- Posted by bcherry (M) on June 01, 2009 at 02:56:47
In Reply to: RE: Another Ultimate Module - Remote Volume/Source Controller posted by bcherry on May 28, 2009 at 20:02:01
DIY HiFi Supply Preamplifier Control System Introduction:
This Preamplifier Control System uses an electronic potentiometer as used in all current Audio Research Preamplifiers, unlike other common volume control chips this device does not contain a build in op-amp. The Preamplifier Control System consists of two PCBs:
Audio PCB:
1. 2 channels
2. 5-way input switching, and
3. Volume control, can be configured as mono balanced or stereo single ended
Control PCB:
1. ALPS rotary encoders
2. LED indication of input & volume, and
3. Power-supplies and microprocessor controlFeatures:
127 step volume control from -52dB to 0dB attenuation with 12 LED level indicators
5 Inputs with LED indicators
Remote control via universal remote control (RC5 code)
Options for shunt operation (-46dB to -3dB or -52dB to -6dB)
5 way Silver alloy relay input switching
LED’s driven on/off, not “multiplexed” to remove digital noise
Audio PCB includes option for fitting two LSK389B Zero FeedBack J-Fet buffer (direct coupled – no coupling capacitors) to make a stand alone buffered passive preamplifier with <50Ohm Output Impedance
Control PCB delivered as one PCB but allows “break-off” of the rotary encoder & LED parts (connection via 20-Pin IDC cables (supplied)
Control PCB can control up to 3 Audio PCB’s (6 channels single ended or 3 channels balanced); with optional transformer can control up to 8 Audio PCB’s (16 channels single ended or 8 channels balanced)
Control PCB connects to Audio PCB via 20-Pin IDC cables (supplied)
Power Supply using schottky diodes and low noise regulators
Torroidal mains transformer with 115/230V Primary capable of supporting 3 Audio PCB’s with buffer fitted included
Mains transformer with 115/230V Primary capable of supporting 3 Audio PCB’s with buffer fitted included
Gold plated, 70 micron Copper PCB’s
Includes drill template (PDF for printing on paper) for drilling front panels for LED's, encoders and fittings
DIY - Done Right!
Edits: 06/02/09 06/07/09
