e-licktronic Forum

Hello all,

I finished building my yocto and everything works perfectly - I have calibrated the noise, handclap balance, and cowbell (did the resistor swap to get the right pitch, and tuned it by ear to an actual 808.)

I have noticed 2 things i'd like to improve:

1. The bass drum doesn't quite sound very good - it's okay at short decay settings, but then distorts pretty easily depending on the longer decay setting, and it is a bit too clicky / distorted in some settings.

what does your BD sound like - how does it compare to an original? Maybe I have a wrong resistor somewhere?

All other sounds are bang on or pretty close..

2. the sounds are all a bit uneven in volume - relative to each other - my maracas are especially quiet relative to the handclap.

I want to resolve these 2 issues and then it will be just about perfect!

Thanks for such an amazing project - the sequencer is ace btw - seems to be like a 707 sequencer in pattern play - with the mute / roll thing being a very good feature! Have to play with it soon and see if it can change between pattern and write mode without topping the sequencer - if so it's perfect!

Hi Fella,

I used the Micheal Fischer samples of an early 808 for reference. These have been systematically recorded at various settings with no external effects. They can be found here and make excellent comparison material:

http://smd-records.com/tr808/?page_id=14

Comparing my Yocto to these and taking into account the variation that occurs in analogue circuits, I came to the following conclusion.

1) My Bass Drum has a slightly shorter decay on the maximum setting. Unless it is in direct comparison you would not notice.
2) My Cowbell is a lot lower, I have seen this comment before in another thread. This is something I am working to adjust.

All the other sounds are absolutely spot on. Loving the Yocto.

discodisco wrote:Hello all,
what does your BD sound like - how does it compare to an original? Maybe I have a wrong resistor somewhere?

mine was too high and boomy but i had swapped 4,7k with 47k resistor value

discodisco wrote: 2. the sounds are all a bit uneven in volume - relative to each other - my maracas are especially quiet relative to the handclap.
/quote]

my handclap is at least 2x higher compared to others instruments, but i suspect a wrong resistor value, or a least something to adapt. as a conséquence maracas are low compared to clap. i certainly was too excited to mount it slowly. the Yocto has a amazing sound, clearly

Hello LFO2VCO,

You will get a proper cowbell sound if you swap the 2 resistors (r44,45 i think) with the ones mentioned in the build thread.. This will allow you to tune the cowbell higher - I did it from ear - it 2 oscillators tuned roughly a Perfect 5th apart. The 2 trimpots tune each voice. I found that tuning the voices to c# and g# (p5 above) gave me the sound of the 808 I compared it to, and the samples I hear on the net. Curiously, Hanging on a String (Loose Ends) has the cowbell tuned higher - roughly d# and a# (p5) above...

uning the voices to c# and g# (p5 above) gave me the sound of the 808 I compared it to, and the samples I hear on the net.

could you please give more explanations ? you are using a guitar tuner ? were do you take signal ?
for example, i recently calibrated a Juno 106 with a guitar tuner, it is easier than with the oscilloscope

Hey Julien,

yes i just tuned it by ear and checked with Cleartune (tuning app)

when it's tuned to roughly a 5th, the cowbell starts to sound normal - then it's just a matter of working out how high or low you want this Perfect 5th to be - like i said, every 808 I've used seems to be a bit different.

Goodluck!

thanks for your kind answer ! i got it : Tuner ! (accordeur)
are your test points on R45* and R44* or the direct out Jack of the Cowbell ?? imo it's the resistors, isn't it ?

#EDIT :
according to calculations and this table from http://jeanjacques.dialo.free.fr/frequenc.htm :
R44* TM1 -> 1,85ms -> 540 Hz -> C4/C4#
R45* TM2 -> 1,25ms -> 800 Hz -> G4/G4#

wahou this method of the tuner is exactly as for the calibration of filter in Juno 106 and is really easier than with oscilloscope
it should be mentioned in the building manual

@discodisco: I've exactly the same problems (both of them) with my Yocto. I used 1% metal film resistors and Panasonic Low-ESR capacitors for my build. Did you find a solution yet?

Bump. Any other users with this problem here?

Bump again.