Sunday, 24 January 2010

Replace Ram battery Resurrection...Yamaha DX11

I got given this synth a while ago (thats right for free!) in a non working state...when I turned it on it proclaimed on its little LCD "cng ram bat" thats what I did. I've had to do this on a couple of old bits of kit in my arsenal now and invariably when you find the ram backup battery it is soldered to the pcb via solder tags that are spot welded to the exception in this case (see pic below). It's sometimes hard to find the required battery with the solder tags welded on so most of the time a better option is to wire a small battery holder to the original pcb points that can hold a comparable battery.

So this battery is a cr2032 which is pretty common but I've still soldered in a battery holder so that in ten years time when I need to do this again I can just clip a battery in without breaking out the soldering iron. For those who may need to do this job in the future and stumble's not immediately apparent where the ram battery is once you get the back off of this synth...this picture shows the board (big green tick) and the corner (green spot) where it need to remove the six screws holding this board to the frame and I found I didn't have to undo all the connectors to the board just the one labelled "cnd1"..that allowed me to lift the board to a workable angle

That last pic shows how I attached a couple of short leads to the points where I'd removed the old battery and connected the new battery holder (actually one I'de scavenged from an old computer motherboard.. most of these use cr2032 to backup the bios ram in battery holders) I taped this into a little space I found so it wouldn't rattle and then put it all back together.

Then I've got nothing else done apart from playing around with it all afternoon! It's a great synth..people overlook them as they are interested in the DX7 which has 6 operators instead of the DX11's 4 but then the DX11 has 6 different waveforms available for each operator (the DX7 only has sin waves) so it's a pretty even match in my humble opinion and can with experimentation create some glorious digital fm goodness.

Monday, 11 January 2010

Native GBA tracking.... M4Gtracker

As yet unreleased in alpha stages...I've been playing with the alphas of this new tracker, M4Gtracker. It's being built by an absolute hero called Smiker...the work this guy is putting in is amazing with new alpha's peppering the last few days. Check the video above where he shows off the fm synth (stick with it sound begins around the 1 minute marker) and read more about it here.

It's definately worth following the progress and if you have a gba and a flashcart or an emulator give the alpha's a whirl.

Sunday, 10 January 2010

DIY Binaural Mics

My good friend Lungwah regularly uses in ear binaural mics and I've always dug the sound he achieves in his field recordings. Having recently got a boss micro br portable 4track recorder I wanted to not only use it as a 4track but, as it can record straight to wav or mp3, as a field recorder too.

So I've made my own binaural mics...its a really simple job. I found a couple of electret mic elements (I had a pair in one of my many scraps boxes but you could buy them here for example) and an old pair of earbuds that are large enough to house the mic elements. Simply crack the earbud cases open, desolder the headphone elements, work out which wire is signal and which is ground and then solder in your mic elements.
Most electret mic elements have 2 solder blobs on the back, one for ground and one for signal, the way to tell which is which is that the ground contact will have a trace going out to the case of the element. If you click the link above these are visible on the picture.

The earbuds I used had a small vent from inside to the exterior of the case anyway but I made it bigger to expose more of the mic element, you can see this in the picture just above the classy gold bands! I then used a spot of hot glue to hold the elements in place and reaassembled the earbud cases. I was done in about 10 minutes.

I'm pleased with the sound results from these and enjoy the fact that you can be doing a field recording and yet not draw any attention as you are only wearing earbuds....which happily had a L and R on them so I even manage to get them in the right ear!

I was asked in comments to upload a sample we are
<a href="">DIY Binaural Mics...walking in lunch hour by concretedog</a>
It's not the wildest thing I've ever uploaded, it's me just walking for a couple of minutes from my office door into town..highlights include, a pram wheeling beside me, cars passing, a phone ringing in a garage and some seagulls! It's recorded on the hifi (compressed setting) on the micro br, then exported on the unit as a mp3 transferred to computer for trimming and converting into wav (for bandcamp). I think you get a good idea of the soundscape if you listen to this through headphones.