Maximizing the sound ! HE-6

Most of you following the HE-6 thread already know  that I have endlessly  tinker'd with associated components and now the HE-6  itself to get the best possible sound out of it.  Since it's going be a work in progress,  I have reserved  some posts below to update  and give impressions on equipment I have used to get there and my thoughts on it. If you have any thing positive to add to what makes a marked difference to help improve the sound of the HE-6, feel free to PM me with the info (or post it) and I might just update my posts with it  so that all the info is available in a concise manner in the first few posts.

Since this thread is about MAXMIZING THE SOUND OUT OF THE HE-6 please stick to the positive attributes that will help attain that goal for HE-6 current owners and those contemplating buying one. If you have owned a HE-6 and were not happy with the sound and have moved on, I can safely say, IMHO,  that it was because of the choice of amplification and source components including cables. For that very reason,  I would like to avoid endless discussions why the HE-6 does not sound good. The HE-6 is just about the most transparent and clean sounding headphones out there, comparable to a great degree in this respect with the Stax electrostatics and  is more apt to show the weaknesses in the audio chain, warts and all. This means that if are using an IPod as a source, MP3s as material or a marginal CD player or an amp with a weak power supply and not enough RMS power (most common); it could be the reason(s) why your HE-6 lacks bass, the treble is forward/tilted and too bright - the most common complaints.

A little bit of background- I have been an audiophile since I was a teenager and have been involved with High End Audio as onetime a part owner of 3 high end boutique stores in Ontario which carried products like Stax, Threshold, Audio Research, Meridian, Wright Electrostatics,  Linn, PSB, Harbeth etc.and also as a distributor that introduced some top tier high end products in Canada.

Some of the more notable audio equipment I have owned personally and was in my system for more than 6 months; besides that  I had access to a lot of other equipment like the HE90.

AMPS/PRE:  ML-1 and ML-2, Marantz 4400, McIntosh 2105, Ampzilla, Stax DA-300,  Bedini Strelioff 200, TVA-1 and M-200 (200 watt mono tube amps),  Krell KMA160/Krell KBL, Audible Illusions, Classe CAV-150, Butler Audio 2250, Proceed HPA, AVP and AMP3.

SOURCE: Ariston RD-11,  JA Mitchell,  Linn LP12,  Panasonic SP-10 Mk2,  Koetsu Black,  Dynavector Ruby,  Breuer Dynamic tonearm,  Esoteric P1 and D1, Wadia 2000 system, Metrum

SPEAKERS:  Braun Active Bi-amped,  Ohm F,  Dayton Wright Electrostatics,  Accoustat,  Snell Type A,  Apogee Duetta Sigs,   Legacy Focus and Sigs III.

HEADPHONES/HP AMPS: Stax Lamda and SR-007s, HE60/70,  K340,  K701,  CD3000,  L3000,  W5000,  HD650,  SE535, T1,  HE-6,  Wheatfield HA-1 and  HA-2 ,  SRPP DIY amp , SRM-007t and the 717,  Rudistor Dual Mono,  Egmont,  HeadCode,  Marantz PM-84D,  Yamaha CA-1010,  Pathos Classic MK3

I  like the finer things in life but with an eye for value and not the obvious. I chose an AP Annuel to wear on my wrist over a Patek Philippe (read Rolex for non watch buffs), I drive a BMW 650i but prefer the 2008 535i overall that I had a few years ago. It kind of gives you an idea.

For me the Hifiman's flagship product, the HE-6 falls in the above category and at $1399 is the winner in its  price range and undoubtedly the best in  price/performance ratio when bought used for about $800 which is a freaking bargain.

When I bought the HE-6,  on first listen it sounded a BIT anemic in bass and had a slightly recessed midrange. But from the get go I always thought the treble was way above par, one of the best,  and is one of HE-6's strong points. As my SRPP (K1000) amp could not properly drive the HE-6, I went looking for a solution, so the following posts underline my journey with the HE-6................................

The beginning-  My HE-6 (sans the cable)  bought used for $800 with 2-3 hours of use.

