My new project in development: KA 567 Chopper tremelo (need some input)

[FUZZZZzzzz]

so.. I'm working on a tremolo that I've accidentally designed (but it sounds great nonetheless).. it still got the usual problems like ticking when nothing is played, but the sound is warm and chopper like.. i put a rotary with 1uf 2.2uf and 4,4 uf for different range.. so it can go really slow and fast.

heres a rough sketch: it should work.. im developing things here so will update if theres progress.. the two major problems i have are: ticking when pedal engaged.. the 100k to ground already filtered some out, but any input is welcome..  problem 2 is when the pedal is off.. theres still a very very low volume almost unnoticable ticking (is this a grounding problem?) its in a plastic box right now...



tell me what you guys think.. sorry about the messy schematic.. the ic used is ka 567 .. the 567 types with letters behind it wont work

[timd]

I will attempt to verify this circuit soon, but I had 2 questions:

1. Would any type of 567 chip work? I know mine is not the "KA" and I think its the "LM" 567.

2. Are both the input and output taken from pin 8?

[FUZZZZzzzz]

I will attempt to verify this circuit soon, but I had 2 questions:

1. Would any type of 567 chip work? I know mine is not the "KA" and I think its the "LM" 567.

i can only tell you that I have two 567s.. one KA567 and one KA567LMZ or something (cannot verify, at my work atm) if you build it let me know if it works

2. Are both the input and output taken from pin 8?

yes, very strange but thats right!

1. Would any type of 567 chip work? I know mine is not the "KA" and I think its the "LM" 567.

i can only tell you that I have two 567s.. one KA567 and one KA567LMZ or something (cannot verify, at my work atm) if you build it let me know if it works

2. Are both the input and output taken from pin 8?
yes, very strange but thats right!

[timd]

Alright FUZZZZzzzz -

First off, I just breadboarded this with a LM567CN chip and it worked fine. The trem is great sounding and you should be applauded. (I like the 1 uf speed cap) But, I agree about the ticking. I have read before (sorry no link - just shooting from memory) on this forum something from Tim E. about the Thing modulator, which is also based (I'm sure you probably know) on the 567 chip. He said something about the noise being inherint in the chip, with no way to remove it.

I hope this is wrong for everyone's sake. If this is wrong, please speak up someone! After all, most trem's and other modulation effects have tons more components than this build (and the Thing) and it seems that we must pay some sort of price (the ticking) for this build simplicity. 

Also, I tried to build your Abomidable Snowman circuit with no luck. Do you have a clip or two? I really want to hear what it sounds like!

[timd]

http://www.diystompboxes.com/smfforum/index.php?topic=67470.0

I found what I was referencing earlier. Go to that link (above) for the full discussion, but here is the summary (after my bad dictation)

Sad, Sad Face. But, I still love the 567 chip. Its like the Pete Rose of the DIY world...great, but likes to make bets it can't handle...no Hall of Fame...

Summary:

I typed "Thing Modulator" and "oscillation" into the engine here on the site and found....

http://www.diystompboxes.com/smfforum/index.php?topic=33308.msg294981#msg294981

Quote
I got the LM567 to work (in a way, anyway) by using the Thing Modulator schem minus the RC network on the power pin (like the Noise 567), and an LDR in place of the TM's 10k, next to the Frequency pot, which I kept at 100k. To quote Tim E :
"with the desire to make the thing shut up when I'm not playing, I found that using both a LMC567...and a 100k/100uF RC network on the power pin go a long way in suppressing the onboard oscillator..."
reading that, I surmised that the 100k/100uF was there just for the CMOS version and built mine like the Noise 567, without the RC network. I also used the cap values from the Thing Modulator (.1uF all round instead of 10uF and 22nF) ...er...for no real reason except that it would be easier to not put them in all the wrong places. The result is a hilarious collection of dirty ring mod, strange atonal fuzzes and quick decay bong/clang/crashing noises, and the worst/best broken speaker/amp/everything-WTF-noise I've ever produced when hitting more than one string. Oh, did I mention the flat out oscillation at some point of the pot arc? Not that useful, but fun all the same. Yes, it ticks through everything, but if I'm not going to stomp on it, I just pull the (DC) power plug.

Quote
If I understand your question correctly, that "ticking" is the result of the LMC567's internal oscillator spitting out a sloppy rectangle wave. And sloppy modulation. My guess is that there's probably not much that can be done about it. Real ring/balanced modulators often use a triangle or sine wave oscillator for much cleaner sound down into sub audio frequenies. In the case of the Thing Modulator, simplicity dictates the all-in-one chip design utilizing with the internal oscillator.

I know of no mod to counter the effect.

