The Fire-Eye Red-Eye Twin is a two-channel preamp from Fire-Eye Development built for players who switch between instruments on stage, such as moving between two acoustic guitars or between a guitar and another pickup-equipped instrument. The maker describes it as an all analog, handmade, high input impedance DI and clean boost solution, with a design focused on high fidelity, low noise and simple plug and play performance1. It lists at $395.00 USD with free US shipping2.
Two channels for switching instruments
The Twin's core purpose is handling two instruments without re-patching or re-setting tones between songs. Each channel has its own separate full-range Gain and Treble controls, so each instrument keeps its own level and tone setting3. The A / B Stomp Button selects the alternate instrument, and the Mode Switch determines whether the Twin plays one channel at a time or blends both instruments together3.
The two inputs also open up another use: a dual-pickup instrument can feed both channels at once. Fire-Eye's support material describes using a short stereo to mono splitter to feed the Twin's two inputs from a guitar with two pickup systems, or a simple mono instrument cable to deliver only the TIP signal from a dual-pickup guitar to either input3.
The controls
| Control | What it does |
|---|---|
| Channel A and B Gain | Separate full-range gain for each instrument, with range for piezoelectric, active or magnetic pickups45 |
| Channel A and B Treble | Separate treble shaping for each instrument1 |
| A / B Stomp Button | Selects the alternate instrument3 |
| Mode Switch | Chooses between playing one channel at a time or both instruments together34 |
| Boost Stomp Button | Amplifies solos, with its own Boost Gain control1 |
| Internal trim potentiometer | Sets the overall gain of the unit; affects gain only, not tone5 |
The internal trim potentiometer is set at the factory so that when the Twin's Gain Controls are centered, the gain matches the single-channel Red-Eye. It can be adjusted clockwise or counter-clockwise for pickups with abnormal signal levels, and Fire-Eye notes it affects only gain, not tone5. The normal channel Gain controls, the maker says, have plenty of range to work with all normal pickups, whether piezoelectric, active or magnetic5.
Power and the XLR output
The Red-Eye Twin runs on a 9-volt battery with long life, listed at around 100 hours1. When the mixing board supplies phantom power over the XLR cable, the unit automatically uses that instead of the battery1. The output itself is low-impedance, balanced XLR at 600 ohms, which Fire-Eye says will drive long cables to a mix board, so the Twin can serve as the DI between the stage and front of house1.
On earlier models without a built-in Pedal Board Power jack, Fire-Eye describes converting the unit to pedal board power by trading the battery for a battery substitute adapter, after which the unit uses 9-volt power only. The maker's instructions involve filing a notch in the chassis rim where the battery terminal end sat, knocking out and blowing out all filings, tying a knot in the adapter cable, snapping the adapter contacts to the battery snaps, and replacing the back cover without crushing the cable4.
Size and design
The Twin is built small for a pedalboard or a gig bag: 1.25 x 3.5 x 4.5 inches and 18 ounces1. Fire-Eye says it was engineered by an electronics engineer with over 50 years of professional experience, and that the Red-Eye design focuses on high fidelity, low noise and simple plug and play performance1. Compared with a single-channel preamp, the Twin's difference is the second channel, the A/B switching and the blend mode; compared with a multi-effect unit, it is a single-purpose analog front end with a balanced output.
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Questions
Does the Fire-Eye Red-Eye Twin run on a battery?
Yes. The Red-Eye Twin runs on a 9-volt battery, and Fire-Eye Development lists battery life at around 100 hours. It can also use XLR phantom power automatically when that is available at the mixing board, in place of the battery. On earlier models without a built-in Pedal Board Power jack, the maker describes replacing the battery with a battery substitute adapter to run the unit from 9-volt pedal board power.
Does the Red-Eye Twin work with phantom power?
Yes. Fire-Eye Development says the Red-Eye Twin automatically uses XLR phantom power, when available, instead of the battery. That means if the mixing board at a gig supplies phantom power over the XLR cable, the preamp draws from that rather than draining its own 9-volt battery.
Is the Fire-Eye Red-Eye Twin analog?
Yes. Fire-Eye Development describes the Red-Eye Twin as an all analog, handmade, high input impedance DI and clean boost solution. The design, according to the maker, focuses on high fidelity, low noise and simple plug and play performance.
Does the Red-Eye Twin have an XLR output?
Yes. The output is low-impedance, balanced XLR at 600 ohms, which Fire-Eye Development says will drive long cables to a mix board. That makes it usable as a DI straight to the front of house, and the same XLR connection is what lets the unit take phantom power when the board supplies it.
How much does the Fire-Eye Red-Eye Twin cost?
Fire-Eye Development lists the Red-Eye Twin at $395.00 USD on its product page as of October 2026, with free US shipping.
Can I use two instruments at once with the Red-Eye Twin?
Yes. The Mode Switch determines whether the Twin plays one channel at a time or blends both, so you can either alternate between two instruments with the A/B Stomp Button or play both at once. Each channel has its own Gain and Treble controls, so each instrument keeps its own level and tone setting.
Sources (5)
- Red-Eye Twin, Fire-Eye Development
- Buy the Red-Eye Twin Two-Channel Preamp, Fire-Eye Development
- Red-Eye Twin, Fire-Eye Development
- Pedal Board Power for Red-Eyes, Fire-Eye Development
- Red-Eye Twin Gain, Fire-Eye Development
