I bought a pair of sennheiser hd220's and sounded great, but the addition of this amplifier gave it the incredible well-rounded filled-out sound. Not the best headphone amp on the market, but is great value considering the price. Also I have owned this product for almost a year and use it about 5 or 6 days a week and have not had any problems. I would recommend this product to anybody who has a budget but would like to enhance their music.