phono-2 is a result of continuous learning which made it possible to meet high level performance of phono-1 and, at the same time, provide more convenient optimization for a wide variety of MM and MC cartridges.
The robust steel chassis houses preamplifier circuits and stabilized and filtered power supply. External power supply is a simple line frequency transformer, dislocated to eliminate influence of electromagnetic fields on the sensitive electronics.
Bottom side of phono-2 hosts micro switches used to set cartridge loading (Load), preamplifier gain (Gain) and output filtration (Low-pass filter). Examples of optimum load and gain settings are listed here. The image below show unit set for 10k load, 55dB gain and 10Hz slow roll-off filter.
Eight discrete loads can be set by using individual switches (47k, 22k, 10k, 1k, 500ohm, 200ohm, 100ohm, and 47ohm). The cartridge load is set by engaging switches as indicated by the legent printed between the switches. Picture below illustrates load setting of 200ohm. By combining loads, many more different combinations are possible(for example - combining 22k and 10k switches, the resulting load will be 6.8k).
If that in not sufficient, similarly to phono-1's load and gain optimization, phono-2 can have unlimited settings available by removing top cover and accessing terminals for insertion of additional loading resistors and capacitors. Those terminals are marked R11 and R12 for loading resistors and C11 and C12 for loading capacitors. NOTE: in order to accurately load the cartridge with the additional resistors, all microswitches on the rear panel should be in the OFF position. When adding loading capacitance, the default capacitance of 50pF should be accounted for: as example - if the total loading capacitance of 200pF is desired, additional capacitor needs to have value of 150pF. Capacitors and resistors with lead diameter in the range of 0.025-0.032" (0.6-0.8mm) can be safely inserted. Larger diameter may cause damage to the sockets.
There are six different gain settings possible: 40dB, 50dB, 55dB, 60dB, 65dB and 70dB. the Preamplifier gain is set by engaging microswitches as indicated by the printed legend next to the switch. The picture below illustrates gain setting of 65dB.
The phono-2 features an innovative extension of phono-1's active offset cancellation circuit to provide output filtration without adding capacitors in the signal path. There are three available settings:
The picture bellow illustrates low pass filter setting "10Hz, Slow roll-off"