[FUZZZZzzzz]

Hi Tim,

Damn... you did some research i must say.. I really really really like the tremolo sound in this one.. but unfortunately i havent found any ' cure' for the ticking problem.. the 100k to ground filtered out some, but theres still some remaining.. its still usable as a studio tremolo with heavy chopped chords but way to loud to use on stage for subtle stuff..

i must say i havent found any 567 tremolos along the way.. so maybe thats the answer? right? good to hear you got it working .. so its at least verified

thanks for words and input.. i will look into the info above..really appreciated!


ps. ka567 and LM567CN work!

[timd]

I agree, the trem sound is awesome. I was messing around with the circuit trying to get the hum out, but all I came up with was rate LED mod, distortion with a switch mod, photoresistor, etc...not the one thing I was trying to do!

I do remember seeing a thing modulator schematic floating around the net that used a red led to filter out the noise of the 567. I'll try to find that again....It might be a start!

[timd]

btw...any Abominal Snowman clips?

[FUZZZZzzzz]

I agree, the trem sound is awesome. I was messing around with the circuit trying to get the hum out, but all I came up with was rate LED mod, distortion with a switch mod, photoresistor, etc...not the one thing I was trying to do!

I do remember seeing a thing modulator schematic floating around the net that used a red led to filter out the noise of the 567. I'll try to find that again....It might be a start!

I also found a led rate mod, but it also changed the sound of the tremolo.. i'd love to see your mods.. if we somehow get the noise to an acceptable minimum we get a very simple and great sounding tremolo.. googling along

[deadastronaut]

hmmm...i was just reading this, and remembered garcho cured ticking on the cmoss 555 by: quote: (from the tiny tremoloooooo thread)

'I used a red LED with a 100mF cap to ground from pin (output) 3, and voila, no clicking.'


just thinking aloud, not sure if this might be ok on your 567 out, but hey worth a try right.....

[timd]

I think the Logan 5 ring mod had some components to tackle the unwanted sound too. These should be attempted to fix the chopper. I'll see if I have time to do this...

[FUZZZZzzzz]

just an update: i looked at the logan 5 schematic for cures and played around on the breadboard, but have so far not been able to reduce or fix this.
will try the led and cap to grnd tonight.. did not see it yesterday.. and will look for the modded thing modulator..

[timd]

I might have stumbled on something here - this is a video for a ring mod that also produces tremelo (hmmm....maybe the 567?). Note that the guy in the video says extra noise was removes via a low-pass filter.


http://youtu.be/LNC4UIiiy5I

If we need a low-pass filter to fix the ticking, I have a link:

http://en.wikipedia.org/wiki/Low-pass_filter

I am not at home right now to try this, and I wouldn't know what values to use off hand.

Hopefully this riddle can be solved....

[timd]

Alright, if this doesn't work, I might have exhausted every avenue with my limited knowledge of electronics. Here is a datasheet for the 567  http://html.alldatasheet.com/html-pdf/17983/PHILIPS/NE567/244/1/NE567.html that shows pin 2 (not used in your schematic) being a low pass filter. Would it be as easy as connecting this pin to ground? I hope somthing I have found online helps out.

[FUZZZZzzzz]

So far.. i have not found any cure.. unfortunate.. coz the tremolo is great sounding. Is there anyone with a suggestion for reducing the tick in a NE 567 / KA 567 ??
I have everything that was suggested or found in other cases, but nothing reduces the tick.. without drastically changing the sound..

any input is welcome.. even if you know its impossible

[timd]

This is such a great sounding pedal, and would be a true diy gem if that damn ticking was removed. I'm really surprised that we don't have much intrest in this topic!

[FUZZZZzzzz]

yes it is.. unfortunately i think everyone is fed up with ticking problems for years now.. and no one likes to reinvent a wheel that has been carved already  beautifully by hand.. dont blame em but i really like the choppery sounds.. maybe i could look into some kind of simple noise gate or something..

[cpm]

what kind of tick "noise"?
if its a ground issue, separate completely the IC gound up to the main power connection, or even add some R like 100 ohm from IC to gnd
if its from the sharp cut (chopping the audio), may be due to the big 10 uF cap. Try a smaller one 100nF ... but this is very dependant on input impedande, a buffered input would be more convenient and will help with a lower value cap

[FUZZZZzzzz]

what kind of tick "noise"?
if its a ground issue, separate completely the IC gound up to the main power connection, or even add some R like 100 ohm from IC to gnd
if its from the sharp cut (chopping the audio), may be due to the big 10 uF cap. Try a smaller one 100nF ... but this is very dependant on input impedande, a buffered input would be more convenient and will help with a lower value cap

hi! thanks for the advice.. the tick noise is probably a ground issue.. i tried your advice, but that doesnt work..  i also tried lowering the output cap, but that only softened the tremolo sound.

[timd]

http://www.diystompboxes.com/smfforum/index.php?topic=96658.0

- That's a link to a PWMish pedal that had ticking until a coupling capacitor(?) was added. Hmmm....

Also, I breadboarded a tremelo circuit using an led/ldr combo using a 386 driving a 555 timer, and it had the same ticking as the 567!!!!! This is driving me nuts - but a good learn too.