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When using a genuine CCxx LEF amplifier module (e.g. CC75 or CC80) a sound quality improvement and design simplification are easy to achieve. Due to the LEF current amplifier and a very low THD voltage amplifier stage a negative feedback loop is not necessary anymore.

Fig. 2 shows such design.
The current to voltage conversion is done passively without any dynamic sound quality degradation. 6 signal “copies” of the traditional design are replaced by just 2 signal “copies” - just one voltage amplifier stage and one LEF current driver.

In addition the basic circuitry of the CCxx modules suites balanced designs much better than any OP-amplifier. Most high quality applications require balanced circuitry. A true balanced circuitry solution with operational amplifiers further increases the number of amplifier stages.


Even though this circuit already improves the sound quality remarkably compared to traditional solutions, it is not perfect indeed. The passive current to voltage conversion causes a voltage swing at the DAC output. Thus some DAC increase the amount of harmonic distortions. The noise figures of a single ended class A amplifier without any negative feedback loop are limited to about 100 dB, which is quite good already.

The voltage amplifier inside the CCxx module produces a higher distortion level than a traditional amplifier with negative feedback loop correction. The total distortion level is about 10 times higher than high quality OP-amplifier solutions. Regarding no use of any feedback loop this is an excellent result anyway.


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