Zynsonix Headphone Cable Video Reviews from AB's Sound Advice

Here are a few video reviews of Zynsonix headphone cables from AB's Sound Advice AZ/AU. You get to enjoy a brief review and Ashley's nice New Zealand accent all at once. These videos are also a great way to check out the different sleeving options to see which you prefer. 

Ballista custom headphone cable for Denon headphones featuring denim remix sleeving and balanced 4 pin XLR

Ballista custom headphone cable for Sony MDR-Z7 headphones featuring soft black nylon sleeving and balanced 4 pin XLR

Ballista custom headphone cable for Klipsch HP-3 headphones featuring Viablue sleeving and balanced 4 pin XLR

Be sure to check out AB's Sound Advice Channel for more great reviews on audio gear. 

Avantone MP1 Mixphones Balanced Headphone Cable Mod

Not a headphone commonly discussed on HeadFi, but certainly deserving of some merit, is the Avantone MP1 Mixphones. They are touted as “suitable for use in live sound, DJ, studio recording, mixing playback and listening applications“. The earpads and cups are quite large, isolating, and comfortable, and house sizable 50mm drivers inside. A client of mine, Steve, with a penchant for unusual looking electronics sent me one to work some magic on to see how we could improve it.

The headphone comes with a 3.5mm input on one side and a little switch on the other side with a rudimentary circuit for adjusting the sound to your liking. Steve had tried the unit with an aftermarket Zynsonix cable first, but wanted to run it balanced, and the only way to do so was to remove this little device, which I assumed would help with the clarity anyway.

The circuit, switch and the 3.5mm inlet would all be removed in favor of mini XLR connectors on each cup. Brainwaves XL Hybrid earpads would also replace the stock pads, which Steve mentioned were comfortable but tended to flatten out over time. I indeed read the same thing from other reviewers online so it appears to be a common issue.

The sound had nice body and warmth, but wasn’t super clear, and the resolution on the lower end of the spectrum was somewhat lacking. I knew some mass-loading damping material would help with this and tighten up the bottom end a bit. On the inside, there are more metal parts than you typically find inside a headphone as metal, while adding mass which can be a good thing, tends to weigh things down. Fortunately the headphone remains comfortable. Avantone lists the weight at 550 grams, however it didn’t feel that heavy on my head. I recall Audeze’s EL-8 titanium as the only headphone I found was heavy enough to be uncomfortable, although some have said the same thing about the new HEDD Audio HEDDPhones as well. Good weight distribution goes a long way in assisting with this.

I placed some damping material on the driver surround and the inside of the cup strategically. You don’t need too much to get the desired result. Once everything was put back together with the new balanced cable, circuit delete, damping material, and pads, the sound was notably more resolving and controlled in the lower-end especially. Note the damping placement below:

Steve’s impressions:

Now, to the unmodified and your modification versions of the Avantone Pro MP1 headphones. Both have Brainwavz XL Round Hybrid earpads. The unbalanced version has a Trebuchet cable. The balanced version has a Ballista cable. They are both driven, not at the same time, from the headphone outputs on the front panel of the Soekris dac1541. Source is a Nuprime CDT-10, output set to 192kHz sample rate, AES/EBU connected to the DAC. Good results began after 15 hours of operation; my observations here are at the 25-hour mark.

As much as I liked the unbalanced version, the balanced version has more of the good stuff: crispness, bass extension, expansiveness, body, blacker background. Surprisingly, this results in a less dry and less analytical presentation than the unbalanced version. This balanced version is easier to listen to for longer sessions. I did try line level balanced output from the Soekris into an XDuoo TA-20 amplifier. [FYI, for this amplifier, balanced in and out is noise free. Any unbalanced, in and/or out, is too noisy for me.] This was not as good a combination. The Avantone headphones, probably because of their very low impedance [16 ohms] and very high sensitivity [113 dB] need the stability and the low noise of solid-state amplification. All in all, a worthwhile and satisfying result.

 

You can see some images below of the unit. Steve took some of the latter. I took far more images during the process however my Canon T7i decided it was time for a summer vacation and didn’t save the images to the memory card.

Anyway, hope you enjoyed this write up, and if you’d like an aftermarket cable or complete recable of the Avantones or other headphones please contact Zynsonix Audio. Thanks very much to Steve for generously sharing his thoughts and time as well!




