Graveyard post

Hi, guys! So, I did end up disappearing for the past few months and I'm sorry for that; the school workload had become a little too much to handle so I had to take some time off this project to make sure everything was all caught up. I do have an announcement to make.

This project is still happening!

However, I won't put any ETAs this time because I can't promise anything, what with having to balance this and my education. I'll start a trickle feed of updates again, but they probably won't appear as often as before so please bear with me. I do have a couple worth mentioning so here goes.

Finally, an update!

I went on the WaveIO website recently and noticed that they have a firmware that's updated compared to the one I was given...

It does show that it works with Windows 10 which was what I suspected was the problem with the WaveIO not working before. Hopefully, I can move forward with this project now...

Soekrates initial test update

Finally got a chance to test most of the electronics involved with the Soekrates build.

The DAM1021 was already updated to firmware version 0.99 so all I have to do now is wait for the Wire LT3042 PSUs and the WaveIO to arrive before I can get music coming from the DAM1021.

I got a nifty USB to RS232 adapter cable with no plug so I could simply connect them to J10 without having to fool around with the plug. I'll probably use something along the lines of this along with a small connector on the back panel of the Soekrates to allow for firmware updates without having to open up the Soekrates enclosure. I did have to install drivers but I can easily put a guide up for anyone who buys the Soekrates.

Small project update and wooden headphones side project

As the Soekrates boards are still stuck in America, I finally caved in and burned roughly $500 to import some DAM1021-2 boards from the Soekris EU distributor. While I wait for them, the transformers and the LT3042-based power supplies to arrive, I'll show you a little something special: another little glimpse of a side project I've been working on.

These are wooden headphones based around a very special headphone driver (which I shall not mention in order to avoid driving up prices). Down below, you can see the basic plans. Wooden cups reinforced with a metal ring around the outside with metal gimbals connected to each other with a single metal wire. Shouldn't weigh too much and it should sound good too.

Back to single small chassis for the Soekrates

I'm excited! I found this thing while browsing the web the other day.

It's called 'The Wire LT3042 Parallel Reg PSU' and is, fittingly, a LT3042-based power supply with two rails per board. The thing is, it's sized at 74mm x 26mm for a DUAL RAIL! That means I need only two for the Soekrates if I parallel the bipolar supply into each DAM board and this allows me to use only one transformer and therefore shrink the size of the Soekrates to a very manageable size.

DAC updates (this is revision 11!!)

I've just realized that the number of times I've updated the DAC design so far is quite daunting. I've again reverted it to the dual chassis design due to not liking the large form factor of the single chassis design.

Backplane board for the Soekrates

I've decided to design my own backplane board for the Soekrates. Here's the circuit diagram that I intend to use (which might change at any time):

The J1, J2 and J3 headers follow this format, and there are two of them because of the dual DAM1021 balanced setup:

DAC update, transformer update and rough bill of materials for parts

Small update to the DAC. Just some size and layout changes. Its size (and colour!) has been changed to be a little larger to accommodate all the electronics.

As the below picture shows, I included the footprint of all the parts that will be attached to the front and back panels which necessitated the slight size increase.

New mouse, new DAC updates, new switches and WaveIO

I was delighted to find a parcel waiting for me today. Opening it up, I found myself with a new mouse, and damn if this one isn't perfect for the kind of work I do. Anyways, with this post and the new mouse comes my motivation, an end to the filler posts and a new major update. Here we go!

Firstly and most importantly, thanks to my great friend Ralph (@thatBeatsguy on Head-Fi), we have a logo for our Philosophy of Sound high-end brand that I'm actually happy with. Isn't it beautiful? He's also the one behind how well formatted and nice my blog looks and I thought I'd give him a shout-out for it now. I really appreciate the effort he's put in for me so far and I hope he'll be happy to continue working with me.

Misc projects

One problem that many DiYers have is that they have a multitude of projects going on or planned at once and I'm no exception to this rule. Since my new mouse still hasn't made its way to me and I'm forced to twiddle my thumbs between waiting for manufacturer quotes, here's a round-up of two of the other projects I have going on, either in my head or physically.

Transformer and $200 ($300) amplifier update

Because of the requirement to power two Soekris boards instead of one, I need a new spec for the R-core transformers and can no longer buy off taobao or ebay. Its now $65 per transformer from what I can tell (ouch) when custom-made to be:

30VA Transformer: 30/(12.5VAC + 12.5VAC + 12.5VAC + 12.5VAC + 4.5VAC) = 30W/54.5VAC = 0.55A per channel.

I then plan to use the five rails in this fashion:

+/- 12V bipolar supply (left mono channel):

• 12.5VAC to +12VDC Left Channel
• 12.5VAC to -12VDC Left Channel

+/- 12V bipolar supply (right mono channel):

• 12.5VAC to +12VDC Right Channel
• 12.5VAC to -12VDC Right Channel

3.3V digital supply:

• 4.5VAC to 3.3VDC isolated I2S rails, toslink module

Also, the amp's price will increase by $100 but this will give me the perfect excuse to call it the Spartan. Perfect!

New $200 amplifier

I also have in the top of my head a ~$200 amplifier. Planned features are:

• Swappable op-amps to modify sound based on user preference
• 0.5x, 1x and 2.5x gain to allow use with a wide range of audio gear
• RCA and 2 x 3.5mm (one in the front, one in the back) input with an input selector
• 3.5mm and 6.3mm headphone outputs
• Compact form-factor to fit on many desks

I haven't decided whether I'll use an external wall wart as a linear power supply or AC in with my own power supply inside yet; that will have to be determined later on after I design the amplification circuit.

Commenting enabled and Balanced DAM1021 firmware!

Another tiny update: I just found out why most people couldn't leave comments so now it should be enabled!

LED colour switch options and more budget case found

My mouse broke! I got a Corsair M65 on the way but until then I can't do any CAD or circuit board design so I decided to make myself useful organizing the supply chain instead. I have set up a poll following my previous post on illuminated switches (there's green, blue, yellow, red, white and orange LED lighting options available, green shown here) so please do vote here if you want customizable LEDs on the pushbutton switch on the front.

Another update to the Soekris DAC

I decided to change the colour of the anodized metal panels from silver to black as I thought that this would match the Liquid Carbon more and looks a bit more sleek in general. Also, wood and silver metal is way overused!

Cables

When I'm bored, I make cables! Here are a few I've made:

From top to bottom:

• 6.3mm to 3.5mm adapter
• 4-Pin XLR to 6.3mm adapter
• 2 x Male to Female 3-pin XLR interconnects
• RCA interconnect

Misc. information

Updated the misc. information with a to-do list complete with pictures!

Progress so far

The reason why I decided to start this whole set-up in the first place was because of the Cavalli Audio Liquid Carbon being introduced as a new transportable option that still had the famous Cavalli house sound. The grey panels will be made of something like anodized aluminium and the wood out of ply as it's easier to shape than a solid block of wood. I plan to offer a more standard option in a generic enclosure (such as a Hammond) if the demand is there in order to keep costs down and simplify the manufacturing process.It's the same 5 by 7 inch footprint but as you can see, it's a lot thicker. A single power switch is on the front with an integrated LED so I don't need to machine a second hole for the LED. I think this could be as elegant as I can get while retaining the LC form factor.

Let's get this party started!

My thread on HF got deleted so for anyone interested in keeping up to date with my Soekris DAC implementation I've made this blog to post my updates on. I will also post stuff about my personal audio journey here!