HD650 Mod - Tinico Magnets

Hey guys,

As I’ve mentioned before, I know the owner of an audio atelier in Bulgaria called Etheraudio. The guy’s name is Asparuh, or Roohy for short. Since I preordered the Focal Elear I visited him on Friday to ask them to wind up output transformers with an output tap that will match the Elear. After a brief discussion he told me to bring my HD650 pair and after he “tweaks" it a little bit I could go and compare it again with my friend’s Elear.

So, I visited him a few hours ago and I brought along another HD650 pair for comparison. He actually didn’t tweak anything. He just changed the whole magnetic system. Enjoy the photos below. The other mods are done by me on both pairs. Since the magnets are easy to remove (just pull!), we swapped magnets from one pair to another. Btw, kudos to Sennheiser for manufacturing with such little tolerances.

A little info about the actual magnets. They are what he referred to as Tinico. He uses it for his RIAA correctors. The alloy consists of Titan, Nickel and Cobalt. Cobalt accounts for 28% of it. Didn’t remember about the rest. He made sure I understood this was expensive stuff that he didn’t use in his speaker drivers, because the price was prohibitive. You can see a comparison between the two magnetic systems in the pictures below. The Tinico system is a lot more massive, we had to glue it eventually. As you can see it’s a central cylindrical magnet, so the vents are located on both sides instead of the back. The large demodulator disk on the back of the magnet does have a hole, but it’s not a vent.

So, how does it sound? In a word, brilliant. Tonally it’s still an HD650 (which i like), with a few differences. The treble is pure silk. The midrange is to die for. The bass is alive and super textured. The overall sense of clarity is so much better. Like i’ve plugged into the audio chain a better DAC or a super clean power supply unit, that sort of improvement.

In the last two hours I listened to Daft Pink, Black Label Society, Mari Nakamoto, Agnes Obel, Marilyn Mason, Merkaba, Tempi, Electrocado. I’ve never managed to figure out what the deal with those Cobalt magnets is. The tonality feels the same in direct comparison, but the actual tone is just killer. It’s mind boggling. And the best thing… I almost involuntarily started cranking the volume up a bit every few minutes, until eventually i hit the maximum. Yes, there’s compression and distortion, but it’s so smooth. It took me to an exhilarating state of joy. It’s never harsh.

And now the drawbacks. Yes, there are drawbacks, though only a few. First, it’s still a 650. Even though the dynamics are significantly better, it doesn’t punch as hard as the Elear. it’s not a hammer. I’m talking from memory, but I’m quite certain that’s the case. The other thing is the bass starts to distort as you feed more and more power to the headphones. The same thing is happening on the neo unit, though the distortion on the tinico unit is sonically more pleasant in order of magnitudes. I complained to the guy about this. According to him I’d need a more rigid membrane and an actual suspension around it to sort this out. So, no perfect happiness, it’s still a 650 in some respects. My last gripe is that the magnet is just so big. I can’t put the back metal grills and it does look a bit ugly, but hey sonics are above all, right? Well, despite the great looks and all, I've cancelled my Elear preorder. Will share a comparison with the Elear in a few days.

So, final thoughts… screw neo, cobalt for the win!

 

sick

 

I knew you would go crazy and do something like this one day. This is real headphone modding right here! Replacing the entire magnet of the driver!

We should have a SBAF europe meet one day.

 

Man that's nuts. Would love to hear it!

 

Great, now I need to add a couple more HD650s to my wish list....

 

Does any part of the new magnet fit into the plastic recess, or is it floating a couple mm away from the voice coil?

 

Looks pretty neat! If the magnet is more powerful than stock, does it not cause greater excursion than the driver was designed for?

"I can’t put the back metal grills and it does look a bit ugly, but hey sonics are above all, right?"

It looks like you could cut a circular hole in the wire mesh and attach the grills in such a way that the rear of the magnet extends outward through the hole.

 

When I was in High School, some guys did stuff like this when their engines needed more room:

 

I can't take much credit. This wouldn't be possible unless someone like the guy from Etheraudio didn't happen to live in the same city as I do. I can only imagine how difficult it is to machine a cast alloy that contains cobalt crystals and titanium as a bond, instead of aluminium. For example, the speaker alnico magnets come from the forge in the form of long thick pipes. Then they cut them into slices of desired length while constantly spraying them with water. It takes a while to prepare one magnet ring.

As for the meet-up, that'd be great to do some day. I don't think there are many audioheads from europe lurking here at present though.

Yep, I'm getting butterflies in my guts just by staring at them If you like the engine analogy, the motor has the same horsepower but it's got a much more precise throttle response.

Judging by ear, I think the efficiency is the same. I suppose this was his design goal. I believe if he simply increased the magnet strength given the same coil design and cone mass, it would tilt the whole frequency response up towards the higher frequencies and the speaker would become unbalanced. I'm guessing he measured the T&S parameters before deciding on the new assembly design. The magnet is simply bigger, about 2cm tall, as neo is stronger, so you need more alnico (in this case tinico, similar to ticonial) to achieve the same strength.

The voice coil has to be properly placed within the coil gap, which on the tinico design is about 1 or 2 tenths of a mm narrower. So the assembly goes all the way down in the recess. The upper part of the assembly is made a bit wider, so that it can bed on the ledge of the recess/cavity. That helps to fixate it properly, otherwise it may wiggle and it would mess up the sound and could even ruin the voice coil. Also, the backplate has a recess, it's indented, so the magnet extends into it.

The magnet has the same strength. I think it will be less painful if I just replace the mesh with a cloth or something.

 

You can also remove the metal grille from the outer plastic ring. That's what I did - looks nicer than removing the whole thing and you still get the benefits in sound quality from removing the grille.

 

If you are interested in modifying grilles for these, I wonder if it would be easier working on HD580 grilles since you would be working with plastic.

 

I don't like the looks of the 580 cups very much. Too plasticy. I'd rather see if someone can handcraft some sort of grills out of wood and I'd apply some cloth to it. Think it would look much better. My only concern is weight. The headphones are already at least 100 grams heavier with the new magnets, wood would probably make them very heavy.

 

Are there any parts lists, tutorials or anything like that? Or do these guys offer this service internationally?

 

Is it possible to get a picture of the front side of the magnet?

 

Here is Etheraudio's website:
http://www.etheraudio.net/

And Facebook page:
https://www.facebook.com/etheraudio.bulgaria/

Nothing about the HD650 magnets on these, though.

 

Check out that price list...
http://www.etheraudio.net/etheraudio-products-pricelist/

 

I’m afraid this mod is beyond the reach of any mod enthusiast. All parts of the magnet assembly are custom-machined. The magnet alloy is expensive and can only be ordered in large quantities.

Not sure which part can be referred to as “front”. You can take a peak at the pole on the photo of the cone.

I don’t think there will be. I’ve asked the guy why hasn’t he built some headphones. His typical response is “real audiophiles don’t entertain themselves with headphones”. I wonder if he follows his business interest. In my view it's simple. Make a DAC/Amp combo and headphones. Ship the whole package over to Tyll. If he gives it “thumbs-up”, he’d immediately generate a few sales. If money can be made, why not? Who cares what real audiophiles want

I respect the guy very much, but the price list, from my points of view as a DIYer, is unreasonable to put it mildly (except for the drivers, they’re priceless). But horns for 15K or amps for 300K?! Nuts! He prices his products in line with the ultra high end brands, because he knows his stuff sounds better. What he fails to comprehend is that the people who have that kind of dough at their disposal buy luxury high end products mainly because of other attributes, different to sonic performance. Sadly, other than that 05 DAC, his reasonably priced products aren’t listed on the site.