New improvements in 2020 production (Q2 and later, designated Lino C 2.2)
Each active device handling the audio signal chain now has its own additional local, ultra low ESR, low inductance bulk storage located less than 2 millimeters away from each device. This improves dynamics and channel separation (which already were excellent) and slightly reduces harmonic distortion. All other active devices supporting other circuit functions (signal level detection, active input stage class A biasing) each have additional ultra low ESR, low inductance bypass.
Why wasn’t this done previously? Selecting high performance components for power supply bypassing matters a lot, and during initial production of the Lino C 2.0 we were still in the process of evaluating dozens of different new MLC capacitors from different manufacturers, selecting for low ESR, inductance and DC bias sensitivity and eventually found some that were substantially better than others, that is, better enough to make a difference. These are all new components that only became available relatively recently. It wouldn’t have been worth it to blindly incorporate such parts without actual testing: spec sheets don’t provide the kind of information needed. Picking parts without careful testing might not have made any difference in the performance of the Lino C. In the process of this testing we found new parts that were absolutely perfect for the Lino C, and updated the PCB layout accordingly to accommodate them.
There is now full isolation of the signal return path for the unbalanced outputs from the rest of the PCB directly to the driver circuitry, and greater isolation of pin 1 for the balanced outputs. There are additional circuit protection devices on all outputs, and better isolation of all inputs and outputs from EMI and RF. The galvanic isolation of the power regulation board is improved, as is the battery management.
Due to improvements to the main circuit board, the impedance of the passive part of the RIAA network has been reduced by over a factor of 3 compared to the original 2.0 version. Lower impedance reduces the effect of capacitor dissipation which in terms of sound quality improves clarity and definition, while also slightly improving SNR. The lower impedance also allowed upgrading the active RIAA amplifier to a lower noise and lower distortion design. The revised 4-layer PCB improves loop current management, improving channel separation and reducing distortion. The RIAA accuracy is improved. Finally the RIAA board now has its own class A auto-bias circuit, since we found that was beneficial on the main circuit board, as well.
