We tend to take roads less travelled in our design of great sounding audio gear. We look forward to sharing this adventure with you. Enjoy!

Morten Sissener
Tortuga Audio Logo Turtle
  • Passive preamps
  • Buffered preamps
  • Tube buffers
  • Photoresistor (LDR) volume control
  • Preamp controllers & displays

LDR300.V25 Buffered Preamp

  • Unity gain active LDR preamp
  • No gain stage to minimize noise 
  • Class A solid state JFET buffer output stage
  • Powerful robust dynamics 
  • Compatible with any source and amplifier 
  • Single ended | 3 inputs & 2 outputs | Cardas RCA jacks
  • No limitations on interconnect cable run length
  • LDR based attenuation same as our passive preamps
  • Built with premium quality components throughout

Unity Gain 100 Step LDR Passive Preamps

  • Dead quiet preamps with a deep dark background
  • Remarkable full range dynamics with solid bass performance
  • Smooth stepped attenuation with zero switching noise
  • No mechanical switches/relays in the signal path
  • No noisy gain stage
  • Optically isolated light dependent resistor (LDR) attenuation
  • Built-in calibration of LDRs – no matching required
  • Single ended & balanced models 
  • Remote controlled via simple Apple remote
  • Menu driven graphic OLED display
  • Firmware/feature updates via USB port
  • 12 V trigger out for controlling other audio gear 

TPB.V1 Hybrid Tube Preamp Buffer

  • Add a touch of tube euphonics to your existing preamp
  • Works with any preamp including passive preamps
  • Ideal complement to Tortuga Audio’s passive preamps
  • No built-in attenuation
  • Slack voltage 6H30 tube input stage 
  • Powerful solid state FET output stage 
  • Unity gain by default – optional +3 or +6 dB gain (jumpers)
  • Remarkable full range dynamics with solid bass performance
  • Single ended & balanced models available

Professional reviews

“The Tortuga Audio preamp equaled or surpassed all basic performance parameters against any contenders I had in house, passive, active, tube, FET and at any price level with regards to faithfulness.”

“Music through the LDR6 is an ephemeral experience. It dances with fire for a brief shining moment and disappears, leaving you wanting more.”

“The performance of the little Tortuga reopens the passive vs. active debate.”

“…you would be hard-pressed—regardless of budget—to find a preamplifier, passive or active, that delivers your music with less editorializing than the Tortuga Audio LDR3.V2.”

Review of the LDR1B.V25 Preamp & TPB.V1 Buffer by Audiophilia.com

“Impeccable clarity, transparency, and neutrality with a dash of smoothness (that made listening non-fatiguing).”

“…capable of transporting the listener to a higher plane of sonic enlightenment, and that’s exactly what a soundsystem should do..”

“The LDRx seemed to be a perfect fit despite its affordable pricing, helping the system have a clear and transparent presentation, wide stage, and big dynamic contrasts, kudos for bringing such great performance at a low cost.” 

“The sound here had my friend contemplating a purchase, beautiful workmanship and elegant, yet exciting sound, great room.”

“There is just a sense of absolutely everything having been stripped free of fuzz and imprecision. Instrumental placement isn’t approximate or inferred. Instead, instruments are precisely located at a fixed and exact distance from the others with the space between performers and the characteristics of the recording environment jaw-droppingly obvious.”

“… the LDR6 produces a sound completely free of colouration, with a soundstage that was just consistently deeper and better resolved than with any other passive pre-amp I have ever used.”

“The LDR1 …. represents the least colored preamp I have ever heard in my system. It also provided greater resolution than any other preamp in my experience.”

A few recent articles

LDRPot.V1 Prototype PCBs

LDRPot.V1 Stepped Attenuator Under Development

A High Performance Stepped Attenuator Tortuga Audio is developing a variant of its LDR (light dependent resistor) based LDR.V25 Preamp Controller as a drop-in replacement for practically any stereo audio volume control potentiometer or stepped attenuator. We are calling it the LDRPot since it uses LDRs and is a direct replacement for a typical stereo

Read More »
ldr3.V25 passive preamp - black anodized front - side view

Tortuga Audio to Release LDR300.V25 Buffered Preamp

Tortuga Audio plans to release its new LDR300.V25 Buffered Preamp on August 28. The LDR300 is a remote controlled, singled-ended, active preamplifier that combines Tortuga Audio’s popular LDR (photoresistor) attenuation technology together with a powerful JFET output buffer to deliver robust sonics that will satisfy the most discerning audio enthusiast. …. Read More >>

Read More »

Customer comments and informal reviews

"If you must have the absolute best, look no further."

“I have just installed the Tortuga LDR board and can say that it is the be all end all of volume controls. It is dead silent and any level changes are seamless and silky smooth. I believe the vision of the Melos circuit of the mid 90s has finally been fullfilled. If you must have the absolute best, look no further.”

