Scratch Build – In Progress The Skull of Gul'dan - 1x DIY Valve Amplifier and 1x Scratch Build

Hello,

I want to show you a rather unusual Project. It´s a 100% DIY Valve Amplifier which is used with high impedance Headphones (600 Ohm).

The guys or gals who know me might not be shocked about this idea since this is not my first Valve Amplifier. I´m addicted to this technology.

I could show you some pictures from other devices too if you´re interested since not every Project had its own worklog.

This Project will consist of two parts: 1x DIY Valve Amplifier and 1x Scratch Build


Concept:

Without further ado, let me show you one picture first. This one is enough of a clue for you, right?



I will call this Project "The Skull of Gul'dan" for a reason. Everybody who knows the Warcraft Universe should have realized that there is a artefact with the same name.

Let´s start with this nice Skull I found in one Fantasy Store.





It was dusty and looked quite depressed to me. I had to buy it and to take it home to make it feel better.

My Amplifier will have to look great from both a optical and a technical point of view. Every single detail will have to fit my expectations.

I will combine Electron Tubes with fantasy and horror elements in order to create something truly unique.

This Valve Amplifier will be designed in such a way that it will work with regular Sound Cards, Smartphones or Mp3 Players.

And the best thing, it will consist of 2 parts, one of which will be a small PC which should fit the theme too.

Both the PC and the Valve Amplifier building progress will be described in this worklog.

That´s enough of a Spoiler right now.


Philosophy:

Every modification is performed through hard work, by hand, without the use of automated processes like eg. Laser, CNC etc.

I try to work as precise as possible and also to document my progress with great care and details.

Whenever it´s possible, I will also develop and build all electrical circuits by myself.

I won´t use prebuild stuff like eg. LED stripes if I´m able to achieve the same results by using my ingenuity.

I would only use this kind of stuff if there isn´t any alternative possible to implement my idea.

Expect everything you could from a guy who has the drive to hold on to his visions.


Social Media:

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PC Hardware Parts for the Mini PC

CPU:
Mainboard:
RAM:
HDD:
GPU:
PSU:


Extra Accessories for the Valve Amplifier:

Headphones:
Sound / DAC: Creative Labs Sound Blaster E5


Sponsors:

Creative Labs supports this Project with a high end DAC.

 

Let´s move on. I got this nice package.




I want to thank Creative Labs for the kind support and for the trust.



There was a nice Sound Blaster E5 USB DAC und portable Headphone Amp inside.

I will only use the DAC for my Project by using the external Line Out in order to connect my Valve Amplifier with it.

Sure, my Valve Amplifier will be designed in such a way that you can use any suitable Sound Card or Smartphone or even a Mp3 Player with it. But don´t forget that the quality of the source matters a lot.



This DAC also has a built in battery which is great in terms of portability. You can use this device eg. during a long train ride with Highend Headphones. This DAC can also drive 600Ohm Headphones at a decent level.


Specifications:

Audio Technology: SB-Axx1™

Signal-to-Noise Ratio (SNR): 120dB (DAC)

Max. Channel Output: Stereo

Platform: USB 2.0, USB 3.0, Bluetooth


Connectivity Options (Main):

USB Connection / Charging: microUSB (PC), USB Typ A (Host)

Audio Input : 1 x 3,5mm jack (Line / Mic / Optical In)


Headphone Out:

2 x 3,5mm jacks


Line / Optical Out:

1 x 3,5mm jack

Audio Technologies:

SBX Pro Studio, CrystalVoice, Scout Mode


Microphone:

Microphone Type: Built-in Mic with auto-orientation sensor (Landscape / Portrait modes)


Audio Fidelity:

Sampling Rate: Up to 24-bit / 192kHz


Studio Attributes:

ASIO: Playback & Recording


Included Accessories:

microUSB cable, Desk Stand, Two Elastic Bands, Mini TOSLINK Cable


Recommended Usage:

Home Entertainment, Portable Entertainment


Dimensions:

110 x 74 x 22 mm (4.3" x 2.9" x 0.9")


Supported Operating Systems:

Mac OS X v10.6.8 and above, Windows® 10, Windows® 8.1, Windows® 8, Windows® 7, Windows Vista®



This DAC is quite small, similar to a external HDD or a Power Bank.



What´s inside this box?



A Desk Stand, suitable cables and some manuals as well as two rubber bands.



This device looks rather simple and elegant. The built in Microphones can be used for eg. recordings but in my case I won´t need some of these functions.



You can also connect 2x Headphones and adjust the volume with the volume knob.



Here´s a picture of the rear connections.



The Desk Stand is nice, I´m going to use it with this DAC for sure.







It´s a lot easier to reach the Power Button, SBX Effect Button and the Lever for the Gain of the integrated Headphone Amplifier.

L is set for regular Headphones, H for high impedance Headphones.



That´s enough describing of the toy I´m going to use. Now let´s play brain surgeon.



The skull ceiling has to be prepared for the complicated operation.



Don´t forget the rear part of the skull too. I know it hurts the candidate but this is the price for curing the depression.



That´s quite some strong material. It resembles artificial stone but that´s not a huge problem to break through if you are persistent. Hannibal was great at opening skulls too in order to reach for the brains but this is a different story. The Silence of the Skulls.

This operation needs to be performed 100% without scuffs. I can do it.