Disclosure: Please remember that using a soldering iron and/or modifying headphones can be dangerous to you and/or your surroundings and should only be performed by a certified technician. The owner of this blog and all associated parties can not / will not be held responsible if you attempt a modification posted above and cause physical harm to yourself or your surroundings.

Removable Balanced Cable Mod for Beyerdynamic DT-1770 Headphones

I'm personally digging the newer, more upscale DT-1770 and DT-1990 from Beyerdynamic. The sound is more balanced and not quite as peaky in the upper midrange. The DT770, 880 and 990 are still incredible values though, and I'd recommend them to anyone looking to get into headphones. 

There's one glaring omission that Beyer could have done better with 1770 and 1990, and that's not using a 4-pin XLR with isolated grounds so the headphones could be run with balanced amps. For a headphone costing nearly $600 and given how little it would cost to implement is a strange business decision. Drop has actually released a version of the 1770 called the DT-177X which uses a 4 pin XLR, so I encourage anyone considering the DT-1770 to get that instead. 

3-pin XLR? That's no good!

Fortunately for Beyer fans, the existing units can be modified for balanced amplifiers. This involves removing the 3-pin XLR and much of the existing wiring and isn't very difficult. 

Below you'll see the offending 3-pin XLR which needs to be replaced. To open up the headphones, first the earpads are removed, then pry off the retaining ring using an envelope opener or similar tool. 

Under the retaining ring are the drivers. If you look carefully, there is a little indent on the outer edge of each. Using a small flathead screwdriver, you can apply some pressure to pry up the driver frame and remove it from the cups. This should all be done carefully as to not damage the drivers or the fabric on the driver frame. 

The drivers will often have a number on them. This is likely for matching purposes at the factory. In addition they will have a red dot near one of the wires. This tells you which side is positive. The wires can be trimmed and the drivers removed. Next the headband has to come off to replace the wire between the cups. There are a couple of screws to remove on the plastic brackets and you can then open up the headband and remove the wire. 

Other items that need to come off are the 3-pin mini XLR and the little strain relief pieces. The mini XLR has a plastic ring that screws it in place. There's a little bit of adhesive but it's not difficult to get off. The strain relieve pieces have a metal retaining piece, remove that and pull them out of the cup. They will need to be cleared out inside with a drill or dremel to provide clearance for thicker wire. 

Once everything is out, the replacement wire is soldered to a 4 pin mini XLR (Switchcraft or similar) and is fed through the strain relief pieces (orange circle below) through the headband and out the other side. The plastic pieces holding the headband in place have small indents where the wire enters and exits (red circle below). Inside, a zip tie should be placed right under the strain relief so the wire can't yank on the driver connection if it gets caught, and some light adhesive can be placed, then the metal retaining piece can be reinserted. 

Once everything is in place, you can insert the mini XLR back into the cavity on the bottom of the cup and screw on the stock plastic ring. Use a bit of adhesive or Loctite to ensure this does not come undone. 

Below you'll see the wire running to one of the headphone drivers. Beyerdynamic is now using small pins and a circuit board for ease of assembly. The pins are too small to solder to directly, so the wire should be soldered close to the board with a little bit of room for flexibility. Adhesive heatshrink should be used to prevent shorting. 

If you decide to try and remove the pin jacks and solder directly to the PCB, be very careful as you can damage the diaphragm wire which is quite thin. I personally do not recommend this as you'll likely find yourself buying a new set of drivers, but if you'd like to try it, godspeed. 

 

Once you have everything in place, you can reassemble the headphone. Below you'll see the modded DT1770 Pro (sans earpads, they were retained by the owner) and a spiffy new Zynsonix Ballista cable to go with them. 

I hope you enjoyed this brief tutorial and hope your mod goes well. If you'd prefer someone else have all the fun, please contact Zynsonix Audio who would be happy to handle it for you. 

Disclosure: Please remember that using a soldering iron and/or modifying headphones can be dangerous to you and/or your surroundings and should only be performed by a certified technician. The owner of this blog and all associated parties can not / will not be held responsible if you attempt a modification posted above and cause physical harm to yourself or your surroundings. 

The Bottlehead Mainline

If you are not already familiar with Bottlehead, they make some fantastic audio kits, mostly tube-based, to power sensitive speakers and headphones. They have some other cool stuff too like a guitar amp, so check them out if you haven't already.

