The Locomotive Audio L72P-1 is a single-channel, V72-style tube microphone preamp for the 500 Series format. It combines house-wound input and output transformers, a three-chamber nickel-core plate choke, dual 6922/E88CC tubes in a cascode configuration, stepped gain up to 54 dB and a dedicated line input—bringing classic German broadcast-preamp tone to modern tracking, mixing and recall-friendly hybrid workflows.
 
The Locomotive Audio L72P-1 is designed for engineers who love the dense, organic and remarkably musical sound associated with classic German V72 preamp modules, but require more gain range, more practical level control and a format compatible with a contemporary 500 Series rack.
Rather than treating “V72-style” as a vague tonal reference, Locomotive Audio focused on the electromagnetic components that form a major part of the original circuit’s behaviour. The L72P-1 uses house-wound input and output transformers together with a three-chamber, nickel-core plate choke designed to reproduce the frequency response and dynamic character of the vintage module. From the multi-chamber input transformer through the plate choke to the screened multi-section output transformer, the signal path is intended to retain the warm, full and naturally dimensional quality that made the V72 a lasting studio reference.
 
The original V72 design is famous for its rich tube gain but typically offers a fixed amplification figure of around 34 dB. Locomotive Audio expands this operating range: the L72P-1 provides up to 54 dB of gain, selected in precise 4 dB steps. This makes it more practical with modern condenser microphones, dynamic microphones, ribbon microphones and a broad range of recording levels. The stepped architecture also makes settings easy to note and repeat, which is useful when recalling vocal setups, rebuilding a session or matching multiple channels in a modular recording chain.
 
A separate five-position output attenuator provides fine level adjustment in 2 dB increments after the gain stage. The result is a more flexible gain-staging workflow than the historic circuit: set the desired amount of tube and transformer gain with the stepped input control, then set the final level feeding a converter, compressor, EQ or other line-level processor. This is particularly useful when you want the preamp’s tonal density and output-stage behaviour without overdriving downstream equipment.
 
The L72P-1 uses two dual-triode tubes in a cascode arrangement. It is optimised for 6922 / E88CC tubes, selected to match the response of the vintage design, while 12AU7 tubes can also be used as an alternative. This modern tube choice was intentional: it avoids dependence on expensive, scarce or difficult-to-source vintage pentodes while keeping the desired V72-inspired gain structure and providing practical future serviceability.
 
The module ships with Locomotive’s “S” Studio input transformer as standard. A non-S transformer configuration is available as an upgrade option at the time of purchase. The difference is deliberately subtle rather than a different preamp concept: Locomotive quotes approximately 0.25 dB difference at 15 kHz and 0.5 dB at 20 kHz between the two versions. A user-selectable internal jumper allows the input-transformer load resistance to be set to 400 kΩ or 200 kΩ, providing further adjustment of input-stage loading and response.
 
In addition to microphone operation, the L72P-1 has a dedicated line input for routing DAW stems, synthesizers, keyboards, drum machines and other line-level sources through the tube, transformer and choke stages. The 20 dB pad supports loud microphone sources, while the 34 dB pad makes the module practical for line-level re-amping and colour processing. This turns the L72P-1 into more than a vintage-inspired mic preamp: it can be used as a compact analogue tone stage to add tube weight, gentle harmonic structure and transformer depth to modern productions.
 
The Locomotive Audio L72P-1 is ideal when a source needs authentic tube richness without exaggerated distortion. It works especially well on lead vocals, backing vocals, acoustic instruments, piano, strings, drum overheads, room microphones, bass and synths. Install one for a distinctive mono recording channel, or combine multiple units in a high-current 500 Series chassis for a matched V72-style multi-channel front end.
 
Key features
Single-channel V72-style tube microphone preamp
500 Series module format
Vintage German broadcast-preamp-inspired design
House-wound input transformer
House-wound output transformer
Three-chamber nickel-core plate choke
Signal-path architecture designed to match classic V72-style response
Two dual-triode tubes in cascode configuration
Optimised for 6922 / E88CC tubes
12AU7 tube compatibility
Up to 54 dB gain in repeatable 4 dB steps
Five-position output attenuator in 2 dB steps
Standard “S” Studio input-transformer version
Optional non-S input-transformer variant available at purchase
Internal 400 kΩ / 200 kΩ input-transformer load-resistance jumper
Dedicated line input for re-amping and analogue colour processing
20 dB microphone pad
34 dB pad for line-level sources
Transformer-coupled tube gain for tracking, mixing and hybrid workflows
Lifetime manufacturer warranty
 
Applications
Lead-vocal recording with classic German tube-preamp tone
Ribbon and dynamic microphone amplification
Acoustic guitar, piano, strings and brass recording
Drum overhead and room-microphone capture
Bass and synthesizer tracking with tube weight
Adding tube and transformer depth to DAW stems
Processing drum machines, keyboards and virtual instruments
Creating an analogue re-amp path in a 500 Series rack
Building a matched multi-channel V72-style recording front end
Recall-friendly sessions through stepped input and output controls