Would this be good with the sennheiser hd660s? . I have heard it would be too overpowered for them but I would be interested to hear other people's thoughts


Jan 17, 2022
If you're worried that the 789 is so powerful that it could damage the hd660s, then your concern may be justified. The 789 balanced output probably produces way more power than the 660s can handle (but not the SE output). The solution is simple - turn down the volume. If the music is so loud that there is a risk of headphone damage, then you are definitely causing severe damage to your ears
Jan 15, 2022
Well I don't own have experience with the hd660s I do own the Drop 6xx which are the drop version of the hd650 so I familiar with sound they share. I have 02/Grace dac combo paired with 789. I been running 6xx with the 789 for past 3 month an average of 5 or more hours straight a day. 789 being overpowering if paired with hd660s seem odd and I don't follow. So I can't speak on 789 being over pairing. The 789 is clean, fast, dynamic and neutral amp it really doesn't add anything but neutral so your source,dac, speakers, and headphones would be only influence really to the sound. The 789's neutral sound can come off flat and sharp to listeners with different tastes. With my 6xx the 789 allow the headphone stand alone be only influence to the sound coming to my ears which I like. The 6xx have emphasis midrange and intimate vocals with mid to high warmth. With the 6xxs being very intimate headphone the soundstage is very narrow. The low end on the 6xx is clean and crisp which may come off as the headphones have no bass. The 789 won't add any bass or add sound stage. The 789 will not will help headphones weak points but will not hinder a headphones strong points either, so If you like what I describe in my setup then I would say you would enjoy 660s as well.