LDR1B.V25K Balanced Passive Preamp Kit


Please note that this kit has been discontinued. 

The LDR1.V25K is a complete balanced passive preamp kit built around our most advanced LDR.V25 Preamp Controller board. When completed, the V25K kit will have a sonic performance the matches many high-end audiophile preamps at a fraction of the cost.

The kit can now be ordered either with a single input & dual outputs or with dual inputs & a single output.

This kit is sonically identical to our LDR1.V25 Balanced Passive Preamp with the only differences being the front panel material and the hookup wire in the base kit model (can be upgraded at additional cost).

All circuit boards are provided fully built and tested. No soldering of components to circuit boards required. 

The kit includes all the parts needed to assemble a complete audiophile grade passive preamp including enclosure, front/rear panels, graphic OLED display, XLR jacks, power supply, manual encoder/knob, remote, wire etc. We provide detailed online information and assembly instructions that even first time DIY builders should have little trouble following.

SKU: LDR1B.V25K Category: Tag:
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Now With OLED Display

The kit has been updated to include our new menu driven graphic OLED display which makes our LDR preamp kits much easier to set up and control.

Kit Version of the LDR1B.V25

The LDR1B.V25K is a lower cost kit version of the LDR1B.V25 Balanced Passive Preamp that Tortuga Audio sells as a finished preamp product.

We encourage you to review the product information for the LDR1B.V25 since it is fully applicable to the kit version but for the exceptions mentioned below.

The differences between the base version of the kit and the non-kit models are as follows:

  • Front Panel – The front panel of the kit is acrylic whereas the non-kit is brushed anodized aluminum with acrylic inlay.
  • Hookup Wiring – The non-kit uses high quality Neotech UP-OCC solid copper hookup wire while the kit uses MilSpec silver coated stranded copper wire (Neotech available as upgrade option).

Comprehensive Balanced (XLR) Passive Preamp Kit

The LDR1B.V25K is an affordable audiophile grade passive preamp kit with everything you need including a pair of V25 preamp controller boards, enclosure, XLR jacks, power supply, wiring, control knob, remote etc.

The kit’s circuit boards are all completed and tested so you won’t be soldering resistors, capacitors etc. on to circuit boards with this kit.

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QuantityStandard Items
2LDR.V25 Preamp Controller Board
12.95" x 6" x 8" black powder coated extruded aluminum enclosure box
1 0.25" x 2.95" x 6" see-through dark acrylic front panel with hole/recess for encoder and knob
1 0.08-0.10" x 2.95" x 6" black anodized rear panel with cut-outs for jacks, etc.
1knurled black enameled Fender Telecaster style encoder control knob
4peel'n'stick urethane rubber feet
3pair of XLR jacks (1 input & 2 outputs...or....2 inputs & 1 output)
1DC power jack
112 VDC Trigger Out phono jack
8sets of socket head black oxide sheet metal screws with washers (for front/rear panel)
1external "wall-wart" or "brick" style external 12VDC power supply suitable for 120 or 240 VAC
14 conductor cable for connecting the encoder to the display module
1ribbon cable for connecting the display module to the V25 board
1rotary encoder module with nut and washer
1blue master display board with IR receiver module soldered in place
1blue slave display board
1ribbon cable for connecting master display module to slave module
1display module mounting bar - plastic angle
4sets of nylon threaded rods with nuts & washers for the master display module mounting bar
1USB cable for connecting V25 USB port to rear panel
10feet of white #24-26 gauge silver coated copper wire (audio hookup)
1foot of red #20 gauge silver coated copper wire (power hookup)
1foot of red #26 gauge silver coated copper wire (trigger hookup)
1foot of black #20 gauge silver coated copper wire (power hookup)
1foot of black #26 gauge silver coated copper wire (trigger hookup)
3foot of green #20 gauge silver coated copper wire ( audio ground hookup)
10.060" x 5.7" x 8"  FRP mounting board
10#4 threaded hex stand-offs for mounting the V25 board and ground bar to mounting sheet
20#4 screws for the mounting standoffs
2#4 screws for the mounting display bar to board
2#4 nuts for mounting display bar to board
1Apple remote
4Power connector wire crimps
22-pin power connector shell
Optional Items
5feet of Neotech 26AWG UP-OCC Solid Copper wire

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Not A Difficult Kit To Build

On a scale of 1-10, 10 being expert level, this kit is probably around a 4-5 difficulty level.  Most of the work involves straight-forward mechanical assembly and point-to-point soldering of wires plus plugging in a few cables. The most challenging part of the kit is getting the point-to-pont XLR wiring done correctly. It’s quite straightforward but the complexity of balanced wiring can be challenging to the novice. Even experts can get it wrong if the mind wonders.

All circuit boards are provided fully built and tested. No soldering of components to circuit boards required. 

In addition to the kit itself, you will need the following items:

  • Solder
  • Soldering iron
  • Allen(hex) wrench for socket head screws used to attach panels
  • Wire strippers for stripping insulation off wires
  • Wire cutters for cutting wires to length
  • Small screw drivers (both regular and phillips) for stand-off screws, encoder knob etc.
  • Wrenches and/or sockets for tightening a few nuts.

Online Assembly Instructions

You can find additional information including detailed assembly instructions with photos in our online product documentation.

Please not that the online kit documentation is specific to the very similar single-ended LDR3.V25K kit. We do NOT currently have detailed assembly instructions entirely specific to the balanced kit. However, most of these instructions are either generally or specifically applicable to both kits.

Optional Items

  • Hookup Wire – Neotech 26AWG UP-OCC Solid Copper
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