The good people at Bottlehead have a slightly unusual naming convention for their products... sex, drugs, and I'd imagine the rock and roll is when you fire up a build for the first time. The Mainline continues this tradition, and if you are ignorant to these references as I was, mean intravenous injection, which I surmise alludes to addictive sound quality... or something like that ;)

Stepping away from the marketing side of things, the Mainline is a headphone amp... and yes, I am building ANOTHER headphone amp. I'm beginning to think I might need to grow a few more ears. The Mainline should be good enough, refined enough, that I won't have to build another for a while... we will see.

The Bottlehead Mainline

The Mainline offers a balanced output for those of you lucky enough to have balanced headphones. If your headphones aren't balanced, you can contact Zynsonix Audio for the conversion, or just take the boring route and use the single ended output on the amp.

The Mainline has 3 tubes in total. A 12AU7 is used for power duty and two 6C45-Pi tubes take care of the signal. The signal tubes each get their own C4S board (often an upgrade on other Bottlehead kits) which provides an active load for the tubes and improves sound quality.

The output is a healthy 600mW with adjustable impedance. Doc, the head honcho at Bottlehead, has stated that the amp works well with the more power-hungry Audeze LCD series. It features the same volume attenuator as the BeeQuiet upgrade that Bottlehead offers on their top-of-the-line BeePre pre-amp. Using a pair of knobs labeled "coarse" and "fine", you adjust the volume. The coarse attenuation has 9dB steps (from 0dB to -45dB) and the fine adjustment has 1.5dB steps (from 0dB to -7.5dB).

The Bottlehead gear makes use of a gravity mount, which uses a wood frame with a rabbeted edge to hold up an aluminum plate, which all the parts are mounted to. It's a nice easy way to make a chassis if you don't have a metal bender and it looks nice too. I like to build my own with some decorative molding and then copper leaf it, which is a process where you take extremely thin sheets of metal and adhere them to the wood surface.

Copper leaf being applied

If you've seen my other builds, I tend to switch out some of the parts for my own personal favorites I've found over the years, namely Teflon tube sockets, Cardas wire, Kiwame resistors, and various boutique capacitors. That being said, the quality of the parts included with the Bottlehead kits is perfectly good, so don't feel like you have to swap things out.

Below is the initial mounting of the parts with a little bit of wiring done. The teflon tube sockets have blue PCBs mounted that give you some extra room for soldering. The blue wires are Cardas 23.5 x 2. The design calls for shielded wire, so the mesh shields are grounded to the chassis.

Additional progress pics below:

You'll note the large Jupiter beeswax flatstack 10uF capacitor mounted on the right. I initially was going to mount a piece of FRP material then mount the caps to that, however I ended up with a standoff and a capacitor mount instead, it offered a slightly cleaner look. The cap narrowly avoids touching the transformer and the clip on heatsinks, and the leads are just long enough to reach. The cool gold colored zip ties are from Michaels craft store.

Very precise mounting of Jupiter capacitor

I re-oriented the capacitor for the final build when I was satisfied with the fitment (outer foil faces inward on the right cap). These are big caps (big and beautiful!) so they needed a second standoff with capacitor mount to keep them nice and secure.

Final interior photo

After some listening tests with the resistor and the choke, I couldn't really tell a difference, but since I had the choke already, I went ahead and installed it. It fits so nicely in the corner. 

This is the final photo of Bottlehead's most sophisticated headphone amplifier to date (at least publicly available, maybe they have something spectacular going on behind the scenes).

The knobs, if anyone is wondering, are matte aluminum made by KILO. You can purchase them from Digikey or Allied Electronics. The copper colored tube shields I believe were from Angela Instruments.

Hope you enjoyed this post. Be sure to visit Zynsonix Audio if you need a great sounding headphone cable or some new interconnects to connect your Bottlehead gear.

The Fine Print:

The owner of this blog and Zynsonix Audio LLC do not have any affiliation with Bottlehead. Please remember that building/modifying circuits can be dangerous to you and/or your surroundings and should only be performed by a certified technician. The owner of this blog and all associated parties can not / will not be held responsible if you attempt a build or modification posted above and cause physical harm to yourself or your surroundings. Many electronics contain high voltages that can kill, and mods, if performed improperly, can be a fire hazard. Please keep this in mind. 

