REVIEW: Meier Audio Corda Classic solid state headphone amp.
 
Introduction
 
My first serious headphone amp was the Meier Audio Corda HA-2 Mk II.  It was something of a revelation to me at the time – I had never heard a headphone amp that sounded as good.  I didn’t have much experience with headphone amps back then, and the HA-2 mk II was a huge cut above anything I had experienced.  The crossfeed was especially important to me as I first got used to headphone listening as a serious alternative to speakers.
 
I’ve probably listened to over 100 headphone amps since then.  Meier has cranked out a pretty steady of very fine headphone amps since that time, including, most recently, the Concerto, which I thought highly of.  The Corda Classic is based on the Concerto, with some feature additions, and some tweaks (like, says Meier, using the nicer and costlier Nichicon FG caps rather than the FW of the Concerto).  The Classic does have selectable two-stage crossfeed, which is a hallmark of the better Meier amps, and often a useful feature.  It also has the subtle bass compensation circuit for the crossfeed, which can be handy regardless of whether one is using crossfeed, to compensate for recordings.
 
Dr. Jan Meier offered to loan me a Classic for review, to which I happily agreed. Most of the time I will not review products that are not already commercially available, and I never review pre-production prototypes. In this case I agreed to review a production unit in advance of the release date, as Meier's reputation is such that I was not concerned that the unit would not come out. [Note to people who are not long-time readers of my reviews - I almost always review only loaner units from manufacturers, although I will occasionally buy units to review.  Such loaner units are provided at no cost to me for the review period, but are NOT "freebies" - following the review I either return them or, on occasion, I will purchase the review loaner]. 
 
 
The Classic, like many solid state amps, outputs significantly more power into low impedance loads than high impedance ones.  Jan provided me the following information:
 

1. Maximum output current: 500 mA / channel
2. Maximum gain factor: 4,9 x (+14 dB)
3. With a source signal of 2V rms the limiting factor normally is the gain factor. Maximum output voltage becomes 9,8 V rms.
4. At 600 Ohm: 160 mW / channel
5. At 300 Ohm: 320 mW / channel
6. At 50 Ohm: 1.9 W / channel
7. At 30 Ohm: 3.2 W / channel

 
As such, I thought it mated very well with the Audeze LCD headphones, The Ultrasone Edition 8, and with the Audio Technica W3000ANV.  It also sounded good with the Beyer T1, which is 600 ohm, but the T1 is VERY efficient.  Something like the 400 ohm AKG K-340 would probably not do well (but I no longer had a pair to try it).  
 
Looks are also “classic” Meier:
 


 
 
Info from manufacturer’s website: http://www.meier-audio.homepage.t-online.de/classic.htm
 
Build quality is very good, with a solid but non-fancy chassis, and, mercifully, an on-board power supply that would make many modern speaker/power amps blush.
 
I auditioned the Classic over several weeks, using the headphones mentioned just above, plus the Ultrasone Edition 8.  I compared it to the Red Wine Audio Audeze Edition with the LCD-3, and to the Trafomatic Experience Head One with the AT, Beyer, and Ultrasone cans.  As always, my comparisons were done by using an SPL meter to match levels to within <1dB, and calibrated at 80 dB A weighted peaks. 
 
 
Sound
 
As with the majority of Meier products I have reviewed, the Corda Classic provided what I felt was essentially neutral, transparent, clean, and generally “out of the way” sound, more or less directly connecting source to headphone, within its power delivery limits.  The real departures from that come when you start to play with the features. 
 
It's a little difficult to describe the soundstaging of a Meier amp that employs crossfeed, and you can subtly change it.  There was no crossfeed setting that gave me the depth or holographic imaging of my Trafomatic or Leben amps, but the soundstage was nonetheless quite convincing.  The soundstage does shift with the two stages of crossfeed, as it takes on better center focus but loses some channel separation.  The effect is actually fairly subtle most of the time, but on some recordings I much prefer the crossfeed on.  The soundstage gains depth and moves out of the head, which is a pleasant effect.
 
