A281 Fully Balanced HiFi Headphone Amplifier Preamplifier without USB Input Replacement for LakePeople V281

A281 Fully Balanced HiFi Headphone Amplifier Preamplifier without USB Input Replacement for LakePeople V281

Description:
- Two 40VA total power (one 25VA, one 15VA) for TALEMA imported sealed ring transformer from the UK, paired with audio capacitors for Philips with a total capacity of 34000UF, provide a continuous source of power for A281 and also the heart of the whole machine.

- RCA, XLR DIG (optional USB input module, which is not included.) with 3 input signal selection channels, Head, LINE with 2 output signal selection channels, combined with 5 control buttons on the panel, provide clear and reliable signal selection function for multiple audio sources.

- A high voltage, large dynamic fully balanced Class A headphone amplifier circuit with 5-level gain adjustment function, paired with two 6.35 TRS headphone output ports and a 4-core XLR card balanced output port. It can drive both single ended and balanced headphone, and different gains can be selected based on different headphones, equipment combinations, and listening experience, allowing the headphone performance to be maximized!

- Independent preamplifier, 5-level gain adjustment, single ended, balanced with two independent preamplifier output ports, as well as fixed level output and volume knob controllable output dual mode selection function, providing a very flexible user experience for preamplifiers; The front LO output port can be connected to both a pure rear power amplifier and a desktop active speaker, making it easy to assemble a compact desktop speaker system. Earphones and speakers are perfect for both repairs, eliminating the hassle of constantly plugging and unplugging signal cables from multiple terminals to switch sound sources. Simply press the button a few times, and the beautiful music will accompany you wherever you go.

- For ALPS RK27 potentiometer, combined with a 50mm antique volume knob, provides excellent convenience and control feel for the operation of A281.

- The protection function that integrates overvoltage, overcurrent, overload, zero drift, and delayed output provides comprehensive protection for your expensive headphone and speaker system. When the machine detects a fault, the protection circuit will immediately cut off the output ports of the headphones and preamplifier to protect the headphones and speakers as much as possible from harm. At the same time, the MUTE indicator light on the panel starts flashing and giving an alarm.

Features:
- A281 uses two sealed ring transformers for Talema, one responsible for the power supply of the preamplification circuit and the other responsible for the power supply of the reverse amplification circuit, each performing their respective duties. Separate power supply for left and right channels and positive and negative bidirectional channels enables A281 to have a channel separation of -105dB and an excellent sound field.

- The capacitance matrix composed of multiple small capacity capacitors in parallel has the advantages of low internal resistance, fast response speed, and good low-frequency control force; The disadvantage is that the material cost is very high, and the capacitance matrix of the same capacity is 3-5 times that of a single capacitor of the same capacity.

- The motherboard uses a 25VA transformer, with 15VA used for headphone amplifier circuits and 10VA used for auxiliary control circuits. 18 famous capacitors for Philips undertake the filtering task of the entire board, making the power supply noise low and inaudible.

- The balanced amplifier board also uses a single 15VA transformer and 16 Philips capacitor matrices to form a powerful rectification and filtering circuit.

- A281 comes with three sets of input signal interfaces: XLR (balanced), RCA (single ended), and DIG (digital). The DIG (without this function) digital input is an optional function and defaults to an empty state. The switching between three sets of input signals uses for Omron fully sealed silver board contact signal relays as switch control components; Relay signal selection has advantages such as fast response speed, low contact resistance, less interference signals, and long service life.

- The independent preamplifier signal processing circuit, combined with a 5-speed gain adjustment circuit, lays a solid foundation for the flexible and versatile application range of A281. A gain range of -12dB to +12dB can be easily achieved through a combination of 4-bit DIP switches, with -12dB, -6dB, 0dB (the position when all switches are turned to the bottom is 0dB), +6dB, and +12dB. By selecting different gains, you can create a powerful customized ear amplifier for your headphones.

- A281 is equipped with independent preamplifier functions, which can be easily connected and used with rear amplification devices such as desktop active speakers. The independent preamplifier is not affected by the amplifier circuit of the headphone amplifier, and can output independently or simultaneously with the headphone amplifier module. The switching function only needs to be lightly pressed on the switch in the control area of the panel. The sound control of the preamplifier output can be selected as direct (uncontrolled), or it can be synchronized and controlled with the headphone amplifier module volume through the large volume knob on the panel. This practical function provides a very user-friendly choice for the volume control of the rear stage active box or power amplifier. When the rear stage comes with volume control, direct can be selected; when it does not come with volume control, it can be synchronized and controlled with the headphone volume. Single ended and balanced output interfaces, making it easy to handle mainstream desktop active speakers on the market.

- A power supply of up to +/- 18V, for WIMA coupling capacitor, OPA2227P operational amplifier, 5-speed independent gain adjustment function, relay output control and other high-end preamplifiers features are all available on the A281 preamplifier module.

Package Included:
- 1 x Host