Sony CD900st Impressions - Official Thread

Sony CD900st

I picked up a pair of these headphones exactly a month ago and I’ve enjoyed them more than I thought I would. I initially picked them up to hold me over as I waited for my Verites and as a daily closed headphone that wouldn’t break the bank. I came across this article that peaked my interest due to a few things. 1) The headphones were commissioned by Sony Japan to sound a certain way, 2) the headphones are still in production since 1988, 3) Nothing has changed to the design since the initial design.

Build Quality
For those who have tried the Sony V6 or 7506, I’m going to assume that it’s basically the same. It’s not heavy and not the sturdiest headphone but it’s not necessarily bad either. People have used these for decades and it’s fairly easy to find parts for. I would recommend picking up the yaxi pads stpads (not the 2). They make closer to over-ear rather than on-ear. Overall, I wish it came with a detachable cable and possibly a softer headband but I think those are things that can be modded.

After picking these up, I can see why people enjoy using these studio monitors for listening enjoyment. Due to the driver design, the vocals seem to be the main focus. For those who enjoy songs with female vocals like me, these headphones make sure that all of the surrounding music does not take away from the main attraction. They also accomplish their goal of conveying whether or not the artist is close or far to the mic. The tuning was also developed in such a way that japanese pronunciation sound musical and soothing so if Japanese music is your main genre, I would suggest taking a look at these.

I’m not going to say that these are giant killers. I’m not even going to say that these are better than mid-fi. What I can say is that the headphones presents the music in such a way that acoustic tracks get me 90% of the way there compared to my verite opens. Even with busy tracks, the Sonys do a good job supporting the vocals and never pulling the attention away from the singer. At the price point, I find it hard to really fault it technically especially for a design from the 80’s.

So should you get these? It depends. :wink: I primarily listen to vocal tracks and have really dove into japanese music after getting these headphones. They actually rival head time with the Verites for me and because of the price point and value that they bring (musicality, closed, great as a daily), the Verites are leaving but these are staying. It definitely isn’t a TOTL headphone and I don’t know how they compare with other big hitters in this price range like the HD6xx but I’m very happy with my experience with them. I have no issue with having these as my only headphone for the time being since I continue to get surprised by what this little headphone can do.

Gear used
Foobar - FLAC
Schiit Yggdrasil
Luxman P-750u
Verite Open (silkwood)
Beyers DT990 600 ohm


Sir, is that a 8k chain going into a sub 200$ headphone…?


Only the best for end game headphones :rofl:


I’d love to if I could get my hands on a pair!

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Can confirm, these are quite nice. Resolution and speed are quite good for the price, and they are quite revealing of source so a good chain isnt wasted on em.

If you listen to an album from a japanese studio, chances are these were used during recording or production at some point. Afaik they’re the industry standard studio cans over there. There’s even some amps with a special jack specifically designed to power the cd900st.

Tonality is recessed in 1-2k so vocals are nice and laid back, yet not lacking in detail.

Internally the driver is (visually) very similar to v6, but the housing is larger with different porting. Don’t be fooled by the similar look, they sound very different.


Great write up @driftingbunnies I’ve moved this to an official discussion for this headphone =)

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@TylersEclectic thanks! can you update the title so it matches the official threads?

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Nice review and very interesting article.

For those interested in this headphone, I also stumbled across a Japanese company that has done a lot of testing with this headphone and sells a modded version.

I ordered a pair with the perfect symmetry mod and am excited to see if there’s any difference between the two. It’s currently on it’s way to my Japanese proxy and I hope they will be a fun Christmas gift to myself. :crossed_fingers:

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Antdroid posted a quick impression of the headphones if anyone was interested.

Tyler also did a pretty good comparison of the CD900st with all the other closed backs he had on hand.


Mine was fully in the subjective “my experience” realm lol, @antdroid yours is a proper review :slight_smile: :grin:

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One thing I’d like to mention from the review on audiodiscourse, the channel imbalance with the bass isn’t due to the age of the headphones (I bought these new in Nov). It’s due to the fact that the design is a single cable design so there is actually a cable look in the left cup and none on the right cup. The modded headphone that I linked earlier actually addresses this imbalance using a dummy cable to adjust the area inside the right cup. But like @antdroid mentioned, you can’t really hear that imbalance when listening to music.


oh ok! lemme fix! :slight_smile:

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wonder if it would be better to try to seal the inside of the cup on the left side better so it doesn’t leak.

