Established physical store, credit guarantee
Our shop is: fever-reducing forum, earphone everyone forum, certified business, industry member
Our shop is Ledi Audio: the total generation of Beijing-Tianjin-Hebei
Ledi Audio Power of Attorney
Front panel
The front panel of the original machine, for comparison only
Internal structure
Strictly follow the original machine testing, production links, and professional instrument testing
Product introduction:
After more than a year of repeated debugging of the FM222MKIII, the re-enacted version of Ledi was finally completed, and a lot of time and energy were spent from debugging to production. The output voltage of the cartridge is very low, and the output of the MM cartridge is 1mv to
Between 5mv, MC cartridge output is lower between 0.1mv and 0.5mv. To get enough output voltage, weak cartridges need to be amplified to more than 1,300 times to provide proper volume. Amplification of weak signals is extremely prone to noise and serious distortion.
FM phono amplifier circuit: using full discrete components to manually calibrate the precision class A module amplification, the accuracy of component selection is more stringent than the previous stage, which is more difficult. To go through high precision
Close adjustment to reduce THD+N and ensure the reduction of vinyl. A slight irregularity will result in low noise ratio and high distortion.
signal input, two truly fully balanced inputs(If the customer has special requirements, it can be changed to a set of RCA input and a set of fully balanced input, it is recommended to use fully balanced input). Input impedance cartridge standard module(The input impedance cartridge can be configured according to the customer''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s cartridge): MC cartridge: 180, 90, 45, 35 ohm; MM cartridge: 100, 47, 33, 24 KOhm. MC input to output 1KHZ: 52dB/62dB (+10dB switch) . Input capacitive reactance: 0.68, 1.5, 2.2uf (this function should be adjusted according to the system hearing). LF filter Z: 12dB/octave linear phase filter, no negative effect on audio signal. RIAA: The unique variable RIAA de-emphasis function can accurately linearize any recording mode. It is better to restore some precious early recording vinyl.
The input module adopts truly fully balanced input, with 100dB suppression of common mode signals such as interference and noise. This amazing interference rejection ratio is not achieved with a non-optimal op amp, but with a class-A circuit with precision trimming discrete components. With the new “HR” 19200 module for truly balanced output, these new modules are different from the 19200 used by the 255, they provide unprecedented accuracy and excellent reproduction and reliability.(We are very mature in the process of producing replicas of FM255MKII and FM266MKII. The precise debugging of the module is so precise that the output square wave is consistent with the positive and negative waveforms of 20KH, which is also an extremely difficult challenge.).
Component selection: The decoupling capacitor adopts the high-frequency low-resistance electrolytic capacitor customized by a military industry manufacturer, and the coupling capacitor adopts the original Nikon series. The transistors are paired with precision aging, and the module is powered on and adjusted by AP calibration. The module box is gold-plated with 0.5 thick tinplate for better shielding and more beautiful appearance(Due to the large workload, high production difficulty and long time, sometimes it may not be delivered on time and the delivery time needs to be extended.).