Review: SONY MDR-R10 vs. R10—The Dark vs. Light Side of The Bass (56K Warning)
Sep 6, 2010 at 6:37 PM Thread Starter Post #1 of 36


Headphoneus Supremus
Feb 1, 2010

“…With the care and affection of the skilled lute makers of bygone days, we shave the wood, polish it and breathe life—sound—into our MDR-R10 stereo headphones…the R10 has been elected to be a musical instrument that reproduces the soul of music.”
[size=10.0pt]----Excerpt from Page 1 – SONY MDR-R10 User Manual, (c) [/size][size=10.0pt]SONY Corporation---[/size]


Much has been said and written over the years of these legendary, limited edition headphones.  Maybe it’s the sign of the times we live in but the fascination about them seems to have gotten ever stronger as the years went by since SONY has ceased production in 2004.  These headphones were hand-built since their introduction in 1989 and only 2,000 of them were ever produced.  Towards the end of the production cycle of the first 1,000 SONY has decided to retune them for enhanced bass response.  The cutoff point is difficult to determine, but there have been consistent claims on Head-Fi that put it around Serial #7-800 with a few exceptions, when only the bass-heavy versions were produced.
Through a series of random events, I have been lucky enough to have come into possession two of them while having the luxury of living with them for several weeks until my high-end series of amplifiers and interconnects have arrived and more or less burned in, so a serious comparative listening session could be conducted between the so-called bass-light and bass-heavy versions of these one-of-a-kind headphones.
For those readers who have not yet had a chance to audition or learn more about what makes these headphones so special, I will transcribe some of the details out of the user manual, as it is not widely known nor published on the Internet.  Those of you already aware can skip this section.


Making of the R10s

These summary excerpts from the manual feature some, but not all of the highlights of the R10 design and manufacturing process, which help to explain why the company has steadfastly maintained that even at its $3,999 retail price, it has lost money on every single R10 unit produced.
The Diaphragm
The SONY research team, in conjunction with Ajinomoto Co., Ltd., had developed a process where a 2-micron-long bacterium, by the name of Acetobacter aceti, produces extremely thin fibers about 0.02-0.04 micron thick, called bio-cellulose.  Using patented biotechnology processes; these cultures are grown in two days to 2mm thickness, and then compressed back to 20 microns to form a diaphragm die.  No artificial material developed since quite lived up to the warm, natural sound these special diaphragms can produce.  As expected, few diaphragms “grown” passed the Q&A criteria and the success to failure rate was small, making this process extremely expensive and time consuming.

After exhausting research and evaluation, SONY has decided to produce the headphone housings for the R10 out of solid heartwood from 200-year old Zelkova trees only found in the Chubu and Tohoku regions of Japan.  The combination of volume, shape and materials have contributed to this decision to pick this particular material that yielded the best possible combination of weight, hardness, timbre, sound transferability that produced natural, distortion-free sound in a 3D-sound stage representation of a concert hall reverberation characteristics.  CAD design process was used to fine-tune the C&C specifications to allow precise machining of the interior wall of the housing with complex compound curves aiding sound characteristics.
Ear Pads
The R10 was specifically designed to reduce and distribute pressure equally around the head with the help of soft Greek lambskin ear pads, which is stripped thing and processed for a uniquely smooth feeling to reduce outside pressure on the auricle.  Each R10 unit required an entire lambskin.
Photo below:  Sony MDR-R10 manuals (1998-version on the left, 1989's on the right)

Technical Specifications
Type: Closed Dynamic Type
Speaker Unit:  50mm diameter dome-type with bio-cellulose diaphragm
Impedance: 40 ohm
Frequency Response: 20 - 20,000 Hz
Sensitivity: 100 dB / mW
Max input: 1,000 mW
Cord: 3 m
Weight: 400 g (Without Cord)

Review R10 Units



R10 Serial #0084 (P)1989 - Bass-Light Version (pictured on the left side on all photos)

Background Summary:  The first 100 units of the R10 series were not sold in retail channels, rather distributed within the company in 1989 as demonstrators.  This particular unit was transferred to the Arts Director of SONY Europe, who used it for trade shows.  This explains the mint condition of the phones themselves and the mint interior of the suitcase, as well as the poor condition of the case exterior, which has been partially restored.  I have purchased this on Ebay a few months ago, but these phones are now being transferred to their new owner, Craig of Whiplash Audio, who will use them for testing and for demonstrations.