HE-6 CABLES AND MODS
 

SMC => Mini XLR MOD:  SMC connectors removed. Hard wired and terminated to Switchcraft mini XLRs.

MOD: Done by Brian Goto of BTG Audio

I had always suspected the SMC connectors were to be blamed for the problems in the bass and the recessed mid range. After I got the modded headphones with the mini XLR connectors I think Mr. Fang is doing a great injustice to his product by using the SMC connectors. The sound opened up giving better sound staging and more cohesiveness from top to bottom in the frequencies.. The bass and midrange energy increased. The mod is no brainer given the cost. If you want to get more out of your HE-6 , you should begin here.

I would personally would have liked a cable grommet/strain relief at the point of entry into the HPs. Probably tough to find, and the plastic cups do not lend to modifications very well, I would suspect, like drilling/hole modification etc.  Also the wire coming out of the entry should not be naked, it gives rise to some cable microphonics when it touches the plastic housing  on the rare occasion. That is an easy no cost fix when getting the mod done. HIGHLY RECOMMENDED.

HARD WIRE: I would suspect this would bring a further  incremental benefit than the above mod as posted by the owners who had this done. For me,  I would rather have the flexibility of using different headphone cables so I prefer the mini XLR mod.

10 Ohm Mills resistor and Banana plugs: I used the resistor across my speaker taps and it had a negative effect on the sound making it closed and taking some of the transparency. And had a similar effect when using banana plugs (two variations of Cardas CABD and CABE; and one other non-brand) where transparency was lost and the sound got more closed and rounded. I find even the Neutrik 4 pin XLR has the same effect but to a lesser degree. 

Update: Burn in effect. When I initially used the Mills resistors, they were brand new and  the sound was just plain bad. So after a 20-30 min listening session I removed the resistors. Last weekend I thought about that the resistors had  no burn in time on them. Re-evaluated them after 20 hrs+ of burn in time. Noise floor dropped with more detail overall. RECOMMENDED

Ideally you would use just bare wire termination for the speaker taps for best results if using a regular speaker amp to drive the HE-6s (CAVEAT: unless your system is bright and you want to tame those highs)

My hybrid Mundorf Silver/Gold DIY cable professionally redone by BTG Audio

This cable keeps the original sig of the HE-6 intact by furthur enhancing and  then complementing the transparent and clean sound without adding much to the sound.(tho the Mundorf does have it's sound sig like all components). The sound stage is different in the respect that the instruments are more localized in their own space. Gives a similar effect as having a lower noise floor. Bass was quick and fast with more impact and there was just more detail. Nothing was lost.  I prefer this over the copper cable but then the price tends to a lot steeper. At least 2X if not more.

HIGHLY RECOMMENDED.

OFC Copper cable with mini XLR => Neutrik 4 pin XLR

The HE-6 original copper cable is good but this is better. (caveat: could not do a direct comparison (different connectors) but the improvements were  more than just because of the mini XLRs) The sound staging was a lot wider, so if your system lacks the sound stage you are looking for this will do it. Cost @ $99 is a lot cheaper than the HE-6 cable so another no brainer if you looking for a cable for the HE series. Bass seems more as it is a bit bloated (over the silver cable) and the detail and local spatialization of instruments is lost into one big sound stage, attributes of a copper cable. Also, if your system is bright, this will tend to ameliorate that to some extent.

If you are getting the above mod done and price is a consideration, I would highly recommend it as both the mod and cable is about $200. A real bargain considering that some Head-fier's have paid close to $1000 for a similar combo/work.

RECOMMENDED OVER THE STOCK CABLE.

AMPLIFIERS:

I tried more than half a dozen amps/receivers with the HE-6 and found that a tube or a hybrid amp/integrated has the best synergy with them. Close on the heels come in the Class A solid sate amps and a distant third are the class ab design followed by the class D.

