Locomotive Audio Model 86B-2: modern Ampex-style tube pre

19 Feb 2022 by Lyubomir Dobrev |

5,0 / 5,0 | Approximate reading time: 2 Minutes

Locomotive Audio Model 86B-2 · Source:

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US manufacturer Locomotive Audio announced a rework of its 286A tube preamp. The unit began as a modern rework of the Ampex 601 tube preamp produced in the mid-1950’s. Audio quality aside, the Ampex pre is known for its many modding possibilities and the many projects they spawned. The successor to the Locomotive 286A, the 86B-2, brings a new front panel, new circuit layout, separate mic and line XLR inputs, and higher DI input impedance. Getting your hands on one may be complicated for a while, but it’s not impossible. Read on…

Locomotive Audio Model 86B-2

The 86B-2 is a 2-channel preamp intened for tube coloration. Each channel has a two-knob layout with Gain and Level controls. From the Gain knob, you can drive the 86B-2 and thereby control the amount of coloration. Additional features include 48V phantom power, 20dB pad, 100Hz high pass filter, a choice of two mic input impedances, line level mode, and high impedance front panel DI for each channel.

The 86B-2 incorporates Wima polypropylene capacitors, MuMetal shielded input transformers and nickel & steel output transformers, an EF86 input tube, and 12AY7 output tube. Max input gain reaches 75 dB which is quite adequate. A nice touch is separating the inputs on individual jacks so you don’t accidentally connect line gear while phantom power is on. The chassis is made out of heavy 16-gauge steel and mains support includes 115 V/230 V AC options.

: Locomotive Audio Model 86B-2 Front

: Locomotive Audio Model 86B-2 Rear

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
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: >70 dB
Dimensions: 19″ W x 3.5″ H x 10″ D (2u rackspace)
Shipping Weight: 18 lb / 8kg
Power Consumption (120/240 VAC): 25 watts

Price and availability

A limited number of Locomotive Audio Model 86B-2 units will be shipping in April, priced USD 1999. You will save USD 200 if you pre-order by March 31, 2022. However, the April units are sold on a first come, first served basis. Check the website or contact the manufacturer for details.