1. Introduction
The dbx 266xs Compressor/Gate is a professional audio dynamics processor designed to enhance sound quality in studio, touring, and portable PA sound systems. It incorporates patented Overeasy® compression technology for smooth, musical performance and AutoDynamic™ attack and release controls for ease of use. This versatile unit supports both stereo and dual-mono operation, offering flexibility for various audio applications. It features professional-grade XLR and 1/4" TRS inputs and outputs, along with comprehensive visual feedback through gain reduction metering and backlit switches.
The 266xs is engineered to manage uneven audio levels, add sustain to instruments like guitars, and enhance drum sounds. It also effectively brings vocals forward in a mix, ensuring greater clarity and presence. This compressor is a valuable tool for achieving a polished and professional sound.

Figure 1 : Face avant view of the dbx 266xs Compressor/Gate, showing controls for two independent channels.
2. Consignes de sécurité
Veuillez lire et comprendre toutes les consignes de sécurité avant d'utiliser cet appareil. Conservez ce manuel pour toute consultation ultérieure.
- Risque de choc électrique : N’ouvrez pas l’appareil. Il ne contient aucune pièce réparable par l’utilisateur. Confiez toute réparation à un technicien qualifié.
- Source d'alimentation : Connect the unit only to the specified power supply (100-120V~ 50/60Hz, 15 Watts).
- Humidité: Pour réduire le risque d’incendie ou de choc électrique, n’exposez pas cet équipement à la pluie ou à l’humidité.
- Ventilation: Assurez une ventilation adéquate. Ne bloquez pas les ouvertures de ventilation.
- Placement: Ne placez pas l'appareil à proximité de sources de chaleur ou en plein soleil.
- Nettoyage: Nettoyer uniquement avec un chiffon sec.

Figure 2 : Arrière view of the dbx 266xs, showing input/output connections and safety warnings.
3. Caractéristiques
The dbx 266xs Compressor/Gate offers a range of features designed for professional audio processing:
- Connectivité polyvalente : Equipped with quality XLR and 1/4" TRS inputs and outputs for seamless integration into various audio setups.
- Clarté vocale améliorée : Optimizes vocals to stand out with improved clarity and presence in a mix.
- Performances professionnelles : Utilizes patented Overeasy® compression technology and AutoDynamic™ attack and release controls for smooth, musical performance.
- Insertion de chaîne latérale : Provides an option for tightening and clarifying frequencies, particularly useful for instruments like bass and kick drum.
- Comprehensive Visual Feedback: Features separate precision LED displays for gain reduction, compression threshold, and gate threshold, enabling quick and accurate setup.
- Application polyvalente : Ideal for both studio recording and live performances, enhancing instruments and providing a polished, cohesive mix.
- Dual-Mono or Stereo Operation: Can be configured for two independent mono channels or linked for stereo processing.
- Program-Adaptive Expander/Gate: Ensures smooth release characteristics.

Figure 3: Marketing image illustrating key features and typical applications for the dbx 266xs.
4. Installation
4.1 Installation physique
The dbx 266xs is designed for standard 1U rack space installation. Its dimensions are 1.75" H x 5.75" D x 19.00" W. Ensure adequate ventilation around the unit when mounting in a rack.
4.2 Connexions
The rear panel of the 266xs provides all necessary audio input and output connections. Each of the two channels features independent inputs, outputs, and sidechain inserts.
- Entrées : Connectez votre source audio (par exemple, la sortie de la table de mixage, le préampli micro).amplifier) to the 1/4" TRS or XLR inputs. Both balanced and unbalanced connections are supported.
- Résultats : Connect the processed audio signal from the 1/4" TRS or XLR outputs to your next device in the signal chain (e.g., power ampamplificateur, interface d'enregistrement).
- Insertion de chaîne latérale : Use the 1/4" TRS sidechain insert jack to connect external processing devices (e.g., EQ, de-esser) that will control the compressor/gate. This is a Tip-Ring-Sleeve (TRS) jack where Tip is Send (output) and Ring is Return (input).
- Pouvoir: Connect the supplied AC power cord to the IEC power inlet on the rear panel and then to a suitable AC power outlet (100-120V~ 50/60Hz).

Figure 4 : Détaillé view of the rear panel, showing XLR and 1/4" TRS inputs/outputs and sidechain inserts for both channels.
5. Mode d'emploi
The dbx 266xs features intuitive controls for each of its two independent channels. Understanding these controls is key to achieving desired audio dynamics.
5.1 Expander/Gate Controls
- Seuil: Sets the level below which the gate will begin to attenuate the signal. Adjust this to eliminate unwanted noise or bleed.
- Rapport: Determines the amount of attenuation applied once the signal falls below the threshold. Higher ratios result in more aggressive gating.
- Gate LED: Indicates when the gate is active.
5.2 Compressor Controls
- Seuil: Sets the level above which compression begins. Signals exceeding this level will be compressed.
- Rapport: Controls the amount of compression applied. A ratio of 2:1 means that for every 2dB the input signal goes over the threshold, the output will only increase by 1dB.
- Overeasy® Button: Engages dbx's patented Overeasy compression, providing a smoother, more natural compression curve. When disengaged, the compression is hard-knee.
- Attaque: Determines how quickly the compressor reacts to signals exceeding the threshold. "Fast" settings react almost instantly, while "Slow" settings allow initial transients to pass through.
- Libérer: Controls how quickly the compressor returns to its normal state after the signal falls below the threshold. "Fast" settings result in quick release, while "Slow" settings provide a more sustained effect. The 266xs features AutoDynamic™ attack and release for simplified operation.
- Gain de sortie: Adjusts the overall output level of the processed signal to compensate for gain reduction caused by compression.
- Compteur de réduction de gain : A series of LEDs indicating the amount of gain reduction (compression) being applied in dB.
5.3 Commandes du système
- Stereo Couple Button: Links Channel One and Channel Two for stereo operation. When engaged, Channel One's controls act as the master for both channels.
- Bouton de contournement : Bypasses all processing for the respective channel, allowing the input signal to pass directly to the output without any compression or gating.

