I got myself a stepped attenuator and a G.E.C CV 2523 tube. Read about it here:    http://diy.koenigs.dk/2014/03/18/stepped-attenuator-legendary-g-e-c-cv-2523-tube/   Tight fit huh?

I made a write-up about building a O2 amplifier with integrated DAC. I hope you'll find some inspiration for your own DIY projects.   Go here for the full write-up: Objective2/ODAC Illustrated write-up     Custom front panel with power plug removed.      Laser cut front panel  ...

I made this little write-up illustrating the process of making the Bottlehead Crack and modding it.   There are 5 parts, but I'm still missing one article about capacitor upgrades for now. I hope you'll find some inspiration here, if you haven't made a Bottlehead Crack yet.    Cabinet and...

Added a few sections to the write-up. Cheers.

Objective2 Amplifier + ODAC Illustrated Write-up   http://diy.koenigs.dk/2014/02/21/o2odac-amplifier-and-dac/        

HI. It's just glossy varnish with 400 grit sanding between the layers. After the last coat of varnish is completely hardened, it has been polished with furniture polish.

  I have just finished this Bottlehead Crack. Default cabinet with three layers of chestnut wood stain, five layers of spar varnish with 400 grit sanding between and a polish of the varnish after a week of hardening.    The panel has been spray painted with 8 layers of hammered dark grey...

      I just made a custom O2 amp + ODAC, but I didn't like the front panel with the power plug in the front. So I designed one myself with a laser engraved silver front and 2 mm acrylics on top of that. I made 4 spare ones. The front panel is 1mm larger around the edge, than the...

Quote: The ones returned and refurbished was bought by another user, they are the only ones that had a faulty driver, and now they are fixed for you and upgraded to MK-II   I just did the upgrade, and I took about two hours including the meassuring. Here are the result. The grey...

Quote:   Actually jfrocke changed his mind and the last pair was sold to devouringone3 instead. I accepted to upgrade them to MK-II before shipping.   I am happy that the last pair is sold to someone who hopefully will like them very much - in the end, this is what is most important...

Due to other projects, I will not be making any more KODA^2 headphones - at least not in near future.   But I do have one pair for sale, except my own private set of course. These are sold at a reduced price at $450 down from $599, because they are "refurbished". They were sold and then...

Quote: I will try that on monday

Quote: Already did that. Bass port tuning and tuning of the dampening felt bass port. :)  

Quote:   I have applied 1/3 octave smoothing. It's the standard setting in HOLM impulse.   Here is the raw response:  

Quote: Seems like sound signature is preserved even when the frequency response is made more linear. The sound is as vibrant and smooth as ever. The soundstage and detail is there too. So it's all good :D  

KODA^2 MK-II is finished and I made new readings compared to the old KODA^2:     Personally I just think they sound amazing - it's fantastic too se how much progress can me made with a decent testing rig. I turned out even better than I hoped.   A little picture - they look more...

Quote: A smaller hole on the dampening on the back and smaller bass port. I could make it even smaller and thus make it very liniar - but it sound terrible them. Dull and boring - and that was not my intention :) There seems to be much more to it, than frequency reponse - I know this is...

KODA^2 MKII   After building a nice test-rig - I was able to confirm Tyll's readings. Of course. I decided to upgrade the KODA^2 design to get a little bit better frequency response, while preserving the sound signature and qualities of the original KODA^2. After altering the design and...

Quote: I'm finishing my final exams monday and finally getting my degree - I'm really looking forward to making your KODA^2's after monday. I'll do my absolute best :)       

Quote: I understand the logic in what you say - and I agree to that to some extend. But the variation from each pair of KODA^2 should be very little, due to the parts are cut with precise CNC equipment. The reason I expect the set Tyll was testing to be fine, is that the chance that...

Quote: I know a user from Head-fi is going to post a review of the KODA^2 soon - maybe this weekend. I think there will be a comparison with both a set of genuine Thunderpants and with the LCD-2. I for one is looking forward to reading this :) 

Quote: There is actually much bass-slam in these headphones. I will get back with new readings when I get some proper microphones that picks up the lower frequencies properly. The microphone I use in my temporary test rig can't really detect fequencies below 75 hz properly. But the...

Quote: That sounds great Tyll - It would be fantastic to get some confirmation before changing too much on my design. When I get my test rig up and running, we can compare the measurements, and see if they share similarities.   I'll have them forwarded to you when possible.   Thanks

Quote:               Red: Right cup     Blue: Left cup    Green: Bad/loose And even more so, that my reading with proper seal shows pretty good readings - it's unbelievable frustrating. I will not modify my design when they sound just right to my ears and to my frequency...

Quote: I agree - but it's the green curve that make me wonder - it's just so similar to his readings, and that is very very stange.