Öogliibox
Öogliibox is OddAudio's "house brand" of DIY projects, named because I built my first battery powered phono preamp inside a thrift store cutlery box (E.G. a butt ugly box). Add some phony Euro flair, an umlaut, and bam: Öogliibox. Having access to a resin 3D printer means I can even make my own badges!
Generally these are components built for my own reference system but I have sold a few of my phono preamps. Given that I obsessively include the best and most expensive components possible it makes no sense financially to sell these designs commercially - plus they are based on open source designs so making profit off of other people's explicitly free work is frowned upon.
ÖogliiBlocks 6-70 Push Pull EL34 Triple Chassis Tube Monoblock Amplifiers
See dedicated page for schematic and design notes.
Peak power 70W/ch in Ultralinear and 35W/ch in Triode. 1% distortion at 65W, 0.1-0.2% (THD+N) pretty much anywhere below that. Frequency response at 1W into 8 ohms is within 0.5db between 20hz and 42khz, with -3db point at 63khz.
The results are spectacular, one of the best tube amps I've heard in my system.
Öogliibox Tube Phono Mark IV/Tube Power Supply Mark I. The more I listen the more I like tubes, at least on the front end (I still like solid state power with the tube magic on the source/pre side to liven up the sound). The next illogical step in the Öoglii line was thus a tube phono stage. And why not go all in and use a seperate tube rectified power supply? Why the hell not indeed. This beast is based on D. Klimo LAR Gold Plus PCBs the Chinese have been selling out the backdoor on eBay. And I can assure you these are not "inspired" by Klimo, they are identical and high enough quality that I suspect they come from the same factory making their boards. What a time to be alive and take advantage of lax Chinese copyright rules so us filthy peasants can build our own knockoffs of equipment we couldn't otherwise afford.Not that this was cheap to build, at least to build my way. Top-tier hand-selected components throughout are driven by new JJ gold pin tubes (Power: EZ81 rectifier, 12AT7 voltage regulators. Phono: E88CC MC gain stage, E88CC+12AT7 MM/output stage).
The result is shockingly good. Extremely low noise, in fact a lower noise floor than my solid state Phono Mark I-III builds. Huge soundstage. Smooth and rich leaning towards the neutral side of tube tone with the JJs I'm using.
My only gripe is the MM stage only has 35db of gain and for some reason it has more noise than the 60db MC input, despite them running the same output stage. I run my Ortofon 2M Bronze through the MC input with the loading adjusted accordingly and it works perfectly - in fact during bench testing I saw over 40V output without clipping, so this thing is STOUT and has an absurd amount of headroom. I was so happy with the quality of this design that I also ordered the line stage PCBs, which I'll be building soon.
Öogliibox Tube Preamp Mark I. I've always wanted to build a pure tube component with point to point wiring, and I like the flavour that tube preamplifiers can give a solid state system on the front end. So after doing some cursory research I decided to build a SRPP push-pull class A preamp based on Bruce Heran's (OddWatt, no affiliation!) Forewatt design. I essentially had to build this unit twice. The first iteration crammed everything into a single chassis and I had significant power supply noise getting into the signal path. I rebuilt it with a remote power supply which solved most of the noise problems, but I found it still had too much background hiss with the tubes I had on hand (it should be quiet, but tube selection and matching is critical for this). The final version incorporates a -10db voltage divider on the output which gives a dead silent background and brings the gain down to a more reasonable level. I also went with some teeny 0.022uF cathode bypass caps to give a slight (1db) boost to the 10khz+ upper frequencies to compliment the slightly rolled off highs of my Magnepans. While the design recommends ECC802S variant of the 12AU7 I had awful hiss with a set of new JJs I bought for the project- while I wait for those to get exchanged I'm currently running a set of vintage Telefunken ECC83s (12AX7) which while not specifically recommended actually sound quite good. I'll experiment with tube rolling but even with these old tubes tossed in it sounds fantastic - clean and smooth with superb soundstage and imaging. It beats my previous benchmark Schiit Saga + by a significant margin, particularly in front to back depth. The bass is a bit tubby with the ECC83s so I look forward to hearing how it sounds with the 12AU7 variants it's designed for.
Öogliibox Mellivora Capensis Power Amp Mark I. Based on the DIYAudio Honey Badger with DIYAudioStore power supply, soft start and speaker protection boards installed in an AliExpress chassis. With a 1000VA Antek transformer and 80,000uF of filter capacitors this beast was built specifically to drive my Magnepan LRSs with as much headroom as possible - a measured 140 watts into 8 ohms and 270 watts into 4 ohms, both channels driven. A sweet sounding class AB amp that has tons of drive, tight bass, and a huge soundstage.
Öogliibox Phono Stage Mark II. My current phono stage which has seen many revisions, it currently resides in a die cast Hammond enclosure with seperate power supply. I intend to build a top spec remote dual rail power supply using a spare 300VA toroidal transformer I have. The stage itself is built upon a Muffsy PP4 board running on +-15V with Burr Brown opamps. You won't find a better sounding or fully configurable solid state phono stage for less money than what Muffsy offers. Put good parts into it and you'll be blown away with the performance for the money.
Öogliibox Phono Mark III. I built this one from spare parts I had lying around and sold it to a local hifi guy. Hopefully it's still running sweetly in someone's system!
Öogliibox Phono Mark I. The genesis of my DIY obsession and the origin of the "Ugly Box". I built this circuit from scratch with point to point wiring on a perfboard using the Audiokarma CNC phono stage schematic. Runs off 9V batteries for around 15-20 hours. Ugly though it may be it was a revelation how much better this was than my NAD PP2e and I never looked back.
