VINYL MKII – MC / MM Phono Preamp

Description

The VINYL MKII is a MM / MC phono preamp (Phonostage) based on two mono-block amp topology in one case, and has all the benefits of a mono-block design. Four gain options and five load options, makes it a very versatile phonostage that can be adjusted to cope with almost every cartridge avilable. Carfully designed infrasonic filter makes it highly durable to disk warps, and other low-frequencies created by the resonance of the tonearm/cartridge combination. A very accurate RIAA curve is achieved by using 3 stage topology design.
The VINYL MKII comes with an external transformer, and has an internal regulated power supply.

All AQUA-AUDIO products are hand made.

Special design features

• Selectable gain settings.
• Selectable load settings for MC cartridges.
• Selectable features made with on-borad jumpers to reduce PCB traces length.
• Selection between MC / MM is made with on-board relays to assure short traces. Gold-plated contacts of the relays assures very high quality signal path.
• Thired-order infrasonic filter.
• Very high separation between the channels.
• PCB topology for optimizing channel separation.
• Very high endurance for RFI and EMI interferences.
• Internal regulated power supply and noise filtering.
• External transformer.
• No digital logic.
• Internal shielded wiring in minimum length.
• snubber capacitors.
• Ferrites on the incoming power lines.

 

Specifications

MM Gain (selectable):	38db / 42db
MC Gain (selectable):	48db / 52db
Noise @ 1KHz shorten inputs:	-115db
Signal to noise:	>89dB
THD:	0.002% @ 1kHz
RIAA deviation:	0.1db
MM Input impedance:	47k / 100pF
MC Input impedance (selectable):	85, 100, 360, 560, 1000 Ohm
Power supply:	AC transformer (2 x 18V/1000mA)
Size (W x D x H):	105mm x 200mm x 65mm
Weight:	530grams (without ps)

 

RIAA curve with and without infrasonic filter:

About The PCB Design
In order to optimize the board’s immunity to external interferences, 5 copper planes were designed; 3 top and bottom ground planes and 2 power planes. The two upper side (one on the top layer and one at the bottom layer) ground planes gives the circuit high immunity to radiated interferences (RFI/EMI). The three bottom side copper plains (one ground plane at the bottom layer and two power planes at the top layer) creates small capacitance (about 120pF for each power rail) that acts like a filtering capacitor to high frequencies that managed to penetrate through the power lines filtering ferrites. One star grounding point reduces ground current noises to the possible minimum, and prevents ground loops.