Balancing the AKG K702 Headphone

The AKG K702 headphone is quite simply a black AKG K701 heaphone with a removable mini 3 pin cable. It's very nice to be able to remove the cable from a headphone with the click of a button, which is where the 3 pin mini-XLR comes into play. Switchcraft is well known for these connectors and offers them in a number of different pin configurations. Clicking the little black button on these connectors allows them to disconnect from the jack, so if a user runs over their cable with the wheel of a chair, desires a shorter or longer cable, or wants a cable of higher quality, it's very easy to swap a new cable in. Zynsonix offers replacement cables for the K702 among other headphones with removable cables if one is in the market.

With the existing 3 pin connector in the AKG K702, the two grounds for each channel are commonly connected. This won't work for a balanced connection to a balanced headphone amplifier where the grounds are run separately, so the existing three pin connector will be removed in favor of a 4 pin mini-XLR from Switchcraft.

In this post, a pair of K702s will be getting repaired with some high quality Eys 99.999% pure silver wiring (5Ns) in PTFE tubing. This particular pair of K702s had the previous jack accidentally ripped out (perhaps the headbanging got a bit too frenetic ;) ), but luckily everything inside is still in good working order. (I've found that with other AKGs, getting the existing jack out can be quite tricky, requiring a Dremel tool and quite a bit of patience). One will notice in the photo below, the white wire is the ground, in which both the left and right ground are commonly connected. In order to get inside the plastic shell, the grill needs to be rotated using a pair of jewelers screwdrivers, then two small screws are removed from underneath the grill.

AKG K702 opened

The first task would be to wire up the Switchcraft 4-pin mini XLR jack with silver wire, this would be replacing the existing wire within the headphone. Each piece was made a little longer than necessary and color coded for easy reference with electrical tape. The solder joints were covered with very small diameter heatshrink tubing to prevent the Teflon tubing from moving while the jack was being installed.

Silver wire soldered to Switchcraft mini 4 Pin jack

Now the jack could be slipped inside of the existing plastic shell. No dremeling or filing necessary is necessary when using a genuine Switchcraft jack. A strong adhesive does need to be used to keep the jack in place however. 

Switchcraft jack installed in the plastic shell

The stock wiring was removed at this point, a desoldering pump used to get off excess solder, and the new wires soldered in place. The solder points for the left driver are at the left-most and right-most points, and the solder points for the right driver travel along the headphone band, which are both closer to the center. Silver wiring was wired to the to the terminals and the plastic shell and grill were reinstalled. 

The plastic shell being reinstalled on the K702s

At this point, the matching silver cable could be built. Starting with a 4 pin mini XLR plug, the silver wires were soldered in place and small diameter heatshrink tubing was placed over the joints to prevent slippage of the Teflon tubing.  

4 Pin Mini XLR plug with wires soldered in place

The metal jack barrel was then slipped in place over the plastic piece housing the contacts. 

Metal barrel covering plastic housing

The wires were then braided in a litz formation and the strain relief clamped down on the wire tubing to prevent movement. 

Silver wire braided and strain relief clamped

The cable was then sleeved with soft black nylon multifilament. The remaining piece of the jack was filed to allow for the large diameter cable, then slipped over the sleeving and screwed to the metal barrel. A piece of adhesive black heatsrhink was added to act as an additional strain relief and help to keep the sleeving in place. 

4 Pin mini XLR completely installed

Cable sans mini connector

A Switchcraft mini connector could now be installed. You can see more details on a mini connector being installed in this previous post: Silver Plated Copper Mini to RCA Cable. The cable could now be clicked into place on the now repaired AKG K702. The mini connector is inherently non-balanced, but the user can now easily upgrade to a balanced cable when they are ready.

Completed cable on the AKG K702 headphones

UPDATE (6/14/12): The Quincy Jones Q702s are nearly identical, although the internal jack proved to be much more difficult to remove. The Q702s below were recabled using Zynsonix Ecs ultra pure ohno cast copper in Teflon.

Rewired with Zynsonix Ecs wire

These AKGs feature a fully balanced cable. 

Quincy Jones Q701 Balanced

I hope you found this post entertaining. Please be sure to contact Zynsonix if you'd like to take the music on your headphones to the next level.

