USB SD AUX RCA FM Radio - Pyle PTA66BT, Wireless Bluetooth Home Audio Amplifier - 100W 5 Channel Home Theater Power Stereo Receiver, Surround Sound w/ HDMI, AUX, FM Antenna, Subwoofer Speaker Input, 12V Adapter - Pyle PFA540BT, AIYIMA Tube T2-PRO Audio 6J1 Tube Amplifier 100Wx2 Bluetooth 5.0 HiFi Stereo Audio Power Amp APTX for Home Theater System (Silver-T2 Pro), OSD Audio 75W Class D Stereo Amplifier – 2 Channel Source Switch System, XMP100, Keshangda 10.1 Inch Double Din Car Stereo Android 10.1 Touch Screen GPS Navigation Head Unit with Bluetooth/Backup Camera/WiFi/FM Radio Receiver,Support All iPhone/Android Phone Mirror Link.