Subjective performance
Adjectives
Descriptive words and phrases that are commonly used by both customers and reviewers to describe the LDR6 passive preamp sound include: colorless, transparent, neutral, articulate, clear, fuzz-free, clean, natural, and high resolution.
Passive performance
The consensus of customers suggest you can expect performance that is superior to conventional passive preamps utilizing even the best audiophile grade potentiometers, stepped resistive attenuators or even most transformer based volume controls.
Features
Passive preamp
Passive means there’s no amplification of the audio signal. The simple truth is that most contemporary audio sources (DACs, CD players, phono stages etc.) do not need active pre-amplification prior to amplification. Any audio system that’s compatible with a LDRx passive preamp will sound sound better than most, and as good as even the best, high end preamps available.
High input impedance
Tortuga Audio produces the only LDR based passive preamp that maintains input impedance at or above 10k over the full attenuation range. The result is superior dynamics, fuller midrange, tighter bass, and satisfying percussive slam.
Digital control
Despite their extraordinary sound, LDRs are both nonlinear and variable and thus make it quite challenging to implement an optimal preamp design using conventional analog means. Therefore, Tortuga Audio employs a software based, microprocessor driven digital design together with proprietary control software to provide a precision matched audio taper schedule. while maintaining a nominal input impedance of ~10k ohms. To our knowledge, Tortuga Audio’s design is unique in the audio preamp market.
LDRs instead of potentiometers
imply put, music sounds better going through LDRs compared to all other attenuation devices including potentiometers, stepped attenuators and even most transformer based volume controls. LDRs combine a photoresistor with a light emitting diode (LED) into an integrated package. LDR resistance (and thus volume) is controlled by controlling the light intensity of the LED.
No moving parts in signal path
In addition to using LDRs for volume control, LDRs are also used for input switching in lieu of conventional relays or mechanical switches. The audio pathway within the LDRx passive preamps is thus purely resistive with no moving parts. There’s nothing mechanical to corrode, fail or degrade the audio signal.