LDR3x user..."floored by the sound quality."

“Today I received the LDR3x board and I am FLOORED by the sound quality. I’ve been using a TVC [transformer volume control] for several years and was very happy, but the LDR simply blows it away. I am hearing detail I never knew existed in recordings I have listened to hundreds of time before. Bass is better, treble is clearer, etc….the sound is killer. I am retired and have been pursuing this hobby seriously for 40 years. The last 20 years of my career was as a music wholesale salesperson – I worked for Telarc for 7 years and then for an indie distributor where I sold several audiophile labels, so I have some serious experience listening. This volume control is fabulous.”   

“I have an LDR-1 and it is fabulous. Best preamp I ever owned at any price. When I bought it I thought I would get super transparent sound at the cost of thinning things out. Usually, that is the price for transparency. I took the risk anyway. I was dead wrong. The transparency is indeed the best I ever heard – but it is so full sounding – I can’t believe my ears. Now, warm and full are not the same. It is not warm. It is truthful to the recording. Regardless, it is that fullness and weight and supreme smoothness without sounding bloated and without giving up one iota of detail which makes this a world class product. I doubt things could get more than 5% better at any price- even $100,000. The LDR1 is the most perfect preamp I could ever imagine.”

“Open, easy, organic, transparent etc., and – above all else – natural. It makes other preamps (esp. active ones) sound electronic and mechanical. “

“So what did the LDR3.V2 do for the sound?  To my surprise, a sense of even more transparency.  There are details in the midrange and treble that are just more obvious now. The treble seems more extended, but there was absolutely no change in tone.  I don’t know why this is possible. I can’t perceive a lower noise floor.  Vocals are even more realistic, and everything has increased texture and is more palpable.  But the best thing of all is the increased speed of transients.  Everything has an immediacy to it.  This even translates to the bass.  Kick drums have speed and an authority that is impressive.  There is a tremendous amount of quick energy there that just wows me on many tracks.  The music has real life and intensity.  It blows me away.  Easily the best I’ve heard.  And I don’t perceive any loss of dynamics and any volume. ” 

"There have been many many goosebump moments.." (LDR3.V25)

“….let me be clear.  I love it!  First listen after completing assembly was to LPs, with the turntable feeding into the Meitner’s phono section and from the Tape Out (fixed level) jacks into the Tortuga. Sound quality is noticeably better than through the Meitner’s own line stage, top to bottom, with a veil removed and better controlled bass very apparent. There have been many, many goosebump moments, with familiar albums often taking on a new beauty thanks to the Tortuga’s superb performance.  Make no mistake, this is a relatively inexpensive preamp with exceptional accuracy that does not in any way add to or subtract from the original recording, IMHO. “

“I can honestly say though even at $2695 this unit will easily blow away stuff that is 3x the cost.  Actually, come to think of it, I’m not sure what else one could want no matter the cost unless you want fancy aluminum cases and bragging rights.”

"my reference tool to judge other preamps"

“From now on, the LDR3.V2 will be my reference tool used to judge other preamps and components in the audio chain. For instance, my trusty Dodd Audio VGP variable gain preamp proves to be close to the LDR in transparency and tonality. Both preamps are pleasant to listen to, with similar full body midrange, sweet highs, and sufficient lows. The LDR is superior, however, in rendering all those ranges in an even lower noise floor canvas, resulting in more organic sound overall, higher volume listening desire, and longer listening session before listening fatigue sets in. The words “chameleon”, “rediscovering familiar music”, “walls of enveloping sounds”, “vocal solidity”, “dynamic”, and “true to the source” come to mind.”

“I’m rediscovering my entire music collection, and have been reduced to tears by things I thought I knew.”

“What an experience! Truly the best sound I’ve ever heard in my system. A layer of “mush” has disappeared and angry high S’es are now pleasant. More details and less harshness, especially in mid-upper-high range compared to the EC4.6. It is absolutely marvellous at low levels, the pot-meters in other preamps I’ve had were all out of balance in the channels at extreme low volumes, now it’s all in perfect balance from 1 through 99 with a beautiful room experience, width and depth in the music.”

A Different Path Taken

No Pots, Switches or Transformers

say not to conventional volume control

Our preamps don’t use conventional volume control technology.

  • No potentiometers (“pots”)

  • No stepped attenuators (switched resistors)

  • No transformers

Why not? Because they don’t deliver the best audio performance.

Light Dependent Resistor | LDR

light dependent resistor gif

Our preamps use “light dependent (photo)resistors” – LDRs.

  • Not new technology

  • Pose unique and difficult design challenges.

  • Easier to use conventional volume control hardware.

  • We took on those challenges and solved them.

Why? Because we wanted to design a better sounding preamp. So we did.

Have Questions?

We’d love to hear from you. No really, we like inquiries about our products.​

Comments or questions are welcome.

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