PLENUE is High Fidelity audio brand of "COWON" wich is once a leader in the MP3 market with iriver. It is a brand that corresponds to the Astell&kern(AK) of iriver. PLENUE L is PLENUE's flagship product. PLENUE is only a DAP that is specialized for sound reproduction. It uses embedded Linux instead of Android, and there is no wireless communication function including BT, WIFI, NFC. The price is lower than AK, despite the amazing performance.Below is a diagram of my equipment.I use apple music to explore new music, but I don't use it frequently. Because I like to own music rather than streaming. PLENUE L has 256GB of internal memory and a micro sd card slot which can expend to 2TB, so I can store more music than my own macbook pro.I also set up PLENUE L to build a complete silent system. Combine with a stand-alone DAC, the LYNX HILO, to get rid of PC fan noise and HDD noise.In speaker system, PLENUE L and LYNX HILO are connected by optical connection. in-ear headphones and headphones are connected to the 3.5mm or 4.4mm headphone jack of PLENUE L. Thanks to these features, PLENUE L is my main music device.See below liink for more information.The following measurements were taken with APx555. For load measurements, a 32 ohm stereo resistor was connected in parallel.3.5mm unbalanced headphone jack measurement with no load condition4.4mm balanced headphone jack measurement with no load conditionThe measurements below are measurements of the 3.5mm headphone jack and are measured at the maximum output with no load condition unless otherwise noted.PLENUE L is equipped with Ess9038Pro. You can select eight filters built into the DAC.The frequency response is very impressive.SNRPLENUE L has no mute function found on some other devices. The mute function turns the amplifier off during the silent interval that occurs during SNR measurement, making the SNR look better.So we do DNR (Dynamic Range) measurements together. DNR measurements are not measured at maximum power and silence, unlike SNR. DNR is measured using signals of -60 dBFS and 0 dBFS instead of silence.By default, the SNR and DNR values must be the same. If it is different, you should suspect mute cheating. However, CCIR-2K weighting is applied for DNR measurements and A-weighting is applied for SNR. It produces a 3-4dB difference between these two filters. The 3-4 dB difference is the difference in the filter, not the cheating.Residual noise @ Maximum Volume. Because there is no mute function, the residual noise value did not change. Very impressive value. Noise could not be heard with very high sensitivity in-ear headphones.SMPTE RatioCrosstalkOutput impedande is 0.876ΩThe following measurements were taken in a 32-ohm load environment.PLENUE L is equipped with earphone mode and headphone mode. There is no difference in the signal path between these two, only the maximum output limit in earphone mode. In each mode, 140 steps of volume are applied. This is the 137-step volume of the 140-step volume based on the headphone mode.A 32-ohm load is connected in parallel and the output is 1.732Vrms. Very low THD level until just before clipping.※ SINAD is the inverse of THD + N.Clipping occurs in Volume step 138 @32Ω.ConclusionPLENUE L is a DAP that shows extraordinary performance. As well as no-load measurement, it shows perfect performance even on a 32-ohm load. Considering the actual headroom of the music source, there will be no clipping on the 32-ohm load. I suspect it will work well at lower impedance loads. Very low output impedance and residual noise can satisfy in-ear headphones with multiple BA.The output from the 4.4mm balanced headphone jack also provides high voltage for driving low sensitivity headphones. I even use the AKG K1000, which is designed to be used in conjunction with a power amplifier, directly to PLENUE L.Thank you for taking a long time to read. I can often have strange expressions because English is not my first language. Perhaps the evolution of Google Translator, which reflects machine learning, will enable better communication.Questions and comments are welcome at any time. Because I wrote at dawn time, I would sleep and get up and answer.