YJCO 6J5 Vacuum Tube Preamp QCC3034 Bluetooth5.1 AptX HD 24Bit 48KHz HiFi Tone Control Stereo RCA Preamplifier for Amp Speaker

Package:Power Amplifier 1No Power Adapter IncludedInstructions:This device adopts two Beijing 6J5 vacuum tubes with a pluggable structure, allowing users to upgrade to higher-spec models independently, such as 6AH6 and Soviet 6M5N. The tone control circuit is equipped with two through-hole NE5532 operational amplifiers, which can also be replaced with other high-end dual op-amps. With excellent upgradability and outstanding cost performance, this unit delivers great value for money.Two Bluetooth versions are available for selection: QCC3034 and Jieli Bluetooth 5.0.The QCC3034 module features Bluetooth 5.1, supporting aptX, aptX HD, 24BIT and 48K audio decoding. Paired with the independent PCM5102A decoding chip, it enables high-fidelity Bluetooth transmission, achieving audio quality comparable to wired connections. The Jieli Bluetooth 5.0 module supports the SBC audio protocol.Usage InstructionsThe rated working voltage of the device is DC12V 2A. Do not exceed 12V, otherwise the device will overheat and be damaged. The power interface adopts a 5.52.1mm specification (inner positive, outer negative).After powering on the device, the indicator lights under the vacuum tubes will turn on to confirm normal startup. Please wait about one minute for the vacuum tube filaments to fully warm up. The audio output will return to normal after the vacuum tubes enter stable working status.The Bluetooth device name is "YJHIFI / YJCO BT5.0". After searching and connecting via mobile phone, the device will automatically switch to Bluetooth input mode for audio playback.Specifications:Model: 6J5Input Interface: RCA, BluetoothOutput Interface: RCAWorking Voltage: DC12V 2AStandby Power Consumption: 1WBluetooth Chip: QCC3034 / Jieli Bluetooth 5.0Bluetooth Audio Protocol: QCC3034 (SBC/AAC/APTX/APTX HD, 16-24Bit, 44.1 48KHz); Jieli Bluetooth (SBC/AAC, 16Bit, 44.1KHz)Vacuum Tube Configuration: Beijing 6J5 × 2Total Harmonic Distortion (THD): Signal-to-Noise Ratio (SNR): 98dBFrequency Response: 20Hz-20KHz (±0.3dB @ 1kHz)Product Dimensions: 137mm × 104mm × 41mmProduct Weight: 400g