Author Topic: ZOmbie Detick question  (Read 4010 times)

vodoochild_ar80

ZOmbie Detick question
« on: May 27, 2004, 04:07:47 PM »
Well I did this a few days ago and did the dethick form Mark Hammer's page, but for my surprise it don't work at all.
So my question will be, did that "dethick" really work , did work for anybody?, or is just me ?, is Mark Hammer losing is abilities :shock: ?

hope somone tell me

PD: sorry for my really bad english

Mark Hammer

ZOmbie Detick question
« Reply #1 on: May 27, 2004, 04:29:16 PM »
What abilities? :?

There are a few de-ticking tricks beyond the one or two I might have offered.

Certainly one is to use a different Vref for the LFO than for the audio path.  Another is to use a small value resistor (e.g., 100R) and cap to ground (e.g., 22uf) to the supply lines of each chip. to decouple them so that momentary current draws by one of the chips does not carry over to another chip cap serves as a small "current reservoir" to carry it through the drain from another part of the circuit).  Finally, watch where you put your pots and try shielding leads that might pick up stray things.

There are many threads related to this general topic in the archives.  I'mcertain there is a lot more useful advice provided by others here.

puretube

ZOmbie Detick question
« Reply #2 on: May 27, 2004, 05:01:56 PM »
ok: did you make a PCB, or "wild wiring" - if you did latter, the cause is to be found in the wires....
did you layout a PCB yourself, it probby can be found in that....


(I may not answer for more than a week, due to witsuntide-vacation)

jrc4558

ZOmbie Detick question
« Reply #3 on: May 27, 2004, 05:04:20 PM »
voodoochild ar80, or whetever. This forum is not a competition, but a cooperation. Please keep that in mind when you come here. Thus posing a question about someone's abilities is as amature as not pulling up the archives is. Indeed, there's at least 200Kb of information on this forum, hence most of the time all you need is to search. It may be the case that you're yet unable to ask the proper question, and thus cannot judge for yourself the relevance of the stuff you may find in the archives. It is normal and can be understood. But still, that doesn't necessarily give you a right to question someone's abilities. Good luck with your Zombie.
IMHO - just build a Small Clone.

vodoochild_ar80

ZOmbie Detick question
« Reply #4 on: May 27, 2004, 10:45:01 PM »
Thanks Mark  

puretube: i did the pcb version and not handraw (with the pcb that is photosensitive (is that right?))

Constatin: dont was my intension to ofend mark or someone else here,just a kind of joke (maybe my elnglish is to poor to expres myself clear).
Mark culd be just amateur  but for me is a genius.

whell thanks for you help, better look on the forum serach to se wath can i find

Yuan Han

ZOmbie Detick question
« Reply #5 on: May 27, 2004, 11:55:56 PM »
yes it works. no more tickytickticktickticktickticks

I used RG's zombie chorus layout deticked with instructions from Mark's website.

Han

jrc4558

ZOmbie Detick question
« Reply #6 on: May 28, 2004, 02:02:54 AM »
Well, as I've said tickity-tick is a trade off of the Zombie minimalist design. It shure does the chorus, but for me personally the sound-to-noise ratio is just bad. Etch yourself a board for a Small Clone, there's a GOOD layout at www.tonepad.com, do the depth mod that they suggest and chorus-chorus-chorus the night away!!!

niftydog

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ZOmbie Detick question
« Reply #7 on: May 28, 2004, 02:06:19 AM »
Quote
did that "dethick" really work , did work for anybody?


I hope so.. I know a few people who could do with a dethicking circuit!  :wink:
niftydog
Shrimp down the pants!!!
“It also sounded something like the movement of furniture, which He
hadn't even created yet, and He was not so pleased.” God (aka Tony Levin)

puretube

ZOmbie Detick question
« Reply #8 on: May 28, 2004, 02:15:58 AM »
important: keep the rate-pot wires away from any audio paths...