TUBE AMPS:

Pathos Classic: The best sound I got out of the HE-6 was with the Pathos Classic MKIII. Not only it is eye candy but has the sound attribute to match. But unfortunately with all tube/hybrid amps the story doesn't end there, you got to use the right tubes to get the best out of the system which in itself can prove to be a major challenge. This proved to be the most challenging and daunting task as I ended up with about 15-20 pairs of different tubes but it did pay off with handsome results. HIGHLY RECOMMENDED

Nick's Tube Amp: This amp puts out about 3 watts into the HE-6 and was one of the best in driving the HE-6 for the short time I listened to it, destroying my claim that you need at least 5Watts to drive the HE-6. I can still say that I was half right as this amp had a stupendous power supply  spec'd for 10watts, so no wonder it did a good job  to fairly loud levels. Full sounding and stupendous bottom end. If it was available commercially I would own one.

I would generalize and say most tube amps should work relatively good with the HE-6 as long as they do have the 'tube (not tubey) sound' and do not verge on the SS leaner sound found in some tube designs. Tho the tube amps did not have the forever extension in the top frequencies as compared to the Class A  SS. I found that it could be more because of the tubes than the amp. More on that later.

Updated: August 17

Ayon Orion: I listened to this amp for an evening on a different system. I liked it enough to call the manufacturer and they were quite adamant/proud of the quality of the transformers that they do not recommend adding a resistor to the speaker outputs to drive the 50 ohm load  of the HE-6. Totally stable and guaranteed not to blow up. I liked that. I would have seriously considered this amp if I did not already own the Pathos tho the Orion II the current model is considerably more $$$. If you make it do double duty as a speaker amp and HE-6 amp it would be worth the price. RECOMMENDED.

CLASS A:

Marantz PM 84D and Marantz PM 94: I own the Marantz PM84 D, the little brother of the famous PM-94 and sweeter sounding but lacking the impact of the PM-94 and it was the first vintage amp I got to drive the HE-6. It does a great job and possibly has the best treble and dynamics I have heard out of the HE-6. Drawbacks were slight recessed mid range  and lacking in the bottom end, not so in the PM-94. I would attribute this to some degree to the age of the caps in my amp so a re-capping is in order. RECOMMENDED

Yamaha CA-1010: This puts out 15w@ 8ohms in Class A and since it does not automatically go into AB mode in higher power ( not that it would have made much difference)  I just did not like the over lush rounded sound of the Yamaha. NOT RECOMMENDED.

CLASS AB SS:

Proceed HPA-2 and AMP3: This was a bit of a quandry. The HPA-2 sounded a lot better than the AMP3 though both are manufactured by Proceed.  The sound stage got all garbled and most of the music just did not sound right. It could have been the Pioneer receiver that I was using as the preamp in this case. Tho the HPA did give some real authority to the bottom end making the HE-6 have more visceral impact.  NOT RECOMMENDED ( I was just experimenting around with this setup- not ideal)

CLASS D ICE AMP:

Pioneer SC-25: This just make the HE-6 sound totally different than what it actually is. Makes everything rounded and too smooth losing out on the transparency and clarity. Very similar to what my HT set up sounds like when the speakers are driven by the built in ICE amps VS the Proceed. You can easily tell the dialogue is not as clear and crisp as the heavier weight Proceed amps. Tonality is out of the window. NOT RECOMMENDED

TUBES:

Since I found that the Pathos was ideal amp for me to drive the HE-6, I experimented with more brand of tubes then I imagined I ever would. Naturally, there was no one clear winner as most of the brands and variants have different sound attributes even if they had the same (house) sound signature.

THE BEST: MY FAVORITES

The Amperex 7308- Made in USA- Orange print circa 1966- These definitely did the most for the HE-6 as it has a more solid bottom end and rather heavy weight in bass with a sweeter midrange ( beaten only by the made in Holland Amperex which does not have the same heft in the lower frequencies). Who says that the HE-6 cannot produce low bass/are deficient in bass?! My go to feel good tube when I want to listen to some upbeat music. The only fault I could find was that it lacked slightly the high end frequency extension. Now this where the other Amperex- actually the RTC 188CC- made in France- circa 1967 comes in; offering the most open and balanced sound from top to bottom. Less sweeter than the other Amperex's but much more dynamic and open sound with great clarity and transparency which matches the HE-6. (without making them sound bright). Bigger soundstage and dynamics. Does most things right for the HE-6. It is what I am listening to now.

