PALADIN: Pre-amplifier control unit. Do you want to join in?

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JimGore

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This is the official thread for the PALADIN relay based pre-amplifier control unit.  In a previous thread I stated that I would need a minimum of 10 people joining in to make this happen (because the minimum board order is 10 units), however I am willing to push this into production if I can get 5 confirmed orders.

What is a confirmed order?  If you put your name down for a unit, I will need you to pay a deposit of R 1000 into my account to secure your unit.  After this has been received on my side, your order has been confirmed. 

Please note that this deposit is non-refundable.  That means if you decide to pull out, you will loose the deposit.

What happens if we don't get the minimum 5 confirmed orders?  In this case (and only this case) I will pay your deposit back to you.  Members with confirmed orders will decide by means of a vote as to when the deadline should be (in the case where we are slow getting to the 5 order minimum).  This will be handled via PM, and not on the open forum.

Why do I need the deposit?  I will personally incur significant expense in ordering the PCBs and purchasing all the parts.  If I order everything and people decide to pull out then I am stuck with all the parts, therefore the deposit is to reduce the financial risk involved in this venture.

I want one!  How do I order?  Take a look at the options below, then send me a PM with the bits you want.  I will then send you my banking details, asking for the deposit.  After I receive your deposit, I will put your name down under the confirmed orders list.

When will we receive our orders?  I will order everything as soon as I have the minimum 5 confirmed orders.  The PCBs should arrive within 2 to 3 weeks.  After that I will need a couple of days to assemble everything and test that the boards work.  Before I ship your boards to you, you will be required to pay the outstanding amount on your order (the total cost - your deposit).  After that I will send you the boards via courier service (at your cost), or you are welcome to collect from my home or office in Johannesburg.

Is this a kit?  Do I need to solder all those ICs on the board?  This is a kit, but not one that you need to populate completely on your own.  I will solder everything except for the attenuator resistors and the analog signal pin headers.  I will provide a link on how to calculate the resistor sizes you need, etc.  Before I send you your board, I will personally test it to ensure everything is working fine.

Is this for RCA (unbalanced) only, or will it support XLR (balanced) signal?  The standard board set is for RCA use, however you have the option of adding a second relay board which will then allow you to use the system for balanced signal processing.

Could I make a 6 channel volume control using this system?  Yes, you could achieve this by simply daisy chaining and stacking additional relay boards.

What kind of remote control will this have?  You have the option of using an Apple remote control with this system.

Can I use a different type of remote? The system will only respond to the Apple remote signals.

I already have a component which uses an Apple remote.  Won't they clash? Apple remotes are "paired" with specific devices, therefore you shouldn't have any problems with multiple Apple remotes.

What kind of attenuator is this?  It is a relay based "logarithmic resistor ladder":

Circuit_diagram_of_logarithmic_ladder_DA_converter%25252C_Mar_2012%255B1%255D.png


It allows for 64 steps of volume using 6 relays, and 24 resistors (12 per channel).

More info here if you are interested:  http://en.wikipedia.org/wiki/Logarithmic_resistor_ladder

What features does this board have?  There are standard features, and optional features.  This is to keep the cost down for people who don't want all the bells and whistles.

Standard features:

*  64 step relay based attenuator (Stereo).
*  Rotary encoder for the volume control.  It has indents, so it clicks when you turn it.

*  Set the MAXIMUM volume level.  This is a great feature for when you are having a get together and need to ensure someone else doesn't blow your speakers up! (Remote control needed).

*  Define a "turn-on" volume level.  You like to listen at level 10?  The system may be configured to be at a specific volume level when it turns on. (Remote control needed).

*  Space for 2 resistors at each point of the ladder.  This allows you to make up custom sized steps by using 2 resistors in parallel when exact impedance or perfect dB steps are required.

*  Space for larger resistors (up to 13mm long) in the attenuation circuit.  We know that superior resistors can be larger in size, so why not allow for it?

*  4x input channels (Stereo)
*  Cycle through inputs by using UP and DOWN push-buttons (push buttons not supplied)
*  1x output channel (Stereo)

*  Mute relay.
*  Mute function via front-panel push button (push button not supplied)
*  All relays are OMRON G6K-2P-Y high isolation units.

*  IR Receiver (so you want to use a remote control).