R10 Serial #00983 (P)1998 - Bass-Heavy Version (pictured on the right side on all photos)

Background Summary:  I have purchased this particular example from a senior Head-Fi member “El_Doug,” who has been a pillar of this community for a number of years.  Doug had made me promise that I would use it for personal, in-depth listening enjoyment and merely for investment purposes.  This review is partial proof of keeping up, my end of this agreement while sharing any lessons learned with the Head-Fi community.  This unit has been reterminated by APS to a 4-pin XLR balanced adapter, while retaining the original single-ended ¼” connector and original cable.  Although the condition of the unit and all original accessories are excellent, it has been used and showing minor signs of wear along the magnesium hanger’s edges.  Overall, it’s a near-mint representation of an 11-year old classic.

Test Equipment and Methodology


Source:   Cary Audio 303T Pro Series SACD Player in NOS DAC and Solid State Output Mode (upgraded tubes were ordered but not yet available for this session) – (burn-in status:  approx. 400 hrs)
  • Ray Samuels Audio “Apache” – Balanced Solid State Headphone Amp/Preamp  (burn-in status:  approx. 200 hrs)
  • Cary Audio SLI80 Tube Integrated Headphone Amp/Preamp in Ultra-Linear Output Mode upgraded with the following tube compliment supplied by Moon Audio (burn-in status [amp+tubes]: approx. 75 hrs—below recommended factory target of 100 hrs)
  • 4 x EAT KT88 Gold Lion Output Tubes
  • 2 x 6SN7 Pre-Driver/Phase Inverter Sylvania Tubes
  • 2 x EAT Cool Valve Gold Pin 6922 Input Buffer Preamp Tubes
  • Stock SU4 Rectifier Tubes (supplied by Cary Audio)
Power:  Belkin PureAV PF-60 Power Conditioner, Locust Design “Raven” power cables
Interconnects (burn-in status: over 300 hrs)
  • 303T->Apache:  Whiplash Elite Reference Balanced XLR IC 1.5m
  • 303T->SLI80:  Whiplash Elite Reference RCA IC 1.5m
Test Albums (in no particular order):
  1. Bella Sonus “Enamoured”
  2. Ann Hampton Callaway “Blues in the Night” SACD
  3. Various Artists “Blue Coast Collection” SACD
  4. Kaya Project “Elixir”
  5. Lesiem “Auracle”
  6. Tierney Sutton “Something Cool” SACD
  7. Tom Coster “From the Street” XRCD
  8. Andrew Lloyd Webber “The Phantom of the Opera” Motion Picture OSD, SACD
  9. Jen Chapin “Linger”
  10. Deep Purple “Live on the BBC” SACD
  11. Magna Canta “Sanctuary”
  12. Michael Jackson “Thriller” SACD
  13. Bon Jovi “This Left Feels Right” SACD
  14. Spyro Gyra “The Deep End” SACD
  15. Jacintha “The Best of Jacintha” SACD
  16. Rebecca Pidgeon “The Raven” SACD
  17. Arne Domnerus “Jazz at the Pawnshop” 4th Edition K2HD Master 99.9999% Silver


R10 Test Preparation Comments

One of the key lessons learned in owning and listening to these R10s, particularly the bass-light version is that:
  • They really demand a lot of your systems to sound their best, but
  • Your ears must be “attuned” to a neutral sound signature prior to attempt to listen to one of these.  Switching from a pair of Denon D7000s or an Ultrasone Edition 8s to an R10 may result in being initially underwhelmed, especially during in an exhibition session or Head-Fi Meets, when there is only but a few precious minutes are available to you to obtain a quick impression
Having realized this I have waited for several months until my overall system was as sophisticated as I could make it and that each listening session of the above recordings have lasted several hours at a time to properly appreciate all the nuances and subtleties that lie hidden until not only the system itself, but the listener especially is attuned to hear them.  I’m afraid with these babies a casual session just won’t do justice.