The bass contour can also drive you a bit mad…is it better with or without?  Hard to tell.  I generally used it when the crossfeed was on, and not when not, but I actually sometimes preferred to use it regardless.  The nice thing with both of these features is you can always choose not to use either of them, and in this case the Classic is still a very neutral, transparent, and high quality amplifier.
 
I would love to say a lot more about its sound, but there really isn’t that much to say, which is a good thing, really.  The Classic doesn’t have much of its own flavor.  It won’t power crazy-hungry headphones like the Hifiman HE-6, but aside from that, it was revealing enough to allow me to easily hear the difference between some DACs I was comparing while it was here.  I thought it was good enough to be the main amplifier for headphones costing 2-3 times what the Classic itself cost, which makes it something of a bargain.  It did a good job with detail retrieval, and was nicely extended at the frequency extremes. 
 
If I had to pick a few nits, it doesn’t provide quite the level of iron fisted bass control of the LCD-2 and -3 that I get from the RedWineAudio Audeze Edition, and it doesn’t have quite the same extension at the very top of the frequency range, either.  There were also a few times when things seemed to get a little congested on the Classic with the LCD-3, whereas the same piece of music, at the same level-matched volume, did not sound congested on the AE.  And the AE may be just slightly more transparent.  But otherwise, the difference between the two was not that significant driving the Audeze headphones.
 
Driving the Ultrasone Edition 8, the Meier again basically stepped aside sonically.  I thought the Trafomatic Head One was a little more open sounding in the mids, and has the slightly more holographic soundstage.  But remember that the Trafomatic is a significantly more expensive amp.  When keeping that in mind, the Meier did very well indeed.
 
I really wish I still had the Concerto around to compare, but in my Concerto review, I felt that the Concerto could on occasion be just the slightest bit bright.  The Classic seems to have resolved that, as I never heard even the slightest bit of brightness from it.  Nothing stuck out at all in its frequency response. If anything, the Classic is just the tiniest bit warm, but only slightly.  And you can subtly change that with the bass level switch.  So you can really do some nice system matching that way.
 
 
Summary
 
If you want a neutral, clean, transparent solid state headphone amp that performs at a very high level without costing a fortune, the Meier Audio Classic is a very good option, IMO.  I still find that almost all mid-priced solid state headphone amps, for me, lack a little bit of musical realism, compared to what I hear from tube amps.  Many will call this effect a coloration, and perhaps it is, although I think it’s more complex than that. And it could certainly be considered a personal bias of mine (although clearly shared by numerous others).  In any case, the Classic isn’t going to be confused for a tube amp.  I still prefer to listen to headphones through thermionic valves.  If it were MY $700, I would buy something like the WooAudio WA6.
 
But many people don’t want to mess with tubes, and in the under $1K price range, the Classic has a lot going for it.  While not exactly cheap, the Classic does provide good value in terms of sonics, rated output, and features, IMO.  Jan Meier has a deservedly excellent reputation in the head-fi community, and I think the Classic is a good example of why.  Another excellent product overall from the estimable Dr. Meier.
 
 

