Steampunk Modified Bottlehead Crack DIY Headphone Amp

If you're here you're probably a fan of steampunk, DIY audio, or hopefully both. I wanted to show off my buddy Greg's absolutely beautiful Steampunk themed Bottlehead Crack. I guess technically you might not be able to call it a Crack anymore given nearly every piece of the kit has been swapped out, but the amplifier section of the circuit the same, a simple tube buffer design. 

The Bottlehead Crack has been a popular staple for aspiring DIYers thanks to the lowish price and accessible build. Bottlehead includes step by step directions with pictures so you don't need to know how to read a schematic (although it's fairly easy for tube amps as they are typically simple circuits, so I recommend learning if you can). The stock Crack has very few parts and lacks output transformers so most can complete it in a single evening. 

That being said, many users like Greg like to customize their Bottlehead gear, so bespoke wooden bases or unique paintjobs aren't uncommon. Others choose to modify the internals to enhance performance.You will see the frequently replaced electrolytic capacitors with big honkin' film caps. Greg also designed a lovely pair of custom brackets to nestle around the Clarity Caps. 

Lots of audiophile goodies inside

You will see a small power filter near the power IEC socket, then a CRCRC high voltage power filter with Nichicon electrolytics, and near the front switch is a rectifier board. The stock crack has you mount the rectifier circuit on solder tabs around the transformer so this is a nice little improvement. Some people also elect to install ultra-fast diodes as another option. The tube sockets are replaced with the high quality CMC Teflon PTFE sockets which can help dampen tube vibration. These were directly soldered to however you can find PCBs on eBay or AliExpress to make things a little easier. CMC is also now making Bakelite versions of the socket if you are feeling especially vintage.

The stock Alpha potentiometer has been replaced by a higher quality Audio Note version, and Greg let me know he has ample real estate there to mount a larger stepped attenuator. You'll notice this Crack does not have the Speedball upgrade. While the Speedball enhances the performance of the amp as a constant current source for each channel, some people prefer the more "tubey" sound of the stock circuit. I can tell you they are two different flavors and each have their charm. I prefer to mate a Crack with the Speedball upgrade with some warm tubes and a I feel like it's a nice compromise.     

While there are plenty of improvements on the inside of the amp, the outside is the bee's knees. You'll see a polished copper chassis adorned with brass acorn nuts, a custom copper heatsink, the obligatory steampunk gears, and an old fashioned double pole knife switch. There is a reason why knife switches have been relegated to Frankenstein films and not household electronics; they are inherently unsafe and can arc when connected to high voltage. A shame as they look bad ass. This one is just for show.  

You will also notice there transformer is a little larger above. In fact Greg installed a dedicated heater transformer for the tube heater pins rather than requiring the single transformer from the kit to do all the work. 

An earlier version of the unit before the heater transformer was added

The whole unit is a work of art and has great personality. Despite being Steampunk, there were unique choices. For one much of the copper and brass is shiny and polished vs. aged/scuffed. I think it's great to not force yourself into one line of thinking; make it unique, make it you! Now Greg might have to make a pair of headphones that look equally amazing.    

For more steampunk related audio gear, check out this post.

Creator's Bio: Greg Ritacco started mis-wiring audio kits in the 1980's. Gradually fire became smoke and smoke became music. Encouraged by this, Greg briefly pursued a career in audio, first building speakers and later working for Threshold in the "lab". Family pressures and a desire to have his own back yard caused Greg to become more "serious" about his career, and as audio became the stepchild to home theater, and CD's washed vinyl away, Greg gave up and bought a Walkman. These days, he has rekindled his love of LP's and exploding electronics, built a few projects, and he and his daughter share their discoveries of new artists.

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. 

Million Dollar HiFi Audio System and More!

I apologize for the lack of updates this year; everyone has been keeping me quite busy with cables, adapters, custom switchboxes, you name it! A long-time client and buddy of of mine in the area, Eric, has been dipping his feet in the YouTube social media scene and was showing off both his system and his friend Ted (also a client, thank you Ted!) with a million dollar audio system in his modified garage. I think it's a great idea. Who cares if you have to dust some snow off your car if you have a beautiful room full of exquisite audio gear! I wanted to share this eye candy with you all. 

Eric's exquisitely impressive system features some intimidating EgglestonWorks speakers (I believe they are the Ivy Signature) connected via Zynsonix Audio speaker cables to some very classy McIntosh gear:

And Ted's jaw-dropping system with the legendary Wilson Audio speakers, beautiful darTZeel NHB-468 monoblock amps (call me crazy but I love that Iron Man color scheme) and the popular and loved dCs Vivaldi Apex DAC system: 

Ted is utilizing some ultra-low impedance Zynsonix interconnects for the critical connection between the turntable and phono preamp. I hope you enjoy! 