Test Session 1 – RSA Apache

Single-ended configuration was used, clearly, not the optimal setup for the Apache output stage.  Using this superbly engineered solid state amp, the bass-light version seriously lacked the bottom end, however, performed admirably during vocal, smooth jazz and electronica/new age tracks, where the bass-heavy unit sometimes introduced a bit more than desirable bass-slam and distracted of that sweet midrange smoothness that are the R10s key selling point above all.
Soundstage experienced on both versions has been well defined and wide, despite the phase splitter of the Apache in use to accommodate the single-ended adapters.  It was not possible to test the bass-heavy R10 in balanced mode, due to the lack of the necessary 4-pin XLR to dual 3-pin XLR adapter, so that El_Doug’s APS mod could be adapted to the Apache.  That issue will be rectified soon, but it is outside the scope of this comparison.
In this session, the bass-heavy R10 triumphed on rock, pop and similar dynamic tracks, being able to more comfortably render the visceral impact of the drums and bass slams than its older sibling.  Yet, instances, where I could even remotely characterize the bass-heavy R10 as “too bassy”—as it is sometimes being criticized—were non-existent in this particular system setting.
Physical comfort level is remarkable on the R10s, especially when taking into consideration of the large footprint of the housings.  They are not as light as the Qualias, but are much lighter and tighter fit as one would assume merely by a visual inspection of these photos.


Test Session 2 – Cary SLI80

I have suspected that a high-end tube amp such as the SLI80, especially rolled up to top-level tube compliment would pair well with the R10s due to the focus on purely natural materials used in their construction and the design philosophy behind them.  Most genres, especially classical and Jazz benefit from the natural warmth of a good tube amp, but I was still overwhelmed by the sonic nirvana this particular pairing provided that was so special with both R10s in their own way.
It was enlightening to experience the gradual improvement as the Cary passed its first dozen hours of—most critical—break-in period and the from the mid-bass all the way to the lower treble spectrum began to smooth out with a glowing warmth that was, indeed, musical to its core.  Instruments came alive with passion and struck hidden emotional cords.  Gregorian chants on the Lesiem and Magna Canta albums enveloped the sound stage, seemingly emanating from everywhere and nowhere in particular.  During these moments of deep listening, the differences between bass-heavy and bass-light became irrelevant to the point I needed to look up to the headphone connectors to identify whether it’s the unmodded (bass-light) or the APS-modded (bass-heavy) version was being used.  At other times, particularly at Jazz at the Pawnshop live tracks or during Deep Purple’s Live on BBC recording, the difference was more pronounced and the two units were easily identifiable, yet remained equally musical and enjoyable throughout all the way, with nothing but a thin layer of personal preference to choose between them.


Final Words

Indeed, much has already been written about these spectacular headphones, and some of the well-deserved praise and hype, no doubt being a consequence of being a limited edition, out-of-production reference model, revered by many while the privilege of ownership necessarily remain restricted to a chosen few.  It has been anything but easy to part with one of them at the conclusion of this session, but even if financial realities were not being a factor, it didn’t seem right to hold onto more than one pair.  I’m confident that the next time you visit a Whiplash stand at Can Jam or one of the regional meets, Serial 0084 will be there for you to experience some of what this review has been all about.  If that happens only a few times, the effort and coordination that went into it has been well worth it.  Ultimately, time will always tell.  As we wait for the release of the next “big thing” in the World of Headphonia—most likely the Ultrasone Edition 10—it is always beneficial to take a step back in quiet retrospection to evaluate the progress (or lack thereof) that has been achieved in these past decades.


I’d like to thank Whiplash Audio for their support in lending one of their exquisite custom-built wooden headphone stands for the photo shoot as it seemed best suited to display the two R10s reviewed here.

Note:  Full-sized photos can be downloaded from here.


