Pioneer SE-700 Vintage Headphone Cable Mod and Balancing

The Pioneer SE-700 were the company’s flagship headphones released back in 1974. The driver is an unusual piezo-electric type. I am personally not aware of any other headphone manufacturer that offered this type of driver, but feel free to share in the comments if you know of one. The SE-700, SE-500 and SE-300 all use a similar element. 

An old advert for the SE-700 touting their specs

I’d describe the sound as airy, crisp, and similar to an electrostat with a detail emphasis. Bass quantity is very low, which I believe is typical of this type of driver. The simple metal frame and gimbals look rather elegant, and the overall unit is pretty light. The way it rests on the head is slightly odd compared to modern headphones, but it’s still very usable.

The piezo-electric driver is a very thin piece of metal foil with a frame going around the perimeter, with the positive and negative connections at the bottom. It is covered with bright yellow foam resembling a dish sponge. It is also quite delicate, so even opening the headphone can damage the driver. The unit is sealed shut with rubber cement or a similar adhesive so it must be opened very slowly and carefully to access the inside. 

An image from the user's manual circa 1974

The wire connections for the driver are circled in red below:

If you’re looking to purchase one of these you can keep an eye out on Reverb, eBay or similar platforms. Price for a good example will generally be between $80 and $150. You’ll probably want to replace the wiring including the 3-meter cloth-covered cable, and the vinyl headband and ear pads which will likely be flaking.

My client Steve who sent me the headphones had already replaced the pads and requested the inner wiring be replaced. The existing wiring contacts had been twisted together and covered with heatshrink (see above image), which seemed like an odd manufacturing choice and not an ideal connection. Running single strands from the connection would sound better. You’ll note both sides of the headphone below after the cabling was replaced.

The headphone was reassembled using 3M double-sided tape so it can be more easily opened if needed. Steve will be crafting a calfskin headband for the unit as a replacement for the original vinyl headband, which I feel is the only visual let-down. It appears EricJ from HeadFi created an excellent tutorial back in 2007 on creating a replacement headband which you can find here. Below you'll see the refurbished/modded unit.  

I hope you enjoyed this post on one of the more interesting vintage headphones out there. If you have a headphone that needs a cable upgrade please be sure to visit Zynsonix.com. 

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. 

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.

A Custom Audeze Balanced Headphone Cable

Anyone who has their hands close to the pulse in high-end headphones has heard of the Audeze. Formed in 2009, they have quickly developed a superb reputation for their planar magnetic headphones, the LCD-2, and very recently the LCD-3. Both headphones make use of a very convenient removable cable mechanism employing a pair of mini 4 pin XLR connectors. Switchcraft makes these for about $8 a piece, and you can find generics for less than half of that. As previous experience dictates; Switchcraft's connectors generally prove to be reliable over time, so I'll be sticking with those for this build. The male and female mini XLRs come in a variety of opening sizes to accommodate different cables. For the females that will be needed for the Audeze cable, the small opening version is the TA4F, and the larger opening is the TA4FLX. Below are photos of the TA4FLX.

The Switchcraft TA4FLX 4 pin mini XLR female

Since each driver only needs a signal and ground, and each mini XLR has four pins, the pins are shorted so that the signal uses pins 1 and 4 and the ground uses 2 and 3, as seen in the below diagram.

These tiny little solder tabs require care to solder to and see the numbers associated with each pin. A lamp can be very helpful to get a good look at the connector while working with it. Neotech UP-OCC copper was used to short the pins below. 

Shorted Switchcraft mini XLR pins

Now comes the time to braid the wire for the cable. The process is started by trimming four identical lengths of wire, then braiding it in a litz up until around 18 or so inches from the end. The last bit of wire is split into two twisted pairs, on for each cup. This particular cable will be made using Cardas litz copper wire in Teflon. 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). This needs to be done for each end that is stripped.

Braided Cardas litz wire in Teflon

The wire is now sleeved with black nylon multifilament, 1/8" for the twisted pairs and 3/8" for the four wire litz. A ViaBlue splitter was placed over the "Y" split of the cable to give it a sleek look. If you'd like more details about the ViaBlue SC-2 splitter, please read my post regarding a ViaBlue Mini to RCA cable build. 