*  Power ON LED connection (LED not supplied)
*  Power OFF (Standby) LED connection (LED not supplied)

*  Separate "control board" and "relay board".  These may be stacked on top of each other if needed.
*  Pre-made ribbon cable to connect the "control board" and "relay board"

*  Isolated digital supply circuit - so the CPU and relay drivers don't interfere with your clean pre-amplifier power supply lines.
*  Digital ground is kept completely separate from the Analog ground (if you use the on-board PSU option).

*  Supply voltage between 15V and 25V DC.
*  On-board voltage regulation.

*  High quality professionally made boards with solder mask, silk screening, and gold plating.
*  Designed and assembled in RSA (by me  8))

Optional features:

*  On-board high voltage power supply which accepts 90 - 305 V AC input.  Adding this option allows you to switch on and off your pre-amplifier using the remote control, or a front panel mounted push-button (momentary, non latching) switch.  It also ensures absolutely that the digital signal from the CPU and other ICs do not interfere with your analog power supply.

*  LCD Display showing input selection as well as the volume level.  There are 2 colors of LCD, as well as 2 sizes.  Inexpensive options have a 5.2mm character size, and the better display has a 9mm character size.

*  Apple IR remote control

*  Panasonic power relay (4.4 kVA max switching capacity) with top mounted fast-on connectors for switching your linear power supply (this option requires the on-board high voltage power supply to work).

*  Additional relay board.  Need to use this system for balanced (XLR) signal?  No problem - just add a relay board.  Need to create a 10 channel pre-amplifier?  No problem - just add 4 relay boards.





Pricing
Please note that the pricing is as per the current suppliers' prices.  If the suppliers change their pricing, I will need to update these prices as well.

Control Board

Control%2520Board%2520Rev%252001.jpg


The board size is 60mm wide x 190mm long, and is mounted via the 4 corners.

The standard board requires you to provide power between 15V DC and 25V DC.  It does not have the following items mounted:  high voltage SMPS, Power Relay, AC Power input terminal, AC fuse.

Supplied with the standard board is an Alps rotary encoder as well as an IR receiver.  No buttons are included!

Standard board price is: R 620.00

Optional high voltage power supply, power relay, MOV, AC Fuse:  R 375.00 extra



Relay Board

Relay%2520Board%2520Rev%252001.jpg


The board size is 60mm wide x 190mm long, and is mounted via the 4 corners.  It may be stacked on the control board if needed.

The standard board is populated completely except for the attenuation resistors and analog pin headers.  You will need to provide and solder on your own resistors, except if you choose an optional extra from below.  The analog pin headers will be sent together with the board, but are not soldered in because some users will want to solder cables directly to the board.

Standard board price is: R 780.00    This will include a ribbon cable to connect to the Control Board.

Optional - I will supply and install 0.6W  1% metal film attenuator resistors for you.  This option is only available for standard 10k, 25k, 50k, and 100k pot resistance:  R 50 extra

Optional - I will supply and install 0.5W  ARCOL carbon comp resistors for you.  This option is only available for standard 10k, 25k, 50k, and 100k pot resistance:  R 150 extra
Please note that the ARCOL carbon comp resistors are only available in E12 sizes and they are rated as 5% tolerance, therefore exacting specifications will not be possible.

Other optional extras

Apple Remote
Apple%2520Remote.jpg


These are about R 300.00 each from various online stores.



Small LCD display with 5mm characters.  Black & white

R8195030-01.jpg


Price is R 110.00 + R 15.00 for the cable and connector = R 125.00



Small LCD display with 5mm characters.  White & blue

R8195036-01.jpg


Price is R 110.00 + R 15.00 for the cable and connector = R 125.00



Large LCD display with 9mm characters.  White & blue

R8195049-01.jpg


Price is R 210.00 + R 15.00 for the cable and connector = R 225.00



16mm EOZ push button switch (momentary, non latching) - for use as power on / off

R6903264-01.jpg


Price is R 95.00



22mm Schurter push button switch (momentary, non latching) - for use as power on / off

RD504053-01.jpg


Price is R 230.00






OK, that was nearly a book worth!  I hope that's everything...

Please feel free to post here if you want to know anything else!

Kind Regards,
Ian.
 

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