[sdiy] TR-808 DIY Mods

[Adam Inglis]

Hi Richie
There is a pdf on this page....
http://www.firstpr.com.au/rwi/tr-808/
that documents the mods Robin Whittle did many years ago to my 808.

They included
Kick tune (very useful)
Separate tuning for the two snare drum oscillators (not critical)
Clap reverb defeat (useful)
Clap "density" (powerful)
Pot for controlling noise injected into snare toms and claps (very  
useful)
Decay for the three tom/conga sounds (on trimmers, so not used much)
Audio input to the cymbal and hi hat filters (only used on two tracks  
in 15 years, but quite like nothing else!)

Robin also made a permanent change to the envelope of the snare sound,  
which drastically changed it's typical 808 character, so a couple of  
years ago I installed a snare decay pot based on the microlarge  
schematics so I could have a choice between fat or thin or in between..

hth

Adam


On 24/11/2011, at 12:09 AM, Richie Burnett wrote:

> Hi all,
>
> I am interested to know if anyone here has a TR-808 with any  
> modifications made
> to the drum voice circuits?  It doesn't matter whether this is an  
> original
> Roland 808 that you have modified or a home built clone with some  
> added extras.
> I am just interested to know if anyone has tried adding extra pots  
> to tweak
> parameters and if any of these mods were considered particularly  
> useful
> creatively?
>
> The only such mod I know of that seems to be quite common is adding  
> a pot to
> allow the bass-drum to be tuned or to lengthen the decay time.   
> There are lots
> of parameters like filter cutoff frequencies, oscillator frequencies  
> and decay
> times that could be tweaked, but it doesn't appear like people have  
> done much
> work in this area.
>
> Many thanks for your time,
>
> -Richie,
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