Prepped and sleeved cable

Since the wires are all the same color, it can be beneficial to color code them to later reference. Hardware stores carry electrical tape in a variety of colors. Typically ground connectors are labelled green, right signal is red, and left is black or white. This isn't always the case, but one can choose a convention for themselves and stick with it. It prevents one from having to pull out the multimeter too often. 

Labelled wires

This headphone cable is going to be balanced, for a balanced amplifier. There isn't an "official" balanced headphone connector, but there are two methods that are 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. This is discussed in greater detail in an earlier DIY Balanced Adapter Cable post.  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 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-

A piece of heatshrink holds the nylon sleeving in place, and the strain relief grip is placed under the 4 pin connector.

4 Pin Neutrik male XLR 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. 

4 Pin XLR attached

The Switchcraft 4 pin mini XLRs are then soldered in place. As mentioned above, the signal uses pins 1 and 4 and the ground uses 2 and 3. The cable is now complete.

Completed Audeze LCD-2 cable

A balanced adapter was constructed so the headphone could be used with single-ended amplifiers. If you'd like to read how this was constructed and learn a little more about balanced headphone operation, visit the Balanced to Single Ended Adapter Cable post.

Completed cable with balanced adapter

Also built for the Audeze LCD-2 was an identical cable using Kimber TCSS copper in Teflon wire. The Audeze has what I would consider a warmer and more laid-back presentation. The Kimber wire helps bring it forward a little bit without being harsh.

Balanced cable for Audeze headphones w/Kimber wire

If you are looking for your own custom made Audeze LCD-2, LCD-3, or LCD-X cable, Contact Zynsonix Audio for a superb sounding Trebuchet Audeze headphone cable, made with 99.99997% pure, custom ohno cast copper.

Zynsonix is an authorized dealer for Audeze headphones which include not only a full factory warranty, but a free Trebuchet headphone cable. Contact Zynsonix for details.



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.

Kimber TCSS - The perfect marriage of Teflon and copper

I've been using Kimber TCSS for years. It's an excellent wire made from low-strand count high-purity copper (as Kimber calls it: Hyper-pure VariStrand™ copper) and the insulating dielectric is high pressure, low temperature extruded Teflon. It's 19 gauge, but the dimensions are small for 19 gauge, so it's easy to work with as interconnect wire, internal hook-up wire, and Kimber even uses multiple strands of the TCSS for it's higher end speaker cables (4TC, 8TC and 12TC). You'll also find it being used in Russ Andrews power supplies and other various cables.

The reason that Kimber TCSS stands out as much as it does is that most of the copper you find with extruded teflon is silver plated. Sometimes a silver plated wire isn't desired for an application, but Teflon, being the pretty much the best dielectric aside from air, is. Teflon, a synthetic fluoropolymer, was developed by DuPont and has a dielectric constant of 2.1. This is slightly better than Polyethylene and notably better than PVC and older materials like Bakelite and Formica. Between the low strand count, high purity copper and the Teflon dielectric, the Kimber wire exhibits a crisp and clear sound.

I've seen some comments on Audio Asylum and the like that the clear and white TCSS variants sound the most clear. Since this has spread around the campfire, Kimber now offers their speaker cables and interconnects using a braid of white and clear. I personally find the clear to be the most attractive, as you can see the copper strands on the inside.

I've made use of Kimber TCSS in a variety of cables, including:

Kimber TCSS and Solid Silver in Teflon Interconnects with Cardas RCAs

Headphone Cables - This one on a Denon Headphone with ViaBlue Connector

Headphone Extension Cables

Phono Ground Cable

TCSS and Solid Silver Mini to Mini Cable

...and another Headphone Cable

Making use of the Kimber wiring as a headphone cable can be a little stiff, but it's generally not too bad on a longer cable. As always, custom cables making use of Kimber TCSS can be requested at Zynsonix.com.