Introduction
The Koss ESP-950 Electrostatic Stereophone system provides high-fidelity audio reproduction through electrostatic transducer technology. This manual provides instructions for the proper setup, operation, maintenance, and troubleshooting of your ESP-950 system to ensure optimal performance and longevity.
The system includes the ESP-950 headphones and the E/90 Electrostatic Energizer, designed to work together to deliver a detailed listening experience. The headphones feature a detachable headband and pivoting ear cups for user comfort.
What's in the Box
Your Koss ESP-950 system package contains the following components:
- Koss ESP-950 Electrostatic Stereophones (Headphones)
- Koss E/90 Electrostatic Energizer Amplifier
- Detachable Headband
- 120 VAC Power Adapter
- Battery Pack (for portable use)
- Audio Connecting Cables (various types for different sources)
- Leather Carrying Case
Setup Instructions
Follow these steps to set up your Koss ESP-950 Electrostatic Stereophone system:
- Assemble the Headphones: Attach the detachable headband to the electrostatic transducers (earcups). Press, slide, and lock each side of the headband into the corresponding slot on the earcups. Ensure a secure connection.
- Connect Headphones to Energizer: Locate the 5-pin connector on the headphone cable. Plug this connector firmly into the "PHONES" input on the front panel of the E/90 Electrostatic Energizer.
- Connect Audio Source: Connect your audio source (e.g., CD player, amplifier, computer) to the E/90 Energizer. The energizer has both RCA line audio inputs on the rear and a 3.5mm input jack on the front. Use the appropriate audio connecting cable provided.
- Power the Energizer: Connect the 120 VAC power adapter to the DC power input on the rear of the E/90 Energizer and plug it into a wall outlet. Alternatively, for portable use, connect the battery pack to the DC power input.
- Power On: Flip the "POWER ON" switch on the front panel of the E/90 Energizer to the 'on' position. The "DC POWER" indicator light should illuminate.
Operating Instructions
Once the system is set up, follow these guidelines for operation:
- Adjust Acoustic Level: The E/90 Energizer features an "ACOUSTIC LEVEL" knob. This knob has independent left and right channel controls. Rotate the outer ring for one channel and the inner knob for the other to adjust the volume for each earcup. Adjust to a comfortable listening level.
- Wearing the Headphones: Place the headphones over your ears, ensuring the earcups fully enclose your ears for optimal sound isolation and comfort. The pivoting ear cups and adjustable headband allow for a personalized fit.
- Listening: Begin playback from your audio source. Adjust the acoustic level on the E/90 Energizer as needed.
Maintenance
Proper care will extend the life and performance of your ESP-950 system:
- Cleaning: Use a soft, dry cloth to clean the exterior surfaces of the headphones and energizer. Avoid using liquid cleaners or solvents, as these can damage the finish or internal components.
- Earpad Care: The earpads are made of a synthetic leather material. Wipe them gently with a damp cloth if necessary, and allow them to air dry completely before use.
- Storage: When not in use, store the headphones and energizer in the provided leather carrying case to protect them from dust, moisture, and physical damage.
- Environmental Conditions: Avoid exposing the system to extreme temperatures, high humidity, or direct sunlight. Electrostatic headphones are sensitive to moisture and static electricity.
- Cable Management: Handle cables carefully. Avoid sharp bends or excessive pulling that could damage the connectors or internal wiring.
Troubleshooting
If you encounter issues with your ESP-950 system, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound or intermittent sound | Loose cable connections, energizer not powered, audio source issue, faulty headphone connection. | Ensure all cables (power, audio input, headphone) are securely connected. Verify the energizer is powered on (DC POWER light illuminated). Check the audio source for proper operation. Re-seat the 5-pin headphone connector. |
| Humming or static noise | Grounding issue, interference from nearby electronics, static electricity. | Ensure the energizer is not placed too close to other electronic devices that emit 60Hz signals. Try using different audio input cables, ensuring they are well-insulated. Avoid using the headphones in overly damp or static-prone environments. |
| Uneven volume between channels | Independent L+R acoustic level controls are unbalanced. | Carefully adjust both the inner and outer rings of the "ACOUSTIC LEVEL" knob to balance the volume for each channel. |
| Squealing sound from ear cup | Internal issue with the electrostatic transducer. | This may indicate a component issue. Refer to the Warranty and Support section for service options. |
| Audio input cables do not fit RCA jacks | RCA jacks may be shallow, requiring specific cable termination types. | Use the provided audio cables or ensure any third-party cables have slim RCA terminations designed to fit shallow jacks. |
Specifications
| Feature | Specification |
|---|---|
| Model Number | ESP950 |
| Audio Driver Type | Electrostatic Driver |
| Ear Placement | Over Ear |
| Form Factor | Over Ear |
| Noise Control | Sound Isolation |
| Connectivity Technology | Wired |
| Headphones Jack | 6.35 mm Jack (on energizer) |
| Material | Leather (carrying case) |
| Item Weight | 4.49 Pounds (total package) |
| Product Dimensions | 11.5 x 6.5 x 9.5 inches (package) |
| Impedance | 100000 Ohms |
| Included Components | Cables, Battery Pack, Leather Case |
Warranty and Support
The Koss ESP-950 Electrostatic Stereophone system is backed by a Limited Lifetime Warranty. This warranty covers defects in materials and workmanship under normal use. Please note that the warranty does not cover misuse of the product.
For warranty service, repairs, or technical support, please contact Koss customer service. You may be required to send the product to Koss for repair, and shipping costs may apply. Refer to the official Koss website or your purchase documentation for the most current contact information and detailed warranty terms.
