Ypsilon Preamplifier & Phono Stages
Conventional wisdom suggests that the most critical part of a preamplifier is the active circuit design. We, however, believe that the means of signal attenuation (the volume control) is the most critical to the overall sound of a preamplifier.
Most designers use resistor attenuators for volume control. We have used resistor attenuators with high quality resistors (Vishay, in the past, felt unsatisfied from the character they induced in the signal. We developed a very special transformer as the means of attenuation, using special winding techniques and highest quality wires and cores. Its performance suppassed that of the best resistor attenuators.
In a transformer the magnetic circuit can be ultra linear when the very best core materials are used. The sound of such materials is much more musical and detailed compared with the best resistors. A transformer attenuator with 31 taps is used in the PST100 mk2 providing a total attenuation of 54db in its lowest tap.
Usually RIAA equalizer circuits are implemented with capacitors and resistors (CR networks). Capacitors present the so called “dielectric absorption” -energy is stored in the dielectric material and is added to the signal with a small delay producing a ringing character in fundamental notes.
This ringing behavior can be noticed in piano notes. In the past an alternative way of implementing a RIAA equalizer the LCR (Inductance-capacitance-resistance) circuit was proposed.
The best way of driving the LCR network is by using a transformer. We design and build ourselves the transformers using a special amorphous c-core material. Winding insulation is paper. A properly implemented LCR RIAA sounds much more natural, musical and open than CR networks with better defined macro and micro dynamics.
The construction uses no printed circuit boards and is point to point silver wired using our own extruded and annealed to spec silver wire.
The MC series moving coil step-up transformers are used to amplify the low level output signal from a moving coil cartridge bringing it to the appropriate level to drive a moving magnet phono preamp.
The MC series transformers are large size single C-core double coil transformers using a proprietary amorphous core material. Special winding techniques were developed in order to minimize inter-winding capacitances and maintain wide frequency response. They are optimized sonically to be as invisible as possible.
The MC transformers were developed in conjunction with the VPS100 phono preamp. They can be used with most of the moving coil cartridges.