MEIER AUDIO CORDA CLASSIC & DACCORD

“Welcome to Head-Fi, sorry about your wallet!” So goes a common refrain at the biggest headphone forum in the world. The chase for the tone dragon can consume any audiophile or headphonista. The quest to keep reaching deeper into the music is never-ending. One thread discusses “end game” set-ups. Occasionally someone will decide that they have found their ultimate system and everyone else takes odds how long that will last.
When I first got involved with audio I worked at a brick-and-mortar audio store. Our motto: “Best sound for the money” – and we strove to make that happen. Sure, we were thrilled to sell the high-priced systems, but we mainly assembled modest-yet-amazing ones. We always kept our eyes peeled for affordable gear that could take you close to the summit.
Jan Meier, Ph. D. founded Meier Audio in 2000. The company began as a result of demand for his innovative DIY Headphone amplifier that incorporated a crossfeed circuit into the amp. He posted the design on Headwize (www.headwize.com) and the demand for his DIY kits was so strong he decided to start Meier-Audio. It is based in Germany and has developed a reputation for making great headphone gear without breaking the bank. The Corda QuickStep and PCStep are widely popular portable units. Meier Audio also offers two desktop devices, the Corda Classic Headphone amp and the Corda DACCORD Digital Audio Converter (which incorporates a Crossfeed circuit you can turn on or off as desired). Each is a stand-alone unit that can be purchased individually and used with other gear. This review will focus on using them as a combo.

“Machined from virgin blocks of carefully mined unobtanium the…”
Many high-end audio components are built with extraordinary casing and spectacular finish. With some components however, a large portion is spent on the appearance alone, perhaps resulting in an exorbitant final price tag. Meier Audio takes the pragmatic approach. Contained in either a standard Black or Silver basic metal case, the front of the Corda Amp is finished with simple universal switches and a single volume knob. The Corda uses a two-position gain switch (a blue indicator light showing whether it is in the high gain position or not). Nothing extraneous is added to the physical structure. The enclosure gets out of the way using clean and simple lines.
The Corda Classic Headphone Amp has two RCA Single Ended inputs and a plug for a typical IEC power cord. Located on the front are an input selection switch, Crossfeed Circuit switch, Tonal Balance, Neutrik Single Ended ¼” (6.3mm) headphone jack, Hi/Lo gain switch, Gain indicator light, Volume control, Power indicator and Power switch.

Daccord
​

The Corda DACCORD boasts two coaxial inputs, an optical toslink and a single USB (that can accept up to 24/192kHz files). Windows users will need to download a USB driver while Mac users can plug and play. The DACCORD is not DSD capable. There are two RCA outputs: One fixed output for connecting to an amp (like the Corda Classic) and one variable output to use the DACCORD as a preamplifier with powered speakers or a power amplifier. Located on the front are: A tonal balance switch, the volume control for the variable pre-amp outputs, the crossfeed intensity switch, the sample rate indicator lights, the input selection switch, a Power ON LED and the power switch.
The DACCORD utilizes a crossfeed circuit to simulate a natural listening environment. The Meier-Audio website has a detailed page on the basics of what Crossfeed is (http://www.meier-audio.homepage.t-online.de) In short, it is a circuit that feeds partial amounts of left channel information to the right earpiece and parts of the right to the left earpiece to simulate a normal sound environment rather than keeping pure left and right information separated. There are three settings: High, low, and off.
I have owned the Decware Taboo III Headphone amp with their Lucid mode circuit and I have spent time with the SPL Phonitor 2 Headphone amp which also offers crossfeed capability. In each case I have found the approach to be intermittantly useful. Generally, I prefer it when listening to small group music such as: Jazz trio’s, chamber music, club settings, et cetera. These types of recordings benefit from an increased sense of space. I find that using crossfeed is distracting for Rock, Big Band and larger orchestral works.

