Known Issues and Building tipps for yocto 808 Clone Batch2 - January 2014 pcb version
Failure in Cymbal Build Instruction before 11.02.2014
(copy von e-licktronic forum)
A customers found a mistake on the schematic.
R108* and R111* in the Cymbal section are switched.
The right value of R108* is 22K and R111* is 18K.
(the building instruction was updated to correct value on 10.2/11.2.2014)
R44 from 100k to 50k otherwise a 100k Trimmer to change the„tuning range“ for TM1 
validation July2014
Chassis
unscrew the nuts from all pots/encoder or the board bends.
if needed use washers together with spacers
Custom Rearpanel:
i´m planning for a second yocto a rearpanel with powerswitch.
in the EPS file i removed the square hole for the powerconnection, i have to connect from the pcb the gnd cable to the switch, see here - same is in the LXR Drumsynth modification.
here is the modificated EPS file.
Yocto_v1.0_Acrylic_Case_ohne_powercon.eps
Custom LOGO:
added a "Rhythm Composer YOCTO at the Frontpanel
and removed the powersupply square cutting at the rearpanel (see custom rearpanel info above)
Yocto_v1.0_Acrylic_Case_ohne_powercon.eps
Noise section:
Measurement AC !!
Adjust the TM4 trimmer for 130mV on pin 1 of 4558.
its important to use a good DMM (multimeter), most cheap DMM have in AC voltage measurement with 3digits high failure rates and cant display 160mV - shows only 0,01.
i highly recommend a 4,5digits or better DMM with 0,1% tolerance
i have at least 250mV so changing R127 to 47K ...
for Handclap section:
http://www.e-licktronic.com/forum/viewtopic.php?f=16&t=146&p=525#p525
hear the issue:
http://m.soundcloud.com/patrickj-ricke/yocto-handclap-issue
808 issue handclap:
http://www.muffwiggler.com/forum/viewtopic.php?t=96102&start=10&sid=d6f73a9fdac17e18f1fde05211f88b3d
This was a little tricky to figure out:
clap reverb mod -
replace r376 (47k) with 100k trimpot
This will vary the reverb between full and completely off.
C144 must have the correct polarity
you have to trim TM3 to get a handclap sound of your choice
make sure that your noise is trimmed between 100mV and 140mV AC (RMS)
please read the TR-808 Servicemanual, you find there addional infos about Gain (you can change 2 resistors to minimize the gain of the handclap section)
if your Handclap reverb dont work: measure with a scope the triggeroutput (Tranny Q29), you find it too on the R360 and the q69 ( you must have this on both ! )
Cowbell
Range: replace R44 to a 50k trimmer
adjiust the trimmer on left hand - after a bleedthru you must trim one trimmer a bit more to get a cowbell.
you can doublecheck them by using a scope
http://www.e-licktronic.com/forum/viewtopic.php?f=16&t=189&start=20
Low Noise Ratio (SNR) for Mastersection
http://www.e-licktronic.com/en/content/39-master
change in the Mastersection all carbonfilm resistors to Metallfilm resistors and change all cheap electrolyt caps to LOW ESR caps..
change the ceramic cap (220p) to a c0g capaciator
Low Noise Ratio (SNR) for Mastersection
http://www.e-licktronic.com/en/content/39-master
change in the Mastersection all carbonfilm resistors to Metallfilm resistors and change all cheap electrolyt caps to LOW ESR caps..
change the ceramic cap (220p) to a c0g capaciator
Noise Reducing SNR/NOISE RATIO generell
in many Voices/sections you can find at the output amps a resistor, to reduce the noise ratio you can change this resistor to a metallfilm resistor and the electrolyt caps to a better low ESR Cap.
Bassdrum: R175 1K, R173 6K8, R174 100K,C50 1uF/50V
Snares: R207 1K , R210 470K, C68 33uF/35V
Rimshot: R295 1K, R327 470K, R330 470K, C126 33uF/35V
Low Tom/Low Conga: R235 470K, R238 1k, C82 33uF/35V
Mid Tom/Mid Conga: R266 470K, C95 33uF/35V, R239 1K
Hi Tom, Hi Conga: R291 470K, R294 1K, C109 33uF/35V
Hihat: R161 470K, R172 1K, C83 33/6,3V, R159 470K, R169 1K, C81 33uF/35V,
Master: all resistors, all Electrolyt caps ( 2x 2,2uF/50V, 3x1uF/50V, 33uF/353V)
Cowbell: R163 1K
Accent: all resistors to metall, C25 + C34 to Low ESR (2x 47uF/35V)
Cymbal: R166 1k, R128 470K, C78 33uF/35V
Handclap: R296 1K, R375 470K, C145 33uF/35V
Powersupply : all to metallfilm and all to low ESR caps ( 100R metall x 25 and 47uF/16V x25, 3x 100uF/35V)
powersupply main: C5,C7 2x 2200uF/35, C11 220uF/35, C12,C13- 100uF/35
= 4x 1uF35V
, 9x 33uF/35V,
2x 2,2uF/50V,
27x 47uF/35V,
3x 100uF/35V,
2x 2200uF/35V,
1x 220UF/35
, 2x 100uF/35V
Shopping basket @ reichelt.de
change the 100uf cap to 35V or more in reichelt basket
http://www.reichelt.de/?ACTION=20;AWKID=866139;PROVID=2084
metallfilm resistors don´t included there due to full homestock..