The AVA Vision Q Phono Preamplifier is a direct-coupled, high-performance, solid state phono preamp with split passive EQ and high current buffered output circuits to handle long cables, complex tape loops, and other difficult loads.
The Vision Q Phono Preamplifier supports both moving magnet and moving coil phono cartridges and provides variable loading and gain for MC cartridges.
The Vision Q Phono Preamplifier provides 40 dB gain for normal moving magnet cartridges and switchable 54 dB, 60 dB, and 66 dB gain for moving coil cartridges. The load input settings for moving coil cartridges range from 30 ohm to 1K ohm with many settings in between. This is all done with a 10-position dip switch per channel.
Vision Q Phono Preamplifier is available both as a free standing unit and as an option that can be built into all new AVA preamplifiers. It is also available as an outstanding upgrade to the phono sections of almost any older AVA preamplifier. If you own a preamplifier without a phono section and now wish you could have great RIAA phono performance without starting over again or spending a fortune, we have just what you need, an Audio by Van Alstine RIAA Phono Preamplifier.
The AVA Q Vision Phono Preamplifier is suitable for any normal output moving magnet phono cartridgeor low output moving coil phono cartridge. It comes packaged in our rock solid 7" wide x 5" deep x 2.5" high chassis. It has gold plated phono inputs, gold plated line outputs, and a lighted power switch. Connect the Vision Q Phono Preamplifier to your line preamplifier or receiver and enjoy records all over again.
Unlike other designs, we do not need a third amplification stage, just a much better choice, an outstanding current buffer to isolate the second passive EQ section from the real world. We tested and listened to almost all the modern linear ICs available, some even surface mount chip types. We finalized the design with the LT1028 ICs for the first and second stage. The third stage uses a LME49600 current buffer to isolate the EQ from the real world and provide nearly one-quarter ampere of current drive to interface with any real world load. This combination provides the low noise and grain free outstanding dynamic range we demand. We never considered dual ICs because of their higher cross talk and distortion issues.
Because the integrated circuits we selected have very low DC offset or drift, all coupling capacitors have been eliminated from the signal path. The Vision Q Phono Preamplifier is direct coupled from input to output. Because the linear ICs are driven to unity gain at DC, you have no worries about which brand or type of coupling capacitors to use there are none. The two capacitors in the passive EQ sections are select polypropylene types. There is plenty of raw power supply built into the Vision Q board itself, along with carefully regulated analog power supplies and decoupling directly at each active device.
Power Supply and Layout
In our 7" x 5" x 2.5" chassis, the power transformer is supplied in a separate small "wall wart" so there is no significant AC noise inside the chassis. The plus and minus 15 volt analog regulated power supplies are built on an isolated section of the audio board. There are no noisy switching power supplies.