The single tube 6N6 tube preamplifier for HOOD 1969 small class A power amplifier is simple and simple, and it is a good partner for you.
In today's many Class A circuits, the circuit with few components and good effect is not Hood 1969.
Hood 1969 pure Class-A amplifiers have slow sounds, high and low frequency extensions are good, and the sounds are round and clear, and they have a bold taste.
In order to find a drunk and simple pre-stage with the Hood amplifier, a tube amplification circuit is used to form a gallstone combination. The front and back gallbladder are mixed and married, which has the charm of the bile and the strength and speed of the stone machine. .
There are hundreds of thousands of commonly used tube models for pre-amplification. After careful selection, the input impedance and input signal voltage amplitude of the Hude small Amplifier are filtered. More than a dozen single-tube circuits are used. I think the single-tube 6N6 is very suitable. Claim.
6N6 is cheap and a cost-effective bile duct. 6N6 is a low-resistance low-power dual triode. Low-resistance high current and good linearity are generally not available in dual-triode electron tubes. It can be used for pre-amplifier voltage amplification or small power output tube. Each screen of 6N6 dissipates 4.8W and the maximum screen voltage is 300V. When using a 250V screen voltage and a grid negative voltage of 12V, each screen current is about 18mA, the screen load impedance is 3.6K, and the actual measured output power is 1.2W. The 6N6 internal resistance manual is 1.8K, which is very easy to drive the Hood body tube machine, and the driving force is full. Of course, it also has a good matching effect with the tube power amplifier.
We have debugged the circuit for this machine, made a reasonable configuration with high-quality components, selected a suitable working point, and accurately matched key components to ensure that the circuit works in the best state.
High-precision 24 gear 100K stereo volume potentiometer Liangyin dual-connected voltage-dividing stepping type, high-precision, non-inductive, low noise metal oxide film SMD chip resistance welding, the error between the two channels is less than 1%. The performance and accuracy and the use effect are far superior to the carbon membrane potentiometer.
The use of carbon film volume potentiometers is one of the main phonemes of sound quality deterioration. Only those who have used resistance welding stepped volume potentiometers know the improvement effect. Some people spend a lot of money on tonic capacitors, resistors, wires, and connectors. Only the potentiometers use carbon films. Whether it is the ALPS blue shell Nissan potentiometer or the Nissan NOBLE noble potentiometer of several hundred yuan, after all Carbon film.
Original American CMC 816U oxygen-free copper plated 24K gold RCA socket. The internal wiring adopts imported Teflon silver-plated wire. The layout is reasonable, the line is quiet, and the effect is excellent.
AC power supply: 220V50HZ (customizable 110V60HZ)
Input socket standard: RCA socket (2 groups input selection, 1 group output)
Magnification: 22 times
Dimensions: 253mm long, 152mm wide and 65mm thick (excluding knobs and terminals). The cabinet is composed of a frame and upper and lower covers. It is made of 2mm thick cold-rolled iron plate, with high precision of die opening size, gray matt paint on the surface, and aluminum alloy legs.
Weight: Net weight 2.9 kg (3.5 kg with packaging)
The reason for the non-linear distortion of the carbon film potentiometer -------- The carbon in the ordinary equal-loud carbon film potentiometer is a non-metallic semiconductor element, located in the IVA group of the second period of the periodic table, Its chemical symbol is C, its atomic number is 6, the electronic configuration is [He] 2s22p2, carbon is a semiconductor, and a carbon film potentiometer is made by coating a layer of carbon film on a horseshoe-shaped paper rubber plate. The carbon film body is formed by coating carbon black, graphite, quartz and other materials on the surface of the substrate. The rivets are used to fix the copper (or iron feet) as the lead-out solder legs. The carbon film plate and the copper feet are two types of conductor materials , PN junction is formed between them. The PN junction is also formed between the sliding copper brush in the potentiometer and the carbon membrane plate. The principle of the PN junction type diode. Overcurrent will produce nonlinear distortion and affect the sound quality. All copper contacts, there is no problem of nonlinear distortion, and the fidelity of sound quality is greatly improved. Therefore, the reason why the high-end premium audio does not use carbon film potentiometers, but the stepping switch volume potentiometers
