DIY Sennheiser HD650 cable build

[ALL212]

I’ve read too many posts, here and on other forums, about the Sennheiser HD650 stock cable being less than it should be. So I decided to build my own. (Sorry, no pictures – maybe next time!)

I bought Cardas HPSC and GRQ SS connectors. The HPSC are the can connectors and the GRQ SS is the ¼” plug. I don’t normally plug the vendors I buy from unless they do something special but I bought these from Dedicated Audio LLC out of Arizona. No hassle, good communication. I ordered two of each of these and they were drop shipped from Cardas. There was some miscommunication and I only got one set of the HPSC’s. Within 30 minutes of emailing Dedicated Audio on a Friday evening I had a reply and shortly after an assurance that Cardas was drop shipping another set to me. I also bought 15 feet of ¼” tech flex. For wire I used 10 feet of Mogami Neglex 2534 which I’ve used for interconnects in the past. Some ¼” and 3/8” heat shrink from my stock to finish things off with. About $75 in parts. You will need an ohm meter if you use this wire – it’s only two colors for four wires.

My headphone amp is a Bottlehead Crack with the Speedball upgrade. I also upgraded many of the internal components as I built it. If you’re curious head over to Bottlehead and in the Gallery forum - a couple pages in now – you’ll find my Crack on Speed with Blueballs. I’m using an Amperex 7316 tube in the 12AU7 spot and a heavy duty Raytheon 6080WC in the other socket. I really didn’t have any issues with the sound of the HD650’s but I needed to hear for myself.

I started on the ¼ plug side and my first confusion was that the plug has no connection for the right side positive – it’s just a barrel! If you’ve not worked with the Cardas line you’ll also find that what they provide to solder the ground to can be tricky if you don’t keep things smooth. I usually dent the inner ring and solder into the dent. This time I got over zealous and broke the ring – it actually worked out better as I could pull the ground wires into the gap to solder. I used about ½ of the shield wire and the two blue wires for ground. Measure out the left and right positive so that the right will have insulation on it as it goes over the left. Solder in the left (center) first. For the right side I just spread the fine wires from the Mogami over the barrel and soldered it down. Because the Cardas and Mogami are good quality it took and was easy to do. You MUST insure this is not a cold joint. Tug on it a bit to see if it holds – I just hook a small screwdriver under the wire and pull up slightly. I then combined the shield wire and the two blue conductors and soldered them into the gap I made. I put two layers of 1/4” heat shrink up into the plug as far as I could – one at a time. Then I worked the tech flex slightly over the connector – then worked the barrel over this and screwed it down. The tech flex is now inside the barrel. I dinged the tech flex a bit working the outside of the barrel over that last inch or so where the heat shrink had built up over the Mogami so I pulled about 6” of 3/8” heat shrink right up to the barrel and heated it down. Once you have all this done there is no going back into the barrel without messing up a great deal of heat shrink and tech flex – so make sure all is well before you begin to pull and heat.

Notice I didn’t keep track of which signal wire went where – I’ll ohm that out when I get to the other ends.

I cut the tech flex back about 12 inches from the end of where the Mogami ended. My stock cables have about 9” of “hang”. I heated a small piece of heat shrink over this end of tech flex to keep it in place. I removed the outside insulation and all of the shield up to this point in the wire and untwisted the two pairs. Mogami wire has a center piece of plastic that you’ll need to cut off as well. Get out the ohm meter. The tip of the plug is the left channel, the center is right and the base is ground. Because both blue wires are ground it won’t matter which of these you mate to the white wires. Once I determined which wire went where I used a small piece of heat shrink to “mark” each side – red to right, black to left. I kept the twists intact for each pair and put enough heat shrink on these pairs to leave about 1” at the connector end. Red on right, black on left. I put tech flex on these two pairs next (the red heat shrink is now just barely visible). In order to pull ¼ inch heat shrink over this (to secure the base) tape the ends at the connector down tightly and the heat shrink will go right over without messing up the tech flex. I finished the junction with some 3/8” heat shrink – a couple of layers to pull it all together. I would not strip less than 12” of wire back – by the time you’ve got this split looking good you’ll have lost an inch or two due to heat shrink. Now I carefully pulled the tape off of the other end and put some heat shrink here to hold down the tech flex. I used my red/black combo again but it’s not necessary because you can see the red heat shrink through the tech flex.
The HPSC connectors do NOT have any cover over the connectors, the plastic is decent but not something you can stand your soldering iron on for a long time. You’ve got to measure carefully. The small pin is the signal pin (white wire), the large pin is ground (blue wire). I had to take one of my ends apart after the work was done because I had a cold joint that broke free – that’s no fun - so take your time and insure those pins are done correctly. I used two layers of 3/8” heat shrink to cover the open area after my soldering was done. You can slip this over the connectors if you forget to put it over the wire before soldering. There is a ridge on the HPSC connectors – you can heat shrink just slightly over this but not too far as it will not connect to the headphones correctly – another learning experience!

Issues – Mogami wire is very flexible but the tech flex stiffens it up – and I’m not loving it. The tech flex can also be “heard” if you move around. Hard to describe – but if you run your fingers up something with ridges you’ll hear it – if it’s smooth you probably won’t. I won’t put tech flex on the next version. It does look nice and clean but…
The ¼ Cardas is nice but I don’t like how it finished. You can’t get 1” heat shrink over it so I’ll get something larger in a 3:1 shrink and see if I can get more of a strain relief on it.

The sound (why this was done in the first place)… OMG!! These aren’t broken in by any means and the bass is over the top. Separation of voice/instruments seems much better. It’s a cleaner sound by far over stock. I’m not going to rave on until they’ve got more time on them but I doubt that the stock cables will ever be used again!