I found the DACCORD’s crossfeed to be subtle. The crossfeed provided a variety to my listening during the ripped CD of Al di Meola, John McLaughlin & Paco de Lucia on theirPassion Grace & Fire album (16/44kHz, 1411 bit rate in AIFF). The ability of the DACCORD crossfeed to open up the intimate trio’s performance offered some nice contrast to the listening experience. The sense of space and placment of each artist made the listening experience an almost 3D event. You could almost see where they were during the recording. Turning off the crossfeed removed some of this clarity and dropped the experience to a more conventional 2D image. Still fun but not as immersive. Turning off the Crossfeed removed the depth from the recording.
On Donald Fagen’s “Out of the Ghetto” from Sunken Condo — in 24/88 in FLAC from HDtracks – I used my HD800’s with Toxic Cables Silver Widow cables and it sounded beautiful. One of the sounds I enjoy when listening to small group or Jazz reccordings is the sound of fingers on strings. The Bass players fretting was clear and firm. The shimmer of the high hat was crystalline. The spacing of the instruments was easily discerned within the recording. Next up was the 24/192 FLAC of Chicago V, also from HDTracks. Terry Kath is one of my favorite 70’s guitar players. His crisp rhythym playing on Dialogue Pt’s 1 & 2 provided a solid foundation to the classic tune. The horns had the full bell like ring that keeps me coming back to the early Chicago albums. The Meier stack did not color or amend the recording. I heard the music and not the amp/DAC.
Just for fun I switched over to my HD650’s (with Toxic Cables Silver Poison interconnects as well). This headpohone/cable combo is a favorite of mine and I listen to it often while traveling. Generally, I am using the Audioquest Dragonfly Version 1.0 or the LH Labs Geek Out 1000 as a portable DAC/Amp with the HD650’s. The Meier combo had substantially more power – as you would expect from a desktop based system. Both the Meier and the Geek Out outperformed the Ver. 1.0 Dragonfly. The GO1000 was not as present on the top end and low end slam as the Meier.
I was pleased but not surprised that the Meier combo outperformed two highly regarded portable AMP/DAC units. Time to see how it stacks up to bigger desktop competition.
My primary headphone rig consists of a modified Cary SLI-80 and a maxed out Wyred 4 Sound DAC2 DSDse with the Femto clock upgrade. The Cary upgrades include all of the factory F1 Mod components, except the Hexfred Rectifier’s. I also have added a 4th input, courtesy of Dennis Had (creator of the SLI-80). The Cary, in this form, retails for around $5,500 and the W4S comes in at $2,549.
On Elton John’s “Someone Saved My Life Tonight” in 25/96 AIFF off of Captain Fantastic and the Brown Dirt Cowboy. This version from HDtracks is the best I have ever heard. Both combos relayed the recording wonderfully. The Meier gear offered a neutral presentaion not coloring the presentation, but delivering it cleanly. Compared to the much more expensive Cary/W4S combo, the Meier was missing the clean high’s that I experience with the Cary/W4S combo. The shimmer of the cymbals extended longer and higher from the big tube unit. The soundstage was also more substantial. Elton John’s engineers added some L/R ambience that was much smoother and more immersive via the tubes and EJ Sarmento’s finest DAC.
My rig provided additional micro-detail. You could discern the sublte differences between the striking of the mallets on the piano strings versus the plucking of the bass strings. Ultimately, I preferred my home rig. There should be some value for the six fold additional cost! But, the Meier gear had nothing to be embarrased about. They provide great value.
Using the HD800’s On Steely Dan’s “Jack of Speed” from Two Against Nature (running at 24/96 AIFF), the superb bass line walked along with balance and slam. I always enjoy the nice “SNAP” of the snare drum with the high hats singing. Once again, the Meier gear provided an engaging presentation, but left details on the table to the bigger Cary/W4S rig. Audio is a cruel mistress. She does not make stepping up to another level easy. You have to build a quality chain of gear and improvements are rarely a little more money, but a substantial step up. Reaching for the last few percents improvement can get expensive. With the Meier stack you can sleep well knowing you would need to drop much more money to make an major difference to your sound.
The Meier combo provided an overall neutral sonic presentation. I have a clear personal bias toward tubes and the character (some say colorization) they bring to the table. When signal rolled off with both units, it was done in a natural way and never abrupt or overly harsh.
The DACCORD uses Wolfson chips and having spent a long time with the Cambgride DacMagic Plus (with the WM8740 chips), I have a strong comfort level with Wolfson’s presentation. I have found Wolfson’s chips to have a more organic presentation than my Sabre Dac devices. Sabre’s can be a bit clinical and more detailed. Each can be enjoyable, yet they do have their particular sonic characteristics. The Meier implementation was smooth and neutral. I never noticed a bias toward too clinical or too soft. Digital files were received and presented in a direct an pleasing manner. Compared to my Wyred 4 Sound DAC2 DSDse with the Sabre ES9018 reference DAC chip, I was missing some of the small micro details that first attracted me to the W4S unit. However, had I not heard them side by side, I would never feel as though I was missing something. It was a complete presentation, yet it simply did not go as far into the detail.
Again, the Cary/W4S combo is over six times the cost of the Meier stack. The Meier combo had nothing to apologize for in the bang for the buck arena. The fact that I’m seriously comparing the two should shed light on how the Meier overperforms it’s pricepoint in a neutral and honest way.
As I mentioned earlier, my early days in audio were spent searching for “bang for the buck” gear. The Meier combo easily qualifies. If you want your money to go toward your sound and not audio jewelery, this is a pair worth auditioning.
 
