Introduction
The Focusrite ISA 428 MK2 is a high-quality 4-channel microphone preamplifier designed for professional audio recording environments. It features Focusrite's renowned transformer-based preamps, offering exceptional sonic clarity and versatility. This manual provides essential information for the setup, operation, maintenance, and troubleshooting of your ISA 428 MK2.
Figure 1: Front panel of the ISA 428 MK2, showing four input channels with controls and metering.
Installation
Proper setup ensures optimal performance and longevity of your ISA 428 MK2. Follow these steps for initial installation:
- Déballage: Carefully remove the ISA 428 MK2 from its packaging. Retain all packaging materials for future transport or storage.
- Montage en rack : The ISA 428 MK2 is designed for standard 19-inch rack mounting. Secure the unit using appropriate rack screws. Ensure adequate ventilation around the unit.
- Connexion électrique : Connect the supplied power cord to the IEC inlet on the rear panel of the unit and then to a grounded AC power outlet. The unit operates on Corded Electric power.
- Connexions audio :
- Entrées microphone: Connect microphones to the XLR inputs on the rear panel.
- Line/Instrument Inputs: Use the 1/4" jack inputs for line-level signals or direct instrument connections.
- Résultats : Connect the XLR outputs to your audio interface, mixer, or recording device.
- Insérer des points : Utilize the dedicated insert points for integrating external signal processors like compressors or EQs.
Figure 2: Rear panel of the ISA 428 MK2, illustrating the various audio input and output connections.
Mode d'emploi
The ISA 428 MK2 offers precise control over your audio signals. Familiarize yourself with the following operational aspects:
Prendre le contrôle
Each channel features a versatile gain range from 0dB to +60dB, with an additional 20dB variable trim. Adjust the gain knob to achieve optimal signal levels without clipping. Monitor the input level meters to prevent overload.
Contrôle d'impédance
The ISA 428 MK2 allows you to tailor the preamp to your microphone with selectable impedance options: 600, 1400, 2400, and 6800 Ohms. Experiment with different impedance settings to find the optimal match for your microphone, which can significantly affect its tonal character and performance.
Alimentation fantôme (48 V)
Engage the 48V phantom power switch for condenser microphones that require external power. Ensure the microphone is connected before activating phantom power to prevent damage.
Filtre passe-haut
Each channel includes a high-pass filter to remove unwanted low-frequency rumble or noise. Activate this filter when recording sources prone to such issues, like vocals or acoustic instruments in a live room.
Mesure
The front panel features clear LED metering for each channel, allowing you to visually monitor input and output levels and prevent digital clipping.
Figure 3 : Angulaire view of the ISA 428 MK2, providing a clearer perspective of the front panel controls and indicators.
Entretien
To ensure the longevity and optimal performance of your ISA 428 MK2, follow these maintenance guidelines:
- Nettoyage: Use a soft, dry cloth to clean the exterior of the unit. Avoid abrasive cleaners or solvents, which can damage the finish.
- Ventilation: Ensure that the ventilation slots are clear of dust and obstructions to prevent overheating.
- Stockage: When not in use for extended periods, store the unit in a cool, dry place, ideally in its original packaging or a protective case.
- Éteindre: Mettez toujours l'appareil hors tension et débranchez-le du secteur avant de le nettoyer ou d'effectuer toute opération de maintenance.
Dépannage
If you encounter issues with your ISA 428 MK2, refer to the following common troubleshooting steps:
| Problème | Cause possible | Solution |
|---|---|---|
| Pas de courant | Câble d'alimentation débranché ; prise de courant défectueuse ; fusible de l'appareil grillé. | Check power cable connection; Try a different outlet; Consult a qualified technician for fuse replacement. |
| Pas de sortie audio | Incorrect cabling; Gain set too low; Phantom power not engaged for condenser mics; Output device issues. | Verify all audio cables are correctly connected; Increase gain; Activate 48V phantom power if needed; Check your audio interface/mixer settings. |
| Son déformé | Input signal too hot (clipping); Faulty cable; Microphone impedance mismatch. | Reduce input gain; Try a different cable; Adjust impedance setting on the ISA 428 MK2. |
| Bourdonnement ou bruit | Ground loop; Faulty cable; External interference. | Ensure all equipment is properly grounded; Try different cables; Isolate the unit from other electronic devices. |
If the problem persists after attempting these solutions, please contact Focusrite customer support.
Caractéristiques
Detailed technical specifications for the Focusrite ISA 428 MK2:
- Modèle: 428MKII
- Chaînes : 4 Préampli microamps
- Plage de gain : 0dB to +60dB (Mic), +20dB variable trim
- Impédance d'entrée : Selectable (600, 1400, 2400, 6800 Ohms)
- Connectivité : XLR Mic Inputs, 1/4" Line/Instrument Inputs, XLR Outputs, Insert Points
- Distorsion harmonique totale + bruit: As low as 0.0009%
- Dimensions (Produit) : 25 x 17.4 x 8.9 pouces
- Poids (article) : 12.1 livres
- Source d'alimentation : Électrique avec fil
- Montage: 19" Rack-mountable
Informations sur la garantie
The Focusrite ISA 428 MK2 comes with a 2-year Focusrite warranty. This warranty covers defects in materials and workmanship under normal use. Please retain your proof of purchase for warranty claims. For full terms and conditions, refer to the official Focusrite webconsultez le site ou contactez leur assistance.
Assistance et contact
For further assistance, technical support, or to register your product, please visit the official Focusrite website:
You can also find additional resources, FAQs, and driver downloads on their support pages.
