These were considered the second rate headphones just below the K701 when they first came out, and were priced considerably lower. I considered my pair almost a gift back in 2007. But the K701 got all the attention in the audiophile reviews. Well, little sister has grown up and she is strutting her stuff. Lately, I have noticed that many shops are selling the K601 at the same or higher price relative to the K701. Maybe raw emotion is selling better than analytical talent these days. Maybe the K701 has the unsurpassed musical skills of an Ella Fitzgerald, but if Xena Warrior Princess walks up on stage, you know who I will be paying attention to, even if the musical skills come in second rate. Maybe Xena would make you forget about musical skills altogether. One thing is for sure, once you get the K601 properly amped and feed it some beat based music, you will forget about analytical audiophile nitpicking minutiae and just get body slammed into the musical performance. The K601 may sit on your head, but it connects to your heart.
You will need to give these cans at least 100 hours of rather loud music to loosen up and deliver up the bass and smooth out the treble. Also, they are 120 ohms, so a low voltage device can't deliver enough current into these fairly inefficient cans. The K701 is an easier drive, but even they are considered rather demanding of an amp in order to sound their best. However, the K601 can tolerate quite a bit of power so lack of efficiency is of no concern if your amp has the drive capability.
Sound from my Sony CD player headphone output is just mediocre. I own the AKG HEARO 999 Audiosphere II, and it has a very strong hardwired headphone amp. The best part is that it sounds best with classic AKG pro type headphones, and the K601 is in that camp. The midrange is glorious, but it is a bit forward of the bass and treble. The HEARO 999 seems to boost bass and treble, especially the bass, of every headphone I have driven with it. In fact, 32 ohm headphones may be overdriven before the volume pot is turned halfway to max. I typically listen to the K601 below halfway up, unless I have a very low volume recording playing, and it is the most inefficient set of cans I have ever had. Even my 600 ohm Sennheiser pro cans needed less rotation of the volume pot relative to these cans. When driven by the HEARO 999, the K601 cans are pure sonic nirvana for hard driving beat based music. These are PRaT cans for sure. However, vocal music is especially well served due to the glorious midrange. Live recording such as Fleetwood Mac's "The Dance" has all the life, edge and rawness of a live performance intact. What is surprising is that the K601 is almost a liquid and smooth set of cans when the music is that type.
For those of you who remember using Kodachrome 35mm film, the K601 would be likened to Kodachrome 64. The slower Kodachrome 25 may have been the most neutral and balanced on a sunny day when everything was perfect, but on an overcast day when everything wasn't just right, the faster 64 ASA film would give you a better look and as Paul Simon wrote in his song, "Make you think all the world's a sunny day". Well, few of my recordings are audiophile perfect and therefore I don't need a headphone made for perfect recordings. If the recording is good or bad, the K601 will let you know it, but it tries much harder than my DT880 cans to make you forget about the bad and just start grooving to what is good. It could be ABBA or Jimi Hendrix or Michael Jackson or Rammstein. If you really liked it before the K601 came along, you will LOVE it afterwards. It's sort of like a stuffed animal coming to life suddenly in front of you.
I have owned at least a dozen cans in my day, Grado SR200, Sennheiser Pro, Beyer dynamic DT880, AKG 999 are some of the models. I don't care too much about absolute quality after a certain level of audiophile quality is attained. It's about how it integrates with the rest of your gear and taste in music that counts. It's about how many times you find yourself up out of your chair and moving with the music that counts, and these cans have done it more than any others. It's best not to microanalyze it and maybe just find another pair and stash them away in case the price climbs any higher. Life is too short to collect a bunch of second rate gear just for comparisons.
Beware the tendency to play these cans very loud. Could you drive a Ferrari and not thrash it around a bit? These cans seem designed to listen to modern music at live concert levels. Since live concerts are a small part of our lives, that's not too much of a danger. Hopefully you will only lose a few hours of sleep after falling in love with these cans, but I find myself listening too loud too long at times.
Look at all the latest audiophile gear that gets good reviews and then is forgotten about or hits the used market at bargain prices. An old Conrad-Johnson Premier One tube amp from the 80's will get sold almost as soon as it hits the used market and there will be no haggling with the seller over the price, which may be more than he paid for it years ago. It may not be the audio reviewers' latest darling amp, but insider music lovers have tagged it as a real Monkey Bone Reference, and the late Bascom King of Audio magazine, an amp designer himself, said it laid out the emotions in music like no other, in spite of what the mediocre lab tests might say. The K601 is a Monkey Bone Reference if you treat it right. The K601 walks all over higher priced cans like a Denon phono cartridge does to its higher priced competition.
FWIW, I have owned a stack of C-J amps for 10 years with no intention of ever selling them. The K601 has the musical involvement of C-J gear, so if you are a C-J lover, give the K601 a try.