Pros:

1. Good bang for the buck sound!
2. Nothing wasted on fashion for fashions sake.
3. Very versatile between Crossfeed and tone controls for sonic tastes.
4. Quiet noise floor for IEM’s or standard headphones.
5. Plenty of gain to drive most headphones.
6. Very neutral presentation.

 
Cons:

1. The manual is not as clear as it could be to describe the switches. Perhaps a translation issue?
2. The review units came with no cables. I do not know if a power cable is supplied when purchased.
3. No DSD Capability
4. Limited to 24/192 USB

 
A quick word about amplifier gain and noisefloor: Using my HD800’s with the high gain employed, I had more power than with my Cary SLI-80. The Meier was also dead quiet at low volumes with the HD800’s. Using my JH16’s at low gain, the unit was dead quiet at any volume. The 63-step attenuation increased with small signals as I increased the amp volume, but no hiss was evident.
 
 

Corda Classic High-end Headphone Amplifier:  USD $720.00

Corda DACCORD DAC:  USD $775.00

 
Meier Audio Web Site:
http://www.meier-audio.homepage.t-online.de
 
DACCORD and Corda Classic web page & technical information:  
http://www.meier-audio.homepage.t-online.de/amplifiers.htm
 
Meier Crossfeed White Paper with sample audio files:
http://www.meier-audio.homepage.t-online.de/crossfeed.htm
 

Associated gear:

MacBook Pro
MacMini
Amarra 3.02
iTunes 11.3.1 (2)
Cary SLI-80
Denon DVD-5900 SACD/CD/DVD-Audio player
Wyred 4 Sound DAC2 DSDse with Femto clock
VPI Scout 1.1 with Dynavector 10X5 high output moving coil cartridge
Cambridge Azur 651P MM/MC Pre-amp
Sennheiser HD800 with Toxic Cables Silver Widow’s
Sennheiser HD650 with Toxic Cables Silver Poison’s
JH Audio JH16 Freq Phase CIEM’s with Toxic Cables Silver Widow’s
 


Review re-posted from www.headphone.guru

This review is intended primarily for those with hearing disabilities.
 
I just bought the Classic-ff and have been very pleased with it. I did not do any direct comparisons with other amps; therefore, I won't comment on the audio quality.
 
I am really enjoying the crossfeed function on this unit as it is helping to negate some of my hearing disability. I have moderate single-sided hearing loss in my left ear and the crossfeed is helping me to hear things that I would otherwise not be able to notice. I can now hear those sounds in my right ear, but I can still tell that the sound is coming from my left side. Sounds that normally come from a single channel are now heard from both channels, but stereo/directional-hearing is still maintained.
 
I find crossfeed to be a much better alternative to mono listening, as with mono there is the loss of directional hearing and also the potential for the loss of information.
 
I went ahead and opened the unit up and changed the jumper position to increase the amount of crossfeed provided. The jumper was glued to the PCB, so I had to clean it off first. I also changed the balance on my PC audio-out to lower the volume in my good ear and set the volume to max on my bad ear. I am not using an external DAC since my motherboard's onboard audio is highly rated. I am using a 3.5mm stereo to RCA cable to connect the amp to the PC.
 
