FiiO E11chat_bubble_outlineFrom real comments

Users consistently praise the E11 for adding punchy, warm bass to portable listening setups. Owners repeatedly describe the E11 as delivering richer, more powerful bass and better overall sound than listening straight from a phone or iPod, especially with headphones like the ATH-M50 and Sennheiser models. One user called it 'the best 75 investment' they've made, and another still enjoys it years after buying it. The bass boost dial lets listeners dial in extra thump for genres like hip-hop and EDM, making it a popular choice for bass-hungry casual listeners on a budget.

A hi/lo gain switch and swappable battery make the E11 flexible but occasionally confusing for newcomers. The rear hi/low power switch is meant to properly drive headphones of varying impedance, with low gain suited to sets like 48-ohm M50s and high gain better for higher-impedance cans like 250-ohm DT990s. The battery compartment is also replaceable, a feature some buyers years later found refreshingly practical compared to modern sealed designs. However, newer users often don't understand the switch's purpose without guidance from more experienced commenters.

Interference, no charge-while-playing, and missing Apple accessories are the main frustrations. Multiple users report irritating static or electric interference when the amp's bass boost is engaged near wifi or bluetooth signals, along with clicking noises between tracks and no onboard equalizer. Another complaint is that the E11 cannot be used while charging, ruling it out as a desktop solution for some. It also doesn't include a dock/Lightning cable for iPhone users, requiring an extra purchase to get a cleaner signal path bypassing the phone's internal DAC.