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They actually also include a washer so that both sides have the same area inside of the cups to kind of bring out the bass. I’ve found that my modded version has less bloom and gives the bass some air. The differences between a stock and modded one isn’t crazy but it’s there. For the additional cost, I would pick up the modded ones any day.


I actually picked up one of the Umbrella Company modded ones a while back. I really did not like how they sounded though. I thought they sounded like a 7506 but worse. I much prefer them stock and reversed most of the mods they did. I did, however, like how they cleaned up the internal wiring and the new cable they used (“900 Quadcore Quattro Cable” or “900 quattro ヘッドホン・ケーブル”. Not sure where to source some since I really like them. On a similar note, my JVC HA-MX100 also uses the same cable.

So these pictures were taken when most of the mods reversed, but essentially they sealed the two holes below the magnet with a sort of porous tape and removed the dampening foam within that was within the magnet. Oh and they also had their company sticker placed on top of the yellow dampening puck. Not sure how that affects the sound if it does. Just thought it was funny.

Blue is Umbrella Company’s mod, Pink is stock

Blue is Umbrella Company’s mod, Red is MDR-7506. The amount of bass on the 7506 surprised me quite a bit.


Thanks for sharing your impressions! I don’t see too many FR graphs of this headphone. I’ve heard that it can be a little difficult to measure.

I’ve been using my headphones with yaxi pads so that might be the difference in our experiences. I felt like the mods helped open up the bass and opened up the stage just a bit. It still retained a lot of the vocal presence that I like about the CD900st. But yeah, I kind of wondered what it looked like before and after the mods.

Do you have any suggestions for people who enjoy the CD900st but want to upgrade to something more technically proficient while keeping that vocal quality?


Hmm, I’m not sure for closed-backs but the Audio Technica ATH-AD2000 might be a good next step, though I’ve only heard modded versions (driver swapped into cheaper ATH-AD chassis). Maybe even the AD2000X though I’ve only had them very early in my “headphone days” so I’m not sure what to make of them now.

If you’re lucky, the original CD900 is also very good and somewhat similar. The original has a bit more bass and a tiny bit more energy in the upper midrange. I think the treble quality is a bit better. With that said however, the reliability of one is very low. I’ve had maybe 2 or 3 pairs and all developed some sort of driver related rattling. Not only that, they go for quite a bit. I paid 300 USD for a dud (which was not as described) and the proxy service I used will not help. Sorry, minor rant.

Forgot to mention/more ramblings: If you may be/are still interested in the hunt for an original CD900, you can identify them by their glossy earcups, coiled cable, and golden left and right indicators. There are CD900 variants that have a matte finish, a straight cable, and blue and red left and right indicators - these I believe are when Sony were transitioning to make the CD900ST. I’ve not tried a pair of those but one of the draw of the original CD900 was that it had “evaporated/amorphous diamond coated drivers.” There’s also the CD900CBS which I believe were only used in Sony’s studios and I believe were produced between the original CD900 and the transitioning CD900 I mentioned. Not sure how those are different but I’m keeping an eye out for one. :slight_smile:


It doesn’t have to be a closed back. I’ve heard maybe the ADX5000 might be something that would interest me as well but it seems like a headphone that’s just really good at one thing and that’s about it. I might try it out someday but for some reason it doesn’t really interest me. Maybe cause of the creaking issue or the fact that it doesn’t look super premium as their TOTL.

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Checking in with my experience with the CD900st.

I’ve sold my stock ones and have been using the umbrella BTL-modded ones. I’m still enjoying them and haven’t found a headphone that had the same vocal sweetness and realism that they have especially for japanese vocals. I haven’t listened to the stock ones in a while so I don’t quite remember how they are so I might pick up another pair down the road.

After getting them, I’ve had the Susvara which actually had a similar tonality with much better resolution, imaging, separation, etc but lost in the timbre of vocals. Vocals are clearer and have a little more texture with the Susvara but still was missing something that the Sonys had.

I’m still pretty happy with this pickup but am definitely keeping my eye out for something that can dethrone these. I currently have them at work but I’m looking for something that can match the vocal quality while being more comfortable. If anyone has any suggestions, let me know!

Current gear:
Work - Centrance Dacport → CD900st
Home - Rockna Wavedream → Luxman L550axii → CD900st or Genesis G

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