Choosing Between RCA and 3.5mm Jack for Sennheiser HD660S Headphones and iFi iDSD LE DAC
When deciding whether to connect your Sennheiser HD660S headphones to your iFi iDSD LE DAC using RCA or a 3.5mm jack, there are several important factors to consider. This guide will help you understand how to make the best choice for optimal sound quality and convenience.
Guidelines for Connection
Whether you should connect your Sennheiser HD660S headphones to your iFi iDSD LE DAC via RCA or 3.5mm jack depends on several key aspects, such as sound quality, impedance matching, convenience, and portability. Let’s dive into each of these factors in detail.
1. Sound Quality
3.5mm Jack
The typical 3.5mm jack is a direct output designed specifically for headphones. It usually includes a dedicated headphone amplifier that can enhance sound quality, particularly for high-impedance headphones like the HD660S. This direct connection ensures that the audio signal is delivered with minimal loss of quality.
RCA
On the other hand, RCA outputs are line-level outputs meant for connecting to amplifiers or other audio equipment. While you can use an RCA output with your headphones, it may require an additional headphone amplifier. This additional step can introduce potential quality issues if not optimized for the specific impedance requirements of your headphones.
2. Impedance Matching
The Sennheiser HD660S has a higher impedance of 300 ohms, which means it requires a more robust signal to perform optimally. The 3.5mm jack on the iFi iDSD LE is specifically designed to handle this high impedance, making it a more suitable choice compared to a standard RCA output.
3. Convenience
3.5mm Jack
The 3.5mm jack is generally more user-friendly for headphone connections. It’s the standard for most headphone cables, making it easier to use and less prone to compatibility issues. If you are concerned about simplicity and ease of connection, the 3.5mm jack is likely the better choice.
RCA
While the RCA outputs on the DAC can still connect to headphones, they may require additional adapters or cables. This added complexity can be a drawback, especially if you prefer a straightforward setup.
4. Portability
For users seeking a portable setup, the 3.5mm output is often more convenient and easier to manage with headphone cables. It reduces the number of cables and connectors needed, making your audio equipment setup simpler to carry and use.
Conclusion
Based on the factors discussed, the best choice for connecting your Sennheiser HD660S headphones to your iFi iDSD LE DAC is the 3.5mm jack. This connection is likely to provide the best sound quality and is more suited for driving high-impedance headphones effectively. The dedicated headphone output ensures that you get the optimal performance from your headphones without the need for additional amplification.
It is important to note that the RCA outputs on the DAC are designed for line-level audio and are not intended for driving headphones directly. If you want to use the RCA output, you will need to connect them to an appropriate amplifier and then to your headphones. However, the presence of both is sometimes included to allow for flexibility in situations where you might be monitoring audio on headphones while simultaneously sending audio to a mixer or other device.
While the Sennheiser HD660S does not have any RCA connection, it is equipped with standard 6.5mm input connections and a newer Pentaconn plug, which is suitable for balanced connections from a device with balanced outputs. For the best sound quality, it is recommended to use the built-in headphone output, which includes a volume potentiometer for fine-tuning your listening experience.