LDR3x Version 2 circuit board design

LDR3x.V2 Preamp Controller Board Coming Soon

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LDR3x Version 2 circuit board design

Version 1 Sold Out & Discontinued

As of 3.2.14 we are sold out of the Version 1 LDR3x Preamp Controller Board. Version 1 has been discontinued and thus we are no longer accepting orders for the V1 board.

Version 2 Availability & Pre-orders

The original LDR3x is being replaced by the soon to be released LDR3x Version 2 (LDR3x.V2). We are targeting release of the LDR3x.V2  by April 1st the first week of May. In the interim, we are accepting pre-orders for Version 2 board at the same $199 price as the original board.

Pre-ordering means you will not be charged until such time as the unit actually ships. You can pre-order the LDR3x.V2 via this link.  [button link=”” size=”small”]Pre-Order the LDR3x.V2 [/button]

Version 2 Pricing

Although we are holding the price at $199 during the pre-order period,  after we start shipping the new board, the price for the LDRx.V2 will increase to $239. The price increase was necessary due to the increased amount for audio goodness  (and more costly bits of hardware) packed into the design. However, you can lock-in the lower $199 price by pre-ordering today!

What’s New In Version 2

Quite a lot actually!

Auto Calibration – Version 2 will no longer be dependent on specialized external test equipment and software tools for initial calibration and tuning of the LDRs. All of that is now self-contained in the board itself. In the event one or more LDRs age differently and drift out of calibration, the LDR3x.V2 can adjust each LDR’s attenuation table to bring the unit back into precise calibration. This also mitigates dependence on having to use matched sets of LDRs in each build. Also, owners are no longer dependent on us for storing and maintaining their calibration data should updates be needed in the future.

Replaceable LDR Modules – LDRs are similar to tubes insofar as they are nonlinear analog devices, they light up inside, they don’t behave exactly the same from one to the next even if the same make/model, their performance characteristics can change over time, some fail early on, and they eventually age and die (although 50,000 hours is a long life). Wouldn’t it be nice to just yank a bad one out, and stick in a nice new one for less than $20? Done!

Increased Precision – Whereas Version 1 used 8 bit digital pots, Version 2 employs  12 bit DACs. This gives the LDR3x.V2 16 times greater precision in adjusting the resistance values of the LDRs. This means more precise channel matching over the full attenuation range and that translates directly into improved stereo imaging and sound stage.

Quieter Power Supply – Version 2 drops the use of a linear voltage regulator for a precision low noise switching power supply module with superior ripple rejection. The result is a darker background between the notes and improved articulation and expression of sound.

Separate Channel Grounds – Left/right channel grounds are kept separate leaving the option of grounding them at the attenuator or elsewhere in the audio signal pathway. The net benefit it to make it easier to isolate grounds and avoid the audible hum inherent in ground loops.

Software Updates via USB – Version 2 uses an on-chip USB bootloader which allows software updates to be handled via a USB connection to a PC. Thus, software updates can be emailed out and owners can download the updates to the LDR3x board from their laptop/desktop PC. Eventually this will also be doable from a Mac as well.

Fewer Control Interface Options – The downside of all these cool improvements is fewer DIY control interface options although control via both infrared remote and manual encoder remain unchanged. Control via discrete inputs and analog pot are no longer available.

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