High-end Custom Audiophile Headphone Cable for HiFiMan Susvaras

High-end Custom Audiophile Headphone Cable for HiFiMan Susvaras

If you are looking for high-end audiophile wire, ultra pure ohno cast copper, aka UP-OCC, should be on your shortlist. The copper is drawn from much larger crystals so it has a much smoother and cleaner appearance under a microscope versus standard oxygen free copper with a more grainy texture. See below: 

Thanks to it's long grain structure, UP-OCC is commonly used for higher-end audiophile cables. But what if we wanted something even better? Zynsonix now has access to ultra pure, ohno cast silver (UP-OCS) wire known for even better conductivity. 

For this post I'll be assembling a Zynsonix UP-OCS Centurian Octet headphone cable for the HiFiMan Susvaras, easily one of the best headphones on the market. The Susvara's are known to be very unsensitive so that's why the Octet formation is recommended to get the extra juice from your headphone amp or speaker amp to the headphones. 

At the start we will need to hand-braid the UP-OCS silver wire, this is a pair of litz quads which will be running in parallel. 

I like to give the cable a nice snug PTFE Teflon wrap to help reduce unwanted vibration and microphonics. 

Next comes the sleeving. We went with ViaBlue's patterned black, red and white patterned sleeving

The next step is to add the Zynsonix blind embossed leather tag and Y-splitter.

And we can terminate the cable with some Cardas Quadeutectic solder, 3.5mm connectors and a Furutech rhodium plated 4 pin XLR for balanced audio. 

This is an extremely high performing audio cable that does the HiFiMan Susvaras justice. It's also relatively light despite the extra conductors thanks to the hand-braided UP-OCS. If you'd like to hear the best your Susvaras can sound, please check out the Zynsonix Imperial Legate. It can be terminated in any balanced or single-ended rhodium connection including 4 pin XLR, dual 3 pin XLR, 6.3mm TRS, 4.4mm TRRRS, 3.5mm TRS, 2.5mm TRRS, bananas/spades, or SpeakON connector for Benchmark AHB2.

 

Sennheiser HD800 Trebuchet Headphone Cable

Your life may change when you pull the trigger on a pair of headphones north of a grand. Your friends may decide that you've lost it, your significant other may give you a serious talk about family budgeting (or decide that the time is ripe to get that Louis Vuitton bag she's been wanting), and your daily consumption of ramen noodles will undoubtedly increase, but you'll quickly discover that there is some really impressive sound to be had in this neck of the woods.

The Sennheiser HD800 hit the streets in 2009 with a fancy 56mm high definition ring transducer that's said to produce a transmission range of 6-52,000 Hz, so even your dog would appreciate them. Lame jokes aside, the HD800 are incredibly crisp, clear and resolving and have earned many fans in the past 6 years.

Sennheiser HD800

What used to be uncommon, however now is more commonplace, is that headphones are more often coming with removable cables. While that is no-doubt a great thing (especially for owners of pets and office chairs), nearly every one of them is proprietary (much like how no one can settle on a portable balanced connector). The HD800 has its very own connector that even the HD700 doesn't share.

So, we've seen some various DIY HD800 connectors out there, there seems to be small barrel and larger barrel versions for thicker cable. Furutech recently hit the market with some fancier ones, namely the rhodium plated FT-800(R) or the CT-800(R) if you're a fan of carbon fiber. Both look quite a bit sleeker than the other variants out there, at least in my humble opinion. The connectors run roughly $50 for the generics and $98-$122 for the Furutech, not cheap at all, but I'd imagine the production run on these is fairly limited. I will also say that the Furutech is more pleasant to work with. You can snag the connectors from Soniccraft, among other purveyors of boutique audio goods.

Furutech FT-800(R)

FT-800(R) Internals

Soldering the HD 800 connectors requires a steady hand, a well lit soldering station and perhaps a magnifying glass. I'm convinced manufacturers are making these things more cumbersome to spite us all ;) Once I finish with each of these connectors, I fantasize about what a great surgeon I would be, truly world class! I digress. I do recommend isolating one of the solder joints with heat shrink as the terminations are oh-so-close, and you wouldn't want a short.

A bit of heatshrink is built up so the set screw has something to hold onto.

Microscopic pins

The Furutech connector then gets slipped in place, the back portion screwed on, and the set screw tightened down. Adhesive heatshrink is used to secure the connector and provide strain relief.

Heatshrink as strain relief

This particular cable is going to be made from Zynsonix Trebuchet cable, featuring super flexible ultra pure ohno continous cast copper in a sleek looking clear dielectric, and will be terminated with a balanced 4 pin XLR connector from Switchcraft. These new AAA-series XLRs from Switchcraft are really well made, with a very solid weight and feel, and they are only two pieces, which eases the build process. If you removed the logo and told me it was made by Furutech, I wouldn't bat an eye. Great connectors.

As you can see below, this cable features a hand braided litz of the slick looking Trebuchet ultra pure ohno continuous cast copper.

