I got my 840As a few months ago to use at work after the headband on my trusty 840s broke irreparably. I loved the 840s and had them for at least 10+ years and they were just a delight to listen to. What I love is that they are accurate without being sterile. I then had a choice, get a new pair of the 840s or go for the 840As. After reading a few reviews I chose the latter and I'm glad I did. They still have that accurate tonal and timbral sound signature to make a piano sound like a piano and they reproduce the human voice beautifully. Where they score above the old 840s is in the bass region. They go deeper without sounding unnatural and there is seamless progression into the midrange.
I'm going to look at possibly removing some of the baffling in the earpads (as Ryan HO hinted at in his YT review) just to see what it does with both the treble and the bass. I did this with my HD580s and it made a big and positive difference.
For the cost, these are a no brainer. I purchased them from Addicted to Audio for $300 Australian and they are a bargain at the price. I run mine out of my work laptop via a Fiio Q1 original model. It does make a difference in sound and is small enough to use in a portable setting (which I don't).
@Alou's advice to use a dongle DAC/Amp is good advice if you do want to go portable. I can't recommend these highly enough. You'd spend quite a bit more money to get a better sound.
I have them in Starbucks right now and commuted on bus. For winter, the next 5 months, these make fine sense as portable. They are a level above the size profile of portable designed ANC headphones, but the last few days , both moving around outside and going in to shops, they manoeuvre just the same as my Sony XM3, slip down around neck and cups flatten on chest. I tied the 3m cable into a 1 meter also!.. I'll probably sort a shorter cable, Shure have one made for this and 440a which has an inline remote and mic, but actually, as I said, it's winter, it's big jacket time here, so everything is just blending in,, cable inside jacket,, and the cans are not out of the ordinary , sticking out noticeably, the design is sleek and modern enough,, and I'm quite enjoying the gold bling if anybody cares to notice! I'll have to get a some extra ceiling volume head room , Wavelet is sweetened right up and the gain limiter is maxed. I'll try a Samsung dongle and fortify it, they break so easily,, but in long run I'll get something nice.. I'm really loving this discovery, it's come after a year of looking at Focal Elegia , Audio Technicas, etcetc, it's only because I went to this art exhibition which had 440a being used for an exhibit that brought me to 840a,, and then the research reviews, Ryan Ho.. I have to come to the conclusion that this is a gem hiding in pain sight because I was really digging hard the last year, of course I was looking at 1540s, but not these,, and I reckon it's because I conditioned myself not to look at anything below 450bucks as a contender. And also I reckon Shure gets eye rolled as old hat and workhorse fare doing a job..So good on Ryan Ho for championing these,, and boy he is 1000% behind these drivers and tuning, and that enthusiasm for me, and the honesty of it, down to the fact that looking at his other videos, and the options he has, he went with these.. Hidden gem for the portable audiophile option!..
. Also yes the baffling,, so there are further explorations to be made,, I'd be terrified of mucking that up!... But it reminds me that I've been thinking about the pad swap option of maybe getting the 940 velours