Major New Product Announcement - Another One!
This is our assault on state of the art volume controllers/selectors.

The Ultimate Volume/Selector Control Module can be installed in an existing amplifier/preamplfier chassis to control volume/source selection
or
can be used standalone in it's own box with optional buffer installed on the output (space provided on the circuit board) to drive an amplifier without worrying about typical impedance issues encountered by passive preamps.

The Ultimate Volume Control System:

Audio Matrix Module

The Audio circuit board: 2 Channels, 5 X Inputs with relay selection, Volume Control, power supply regulation and optional J-Fet output buffers

Provisioned are five selectable inputs, one Record/Tape output which may also be used as “direct” input, bypassing input switching if only one input is required.

Also present are connectors for one buffered output (requires optional LSK389B, 3-Pin terminal and some 0.1uF/100V capacitor) and one direct output.

These Audio Matrix Modules can be “stacked” at 25mm intervals with short IDC jumper cables daisychaining the modules uP-PSU connections.

Control Matrix Module (consist of 3 separate circuit boards linked together, (i) Input Select, (ii) uP/PSU, and (iii) Volume Control)

The Control module is in sections able to be “broken off” for independent mounting of the controls and indicator LED’s (see attached drawings).

When separated this makes 3 modules: Input selector rotary & LED’s (58mm X 56mm), uP/PSU PCB (94mm X 56mm) and Volume control rotary and LED’s (58mm X 56mm).

First, they may be mounted using the standard threaded bush and nut system (7-8mm hole required), where front panels is up to appx. 3mm thick.

Second, M3 threaded standoffs, 6mm long, may be used to mount the module to the front panel via three countersunk M3 screws extending through the front panel with the encoder module mounted to the threaded standoffs with M3 screws. The holes will be on a 22mm circle, so any knob larger than 30mm in diameter will cover the screws.

Finally the encoder module may be mounted to (threaded) blind holes in the back of the front panel using either the three hole pattern on a 22mm circle or four holes on a 48mm X 45.5mm square centered on the encoder shaft.

Some things to note:
the Control System allows either remote control or front panel knob control
Volume control function uses same devices as employed some of the biggest highend names such as Audio Research
Audio Matrix module is for 2 channels but can be stacked for 2, 4, 6 extra channels.

More to come.
DIY - Done Right!

 RE: Another Ultimate Module - Remote Volume/Source Controller - jsamp05 17:28:45 08/22/09 (2)
 RE: Another Ultimate Module - Remote Volume/Source Controller - bcherry 17:45:00 08/23/09 (1)
 RE: Another Ultimate Module - Remote Volume/Source Controller - jsamp05 19:34:21 08/23/09 (0)
 Ultimate Volume Control - Why? - bcherry 03:38:16 06/11/09 (0)
 Ultimate Volume Control System - Control Board Walk Thru - bcherry 18:34:09 06/08/09 (0)
 Ultimate VC System - Audio Board Walk Thru - bcherry 17:49:41 06/08/09 (0)
 Ultimate Volume Control System -- Applications - bcherry 03:00:25 06/01/09 (0)
 Ultimate Volume Control System -- Specifications - bcherry 02:58:22 06/01/09 (0)
 Ultimate Volume Control System -- Features - bcherry 02:56:47 06/01/09 (0)
 RE: Another Ultimate Module - Remote Volume/Source Controller - WAYNZWORLD 00:20:26 05/30/09 (1)
 RE: Another Ultimate Module - Remote Volume/Source Controller - bcherry 02:38:37 06/01/09 (0)

We refer to the Control Board as the Control Matrix because it is actually 3 modules -- Volume, Selector, Logic/PSU -- which can be snapped off and positioned to suit any size faceplate (the Volume and Selector modules communicate with the Logic Module through ribbon connectors). Or it can be mounted as one unit to a suitably sized faceplate. The 240mm Projekt chassis happens to be one that is.

The center module contains the Logic and the PSU. Note: no extra transformer is needed; as you can see, it is in place on the module and ready to be connected to either 115 or 230v mains. Signal stays on the Audio Board; the Control Matrix is programmed to do all the switching and housekeeping and via ribbon cable tells the Audio Board what to do with the signal.

The selector and attenuator switches have a shaft which allows a knob and manual control from the front panel -- or remote control using standard RC5 encoding.

The blue LED are meant to be visible through the faceplate and a drilling template is provided. The selector module has 5 LED installed -- one for each input. The Volume Control Module has 12 LED installed BUT there are actually 127 steps! We didn't think you would want to drill 127 holes for 127 LED.

Native attenuation is -52db to 0db from a reference 3.5V rms. But you horn guys are going to love this: Shunt mode allows -66db to -15db!
DIY - Done Right!

* 5 INPUTS
* REC. can also be used as a direct in (ie single source). More about this later.
* DIRECT OUT which has an output impedance of 25Kohms
* JFET OUT which uses the optional JFET (LSK389-A) devices as shown installed and has an output impedance of 50 ohms

To use as a volume control in your amp or preamp just route all signal to the audio board and use the direct out connector block. EZ drop in to replace your existing attenuator.

But there is also a possibility to build a simple standalone linestage by using the JFET outs.
For example:

* Projekt chassis 240mm is perfect (we will be offering a premounted faceplate for the Ultimate VC)
* handful of RCA jacks
* Ultimate VC System with JFET option

Now you have a fully DC coupled, 50 ohm output impedance, unity gain linestage which has NONE of the problems of passive linestages. To paraphrase one of the masters: Sort of a like a 21st century Aunt Corey's Passive Preamplifier
We are doing a buildup of this now and will blog it shortly

Next: The Control Matrix

DIY - Done Right!

• Aunt Corey

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 control

Features:

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!