A little history
The LDR3.V2 is an evolution of the LDR1 & LDR3. Both were built with the earlier V1 controller technology and were themselves derived from the LDR6 with its V0 controller. As part of the upgrade to the V2/V21 controller, the LDR3 now incorporates a visual 7-segment display. Detailed information on the V2 controller itself can be found here.
The Absolute Sound awarded the LDR3.V2 with both its coveted Golden Ear Award & Editors’ Choice Award in 2016.
A passive preamp
The LDR3.V2 is fundamentally a passive preamp. “Passive” in this context means there’s no amplification of the audio signal. That means that no external power supply connects directly to the audio signal within the preamp, something that every conventional active preamp does by definition.
The simple truth is that most contemporary audio sources (DACs, CD players, phono stages etc.) do not need actual active signal pre-amplification prior to amplification. Any audio system that’s compatible with a passive preamp will sound as good or better than even the best, high end active preamps.
LDRs | Light Dependent Resistors
The LDR3.V2 employs pairs of in-situ calibrated LDRs as voltage dividers for volume control. Each LDR is calibrated using a proprietary built-in system that measures and stores control settings for each volume control step. As far as we know, this is unique to Tortuga Audio’s design with respect to how LDRs are used.
Digital control of an analog system
There is nothing digital about LDRs. The LDR3.V2 is fundamentally an analog volume control device controlled through digital means. Tortuga Audio employs a digital microcontroller with proprietary control software to control the LDRs such that they produce a defined audio attenuation schedule, also known as a “taper”.
The control signals that set the LDR resistance levels are precision analog signals from the microcontroller.
No moving parts in signal path
The LDR3.V2 uses LDRs for both volume control and for input switching in lieu of conventional relays or mechanical switches. The audio pathway is thus purely resistive with no moving parts. There’s nothing mechanical to corrode, fail or degrade the audio signal.
Optically isolated signal path
The audio signal is optically isolated from the power supply and the control circuitry. The audio signal only “sees” purely resistive LDRs. Electrical isolation between multiple incoming audio signals is well in excess of 5 mega-ohms.
Subjective Performance
Descriptive words and phrases that are commonly used by both customers and reviewers to describe the Tortuga Audios passive preamp sound include: colorless, transparent, neutral, articulate, clear, fuzz-free, clean, natural, and high resolution.
The consensus of customers and reviewers is you can expect subjective performance that is superior to most other preamps regardless of type.
Specifications
Product specifications and related technical information are available in our online product documentation.
