On the workbench this time is a Roland TR-808.  The maracas weren’t sounding too healthy and the snare sounded a little strange. I suspected the noise generator was at fault since this drives both voices. After inspection and some work my suspisions were correct. Now the maracas sound great again and the snare sounds considerably fatter than before the surgery.  All in all this 808 now sounds as phat as it should.

Boom-Tish-Boom-Tish!

Here’s another familier job, this time it’s fitting a midi kit into a Roland TR-808. As we did before, the midi kit is fitted internally and a new socket is placed where the din sync socket used to be. What this means is that cosmetically nothing is changed on the machine. The new socket doubles as din sync as well as midi. The new switch has three positions instead of two. Operation is the same except when the switch is in the middle position midi is activated. You can play all the drums from a standard midi keyboard with a special midi/sync cable (comes with the kit)

Here’s a video of the completed job

Here’s what we get up to when there’s no real work to be done haha. It’s just a little live jam with myself on the TR-808 and Fredrik on the System 100 patched into a Dynacord Super 76 tape echo. It started since we were curious to see if the Dynacord was working, then I just had to go grab an 808 and get things bouncing.

So finally the parts I needed to complete the cowbell fix on the other TR-808 had arrived. I still need to find a solution to finding the start/stop buttons since this one is completely shot. Currently I’m using a button plugged into the external footswitch controller which is enough to do the job, but it would be nice to finally fix the last problem with this machine so I can add the retro kit. Anyway here’s a few videos.

Here you can hear the broken cowbell

Here you can hear what it sounds like after changing the schmitt trigger

And finally here’s what it sounds like once it’s calibrated and reassembled.

After a lot of extensive testing and part replacement I’m happy to say that the din sync problem is thankfully now resolved on the second TR-808. I’m now working on a second problem I found while testing this machine, the cowbell. It wasn’t sounding correct in my ears, so I did a few tests, changed a few parts and I think I’ve now backed the problem into a corner. Of course I wont be sure of that until I change a few more parts, but I’m hoping that I’ll resolve this soon so that I can get on and fit the second retro kit. Waiting in the wings for repairs/renovation is an Oberheim 8 voice, the MC-202 and a revisit to the Arp Odyssey.

Finally some pics, there was a problem with the picture upload last week so unfortunately there was a distinct lack of posts. I trust you had a good easter, I know I did. Anyway here’s what should have been posted last week about the retro kits.

So the second TR-808 sync drift isn’t solved yet and in the process I’ve also discovered problems with the MC-202 sync. So I’ve been using a TR-606 for sync duties. It’s a lot simpler to use for testing since it has similar input/output sync control to the TR-808. Perfect for testing sync in both directions. Anyway I think I’ve narrowed it down to a single IC on the TR-808, but I’ve still a few more checks to perform before I go ahead and order a replacement.

I’m currently retro fitting the TR-808’s we have here while also giving them a service and clean. The kits are relatively straightforward with clear instructions. Makes a change to have a clear goal when working on something, instead of trying to fix an erroneous error. Anyway here’s a couple of videos of the first fitted retro kit. They show me playing the sounds from a midi keyboard and also testing the din sync with a Roland TR-606.

The second TR-808 has a problem with din sync drift which I’m currently investigating, once I solve that I’ll be fitting the retro kit and adding some more pictures.

We use the kits from Czech company CHD Elektroservis.