Now that´s one interesting view. You can see how this skull has been manufactured.



The skull ceiling needs some milling. I´m going to play further games with this candidate. Let´s pick a Saw later and see where it gets.

That´s it for now.

 

the skull makes me curious to see more!!!

 

Thanks, the Skull will turn into something truly evil

 

Here´s another update.



First I had to think about a layout, what I want to attach to the skull ceiling. I have to plan the rest of the skull as well since this one is going to be pretty cramped full in the end.

Let´s think about the positions for the valve sockets and other connectors and drill some holes.



Here you can see the mounted Valve sockets as well as the RCA Connectors (also known as "Cinch Connectors") and the Headphone jack.

I used only high quality components. Saving too much money on these parts is a bad idea.

Just have a look at this Headphone jack. This is something you see in eg. professional stage equipment.
Pretty solid and rugged, nothing to worry about later.

I used this type of Headphone jack in other Projects too and never had any trouble with it.



How to attach the skull ceiling again? This piece needs to be mounted in such a way that it can be removed later without problems, just in case one component fails and needs to be replaced. High quality devices need to be easy to repair.

I created a mounting system out of silver plated braid. These 4 pieces resemble seams and give the skull the touch of "Frankenstein".



I had to perform some milling in order to be able to attach some of the needed components and connectors later.
There won´t be much space left for the circuit since some components need a lot of space.

Don´t wonder about the "point to point" connections, I won´t use any circuit boards for the Valve Amplifier itself.
This is a technique which is common for older Valve devices, especially since these connections have to withstand a great amount of heat.

That´s it for now. What do you think about these steps? Do you have any suggestions?

 

Update time!

The modified skull needs some further adjustments. I also need extra space for further electronics components and circuits.



Let´s build some sort of wooden throne for it. This throne will get a nice coating later.



The throne has to be sturdy.



The upper part won´t be visible later.

Let´s drill some holes.



The skull needs some extra holes too. This looks promising enough to me.



And proceed with more holes.

That´s it for now.

 

This throne is not finished yet.



Just drill some more holes.



And attach a power socket.



And a mount for one transformator.



I will use more transformators. I have to get rid of what I have first before buying new stuff.



In order to hide all the holes I cut a piece made of Aluminum. This one doesn´t fit 100% yet but you see where this is going.



This Aluminum cover will also function as a shield and will be grounded too. Better ground your devices before they ground you.



I won´t use any cable inlets this time. The holes through the Aluminum cover are slightly larger than the plate below. The cables won´t be damaged.



Doesn´t look that bad,eh?

 

Here´s another update.



Let´s paint the throne.



Attach the Skull later.

Stuff the sockets with some Valves and a Potentiometer. You can see where this is going, right?

He´s still missing the electronic circuits.



And speaking again about electronics, I want to recycle as much stuff as possible.

This can look like this. Not pretty but rare.

Soon I´m going to solder his guts.

 

It´s time for another update.

I´ve calculated different versions of the amplifier circuit and after some optimizations I was ready to solder the stuff I needed.



The Skull got some "Brains".

Everything is modular and easy to repair.

Well, what do you think of it?

 

And here´s some more electronics.



As usual, everything is built from scratch. Some of you might recognize the heatsinks used by me

Well, better use them for this purpose instead of throwing them away in the junk?

Recycling is good for the environment and saves money too.

Don´t worry about the cables, I will improve the looks of them later.



Safety first. Don´t forget to use some sort of protection. There´s high voltage inside.

The throne also got some nice feet.

 

Pretty cool but I would have put the volume control on the box and not the head.

 

Thanks, I had the idea before but in the end I would have to use quite some long connections for the volume control. I think it´s better if the whole amplifier is inside the skull ceiling since it´s a lot easier to repair.

Having too long connections, even when using shielded cables can be a bad idea since some electron valves like to oscillate. Too long conections are ideal antennas

 

It´s time to update the build log again.

This device works but still lacks a few details.











Just have a look at the DIY Piercings



These are the Headphones I own right now. Some of you might recognize the old version of the well known Beyerdynamic DT990 with a impedance of 600Ohm.

I´m pretty sure that the modern version would look better and also be a huge upgrade in terms of sound quality.

And how does this amplifier sound? There is no audible noise, hum or distortions.

It´s hard to describe the way tubes sound, you have to listen to this combination in order to get a clue.

Don´t worry, the amplification factor is very high and you will surely blast your brains out if you want to.



Let´s turn this thing on. The eyes glow green and the Skull itself white.

The high voltage power supply has a soft start function in order not to stress the cathodes of the valves.











How do you like this device so far?

There is still enough to do left but make sure to visit the DCMM stand during the gamescom if you want to see this Skull live in person

 

Awesome!

 

I´m glad you like it

 

I smell epixx!

 

wow nice build

 

The DCMM which took place during the Gamescom in Cologne was great.

There were many nice Modders and Projects.

It was nice as usual to talk about this hobby which keeps us together.

Here are a few pictures:



These are my 2 latest Projects.

Some of you might recognize The Punisher.





I´m happy that the jury liked this mighty Skull and rewarded it with the 2. price in the category of CE-Mods.

But don´t worry, this Project is not finished yet since this was only the first part.

I´m going to think about the Mini PC which will complete this build log.