I definitely recommend this unit (or the less costly non-ff version) to anyone with minor to moderate hearing loss in one ear, and anyone looking for a hardware-based crossfeed. For people with more severe hearing loss, I would recommend sticking with a software crossfeed solution.
 
I found the LEDs to be far too bright, but remedied it by using a toothpick to push them in and behind the faceplate.
 
Ordering from Meier through email was straightforward and he was quick to respond. Shipping to the USA was slow (2 weeks) but that's to be expected.

BACKGROUND:
 
After having the experience of using a less expensive tube amp, the Bellari HA540, I was interested in upgrading my desk amp. without going through multiple expensive tube trials.  Tube upgrades add significant cost and time to the process of headphone listening.
I also had the positive experience of using the portable ALO Audio MKll amp. on all my current headphones.  I found the solid state amping up to the task of amping my efficient 600 ohm Tesla T1's and my less efficient 600 ohm vintage AKG K240 sextet's.
 
I spent time on Head-Fi and multiple other web sites researching DAC/Amps at the cost point I was looking for; roughly $1000. The Meier Stack made the most logical sense.  I haven't found many other quality audio manufacturers that are willing to discount their end game products in combination.
 
SETUP:
 
DAC:  Meier Daccord  
HP:  HE-400, B&W P5, Senns 595, Tesla T1 and vintage AKG K240
Source:  MacAir>Amarra 2.5.1 
Cable:  Meier stock
CD:  Muse "Black Holes and Revelations," Jake Bugg "Jake Bugg," The Cars "Heartbeat City"
Lossless:  The Beatles "Abbey Road," Yes "Fragile," Heart "Dreamboat Annie," Traffic "John Barleycorn Must Die"
 
REVIEW:
 
I found that the Meier Amp was efficient at dramatizing the best and worst that the headphones offered.  If you like the sub bass on the HE-400's this is a good thing. "Come Together" by The Beatles thumped in the low range as did "Supermassive Black Hole" by Muse. On the other hand the treble deficiency of the HE-400 are more revealed in Heart's "Dreamboat Annie" the title song.  
The Senns 595 were well balanced, but not spectacular, still upgraded from any other amp I had previously used with them. The Beatles "Something" and "Oh Darling" were well suited with these HP's. 
The T1 really shined with this amp, displaying both depth and imaging. The soundstage and separation of sound in particular on The Cars CD "Heartbeat City" were at a level I had really not experienced before. The balance and clarity of the Jake Bugg album and the jazz infused rock from Traffic were stunning.  The transparent amp and transparent HP made me feel as though I was I was moving closer to the original recording sound. Music is revealed from recordings I've heard for years.
The B&W P5 were solid in the mids, less so at bass. I primarily use these as my go to HP's for portable listening.  They are light and are easily amped with portable players.  They add some level of isolation but are not at the same level of my desk HP's. The Meier amp punched up the mids improving the imaging of "Crazy On You" by Heart.
The vintage AKG K240 was the most suprising. This HP is really hard to drive. The HP meshed beautifully with this amp.  Mids stood out more with improved separation and individuation of instruments.  The bass is not great but easily made up for by the added fun that these HP's have to offer.  Yes "Roundabout" really stood out for me, as did The Cars "Magic" which danced all around my ears. 
 
I originally questioned the need for the cross feed, but after hours on the Amp/Dac combo the level of audio separation increases fatigue.  Mixing the sound to create a more of a natural audio experience makes sense.  You can mix the cross feed at multiple levels to match your own taste. I found the cross feed was more useful with the complex instrumentation of Yes and Traffic.  
 
Summary:
 
For the price a well built quality amp.  This amp is not as gorgeous as some of the tube amps at the same price point.  On the other hand I'm not going to spend hours researching and buying expensive tubes. 
 
