No.6.4 is an integrated transistor amplifier with remote function. With low-price it mainly aims to family use. Its appearance looks penny-plain, quiet, connotative and straight-ahead and circuit uses our patent one that has been registered with the State Intellectual Property Office of P.R China. The protected range of its circuit involves four contents as below.
1. Single-end common-collector and common emitter configuration in voltage amplifier.
2. Bi-directional zero climax compensation network.
3. Comparatively bucking circuit for negative feedback distortion.
4. Circuit connection method to improve common-mode rejection ratio
The original intention for the development of this circuit originated from the study and parse of favorable effect of tube audio amplifier, referring to aesthetic psych and custom of general musical fans and audiophiles to make the audio amplifier richen capacity of musical expression and sonic beauty.
The kernel part of the circuit, “voltage amplifier with single-end common-collector and common emitter configuration”, is different from conventional voltage amplifiers with common-emitter and common-base configuration. For instance, its common-collector amplifying stage switches from voltage signal provided by input difference amplifying stage to current amplification and this effectively improves the distortion at the network interface between common-emitter voltages amplifying stage and input difference amplifying stage. Also due to the circuit characteristics of common-collector amplifying stage, the spectral characteristic of voltage amplifier reaches a design goal------among the element of total harmonic distortions, even harmonics is much more than odd harmonics, and as a result the harmonic distortion at high-frequency band (10 KHz-30 KHz) is well improved, having a lower harmonic distortion than at mid-frequency (1KHZ). So in the way of this it is very different from other normal transistor amplifiers. The “bi-directional zero climax compensation networks” compensate respectively bidirectional compensation, lead and lag, for the characteristic of open-loop and closed-loop. Three points are set up at the network that features 6db/OCT with ideal internal and external characteristic. The curved line of frequency response drops simply, smoothly and slowly without any peak-to-valley, approximating1MHz at zero position.
During the design we used software, PSpic, to make the circuitry emulative optimization.
No.6.4 adopts the PCB with 2oz copper-foil and widens fusion tin at the place where large current pass through. And special-designed toroidal transformers and imported components in high quality are used.
Specifications:
- Output Power:80W(8ohmRMS) 120W(4ohmRMS)
- Total Harmonic Distortion(THD+N):0.015%(1KHz 80W 8ohm) 0.015%(10KHz 80W 8ohm)
- Intermodulation Distortion:0.09%(70Hz/7KHz=4:1 50W)
- Frequency Response:5Hz-125KHz(-3dB 80W)
- Gain:36.5dB
- Load Impedance:4ohm-16ohm
- Input Sensitivity:0.38V
- Input Impedance:50Kohm
- S/N:101dB(without weight)
- Input Interface:RCA 4groups
- Power Voltage:Customized according to different mains voltage in different countries and regions.
- Static Consumption: 12W
- Dimension:430(W)×260(D)×65(H)
- Packing Dimension:470mm(W)×410mm(D)×150mm(H)
- Net Weight:7.4Kg
- Gross Weight:10Kg
