Single crystal copper 5N Cu+Ag OCC degree silver enameled wire wound 20Ω 40Ω: 3K6 permalloy LP MC cartridge balanced output transformer.
The MC pickup booster transformers on the market are mostly single-ended outputs, and the balanced output is very small. The permalloy LP MC cartridge balance output transformer wound with single crystal copper 5N Cu+Ag OCC silver enameled wire has almost no use. The balance of the MC pickup booster transformer with good material winding is obvious.
Use Shanghai Jizhen series single crystal copper enamel wrapping material to wrap the transformer. As long as your playing equipment is good, you can listen to it, you can obviously hear the difference, especially the AB switching contrast immediately to hear the difference, for ordinary equipment and wooden ears. Fans don't want to join in the fun.
Single crystal copper wire (OCC for short) is used in the production of audio wire, which is a major breakthrough in the audio wire manufacturing industry in recent years. Scientific experiments have shown that single crystal copper is a kind of high-purity oxygen-free copper, and its whole copper rod is composed of only one crystal grain, and there is no "grain boundary" generated between crystal grains. The "grain boundary" will reflect and refract the passing signal, causing signal distortion and attenuation, and thus has high signal transmission performance.
5N Cu+Ag OCC single crystal copper silver plated gold film series enameled wire is quite different from general enamelled copper wire, especially in high conductivity or anti-interference characteristics and various efficiency, high density smooth The paint surface is not comparable to ordinary OFC copper and low-purity copper enameled wire. It is widely used, especially for sound, and has a positive impact on sound quality.
Single crystal copper wire (OCC for short) is used in the production of audio wire, which is a major breakthrough in the audio wire manufacturing industry in recent years.
5N OCC single crystal copper enameled wire is used for audio signal cattle, vinyl MC pickup booster cattle, amplifier input and output cattle, passive booster cattle, audio signal lines, etc., with outstanding performance.
This MC cartridge balances the transformer, inputs three lines, outputs three lines, and the head balance amplifier is used together.
Suitable for 3Ω to 100Ω MC cartridges. Can also be ordered to order!
The MM phono amplifier is preceded by an MC hopper booster transformer, which becomes the MC phono amplifier. There are a variety of MM phono amplifier boards in this part. It is equipped with integrated block assembly and useful tube assembly. Look in the LP phono amplifier column. .
The LP record is attenuated at the low frequency during recording, and the high frequency is aggravated. The RIAA equalization curve needs to be compensated when the phonograph is played. The advanced record player uses the MC moving coil phono, and its impedance is only a few ohms to ten ohms. The output voltage Only 0.05~0.5mV, need to boost the booster plus preamplifier.
The primary impedance of the step-up transformer is 3 to 5 times the output impedance of the cartridge. If the MC pickup impedance is 10 ohms, the primary impedance of the transformer is 30 to 50 ohms, the ratio is set to 1:10, and the impedance ratio is 40:3600. In order to avoid the electromagnetic field interference to the transformer, it is necessary to use double-layer or multi-layer isolation shielding with permalloy sheet and aluminum or copper to prevent interference.
The imported material with nickel content of 85% high magnetic permeability nickel material is punched and cut, placed on a high speed punching machine and punched with a special tungsten steel mold at high speed, placed in a hydrogen furnace and subjected to a complicated heat treatment process without rusting. Corrosion resistance can be used for a long time. The initial magnetic permeability of this EI film is 100,000 and the highest magnetic permeability is 400,000. Used to replace the ordinary transformer core can greatly improve the inductance of the transformer core, the quality of the sound quality and leap, the best material for the MC cartridge transformer.
With this EI film winding LP pickup booster or signal coupling transformer small size and large inductance, it has a very good effect. Core size: length 25.5mm × height 19mm × stack thickness about 12mm, transformer sheet thickness is only 0.16mm as shown below.
This transformer is an acoustic LP vinyl MC pickup booster transformer. It disassembles a variety of famous cows to improve the winding, copper foil shielding, and uses complex winding method to reduce leakage inductance and distributed capacitance and expand the frequency response.
Luge LG 20Ω 40Ω: 3K6 Permalloy LP MC cartridge transformer The measured parameters of the transformer are as follows
Frequency response: 10Hz ~ 170KHz -2.8DB
The primary of the transformer, the copper resistance is about 24 ohms, and the inductance is about 4.6H.
The secondary pole copper resistance is about 270 ohms, and the inductance is about 380H.
20Ω and 3K6. The turns ratio is 13.5 and the boost is 13.5 times.
40Ω and 3K6. The turns ratio is 9.5 and the boost is 9.5 times.
Test Equipment:
Signal Generator: Japan LEADER Lida LAG-120A
Level meter: Japan KENEOOD Kenwood VT-186
Oscilloscope: Japan KENEOOD Kenwood CS-5175 100MHz
Bridge: VICTOR wins 4090B bench-top precision numbers.
Transformer data is measured, welcome to the site to communicate
The inductance is based on the VICTOR victory 4090B benchtop digital precision bridge 100HZ frequency test.
