808 bassline synth lacks punch/attack

[iainpunk]

i am currently working on a synth/oscilator (i know, this is not particularly the right forum, but i think you guys would have a different insight) and there is a problem with the attack, lemme explain,

in modern trap/hiphop there is extensive use of "808 basslines" which are basically bass/kick instruments based on the sound of a TR-808's kick, compressed, distorted and elongated. most producers use VST synths to create their own unique "808's" but the recipe is almost always the same, consisting of 2 parts:
a thicc bass note
a hard attack usually having a descending pitch sweep that is very particular.

this video explains it very well: (only the part between 0:23 and 1:10 are really relevant, but its a fun watch and an opportunity for education on what the kids today are listening to)

the bass note and pitch sweep are working really good, but it misses a certain punchyness.

the thing i have works with a thyristor and zener based oscillator. the pitch is dependent on current. i use a potentiometer and automated voltage to create this current. the voltage sweeps from 9V to 4V to create the pitch sweep and the potentiometer determines the sustain pitch. i use a pitch shifter pedal to change notes so i can actually play this thing

here comes what i want to ask y'all:
i want to add a punchy attack like a kick drum, it doesn't need to sound good, its just there to give punch. there is a trigger signal present that gives a short 9V pulse (60ms) but that isn't punchy enough...

does anyone have a good idea for just creating a punchy click?

cheers,
Iain

[willienillie]

i want to add a punchy attack like a kick drum

Have you considered using a kick drum?  They usually sound a lot like kick drums.

And what the hell is trap?

[nocentelli]

And what the hell is trap?

Twenty year old genre of hiphop

[frequencycentral]

AFAIK the 808 BD is a damped sine oscillator. To get the best out of it you'll need to ping it with just the right length of trigger, too long and it'll be sluggish.

[nocentelli]

http://www.ericarcher.net/wp-content/uploads/2014/07/tr-808-bass-drum-diy-project.pdf

[iainpunk]

im not looking for the original TR-808 kick, but a derivative of a derivative of that sound. i'm building a different beast where the sustain is infinite until you let go of the button, but with the same kind of swoop in the attack. i found that a fuzz pedal really brings out the thick nature i was looking for, and putting a chorus before the fuzz works magic on the attack adds a huge mount of crunch, so i think my question is redundant now i found that trick.

And what the hell is trap?

trap is a sub-genre of hip hop originating in Houston, TX, but in recently became more popular than ever before. a prominent part of the music is what they call "808 bass lines" which are bass lines with a kick like attack and a 'grimey' sound.
the trap scene and hip hop scene in my city are quite separate. the trap scene has a strong DIY ethic which got in contact and fused with the DIY 'punk' scene in my town. that is how i got introduced to trap and why i am building this bass oscillator/drum synth.

cheers,
Iain

[nocentelli]

Very interested in seeing what you came up with for the bass synth part. I think I'm pretty much done with building fx pedals for now, but I'm quite keen on the idea of building a simple hardware drum machine + bass synth + sequencer

[iainpunk]

yeah, its not really the most ideal bass synth in the world because it is a shitty (less than ideal) sawtooth oscillator, which isn't ideal for bass notes to begin with, but with enough filtering and distortion, it sound quite nice and thicc, also octave fuzz/full wave rectifying seem to soften it out instead of make it harsher, which is nice.

it does not really work with trigger signals due to the nature of the switch's function. i use a limit switch spdt momentary with the normally closed side to the 100ohm so the capacitor is at 9V whenever i release the switch so that if i press it again, the pitch dive happens again

it doesn't take pitch CV because i use my EHX Pitch Fork and it's CV because i already have it laying around and its convenient that i have a "keyboard" for it

the oscillator has a 1uF capacitor because smaller caps + bigger feed resistors seem to be noisy and less stable in pitch, but thats my experience


the transistors are all BC547B or BC557B and the zeners might need some tweaking dependent on your particular transistors, but those values are a good starting point.

the next version will have a 555 timer and some better features, like symmetry for the triangle and maybe even a square wave out. maybe even a trigger input, but thats for later

cheers,
Iain