The Fine Print:

The above steps detailing the repair and recabling of a headphone are for entertainment purposes only and not to be performed under any circumstances. The owner of this blog and all associated parties can not / will not be held responsible if you attempt the process posted and cause physical harm to yourself, your surroundings or your property. Please keep this in mind.

 

A Balanced to Single-Ended Heaphone Adapter Cable

Balanced circuits have been around for quite some time, but the first commercially available balanced drive headphone amp was created by Headroom nearly ten years ago. Balanced drive doubles the slew rate and voltage swing available from a circuit and reduces distortion. For balanced headphones, it also eliminates the ground connection between the left and right drivers, preventing crosstalk. There are many headphone amp manufacturers producing balanced headphone amplifiers now, including Ray Samuels, Eddie Current and Bottlehead just to name a few.

There isn't an "official" balanced headphone connector, but there are two methods that seem to be the most common; a dual-three pin XLR where only two of the three pins on each connector are used, and a four pin XLR where all four pins are used. Headroom, being the first to market with their balanced headphone amplifier, went with a dual-three pin XLR. Many manufacturers offer both options. I'm personally of the opinion that a 4 pin XLR should be used; it's a cleaner, easier cable to produce and a lot less heavy if using a balanced to single-ended adapter. 

The Eddie Current Balancing Act Features both 3 and 4 pin connections

Headphones, in order to be balanced, require a complete recable or a retermination if the left and right ground are isolated from one another. Balanced to single-ended adapters are used when someone has had their headphone recabled or terminated to a balanced connection but wants to listen to a single-ended headphone amplifier. In the case of the 4 pin, it's a 4 pin XLR connector to a TRS cable. This cable connects the two grounds to the Sleeve, the "S" of the TRS (TRS stands for Tip, Ring Sleeve). 

In this post, I will be creating a 4 pin XLR connector to a TRS cable using a 4 pin gold Neutrik XLR jack, a Furutech TRS (FP-704 G) and some Cardas litz wire in Teflon. It doesn't appear that there are any boutique 4 pin XLRs at the time of this writing, but the Neutrik 4 pin should not be discounted, it is very well made and solid.

My adapter cables are typically one foot in length, they can be less, but the connectors themselves are large and there should be appropriate space between them so the cable has plenty of room to bend. The process is started by trimming four identical lengths of wire. Cardas litz wire is a number of different gauges of wire, each covered in enamel that needs to be melted away with hot solder (a solder pot is especially helpful). Each length of wire is stripped at the end, the enamel melted away, and soldered to the solder tabs on the 4 pin XLR. One can cover the solder tabs with heatshrink to be extra anal ;)

The wire is then braided into a litz configuration in preparation for sleeving. 

3/8" Black Nylon multifilament sleeving is trimmed with a hot knife and slipped over the braided wire. Two pieces of heatshrink holds the nylon sleeving in place, and the strain relief grip is placed under the 4 pin connector. 

The metal sleeve is slipped on top of the 4 pin connector and the plastic strain relief grip is covered by the bottom piece which screws in place, creating a strong grip on the heatshrink and nylon sleeving. 

A logo'd piece of heatshrink is added underneath the existing piece so it will be exposed under the Furutech connector. The other side of the wires are stripped and tinned with solder. 

The Furutech TRS is dissasembled in preparation to be attached to the cable, you'll see the four pieces below.

The wire is now soldered in place. The typical wiring configuration for a 4 pin XLR is as follows:

Pin 1 - L+

Pin 2 - L-
Pin 3 - R+
Pin 4 - R-

Therefore pin 2 and 4 are connected to the sleeve of the Furutech, pin 1 the tip (left channel), and pin 3 the ring (right channel). The plastic strain relief grip is set in place under the TRS and the metal top and bottom are slipped in place.

The metal top portion of the connector compresses the strain relief grip, the bottom metal portion can now be screwed in place. 

The cable is now complete and is checked with a multimeter for continuity and resistance. 

I hope you enjoyed this step-by-step process of building a balanced to single-ended heaphone adapter cable. Zynsonix can build you one just like it or one built to your specifications.

The Fine Print:
The above steps detailing the building of a cable are for entertainment purposes only, and not to be performed under any circumstances. The owner of this blog and all associated parties can not / will not be held responsible if you attempt the process posted and cause physical harm to yourself, your surroundings or your property. Please keep this in mind.