When the transformer is sold, the test parameters are marked on the transformer and the similar matches are selected. The permalloy shield is connected to the circuit board as shown below.
The permalloy screen upper and lower cover is connected with the double-layer circuit board as shown below.
The transformer is provided with a three-layer shield cover, a double-layer circuit board, and a shield cover welded on the circuit board to effectively isolate and dry.
The outer second layer is a shielded iron cover, and the inner layer is a permalloy shield, which can shield most of the magnetic field and electric field interference. The copper cover, the aluminum cover and the iron cover cannot be compared. This is why the recording head, MC cartridge transformer, and MC microphone transformer use a Permalloy shield. Otherwise, it is easy to capture or inductive interference, and it always makes a clean communication sound.
The cover is available in green and silver and shipped randomly.
How to make MC step-up transformer, the first is theoretical design, then the material selection and winding process.
The preferred material is an excellent performance and heat-treated permalloy material containing more than 85 nickel. Why use this precious metal material? What happens with silicon steel sheets? Its practical silicon steel sheet is not easy to do well, the indicators are not going up, the effect is far less than the use of permalloy materials.
reason:
1; MC output is only 1 MV or less. This requires a very large initial magnetic permeability, which is not possible with ordinary silicon steel sheets.
2; 10 times or more of the ratio, the secondary needs a large inductance to support ordinary silicon steel sheet, because the ordinary silicon steel sheet magnetic permeability is not enough, to use silicon steel sheet to achieve this inductance, the volume should use the transformer iron state above EI48, it itself The iron loss and copper loss are almost exhausted for the 1 MV signal, and the large-capacity distributed capacitance and leakage inductance are very detrimental to the high-frequency attenuation.
Permalloy is actually a nickel-iron plate. It is divided into PC and PB according to the different import standards of nickel. The content is about 85% and 50% respectively. The corresponding Chinese standard is IJ85-75 and IJ50 is actually the nickel content.
The significance of the nickel-containing ratio is the most expensive in 70-90% of nickel-containing sheets, mainly for small signal picking, such as the magnetic head of the cassette and the pickup of the LP. Utilizing the high initial permeability and very low iron loss of permalloy, excellent frequency characteristics, etc., it is suitable for use in MC transformers or pre-stage cattle.
A good iron core should have a good enameled wire. The wire used in this booster cow is thinner than the hairline, because the large iron core will bring a large leakage inductance and a large distributed capacitance, MC does not need a large current, which determines the use of a relatively small core, with fine Wires are wound thousands of turns. This kind of thin wire can be directly welded by QA specification without stripping, and the loss of film medium is small to help high frequency. If it is not a high-grade pure copper, it is impossible to pull out such a thin line, so the finer the line, the higher the purity requirement for copper.
E25 permalloy is more suitable for LP booster cattle than E19 permalloy. This part has been tested several times.
Leakage inductance is the culprit of high frequency and detail, and the winding process is a means and method to reduce leakage inductance.
Material and design optimization is important to minimize the loss of copper resistance to the signal.
The impregnating material is low in loss by the high frequency wax medium.
Wind the equipment with good materials and good CNC machinery.
For the very low voltage output of the MC cartridge, it must have good impedance adaptability, increase the voltage of a few millivolts by a factor of 10-20, and filter the clutter to increase the signal-to-noise ratio. The high ratio has brought about high difficulty. Through a lot of practice, the frequency response of the MC cartridge transformer has been finally solved, and the sound is more powerful.
The adaptability of the MC cartridge step-up transformer to impedance is tested from variable frequency and 2-100Ω source impedance. The index is basically consistent with the design and the effect is satisfactory.
The output impedance of the general signal source is 50-600Ω, and the output amplitude is far greater than the voltage amplitude of the cartridge. During the test, the impedance converter is externally connected to the signal source output 600Ω impedance to 10Ω impedance, so that the source impedance matches the impedance of the test transformer. That is, Zr=ZL, the test result is accurate. This impedance converter uses the famous Swedish LUNDAHL
Lunda converter.
Test situation
1 Inductance, relative to the primary impedance 10Ω MC cartridge, to meet 20Hz (-1dB) requires about 0.19H inductance, considering the voltage of the pickup 0.2mV, the cartridge transformer must have high enough inductance to avoid attenuation and Reducing the insertion loss, a 0.2mV voltage attenuation is a pity, and it also affects the details of the music. For the ultimate, the low frequency 20Hz is further reduced by 10 times, that is, 2Hz, the primary inductance is 1.9H at -1dB, and the measured L-4.6H of the pickup transformer is much larger than 2H (bridge 100Hz 1V test). The secondary inductance is 560H.
2 Primary DC resistance optimized design, measured R = 24Ω.
3 Frequency response 10Hz ~ 170KHz -2.8DB, 1KHz 0dB reference point.
4 square wave test frequency, 20Hz, 40Hz, 100Hz, 1KHz, 10KHz, 20KHz.
The above test data can be mutually confirmed. For example, if the primary inductance is <1.9H, then the frequency response of 2Hz (-1dB) cannot be achieved.