Figure 5: Front panel controls, illustrating the Expander/Gate, Compressor, and System controls for each channel.
6. Entretien
Proper maintenance ensures the longevity and optimal performance of your dbx 266xs.
- Nettoyage: Use a soft, dry cloth to clean the exterior of the unit. Do not use liquid cleaners or aerosols, as they may damage the finish or internal components.
- Stockage: Lorsqu'il n'est pas utilisé pendant une période prolongée, rangez l'appareil dans un endroit frais et sec, à l'abri de la lumière directe du soleil et des températures extrêmes.
- Ventilation: Vérifiez régulièrement que les ouvertures de ventilation sont dégagées de poussière et de débris afin d'éviter toute surchauffe.
- Connexions de câble : Periodically inspect all audio and power cables for wear or damage. Replace any faulty cables immediately.
7. Dépannage
If you encounter issues with your dbx 266xs, refer to the following common troubleshooting steps:
| Problème | Cause/solution possible |
|---|---|
| Pas d'alimentation / L'appareil ne s'allume pas |
|
| Pas de sortie audio |
|
| Son déformé |
|
| Gate not working or always open/closed |
|
| Compressor not engaging or over-compressing |
|
If the problem persists after trying these steps, please contact dbx customer support or refer to the official user manual PDF for more detailed troubleshooting.
8. Spécifications
Below are the technical specifications for the dbx 266xs Compressor/Gate:
| Catégorie | Spécification |
|---|---|
| Entrées | 1/4" TRS and female XLR (pin 2 Hot), Electronically balanced/unbalanced, RF filtered |
| Impédance d'entrée | Balanced: 50kΩ, Unbalanced: 25kΩ |
| Niveau d'entrée max. | +22dBu balanced or unbalanced |
| Sorties | 1/4" TRS and female XLR (pin 2 Hot), Impedance-balanced/unbalanced, RF filtered |
| Impédance de sortie | Balanced: 100Ω, Unbalanced: 50Ω |
| Niveau de sortie max | +21dBu balanced/unbalanced into 2kΩ or greater |
| Insertion de chaîne latérale | 1/4" TRS Phone Jack (Tip=Output, Ring=Input) |
| Sidechain Impedance | Tip: 1kΩ (Output), Ring: 10kΩ (Input) |
| Compresseur | Threshold: -40dBu to +20dBu |
| Rapport | 1:1 to Infinity:1 (Selectable Overeasy® or Hard-knee) |
| Attaque/libération | Program-dependent AutoDynamic™ |
| Extenseur/Porte | Threshold: -60dBu to +10dBu |
| Expansion Ratio | 1:1 à 4:1 |
| Attaque/libération | Dépend du programme |
| Performances du système | Bandwidth: 0.35Hz - 90kHz (+0/-3dB) |
| Réponse en fréquence | 0.5 Hz - 160 kHz (+0/-3 dB) |
| Bruit | <-93dBu, unweighted (22kHz measurement band) |
| THD+N | 0.04% typical at +4dBu, 1kHz |
| Distorsion d'intermodulation | 0.08% typical SMPTE |
| Plage dynamique | >113dB, unweighted |
| Diaphonie | <-90dB, 20Hz to 20kHz |
| Rejet de mode commun | >40dB, typically >55dB at 1kHz |
| Couplage stéréo | True RMS Power Summing™ |
| Alimentation électrique | 15 Watts, 100VAC 50/60Hz, 230VAC 50/60Hz |
| Vol d'exploitationtage | 100-120V~ 50/60Hz or 230V~ 50/60Hz |
| Température de fonctionnement | 0°C à 45°C (32°F à 113°F) |
| Physique | Dimensions (H x D x W): 1.75" x 5.75" x 19" (4.5cm x 14.6cm x 48.26cm) |
| Poids unitaire | 4.84 lb / 2.19 kg |
| Poids à l'expédition | 6.6 lb / 2.99 kg |

Figure 6: Official specifications sheet for the dbx 266xs, detailing electrical and physical characteristics.
9. Garantie et assistance
dbx products are designed and manufactured to the highest standards. For detailed warranty information, please refer to the warranty card included with your product or visit the official dbx website.
For technical support, service, or additional information, please contact dbx customer support:
- Manuel d'utilisation officiel (PDF) : Manuel Télécharger PDF
- dbx Website: www.dbxpro.com
- Phone (Sales): 1.801.568.7660
- Phone (Int'l Fax): 1.801.568.7583
- Télécopieur (ventes) : 1.801.568.7662
- E-mail: client@dbxpro.com
- Adresse: 8760 S. Sandy Pkwy., Sandy, Utah 84070, USA





