hysteresis oscillator

[1878]

Just looked through my box of bits and I've got all the required parts to build this...

http://www.geocities.com/worthekik/hysteresis.html

Has anyone built one ?? I've read on this forum that some peeps can't get it to work, where as some

http://www.diystompboxes.com/smfforum/index.php?topic=62184.0

have said they did. Should I only use a certain type of 555 chip ?? Also, the schematic asks for a 1N4148. I've got a couple of 1N4001's left over from my UglyFace build, will these suffice ??

Thanks in advance.

[oldrocker]

Well I have built it a while back and it works great.  Since I had already built the Nyquist and Bit Crusher I noticed that the Hysteresis could come fairly close to sounding like those pedals with a lot less work and parts.  The choppy tremolo feature is a nice cool bonus.  I added an 847 wah circuit after the Hysteresis in the same enlosure with a pot (no foot control) to adjust the frequency.   As for the diode I'm not sure how it'll work but I would try it since it wouldn't be too hard to replace.

[1878]

Thanks for the reply.

Did you use the Worth Ekik layout ??

[oldrocker]

Actually I perfboarded it but it worked great.
http://i218.photobucket.com/albums/cc93/ftrock/Hysteresis2.jpg

[1878]

I'll be going along the perfboard route myself. I'll post the results when it's finished.

Thanks again 

[frequencycentral]

Well I have built it a while back and it works great.  Since I had already built the Nyquist and Bit Crusher I noticed that the Hysteresis could come fairly close to sounding like those pedals with a lot less work and parts.  The choppy tremolo feature is a nice cool bonus.  I added an 847 wah circuit after the Hysteresis in the same enlosure with a pot (no foot control) to adjust the frequency.   As for the diode I'm not sure how it'll work but I would try it since it wouldn't be too hard to replace.

Do you find the Nyquist and Bit Crusher to be useable effects? How do you use them? I made up a Bit Crusher on my modular synth - didn't really find it very musical - am i missing something?

[oldrocker]

No you're right the bit crushers are not very musical.  I use them so I can make wierd sound effects with my guitar.  They tend to flatten or somtimes sharpen the note at times.  The bit crushers are not for everyone but if you just want to mess around making your guitar sound freaky they're a blast.

[1878]

Thanks again for the replies.

I've built it and it doesn't work Checked the wiring against the layout and I haven't made any mistakes. The only thing I've done differently is a 1N4001 in place of the 1N4148. I'll take the schematic into work tomorrow, do my own layout and see if that works.

Any help would be greatly appreciated.

[MikeH]

I built one and it works fine.  Almost more of a noise maker than an effect.  The trem is really choppy/clicky like crazy robot sounds or something.  It's a fun one though.

[1878]

MikeH:

Did you build it according to the layout or the schematic ??

http://www.geocities.com/worthekik/hysteresis.html

I've just double checked everything against the layout and I've wired it all correctly. As I said, the only thing I've done differently is a 1N4001 in place of the 1N4148. I'll order the 1N4148's tonight and go from there.

Thanks again everyone.

[MikeH]

I just went by the schematic.  I think I just whipped it up on vero on the fly, I don't think I actually designed a layout.

I'm not exactly sure what that diode does... but I do know the circuit is pretty particular about the components used.  I tried to use a value other than 22uf for c4 at first and it did not work.

[1878]

Been busy recently, so it's taken a while to get round to having another go at this.

Basically, I bought the 1N4148's and it still doesn't work. Double checked all the wiring and everything's as it should be. I'll work from the schematic rather than the layout next time. What 555 did you successful people out there use ?? I'm using a TA7555P left over from my UglyFace build. Can anyone see any problems with this ??

Thanks again.

[1878]

Hmmmm...

Just plugged it in again, and apart from the actual chop, everything works ?!?! But, when I turn the chop control, it cuts out and I have to 'reset' it by disconnecting/connecting the battery.

Any help would be greatly appreciated.

[MikeH]

This post got me thinking this past weekend so I cracked mine open to check it out; I was using a jrc555 in mine, I switched it out for another 555 (don't remember which brand) and it did NOT work.  So maybe it is the brand of 555 you're using.

Also I noted- I ended up using a 1M pot instead of 250K, which allows it to get really slow, and produce this funky, clicking, thumpy tremolo.  Pretty cool, and you can still get all of the other sounds out of it.

[1878]

Just replaced the 555 and it works !! It was the same make and model, the other must've been fried in some way.

I also replaced the 250K pot with a 1M (thanks Mike !!) and it makes it a much more usable effect in my opinion. I feel I should hate the 'clickiness' of it, but it just adds to the overall personality. I'll box it up over the next few days and post a couple of samples if anyone's interested.

Thanks everyone for your help.

[1878]

Something I've found since I've built this effect...

I've found the volume control is only any use if you want to lower the volume. It's the same volume maxed out as when the effect is bypassed, so, I disconnected it. The middle wire from the top row of the 3PDT now goes straight to C1. I'm using a small(ish) enclosure, so this gives me more room to manouvre.

Thanks everyone.