Norgatronics

An accent feature is missing from the SoundForce 808 Snare. Adding one is a matter of replacing a 12V rail voltage with the accent voltage. And that’s where a rabbit hole entrance lies in wait.  So Common The TR-808 has one global accent track where you program steps affecting all active voices with an increased trigger level. There is only one global level setting for the amount of accent. This accent is sent globaly on the COMMON TRIG line to all the instruments.   It’s one of those deceptive tricks of the 808 design which in this case makes it's timing special. The common trig signal is always running and consists of a 1ms pulse on every step. The instrument ("data") pulse, which is sent for each selected step is slightly wider so when they are combined there's no chance of them missing each other.  When AND'd together the result is perfectly in time with every instrument in lock step.    The common trig signal is passed through the global accent control, alt...

Nevermind 80’8, what about 81’82? Overlapping the TR-808’s 80-82 production run the CR-5000 and CR-8000 were made by Roland from 1981 to 1982. They both feature a dual bridged-T snare drum circuit, practically identical to their big brother. You can find those who claim that these drum machines have identical sounds, but, as I’ll explain, it’s not that simple. In common with the 808, the SD tuning was updated during it's production life. The CR x000 Service Notes are headed First Edition December 8, 1981 (reprinted July 12 1983). That’s six months after the updated 808 notes, so not the same moment. The CR-x000 design must have been in the final stages by mid-1981 though, the same period as the 808 tuning changes, right? No! Wait! We can do better than that. Much better.    All Change! All Change! Flick through the notes to the voice board pages till lo and behold: CHANGES IN COMPONENT WITH SERIAL NUMBERS CR-5000 101400 CR-8000 101300     The changes are all over the...

This post originally appeared on the SS-30M blog on 08/08/21   As I continue to ponder  the wisdom of making my own 808 snare drum module, the ticklish matter of white noise requires my attention. Oh, and today is 808 day! Transistors' Histories The tickling mostly comes from the unobtanium transistor that Roland used. As explained by Roland's founder Ikutaro Kakehashi in 808: The Movie there was a rejected part that they specifically used to get the exact right kind of white noise. No longer available because the transistor manufacturing was improved, there is a no way to rebuild 808s like the did back in the day. Or is there? I see there's someone in Spain selling genuine spares, but with a price with shipping getting on on for £50 something else is needed.   Matsushita 2SC828R from https://secretlifeofsynthesizers.com - Note the white dot on top indicating it was selecetd for the specific quaility of its noise. Some work has been done on testing this  story's...

This post originally appeared on the SS-30M blog on 21/10/21    tl:dr  I tried to set my Hexinverter Electronique Mutant Snare (MS) module to match the TR-808, on which it is based. I found that the tuning of the MS 'shells' is quite high and not like most 808s. The original 808 schematic values give a frequency for the high snare oscillator of 499 Hz and later component change brought it right down to about 335Hz. My research, which included checking more examples' frequencies, shows that most 808s and its modern clones use the revised component values and thus a lower pitched snare 'shell'. That's including the Roland ACB digital products. The MS is using the original component values, hence is higher in pitch. Noting the variation in tuning ratio between the two oscillators and also bearing in mind that the Q value changes decay time, it should be possible to modify the MS to match the sound of most 808 snares and clones. Ensnared The Roland TR-808's...