Mark Hammer

ZOmbie Detick question
« Reply #9 on: May 28, 2004, 09:13:07 AM »
Quote from: niftydog
Quote
I know a few people who could do with a dethicking circuit!  :wink:


I know I've probably got the partslying around.  If somebody could direct me to a schem, I'm pretty sure it would make my cardiologist and my wife very happy.  :wink:

vodoochild_ar80

ZOmbie Detick question
« Reply #10 on: May 28, 2004, 11:30:15 PM »
Hello  
I try the  resistor and cap think but  i think that my problem is just that a don't understand where goes the cap and the resistor or how.
The tick-tick thing  really dont sound to high but there's a noise like an AM radio in the small clone mode thats really a pain in the a**. May be i put wrong something and thats the reason of the unsolve tick, or is that noise normal?.

Great idea to get a dethiking circuit

jrc4558

ZOmbie Detick question
« Reply #11 on: May 29, 2004, 01:42:26 AM »
This AM radio noise IS exactly the price you pay for such a simple design.
John, the creator of the Zombie(s), left the filteering transistor stages out of the design... It's still a chorus, but a noisy one... :)

vodoochild_ar80

ZOmbie Detick question
« Reply #12 on: May 30, 2004, 12:11:49 AM »
The zombie chorus have a great sound, it could be such a great chorus even with the noise i like it but is not good to play live.
So i will try the small clone if it so good as all say  it will be cool but i need a reemplaze (equivalent) transistor for the 2n5087 cos' here were i live dont have any. Any idea?

THX to all

jrc4558

ZOmbie Detick question
« Reply #13 on: May 30, 2004, 01:38:28 AM »
2N3906

vodoochild_ar80

ZOmbie Detick question
« Reply #14 on: May 30, 2004, 07:48:17 AM »
THANKS
hope this chorus works fine

Mark Hammer

ZOmbie Detick question
« Reply #15 on: May 30, 2004, 11:13:24 AM »
Where does the deticking go?

Normally, we think of AC as needing filtering to make it usable without hum, but DC (batteries) does not *need* filtering.

Wrong.

If two semiconductors are "competing" for current from the same DC source, then sudden big demands for current from one of those semiconductors has an effect on the other.  It is as if there was a sudden drop in battery power to the other semiconductor.  The"ticking" that people hear with anything that uses an LFO comes from the sudden demand for current that the square wave generator of the LFO causes each time it swings from one direction to the other (the triangle comes from smoothing out that square wave - we *use* the triangle wave but the square wave is still always there and running inside the circuit).

The deticking is basically a lowpass filter connected to the power lines.  Any time you have a resistor in the signal path, and a capacitor going to ground - what is called an RC circuit - you have a lowpass filter that rolls off or restricts passing signals at the slope of 6db/octave.  The point where the filtering action becomes noticeable is calculated by Freq = 1/(2*pi*R[in meg]*C[in uf]).  If  I stick a 100R resistor between the 9v battery and the V+ input of an op-amp, and stick a 100uf cap to ground from that same pin, what I have is a filter on the V+ path that rolls off at around 16hz, meaning that any variation in the supply voltage is smoothed out.

This is also called "decoupling" because the capacitor acts like a little battery itself. The cap stores current like a rain-water barrel.  When there is a drop in available current to that chip because some other part of the circuit needs a lot of current at that moment, the "rainwater barrel" still has some current left over to help the chip "get through the drought".

Because the lowpass filter depends on both the cap AND resistor, very often you can increase the amount of supply filtering for each chip by increasing the resistor....without making it big enough to "starve" that chip.

Another thing is that each device in the circuit could probably benefit from having its own "rainwater barrel".  In the Zombie, the audio chips need the decoupling to "protect" them from noise coming from the LFO, but at the same time the LFO provides benefit to the whole circuit by having its own reservoir so that it doesn't demand too much from the rest of the circuit.

Make sense?