DESIGNED AND HAND CRAFTED BY MR LABS

BASED ON SWISS PRECISION ENGINEERING

VERA 20 Phono Preamplifier - Product Details

The VERA 20 is a five stage design, comprising

  • Active Input Stage
  • Passive Treble Equalization Network
  • First Amplifier Stage
  • Passive Bass Equalization Network
  • Second Amplifier Stage

The active input stage is identical to the one of the VERA 10

Following the input stage, a passive frequency equalization network is provided, yielding the proper treble equalization of the RIAA recording curve. Also in this case, only the highest quality components are used for this passive network, particularly AudioCap Theta polypropylene film and tin foil capacitors and Vishay CMF precision metal film resistors with excellent high frequency characteristics, exceptionally low noise and low temperature coefficient. Each set of capacitors and resistors of each channel of the VERA 20 phono preamplifier is individually matched to ensure that the specified accuracy of RIAA equalization is met or exceeded.

The equalized signal is fed to the input of the first amplifier stage. It has the topology of a discrete fully complementary operational amplifier operated in pure class A, having an open loop gain of around 70db, a unity gain frequency response of >1MHz and an output impedance of <2Ω. The closed loop gain of this stage is user-selectable in five steps. Due to the use of highest grade components and careful manual matching of parts, the behavior of this stage comes very close to an ideal operational amplifier.

A further passive bass equalization stage follows the first amplifier stage. The same is true regarding the components quality and the matching as is outlined in connection with the treble equalization network herein above.

Finally, a second amplifier stage follows the bass equalization network with the same characteristics as the first amplifier stage, except the gain is fixed.