Trebuchet wire braid

Switchcraft AAA Series XLRs

Remember that 4 Pin balanced connector pins are typically:
1: L+
2: L-
3: R+
4: R-

And wrapping up, the final product:

Zynsonix Trebuchet HD800 Cable

I hope you enjoyed reading this DIYAudioBlog entry, please be sure to contact Zynsonix if you'd like a Trebuchet HD800 cable just like the above, or any other audio cable you happen to need. Until next time.

The Fine Print:

The above steps detailing the build of a headphone cable are for entertainment purposes only, and not intended to be used as assembly instructions. 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. 

Modifying the Music Hall MDR-1 Table Radio

I'll start by saying that I respect Music Hall equipment and it generally represents a good audiophile value, but the Musical Hall RDR-1 Table Radio left a little to be desired in my humble opinion. Music seemed to have a compressed and uninvolving presentation, even compared to other table radios such as the Sony ICF-M1000.

I was on the verge of selling the unit, but I decided it had it's utility, and I assumed that the main issue lay with the 3" driver, which shouldn't be very difficult to replace with a more expensive driver. I popped open the unit to see what other little tweaks could be done while I worked on the unit, mostly because I really enjoy tweaking things :)

I decided that the easiest and most cost effective mods would be replacing the driver with a Fostex full range driver FF85K, lining the cabinet with Dynamat damping sheets, replace the wiring leading to speaker with Cardas 20.5 gauge wiring, and replace the easily accessible power supply caps with a known brand, Rubycon.

I opened the unit by unscrewing 6 screws, sliding out the front cover and disconnecting the ribbon that connects the display to the circuit board. The back then slipped out without issue.

Below is a comparison shot between the two drivers. The left one is the stock driver, and the right is the Fostex FF85K.

Stock and Fostex drivers

 I opted to use the FF85K over the FE83E because of the bulkier magnet. The FF85K weighs in at a sizable 565g. You can find more driver specs here. Fostex full range drivers are looked upon very favorably by the speaker DIY community, the brand wasn't an arbitrary choice by any means.

I found that the Fostex driver was slightly larger than the stock driver, so I had to melt the surrounding plastic a bit to get the driver to fit. I'd imagine the plastic could be dremelled as well, but I didn't want plastic bits ending up in the sealed display compartment. 

Melted plastic to allow driver clearance

With the new driver in place, a generous bit of Dynamat was applied to the back of the driver and the plastic casing the front display.

Dynamat mounted on driver magnet

 Dynamat was then used to line a portion of the cabinet and the port. Since the Dynamat is foil lined, I made sure to keep it away from the circuit board and anything else it may touch. 

Dynamat Xtreme mounted

 It was now time to replace the power supply capacitors with the Rubycons. 

Original power supply caps

 The Rubycons are about 30% larger, despite the same rating.

Rubycon capacitors mounted

Finally, the Cardas 20.5ga wiring was installed. There was a bit of glue on the circuit board that had to be removed before this was possible. 

Cardas wiring in place

 Here's the finished product, it looks basically stock from the outside:

Finished product

Bass extension, clarity and midrange quality was all improved, and the driver still needs time to break in. Most importantly, the radio is now very enjoyable to listen to. Perhaps I'll have to get a thicker C7 power cable for it next. Mods were in the neighborhood of $75 or so dollars for anyone wondering. 

The Fine Print:

Please remember that modifications 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 posted modification 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. 

Introductory Post - Zynsonix Blog

Welcome to the Zynsonix - DIY Audio Electronics Blog. Although this is my first post and my first blog, I frequent and post to many forums online (mostly audio related). You'll find me as HiGHFLYiN9 on Head-Fi, Bottlehead, DIYTube, DIYAudio and AudioCircle, just to name a few. You may be wondering what Zynsonix.com is; it's my own site featuring high-end audio cables and headphone recabling service (/shameless self promotion).

I've started this blog in the interest of having a conduit to post new builds, completed cables, audio experiments, recabled headphones, and perhaps even some artwork. I encourage you to visit the links on the right hand side of the page, they are all various amps, preamps, cables and other audio gear I've created, rebuilt or modified and added to this blog. The steps detailing the creation of any and all equipment are for entertainment purposes only, and not to be performed under any circumstances. Please remember that attempting to make anything displayed in future blogs can be dangerous to you and/or your surroundings. The blog owner and any associated parties can not / will not be held responsible if you attempt the process posted and cause physical harm to yourself or your surroundings. Many electronics contain high voltages that can kill, and DIY power cables can be a fire hazard. Please keep this in mind. 

With that out of the way, I encourage you to keep an eye on this blog for future posts and some eye candy ;) I've listed some examples of some of my DIY gear below, click on the links below the photo to check them out:

Bottlehead S.E.X. Headphone Amplifier

Bottlehead Crack Headphone Amplifier

Completely Rebuilt Dynaco PAS Pre-amplifier

Brand New Dynaco ST-70 Kit