V4 board with LDR module installed
OLED display assembly front view with cabling and encoder
quad ldr module2 - side view
Apple remote alternative | the "Function" remote
V4 board with LDR module installed
OLED display assembly front view with cabling and encoder
quad ldr module2 - side view
Apple remote alternative | the "Function" remote
$523.00

ePot.V4 bundle

$523.00

The V4 bundle combines a V4 electronic stepped-attenuator and preamp controller board together with its companion OLED display module, rotary manual encoder, and infrared remote, all for a 15% discount over purchasing these individually. 

Everything we offer by way of the V4 system is included in the bundle. However, please be aware that the V4 bundle is NOT in any way a complete turnkey preamp kit. 

Items included in the bundle are also sold individually. 

Print Friendly, PDF & Email

Looking for just a V4 board and not a complete bundle?

The V4 can be purchased by itself, both with and without an LDR module and/or a remote. Check out the ePot.V4 by itself.

The V4 “bundle”

The V4 bundle combines the ePot.V4 board together with its LDR module, OLED display assembly, and infrared remote into a single convenient package discounted at 15%. The bundle is a collection of parts we make and/or sell but does not represent a comprehensive preamp project kit (see “what’s not included” section below). You can also purchase all these parts separately.

A bundle comes in 2 flavors, passive and active. The passive version is simply the ePot.V4 system as its default self. The active version is identical except for the addition of a SSBM.V4 solid state buffer module that mounts directly to the V4 board itself. The SSB.V4 buffer board turns the passive V4 into direct coupled active preamp with optional gain.

What’s included?

The following items are included with each V4 bundle:

  • A fully functional V4 board that has been calibrated
  • Quad LDR module installed, tested, and calibrated
  • OLED display assembly including encoder, IR receiver, and cabling
  • Power cabling to the V4 board
  • 4 sets of mounting standoffs with screws

What’s optional

You may include the following options offered by Tortuga Audio:

  • Active version of the V4 by adding a compact SSBM.V4 solid state buffer module that plugs directly into the V4 board.
  • You may also opt to go with our low noise LPS5.V4 5 volt linear power supply in lieu of providing your own 5 volt power source.

What’s NOT included that you’ll need?

The following items are not provided but are typically required to have a fully functioning V4 system:

  • RCA and/or XLR audio jacks and sockets for connecting audio signals to the V4 board
  • A 5 volt power supply rated at least 1 amp. You can probably get away with a 0.5 amp power supply but we recommend 1 amp.
  • Some type of enclosure or plinth to which you can mount all the V4 hardware. If you’ve never built your own preamp or amp before, please be aware that the greatest build challenge is often the enclosure needed to accommodate everything effectively.

Each of the components in a V4 bundle are listed below along with links to their individual product page. You can buy the bundle at a discount, or buy any component individually.

Each item in the bundle is listed below together with links that will take you to each product’s listing.

ePot.V4 attenuator & preamp controller

V4 board with LDR module installed
V4 preamp controller LDR module install diagram
quad ldr module2 - side view
V4 preamp board with solid state buffer module - back end view
V4 preamp board with solid state buffer module - front end view
V4 preamp board with solid state buffer module - right side view
V4 board with LDR module installed
V4 preamp controller LDR module install diagram
quad ldr module2 - side view
V4 preamp board with solid state buffer module - back end view
V4 preamp board with solid state buffer module - front end view
V4 preamp board with solid state buffer module - right side view

The ePot.V4 is Tortuga Audio’s 5th generation LDR preamp controller — the result of over 15 years of developing an alternative to conventional volume control for DIY audio enthusiasts and audio OEMs.

The V4 is a complete platform for building a full-featured, remote-controlled preamplifier — passive by default, or active with the optional SSBM.V4 buffer board. A high-contrast OLED display provides real-time feedback for volume, balance, input selection, and system status.

Volume is controlled entirely by light dependent resistors (LDRs). No mechanical potentiometers. No stepped attenuators. No mechanical contacts in the signal path.

Quad LDR module

quad ldr module2 - top view
quad ldr module2 - side view
quad ldr module 2 - end view
quad ldr module2 - top view
quad ldr module2 - side view
quad ldr module 2 - end view

A quad LDR module with two pairs of LDRs — one pair per audio channel, each forming a voltage divider for volume control. One module provides full two-channel stereo attenuation.

Required for all V3 and V4 series controllers. Typically purchased as part of the ePot.V4 Complete System but available separately as a replacement.

SSBM.V4 solid state buffer module

ePotPi.V4 Rev B buffer board prototype pcb
solid state buffer module - without LDR mdoule
V4 preamp board with solid state buffer module - right side view
ePotPi.V4 Rev B buffer board prototype pcb
solid state buffer module - without LDR mdoule
V4 preamp board with solid state buffer module - right side view

The SSBM.V4 is an optional buffer board that plugs directly into the ePot.V4, turning it from a passive attenuator into an active preamp.

A buffer acts as a high-impedance firewall between your volume control and amplifier. It doesn’t make audio louder — it’s a current amplifier, not a voltage amplifier. What it does is preserve the energy and dynamics of the original recording, especially when driving longer cable runs or lower-impedance amplifier inputs.

The SSBM.V4 is direct-coupled with high input impedance, low output impedance, and adjustable gain defaulting to unity. For best performance, pair it with a higher quality 5V linear power supply.

OLED display assembly

OLED display assembly front view with cabling and encoder
OLED display assembly with encoder attached
EastRising OLED display dimensions
OLED display assembly front view with cabling and encoder
OLED display assembly with encoder attached
EastRising OLED display dimensions

A 256 x 64 pixel, high-contrast white-on-black graphic OLED display designed for use with Tortuga Audio preamp controllers and finished preamps.

The display provides an intuitive, menu-driven control interface built around a 7-button Apple or compatible remote. Volume, balance, input selection, and system settings are all managed through clear on-screen menus.

The assembly includes a custom adapter board with an installed infrared receiver, an encoder header, and all cabling. Fully tested and ready to connect — no assembly required.

Function remote control

Apple remote alternative | the "Function" remote

The Function remote replaces the silver Apple remote, which is no longer in production. It’s an infrared remote that works with all V4 series controllers and preamps.

Well-constructed with a quality feel, responsive button action, and a simple layout that maps directly to the V4’s menu-driven interface. 

V4 manuals

The online product documentation system (“Docs”) has 2 manuals for the V4; an operations and control manual and a hardware manual. Each are discussed briefly below.

V4 Operations u0026amp; Control Manual

This manual describes the how to operate the V4 via infrared remote, local rotary encoder, together with its menu driven OLED display .

V4 Hardware Manual

This manual describes the design basis, hardware features and interfaces of the ePot.V4 Max (“V4” or “Max”  ) LDR stepped attenuator & preamp controller.

You may also like

Previous Next