Was it worth $75 and a couple of hours? Absolutely.

[Ern Dog]

Very cool. I considered doing this for my Senn 600's but opted not to because I rarely use them. I heard lots of good results from people using the Mogami cable also the Cardas cable and the Canare.

[blairfrischx]

I actually used the Mogami Neglex 2534 when I made a custom cable for Denon D2000s. It's very good stuff.

Do you at least have any pictures of the finished product? I think you did a good job describing it and the process, but I'd be interested to actually see it.

As for the sound - I upgraded the cable on both my D2000s my HD600s, and I've never looked back since. I haven't tried it with the DT880 yet, but I may in the near future (and make it detachable)

[sucks2beme]

The old style Cardas blue "smurf" cable is pretty flexible. But of course it doesn't look as nice.

[ALL212]

Da pics...

I have a hook above the amp to hold the cable straight up. I didn't like the way it looked without that - kinda kinked over.


Just don't like the way this ended - I'd like to put some heat shrink over the body of the barrel and continue it down the tech flex.








Junction could be cleaner but it works.

[agfrost]

Cool Aaron. Thanks for sharing your experience.

[pmosh93]

Thanks for the post...it was very helpful.

[Recstar24]

Glad I found your thread, very helpful. I have two thumbs unfortunately but an eBay seller is making me a 20' with mogami mini quad for my 600's for about $85. Thanks for your impressions.

[SCompRacer]

Da pics...

I have a hook above the amp to hold the cable straight up. I didn't like the way it looked without that - kinda kinked over.

The other thing is you need some headphone wire poles to keep the cable more horizontal. Your cable dips down towards floor and back up; makes it hard on the electrons to get up to the headphones. Some of them get tired and forget what they were supposed to do, degrading SQ.

Good work Aaron!

[sucks2beme]

The other thing is you need some headphone wire poles to keep the cable more horizontal. Your cable dips down towards floor and back up; makes it hard on the electrons to get up to the headphones. Some of them get tired and forget what they were supposed to do, degrading SQ.
Good work Aaron!

Only with tube amps. SS amps push holes.

[heiney9]

But, but, but Aaron, we all know cables don't matter.

Nice work and write up, as usual. I am not a headphone guy but if I was I'd sure give this some thought as well as having a cool headphone amp like your Bottle Crack Blueball.

H9

[ALL212]

I was considering cooling the cable with liquid nitrogen to help make the cable slippery. I figured less resistance but then I thought about it and realized it would only be worse with the ice forming and the electrons truly sliding back down. I've got an old bit bucket I used to use on the 'puter that I've converted to analog. Every couple of minutes I empty it back over the tubes. I suppose I could use a sump pump to make it automatic but if I put that in the wrong place it could suck the music out of the headphone cable.

I'm really lost here...I need help.

[nspindel]

If you ever want to win the "cables do matter" argument, all you need to do is demonstrate the HD-650 or HD-600 with the stock cable versus just about any other cable. It's clear as day.

One thing I would have done differently is make the left/right split outs a bit longer after you form the Y. The cable will be more comfortable to wear that way. Nice work though!

[sucks2beme]

As obvious as it is to us, the flat earth guys will tell you otherwise.
Amps, cables DACs, etc. don't matter. I guess that logic makes dating
fat girls easy. It's all in your head!!!

[ALL212]

Update: Couldn't take it - too much noise from the techflex. I pulled all the heatshrink and techflex off of the can end. Stripped back another 6" or so of cable. Put in a cable pant and minimal heatshrink and then curled the ends of the heatshrink at the connectors away from my body. Much better...

[cnh]

If you ever want to win the "cables do matter" argument, all you need to do is demonstrate the HD-650 or HD-600 with the stock cable versus just about any other cable. It's clear as day.

One thing I would have done differently is make the left/right split outs a bit longer after you form the Y. The cable will be more comfortable to wear that way. Nice work though!

That is not only TRUE! But a "great" suggestion that might just end some of these interminable debates!

cnh

[ALL212]

Another round...

Da Parts..


1/4" end completed.


Starting the "Y"


Stripped Y.


Y completed.


Left and Right.



Twisted!!

[ALL212]

Finished:

[Ern Dog]

Nice work. How does it sound?

[ALL212]

When I first got the HD650's I liked them - but really didn't listen to them much. They were "o.k.".

With these cables I don't listen much to the main system!

Its'a nice'a improvement!

[Keiko]

The other thing is you need some headphone wire poles to keep the cable more horizontal. Your cable dips down towards floor and back up; makes it hard on the electrons to get up to the headphones. Some of them get tired and forget what they were supposed to do, degrading SQ.

Good work Aaron!

Precisely why I never let my wife get on top.

[SCompRacer]

Precisely why I never let my wife get on top.

Are you referring to that radiation term, fallout? With headphones, that means the music stops.

[Keiko]

Are you referring to that radiation term, fallout? With headphones, that means the music stops.

Time to corral the tadpole, men. Put a helmet on that soldier.

[theta]

I like the look of how they turned out. Techflex looks much better, but you're right about the noise transmission... Annoying as hell.

[jumpindick]

Great info. Thanks for sharing.

[amgala]

I see that the Y area has a rubber/plastic sheath on it. Is it a pre-made y-shaped sheath? Or did you make it? If it is a pre-made sheath, could you let me know where you got it from? Thanks.

[amgala]

I see that the Y area has a rubber/plastic sheath on it. Is it a pre-made y-shaped sheath? Or did you make it? If it is a pre-made sheath, could you let me know where you got it from? Thanks.

After some further research, I have found out that they are called cable pants.