Sep 6, 2010 at 7:03 PM Post #2 of 36
Another awesome writeup. I would love to see a comparison of all of your headphones sometime down the road.
Sep 6, 2010 at 10:42 PM Post #3 of 36
Great review. I hope I can hear a pair of R10s at some point.
Sep 7, 2010 at 5:09 AM Post #4 of 36
Thanks for sharing, great write up, great pics and great set up.
I agree that they need the system and some time to adjust your ears to the sound sig, otherwise its pointless. Hoping to get my hands on them one more time in short time.
This one is bit out of topic, but I was always interested in EAT KT88, but their crazy price tag was not helpful at all, however my question to you, if you ever compare them, how well they do vs. NOS GEC KT88?
Sep 7, 2010 at 8:23 AM Post #5 of 36
Thank you, warp for such great review 

Sep 7, 2010 at 8:40 AM Post #6 of 36
Super write up. I look forward to your impressions on the HE6. I love than Cary intergrated and was wondering your impression on that amp. I have long lusted after one and they can be found  on the used market for attractive prices.
Sep 7, 2010 at 10:46 AM Post #9 of 36

This one is bit out of topic, but I was always interested in EAT KT88, but their crazy price tag was not helpful at all, however my question to you, if you ever compare them, how well they do vs. NOS GEC KT88?

Honestly, I've only been listening to them for a short time, but I did order the amp with the best tubes available, and I was told the EAT KT88s were heads and shoulders above everything else.  $2K later, I tend to believe that.  Aside from the rectifier tubes, these upgraded EAT tubes simply blow away the stock tubes and that's with a new amp, yet to be fully broken in.  As usual, if you want the best, you will have to reach deeper into your wallet, but in this case I think you get your money's worth.
For more information on these tubes, you may want to ping Drew Baird at Moon Audio.  He's far more knowledgeable about these particular amps and tubes than I am and probably ever will be.
Sep 7, 2010 at 10:51 AM Post #10 of 36

Super write up. I look forward to your impressions on the HE6. I love than Cary intergrated and was wondering your impression on that amp. I have long lusted after one and they can be found  on the used market for attractive prices.

These are great amps, both the SLI80 and the CAD300 and if you can get a good deal on one of them in mint condition, I'd say go for it.  The only downside is that they are single-ended, but with upgraded tubes I can't tell the difference in terms of sound stage between it and the Apache in balanced mode.  There are differences in overall sound signature, of course, but not in sound stage, at least to my ears.
Ray's B52 was another possibility, but he didn't have one available to sell.
Sep 7, 2010 at 10:10 PM Post #11 of 36

Another awesome writeup. I would love to see a comparison of all of your headphones sometime down the road.

Glad you liked it. Well, I'll have the Head-Direct HE6 East-Coast Loaner for a week and I'll post my impressions on that thread next.  Otherwise, if I ever get my hands on a HE60, I'd love to compare it with the O2mk1 using the RSA A-10.
By that time the Edition 10s should be available and so on and so on

Sep 7, 2010 at 10:26 PM Post #12 of 36
HE-60s are under-rated. Good luck finding a pair, though.
Sep 8, 2010 at 9:02 AM Post #15 of 36
I also had one bass-heavy and one bass-light R10 at one time, but sold the bass-light unit.
I thought the b-light unit had an especially good midrange. Female vocals sounded superb, the voices had a delicacy and vibrancy that the b-heavy unit couldn't match. However, there just wasn't enough bass, and however enchanting the experience, I couldn't just listen to female vocals+piano music all the time.

The b-heavy R10 has almost as good a midrange, and to me is more balanced.
I believe there's foam stuffing inside the R10 housings that may deteriorate over time, and this may affect the quantity of bass. The b-light versions made in 1989 could be more affected by this than the units produced in the late 90's and afterward. I haven't tried replacing the foam yet, but when earpad-replacement time eventually comes it should be a good opportunity to open the housings and take a look.
Oh, if I had to choose I would choose the HE60 over R10. HE60 driven by BHSE, R10 by Zana Deux or Beta 22. The HE60 is very good.

Here's a photo when I still had the two units. It was supposed to be a Team Sony shot, so please excuse the presence of the PFR-V1 (I no longer have it).


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