Tag Archive | Modding

Odyssey, VCF replacement

Came across ARP Tech’s Dual VCF module earlier this week and was instantly inspired. Whilst later Odyssey’s (models II & III) come with a 24dB/oct low pass filter (model 4075), the Whiteface is equipped with a 12dB/oct model (4023). Despite the latter is generally considered more musical, having a steeper cutoff slope naturally produces more classical “synth” (resonant?) sounds. Moreover, as ARP Tech’s module has both, having them both in a single synth would kick ass.. To say the least ;). So today, I decided to etch a PCB for the module!

Dual VCF board with few IC sockets installed

Luckily enough, the Odyssey service manual does provide instructions to upgrade model I synths for the 4075 module so installing the completed board should be a walk in the park. But first, I need to order some parts.

Not that there’s anything wrong with the filter module on my Odyssey, far from it. The dual cutoff mode just outweights maintaining the original parts at this very moment! Promise I’ll make the installation reversable ;)

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Odyssey

Not much happening on the DIY front for quite a while, but now I can haz a model 2800 whiteface Arp Odyssey \:D/ Yay!

What a classic synth, I have no doubts that this will swiftly become my precioussssss-sssss. Downside, it’s going to need a whole bunch of repairs. Keyboard bushings, sliders, damaged components, you name it. Probably every bit you could expect to be broken in a synth that’s +30 years old.

So repairs it shall be then. To get started somewhere, I gave the internals a quick glance to map out the most “obvious bits”. Someone had been servicing (or “servicing”?) the synth previously to say the least; there were some extra components added to the solder side of boards A and B and the power supply cable had been swapped.

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Sega Dreamcast VGA mod

Came acrossa a bargain Sega Dreamcast bundle and simply couldn’t pass it by, so here I am with yet another console post!

As far as modding instructions go I’ll once again default to one of my favourites, Mmmonkey, and his Dreamcast Internal VGA -page. Not much to add to the instructions, so I’ll just skip to the photos. Do check out Mmmonkey’s page for further descriptions if you like.

With my Dreamcast I chose to cut a small piece from the EMI shielding plate and install the connector and the switch to the ventilation openings. Snug fit, but in did the parts go!

Atari Jaguar ROM switcher

Seems like I’m getting more and more a console-fanatic, as I found myself fetching a Atari Jaguar from the post some weeks ago! Digging through resources for this console around the net, I came across with JagOS and BJL. Despite not being much of a coder, I thought maybe a simple boot ROM switcher would be of some use anyway. With simple I mean a circuit where the Chip Enable (CE) signal from the CPU is routed through a SPDT switch to two different boot ROMs. Prior powering up the system, one of the ROMs is selected by flicking the switch.

Not much to this mod really, all in a couple hours of work. Desolder the original ROM, solder in a socket, make a adapter board for the boot ROMs, install switch to control CE routing and program the additional ROM with JagOS..


.. or well, the top halve of the case did need a bit of reworking thanks to yours truly winging the design without any measurements. Luckily the switcher board did fit in so I didn’t have to redo it :). Now then, a RGB cable for this console would kick ass..

2013-09-15, ERRATA: Apparently also _OE (pin 24) needs to be switched, otherwise there’ll be signal conflicts if both ROMs are installed. I’ll get this post fixed and do a new set of photos as soon as I can. Sorry!

Sega Menacer power supply mod

Bought a Menacer light gun for the Megadrive some weeks ago.. Can’t say I’m too happy about the battery operation, six triple-A batteries worth of W-T-F! I’d rather have it running on a separate power supply vs. keeping the option of ducking behind the sofa for a reload, so time for a power supply mod then! Figured I’ll go for that default 9VDC wall-wart (like with my Megadrive)..

Menacer, electronics

Hot glue, the (not-so) secret weapon of the tinkerer..

Menacer, through-hole for the connector

Dear me, what a neat hole!

Amazing display of plug’n play.

Now if only this mod would improve the quality of the bundled games.. :)