The NUX Queen of Tone (NDO-6) is a dual overdrive pedal from NUX that stacks two of the company's drive circuits in one enclosure: the Horseman on one side and the Morning Star on the other1. The Horseman is based on the legendary Klon Centaur, while the Morning Star is based on the legendary Marshall Bluesbreaker circuit, a very transparent, low gain drive1. Each side also hides a second mode behind its footswitch, giving a player four distinct drive voices from one box.
Guitar World's reviewer Paul Riario described it as a dual-sided pedal that "merges Bluesbreaker and Klon-style tones, all at half the price of the ToT," referring to the Warm Audio Throne of Tone, with similar functionality and familiar controls2.
Where the circuits come from
The Queen of Tone is essentially two NUX mini pedals joined together. Delicious Audio described it as marrying the company's popular Klon-style circuit on the left channel, also available as a single drive under the Horseman name, with its Blues Breaker-style circuit on the right channel4.
- Horseman side: based on the legendary Klon Centaur, with a modified circuit to access a secondary function by simply holding the footswitch1
- Morning Star side: based on the legendary Bluesbreaker circuit, described by RockBoard's PedalPedia as a very transparent, low gain drive1
Both circuits also exist as standalone NUX pedals, the Nux Horseman and the Nux Morning Star. The Queen of Tone instead puts both in a single dual pedal, part of NUX's Verdugo Series of stompboxes5.
The controls
Each side of the pedal has its own three knobs and its own footswitch, plus a hidden second mode143.
| Control | Side | What it does |
|---|---|---|
| OUTPUT knob | Horseman | Controls the output level of the Horseman circuit3 |
| TREBLE knob | Horseman | Sets the treble of the Horseman circuit1 |
| GAIN knob | Horseman | Sets the gain of the Horseman circuit1 |
| DRIVE knob | Morning Star | Controls the gain of the Morning Star circuit4 |
| TONE knob | Morning Star | Controls the treble frequency of the Morning Star circuit4 |
| LEVEL knob | Morning Star | Controls the volume of the Morning Star circuit4 |
| BF/TB switch | Back of pedal | Toggles Buffer-Bypass or True-Bypass4 |
Gold, Silver and SHINE modes
The two hidden modes are the pedal's extra voices:
- Gold mode (Horseman): mimics its classic predecessor, the transparent Gold Centaur overdrive pedal3
- Silver mode (Horseman): a powered-up version with an extended gain range, which RockBoard's PedalPedia says offers massive headroom usually requiring an 18V input1. You access it by holding the Horseman footswitch for 1 second3
- SHINE mode (Morning Star): a crystal clear treble boosted tone, engaged by holding the Morning Star footswitch1
Each mode has its own indicator: the SILVER indicator turns on while Silver mode is engaged, and the SHINE indicator turns on while SHINE mode is engaged4.
Power and connections
The pedal runs on 9V DC with a center negative, negative tip power supply, drawing 52mA31. NUX specifies using only 9V negative tip power with 100mA3.
Connections are straightforward: your guitar side goes to the INPUT jack, and the OUTPUT signal connects to the amp side3.
The BF/TB switch on the back of the pedal selects Buffer-Bypass or True-Bypass. NUX recommends BF when you connect several pedals in your signal chain, to solve the tone loss that long true-bypass chains can cause3.
The EXT. SW jack lets you use an external foot controller, like the NUX NMP-2, to remote the pedal3, which is useful if the pedal sits in a loop switcher or out of reach on a large board.
How it compares
The obvious comparison inside NUX's own range is the Ace of Tone, another dual overdrive that stacks the Tube Man MkII and Morning Star mini circuits instead of the Horseman and Morning Star. Players who want the Klon-plus-Bluesbreaker pairing specifically will find it in the Queen of Tone; the Ace of Tone swaps the Klon-style side for a Tube Man-style circuit24.
Guitar World positioned the Queen of Tone against the Warm Audio Throne of Tone, another dual pedal built on the same two circuit families, noting that the NUX offers similar functionality and familiar controls at half the price of the ToT2.
What reviewers said
Pedal of the Day reviewed the Queen of Tone in April 2023 and came away impressed by its range5:
"this 2-for-1 gives you just about all the overdrive options you could need…and maybe a couple more, too…"
The same review noted the two circuits are "extremely complimentary" drive circuits, and covered the routing and bypass switches alongside the Gold, Silver and SHINE modes5.
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Questions
What does Silver mode do on the NUX Queen of Tone?
Silver mode is the second voice of the Horseman (Klon-style) side. You hold the Horseman footswitch for one second to switch between Gold and Silver. Gold mimics the transparent Gold Centaur overdrive, while Silver is a powered-up version with an extended gain range that NUX says offers massive headroom that usually requires an 18V input.
Is the NUX Queen of Tone true bypass?
It can be. A BF/TB switch on the back of the pedal selects either Buffer-Bypass or True-Bypass. NUX recommends BF when you run several pedals in your chain, since the buffer helps solve the tone loss that long bypassed chains can cause.
What is the difference between the NUX Queen of Tone and the Ace of Tone?
Both are NUX dual overdrives, but they stack different circuits. The Queen of Tone pairs the Horseman (Klon Centaur-style) and Morning Star (Bluesbreaker-style) circuits. The Ace of Tone instead stacks the Tube Man MkII and Morning Star mini circuits.
Is the NUX Queen of Tone analog?
Yes. NUX lists the Queen of Tone as an analog dual overdrive pedal, with two separate drive circuits: the Horseman side based on the Klon Centaur and the Morning Star side based on the Marshall Bluesbreaker.
Can the NUX Queen of Tone be switched remotely?
Yes. The pedal has an EXT. SW jack for an external foot controller such as the NUX NMP-2, which lets you remote the pedal without touching its own footswitches.
How much does the NUX Queen of Tone cost?
Guitar World listed it at $149 in the US and £99 in the UK in its 2026 review. A 2025 Gearnews review listed it at $107.00 USD and £96.00 GBP, so street prices vary depending on the retailer and date.
Sources (5)
- Queen of Tone (NDO-6) by NUX, RockBoard PedalPedia, 2026
- Warm Audio Throne of Tone pedal review, Guitar World, 2025-10-17
- Queen of Tone, NUX Audio, 2025-11-06
- NUX Queen Of Tone, Delicious Audio, 2023-04-12
- NUX NDO6 Queen of Tone Dual Overdrive, Pedal of the Day, 2023-04-29
