Original OPA-4A EL34 tube integrated Amplifier HiFi Headphone Amplifier Brand New
- The machine adopts high quality PCB welding to maintain stability and stability.
- Two EI type output transformers with high quality broadband and high quality Z11 core are used.
- Design of ring type power transformer specially designed for this machine
- In the former stage, two 12AU7 vacuum tubes were used, and two EL34 vacuum tubes were used for class a single ended power amplification. The pentode EL34 circuit adopts the triode mode of operation, which fully reflects the unique luster of the EL34 thick personality.
- Input has BALANCE/RCA/ Bluetooth selection.
- Headphone output can choose four core balanced output and 6.5 head output.
- Function of external speaker
- Boot up silent delay function (about 30 seconds)
- The volume potentiometer uses the Japanese ALPS (ALPS) 27 potentiometer.
- Easy installation of plug type vacuum shield
Balance and RCA / Bluetooth mode are selected. Balance input is converted into unbalanced signal by high quality op amp, and is adjusted by volume potentiometer and input to amplifier circuit.
It has external speaker function and headphone output function. The headphone can choose four-core balance output and 6.5-head single-end output. The four-core balance output is isolated and amplified by the output transformer. The balance signal of positive and negative waveforms is driven by special technology.
The output mode of headphones is variable voltage output.
- Output impedance: speaker 6 ohm headset 64 ohm
- The output impedance of the earphone is balanced: 64 Omega 6.5 output 32 ohm.
- Electronic tube EL34 is used for poplar and 12AU7 for dawning.
- The first stage uses a double triode 12AU7 preamplifier and a cathode resistor connected in parallel with a capacitor of 100 mu. The aim is to obtain a better low frequency response and a faithful sound base.
- The second stage also uses the double triode 12AU7 as the driving stage in the cathode output mode, in order to have a better low resistance to push the EL34.
- The third stage EL34 adopts self-supporting bias triode operation mode and AC ignition power supply mode.
- Power transformer and output transformer are specially designed and customized for the machine, using high-quality wide-band sound and high-quality Japanese Z11 core.
- Rated output power: external speaker output: 4W + 4W (4-8 ohm load).
- Balanced headphone output: 2 200 M W + 2 200 m w (32 m load)
- Single ended headphone output: 600MW + 600MW (32 ohm load)
- Whole machine frequency response: 20Hz to 50kHz (-1.5dB)
- Harmonic distortion: 0.5% (1kHz)
- Signal to noise ratio: 89dB
- Input sensitivity: 220mV
- Input impedance: 100K
- Use vacuum tube: 12AU7 X2, EL34 x2
- Working conditions: temperature: 0 ~ 40 ~ humidity: 20% ~ 80%
- Storage conditions: temperature: -20 ~ 70 C humidity: 20% ~ 90%