Audio MODEL 86B-2 – 2-Channel Stereo Tube Preamp
OVERVIEW
An American-Style Stereo Tube Preamp Designed for Versatility
The Locomotive Audio MODEL 86B-2 brings two channels of lush tube gain to your rack, offering a wide range of tones from warm and transparent to overdriven and harmonically rich. Inspired by classic 1950s American preamp circuits, the 86B-2 provides a massive harmonic footprint that can breathe life into sterile digital tracks or add vintage character to any recording chain. Whether you need glowing vocals, natural acoustic depth, punchy drums, or gritty saturation, this preamp delivers with style and versatility.
With EF86 and 12AY7 tubes per channel, premium MuMetal shielded input transformers, and a nickel/steel output stage, the 86B-2 ensures superior fidelity with classic coloration. Features like a 20 dB pad, 100 Hz low-cut filter, selectable input impedances, and a dedicated Line mode make it a flexible tool for tracking or re-amping mixes through tubes and transformers. Built in the USA with rugged construction and backed by a lifetime warranty (excluding tubes), the 86B-2 is a must-have for engineers and producers looking for true American tube character in a modern format.


Missing Some Flavour?
Want more colour options from one box? Tired of switching between preamps? Maybe you’re low on rack space or just starting your first collection of outboard gear and need some versatility. You might just need the kind of versatility that offers recording with mics, then sending recorded audio back through tubes and transformers in ‘Line’ mode for more coloration.
Tubes, Transformers, and an Amplifier Design You Will Love
The 86B-2 is designed to get any amount of tube coloration into your audio easily. Its two-knob system allows the engineer to fine-tune the type of character needed. You can drive the 86B-2 and control the amount of tonal coloration in your audio. Save time with one preamp that can achieve a variety of sounds.
Rounded out with features like a 20dB pad, 100Hz high pass, two mic input impedances, line level mode and high impedance front panel DI on each channel, the 86B-2 won’t sit idle in your valuable rack space!
86B-2 LineageÂ
Introduced in 2014 as a modernized version of the Ampex 601 “suitcase tape recorder,” the Locomotive 286A (86B-2 predecessor) showcased several of the best attributes from the 601. A pentode EF86 and a dual triode 12AY7 were a crucial part of the sound worth keeping. The 601 could sound so smooth, but also be pushed into full distortion due to its wild amount of gain. This was a great way to get a large amount of use out of one piece of gear. On the contrary, the 601 was never designed to be used with high-output mics, so it lacked input headroom and needed input padding much of the time.
Taking this into account, we designed the Locomotive 286A by using the Ampex 601 circuit and modified it for modern use. We also added all the important mic preamp features like phantom power, pad, polarity, low cut, and DI.
Now, the all-new 86B-2 updates the 286A with a new front panel, new circuit layout, separate mic and line XLR inputs, as well as a much higher DI input impedance. And best yet, a much lower pricetag!
Unlock Your Creativity
Finding the right piece of gear to give your sound that “special something” might be one of the hardest parts of engineering. In our opinion, having an exciting combination of tools at your fingertips is the best way to get your creative juices flowing. The 86B-2 will help to unlock your audio engineering mind and allow you to focus on creating truly impressive audio.
KEY HIGHLIGHTS
TRANSFORMERS:
Super Premium MuMetal shielded inputs and nickel & steel outputs set the stage.
TUBES:
An EF86 input tube and a 12AY7 output tube amplify the signal with 75 dB of max gain.
DUAL OUTPUT LEVEL LED:
A 3-colour LED indicator per channel shows the signal level – Green -> Yellow -> Red
LINE MODE:
Dedicated XLR input connectors for sending audio ‘out-of-the-box’ without fear of phantom power being applied.
FEATURES
- Microphone and high impedance instrument inputs
- One EF86 & one 12AY7 per channel
- 4-Position Input Switch: 500 Ω & 1.8K Ω Mic, 10k Ω Line, 1.6meg Ω
- Polarity reverse switch
- 20 dB pad switch
- 100 Hz low-cut filter switch
- DI on for each channel
- +48 V phantom power​
- XLR mic input, line input, and line output connections
- Premium input and output transformers
- Wima polypropylene capacitors in the signal path
- Built in the USA
- Heavy 16-gauge steel chassis
- 115 V/230 V AC mains option on rear
- Backed by lifetime warranty parts and labor – excluding tubes
TECHNICAL SPECS
Microphone Input Load Impedance: 500 Ω or 1.8k Ω
Line Input Load Impedance: 10k Ω
Output Impedance: 300 Ω
1/4″ DI Impedance: 1.6meg Ω
Dual Output Level LED Colour:
- Greater than -10 dBu = Green
- Greater than +10 dBu = Orange
- Greater than +18 dBu = Red
75 dB of Gain
Frequency Response: 20 Hz – 20 kHz
Maximum 20 Hz & 1 kHz Input Level for 1% THD: -18 dBu (+2 dBu with Pad)
Maximum Output Level: +24 dBu
THD+N: < 1%
S/N ratio: > 70dB
Power Consumption (120/240VAC): 25 watts
Dimensions (2U Rackspace):
- Width — 19″
- Height — 3.5″
- Depth — 10″
Shipping Weight: 18 lbs.