TECHNICAL SPECIFICATIONS

• Circuit Design: Classic 512-style console topology with Discrete Op-Amp (DOA) architecture

• Format: 500 Series (VPR Alliance & GDIY 51X compatible)

• Gain Control: 26 dB to 60 dB stepped gain via high-precision Grayhill switch

• Input Stage: 1:10 input transformer (standard kits include Link Audio LA7510; compatible with AVD BT1019, Cinemag CM-75101A)

• Output Stage: Balanced 2503-style output transformer with internal output ratio jumper (2:1/3:1) (standard kits include Link Audio LA2503; compatible with CAPI EA2503, AVD 2503, UTM3503, Cinemag CMOQ-2S)

• Op-Amp Compatibility: Standard 2520 DOA footprint sockets (DOA not included in kit)

• Expansion: 1x DIYRE Colour Module compatible slot

• Power Requirements: Standard ±16 V/+48 V DC (500 Series rack)

DETAILED FEATURES

• Transformer-Balanced Tone Shaping & Ratio Control:

  • High-ratio 1:10 input and 2503 output transformers deliver unmistakable grit, weight, and harmonic warmth

  • Internal Output Ratio Jumper (2:1/3:1): Configures the 2503 output transformer winding ratio. Switching to 3:1 lowers the output level, enabling deeper saturation of the DOA and core circuitry before attenuation.

• Stepped Grayhill Gain Control: 26–60 dB continuous steps for 100% accurate recall between sessions

• T-Pad Output Attenuator (-∞ to +0 dB): Positioned post-preamp to fine-tune final signal levels into digital audio interfaces

• DIYRE Colour Module Compatibility: Add an extra layer of analog saturation, compression, or EQ directly inside the preamp

• Dual High-Slope Filters:

  • Low-Cut filter: 10 Hz – 250 Hz (steep 24 dB/oct slope)

  • High-Cut filter: 3.5 kHz – 20 kHz (steep 24 dB/oct slope)

• Complete Channel Utilities:

  • +48 V phantom power switch for condenser mics and active DIs

  • Polarity (phase invert) switch

  • -20 dB input pad for hot line-level sources or loud drum tracking

• Visual Monitoring: Multi-segment signal level meter and Peak LED for instant input monitoring

• Premium Build Components: High-quality conductive plastic potentiometers and gold-plated sockets

WHAT'S INCLUDED IN THE KIT?

This is a full DIY kit including all hardware and electronics:

• Powder-coated front panel with high-quality printing

• Complete set of Link Audio transformers (LA7510 input and LA2503 output)

• Stepped Grayhill gain switch and conductive plastic potentiometers

• All electronic components, ICs, sockets, and hardware

(Note: Requires assembly and soldering skills. A Discrete Op-Amp (DOA) is NOT included in the kit so you can select your preferred model. Interactive assembly guides are available in our Build Manuals section.)