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Douk Audio EQ5 Mini 5-Band EQ Preamp Equalizer for Home / Car Audio Review

A pocket-sized 5-band equalizer at $64.99 built on five JRC4558 op-amps, one per band, with a bypass button for untouched sound, gold-plated I/O and USB-C power for home or car use.

3.73.7 out of 5 starsUpdated October 14, 2026
$64.99Price checked October 14, 2026
Check price at Douk Audio
Douk Audio EQ5 Mini 5-Band EQ Preamp Equalizer for Home / Car Audio

Our verdict

The EQ5 is a $64.99 five-band equalizer that treats each frequency band to its own JRC4558 op-amp, from 100Hz to 10kHz, with plus or minus 10dB of range. A bypass button restores the untouched signal at any time, and gold-plated RCA and 3.5mm connections keep the path clean. It is small, USB-C powered and ready for a desk or a car, as long as you give it a dedicated 5V supply and connect one input type at a time.

Best for
Listeners who want hands-on 5-band EQ control and a bypass switch in a compact box that works in a home rack or a car.
Skip if
You want digital EQ with presets, or you plan to daisy-chain it off your computer's USB port.
Check price at Douk AudioHow we research

The Douk Audio EQ5 is a mini 5-band EQ preamp and equalizer priced at $64.99, sized for both home and car audio setups at just 120 x 60 x 38mm, and weighing 224g. It sits between your source and amplifier, shaping the signal as it passes through.

The design uses five JRC4558 op-amps, one responsible for each frequency band, so 100Hz, 400Hz, 800Hz, 4kHz and 10kHz are each processed independently with a dedicated control knob. Gain range is plus or minus 10dB. When you want the untouched signal, the bypass button routes audio straight from input to output without any processing. Even bypass mode works without power connected. The measured specs are strong for the class: frequency response of 5Hz-154kHz, THD of 0.003% at 1kHz, 50K ohm input impedance and a 47 ohm output impedance.

Connections cover stereo RCA and 3.5mm AUX on both input and output, all gold-plated to keep connections tight and transmission smooth, with a gold-plated PCB panel and aluminum knurled knobs inside an all-metal case. Power comes over USB Type-C at DC 5V with at least 500mA.

Douk Audio attaches two important operating notes. First, do not power the EQ5 from the USB port of a computer or share its supply with the audio source, or common-ground noise will result; use a separate USB power supply. Second, the RCA and 3.5mm inputs are connected in parallel, so the two inputs and outputs work simultaneously and you should not connect RCA and 3.5mm input at the same time to avoid mixing. The package includes the EQ5, a USB Type-C cable, four rubber feet and a manual.

Douk Audio ships worldwide with free and expedited options, and the cost varies by destination country. Packages under 2kg go by airmail (10-25 days); heavier orders ship via DHL, UPS or FedEx (5-8 days). Import duties or customs charges are the buyer's responsibility. The store offers a 30-day free return or full refund and a 1-year warranty on all items, excluding orders placed by mistake, man-made damage or misuse, subjective change of mind, and anything outside the warranty terms.

What we liked

  • Five dedicated JRC4558 op-amps, each processing one frequency band independently, instead of shared tone circuitry
  • Bypass button returns the signal from input to output untouched when you want the original sound
  • Gold-plated RCA and 3.5mm inputs and outputs plus a gold-plated PCB panel for the tightest connection
  • Handles 5Hz-154kHz with THD of 0.003% at 1kHz and a low 47 ohm output impedance
  • USB-C powered and small enough to move between a home system and a car setup

Worth noting

  • No power adapter is included, and Douk Audio warns against powering it from a computer USB port or sharing a supply with the audio source, which can cause common-ground noise
  • The RCA and 3.5mm inputs are wired in parallel, so connect one at a time to avoid mixing signals
  • Bypass mode works without power, but the EQ section needs its own DC 5V supply

Questions before you buy

Which frequencies can I adjust?

Five bands: 100Hz, 400Hz, 800Hz, 4kHz and 10kHz, each with its own knob and a gain range of plus or minus 10dB, processed by a dedicated JRC4558 op-amp per band.

Can I disable the equalization?

Yes. The bypass button turns off EQ preamplification and routes the signal directly from input to output without processing. Bypass works even without power connected.

How should I power the EQ5?

From its own USB Type-C supply at DC 5V / 500mA or more. Do not use a computer's USB port or share the supply with your audio source, as that can introduce common-ground noise.

What is the return and warranty policy?

Douk Audio offers a 30-day free return or full refund and a 1-year warranty. Exclusions include orders placed by mistake, man-made damage or misuse, and subjective change of mind.

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