Balanced XLR to single-ended RCA output dual op amp line finished board: line by the famous British amplifier designer Douglas Self design, line design unique, making the circuit with ultra-low distortion of the excellent performance, the noise is very low. New PCB is Blue Color.

 

The distortion and noise of this line is much lower than the average circuit, so the circuit looks less simple and slightly complicated, the purpose is low distortion and low noise. In general, the balance signal should be converted to unbalanced (single-ended) output signal, you can use 1/2 of the NE5532 plus 4x10K resistance, according to the schematic diagram IC2A can be achieved. At this point in the figure R5 ~ R8 are taken 10K, a pair of balanced signals from the left side of the R5 R6 input, from the right end of R9 can be single-ended output signal. This differential amplifier circuit is fairly simple. Output noise is also low, roughly up to -104dBu (0dBu = 775mV), but still feel the noise is large, for this purpose using the so-called double balance level, that is, by the IC2A, IC2B composed of two differential amplification stage, they were simultaneously received The balanced input signal is then added so that the irrelevant noise is partially offset, resulting in a 3dB reduction in noise while also improving the circuit common mode rejection ratio (CMRR).

 

Further improvements are also in the IC2A, IC2B before the increase of a voltage follower IC1A, IC1B. This is not only improve the input impedance, but also to IC2A, IC2B 8 resistance R5, R6, R7, R8, R13, R14, R15, R16 resistance from the original 10K down to 820ohm, greatly reducing the thermal noise resistance, Ultimately, the level of noise reduced by -112dBu, than the traditional single differential circuit to improve the 8dB as much.

 

 

Friendly reminder: use the time to pay special attention to the supply voltage should not exceed ±18V.

 

Three lines balanced XLR signals not take the wrong. NE5532 manifold circuit board and some electrolysis is used to disassemble genuine. Some capacitors used brands, models, specifications will be slightly different.

 

Exquisite double-sided FR4 fiberglass boards, high-quality PCB board (77 X 37mm), thickness 2mm arc traces a little ground. Continued ±5V~±15V stable voltage to work.

 

Work mode: The circuit board used in the CD player, XLR balanced output signal via line converted to a single-ended RCA outputs to the next stage (pre-amp / amplifier).

 

The board can put a better op amp, such as AD826, AD827, OPA2134, OPA2604, OPA2111 op amps and other high, the effect will be extraordinary.

 

Package Included:
1x Balanced to unbalanced XLR to RCA pre-amplifier Bare PCB