The Valvo CCA closely follows the Amperex. These are nice and warm sounding and make good music for the HE-6. Very  musical while retaining good neutrality. I suspect these were probably made by Philips as they do not sound as thin (and anemic) like the Siemens and are lush(er)  like the  Amperex and the RTC made by Philips. Remember this is all comparatively.

OTHER NOTABLES:

I initially liked the made in Holland Amperex 6922 D Getter tubes circa 1960- the less noise version of the pinched waist D getter that go for upwards of $600/pair. These are still the detail king but I find them a bit brighter for my liking on the HE-6. In the past I have used D getter tubes and they take a longer time to settle in. Since this was/is one of my favorites still I will am willing to give it the benefit of doubt of not enough burn in. If you mix a regular 6922 in one of the channels it tones down the brightness and sounds a lot better. Will update later.

The regular 6922 made in USA and Holland are a strange bunch. I have a pair of USA made Amperex 6922 circa 1964 that I like quite a bit and then the other pair manufactured a few years later is just plain average. The Holland made equivalent E88CC lacks the punch of the USA brother.

While on Amperex- I love the Amperex 6DJ8 Orange globe for the clarity in sound it provides and it offers the best value of the lot.

Siemens: I prefer the sound of the Siemens E188CC (not a matched pair or production)  over the E88CC circa 1964 which is what the famous Siemens CCA tube is based on. They are good tubes but just don't do it for the HE-6. You just don't want to have your HE-6 sound thinner and bass anemic . Just the kind of sound most HE-6 owners are trying to get away from. At its very the best it still strips the HE-6 of any body/soul to the sound.

SOURCES AND SOURCE MATERIAL/SOFTWARE

OTHER THOUGHTS

Quote:

Originally Posted by Face 

I recently switched from the headphone to speaker amp section of a Wyred 4 Sound mINT for powering a pair of HE-6's.  IMO, the headphone section of the mINT does an excellent job powering the HE-6 and I was surprised that there was only a small improvement in dynamics after the swap.  Another thing I noticed was the top end is now a little tilted downward.  I would say they're a bit polite connected to the amp section vs. head amp section, so some additional A-Bing is needed to see which I prefer.

Just what more power does to the HE-6, an indication of that it is being driven better, takes that brighter top off that most complain of and also results in better dynamics. In the old days, we would have attributed the bright top end to clipping and distortion brought on by the amp not being able to handle the (impedance) load or plain 'running out of juice'.

Quote:

Originally Posted by preproman 

Great thread.  Very interesting.

 

The question I have is this:  Does a class A/B amp ever go into class B when driving the HE-6s?  

 

The amps I have my HE-6s on now belong to my Home Theater system.  I would like them to go back home.  However, that means I have to purchase a amp or duel mono block amps for the HE-6.  I'm a solid State Kinda Guy...

 

I can safely say the Yamaha rated at 15W Class A (23W on bench) did clip in Class A mode (it has a manual switch between Class A and Class AB so I could easily compare between them) so my guess is that the Marantz which is rated at 25W Class A (30W on the bench) would probably  go into Class AB when power demanded. This is what made the PM-84Mk2/PM94 as one of the best integrateds ever made. The more widely known PM94 still commands over $1500 used even though it is known to go up in smoke sooner than later. I am currently using a 70W hybrid and it is just about at its limit when powering the HE-6. Sadly my Marantz is out of commission as after a recap (by a professional) it smoked so I have to take it to another service center to see if it can be fixed. Unfortunately, no service manuals are available anywhere for the PM84Mk2.

I would go for a SS amp that is sweet sounding with a very good extension on the top end. Read the reviews to get a general impression if you cannot audition. That should bring out the best in the HE-6. The bass in the HE-6 is much maligned but I found if you gave it enough power (read: hefty power transformer- that is if it roughly doubles the power into a half - 4 ohm load, you are good) it generally shone through if the amp was putting out 70W@ 8 ohms.

Sorry about not updating this thread. I have been busy and I have to go on an extended trip overseas as well.

PS: Updated the Amp section adding the Orion.