Service : Excellent customer support

I bought it to use with Ultrasone Pro900 and blue-ray player, tv DAB receiver and of course for music with Daccord. Mine is in silver with red LEDs.

Hello all. This is my first review and I want to tell you about this fantastic headamp.
 
A view months back I bought an Audio Technica W1000 (not X !) headphone.   I like it’s sound; very transparent, a  little bright, certainly not dark, a sweet rolled off treble and a very tight, but not to  much bass.  And most of all; very involving.  It has something special, it let’s you here beautifully the acoustics of the recording room.
 
But it didn’t pair well with my NuForce HDP.  I think mainly because that one also has not much bass.   I am certainly not a basshead, but there must be a natural balance.  With the headphones I used it (AKG K501 and ATH-W1000), the sound was too thin.  With the somewhat dark and bassy sounding Senn HD600 I had for a while, the tonal balance is much better.   Besides that, the HDP has a wide soundstage.  I also noticed that when using it as a dac for my speaker set-up.  When listening through headphones to music with instruments mixed a little bit to extreme to the left or right, it becames not natural and thus can cause listening fatigue. Some cd’s were really unlistenable for me with the HDP with headphones.  A good example is Eric Clapton’s MTV Unplugged cd, where on a lot of songs (for example Tears in Heaven) you hear a guitar on the left, which can sound isolated from the rest of the band.  Like he’s  not on the stage and mixed in later.
 
So I decided that my next headamp must have a crossfeed switch.  And a sophisticated volume control.  Not a conventional volume pot, because they can crackle after a while and they often have channel imbalance at low settings (and I listen at low volume settings with a sensitive and low impedance AT headphone).  I already have an Meier 2Stepdance headamp for portable use, and that is a very good build and sounding headamp.  The 2Stepdance also has a sophisticated volume control which works very good.  I have faith in Jan Meier and the quality of his products, so the Corda Classic could be the headamp that satisfies my needs.
 
Well, it certainly is!  The Corda Classic is uncoloured,  transparant and detailed, has a powerfull  tight bass and a big soundstage.  I think it sounds good with 99% of the headphones.  And the crossfeed and tone switch works exactly as Jan describes on his websites.  When switching the crossfeed, the difference seems to be very subtle, but when listening over  longer periods, using crossfeed on and off, it is clear that with  using crossfeed, it sounds much more natural, more like listening to speakers than headphones.  Much more relaxed, you can listen the whole day without getting listening fatigue.  The guitar on “Tears in Heaven” is still on the left, but now he is on the stage with the rest of the band.  From now on I always listen to music with crossfeed switched to the high level.
 
I also like the tone switch.  This is not a bass-boost or loudness.  It’s to elevate frequencies below 2 kHz a little bit.  See the website for the explanation.  With the little bit bright sounding  W1000 headphone I prefer the lowest (medium) position, which makes it sound less bright, a little bit darker.  With the AKG K501 I prefer the middle (off) position. 
 I never liked the NuForce HDP as a headamp, except with the Senn HD600 which I had for a while.  But even with the HDP, the HD600 has to much bass (for me) with many recordings.  It becomes tiring after a while and gives listening fatigue.
 
For me, the Corda Classic is the perfect partner for my Audio Technica ATH-W1000.  It’s relaxed, powerfull,  you get all the bass the W1000 has in it in a very controlled way, the W1000 is less bright thanks to the tone switch, no tube replacing, it doesn’t get very hot so you can leave the amp switched on always, very good build quality, a beautiful volume control with small steps,  and it’s not gonna cost you a fortune.
 
The cheap portable P2V2 amp is good to start with, but sounds midfy, with a warm and muddy bass (depending on the headphone using), the Meier 2Stepdance sounds much better but has short battery life, the NuForce HDP lacks bass and crossfeed and can have channel imbalance, and at last the Meier Corda Classic which, for me, does everything right.
 
Thanks for reading!