How important is it to use a CMOS 555 in the Uglyface? I've read that a standard 555 is identical to a CMOS (7555), except that the standard chip has a higher current draw. Will I get by with a standard 555 in the circuit?
The Schematic on Tim Escobedo's site specifies that it must be a CMOS...
I didn't in the one I built and it works fine. It might the fact the the packaging the chip came in didn't say it was a CMOS when it actually was. They had one that did say CMOS on the package but I used the other one.
Quote from: oldrocker on September 19, 2006, 11:17:55 PM
I didn't in the one I built and it works fine. It might the fact the the packaging the chip came in didn't say it was a CMOS when it actually was. They had one that did say CMOS on the package but I used the other one.
What's the code on the chip? IIRC, different prefix or suffix letters signify a CMOS.
Would a different power consumption lead to a different performance in the chip? As long as voltage requirements are met should there be a difference?
If you can get a reular 555 to work, then good for you. I got inconsistent results, at best. So I specify the CMOS 555. They go by different names, but all will be described as a CMOS 555. They are not hard to find.
You woundn't believe how many emails I get saying "my Uglyface won't work", and continue to tell me they subbed a regular 555 in place of a CMOS 555, despite instruction not to do so. ;D
Thank you. I just needed a definitive "USE THE CMOS, STUPID!" ;D
I know the CMOS 555s are easy to get, it's just that I've got a bunch of standard 555s, and no use for them. :(
Thanks again.
if you havent given them all away, here's some things you can do with them :) http://avensonaudio.com/tech/MiniNoteBooks/MiniNotebook%20555%20Circuits.pdf (http://avensonaudio.com/tech/MiniNoteBooks/MiniNotebook%20555%20Circuits.pdf)
the original schematic of what is now called 'The Atari Punk Console' is in there :)
Fun Stuff!
Rat Shack even sells the CMOS 555 so you shouldn't have a whole lot problems getting one in a hurry even.
The Hitachi HA17555 is a CMOS version of the 555??? Thanks!
Andy
I used the LM555 chip from Radio Shack and not the TLC555 CMOS chip. My UglyFace works great so far. Are they the same? The guy a Rat Shack said they were close enaough. I'm glad it's working but I'm thinking of going and getting the TLC555 anyways. The orginal one I had in there burned up on me (had it installed wrong on the breadboard) so I went and used the LM555 which worked so far. The Ugly Face is such a cool pedal. I always show it off when someone new comes over. It freaks them out when they hear it.
Quote from: oldrocker on September 21, 2006, 03:25:05 PM
I used the LM555 chip from Radio Shack and not the TLC555 CMOS chip. My UglyFace works great so far. Are they the same? The guy a Rat Shack said they were close enaough. I'm glad it's working but I'm thinking of going and getting the TLC555 anyways. The orginal one I had in there burned up on me (had it installed wrong on the breadboard) so I went and used the LM555 which worked so far. The Ugly Face is such a cool pedal. I always show it off when someone new comes over. It freaks them out when they hear it.
From what I've been able to gather, the LM is not CMOS. The fact that your Uglyface works with it gives me hope, but I ordered some CMOS 555s...just to be safe.
Otherwise, I'm just waiting on the Vactrol, and I hope to have it up and running this weekend.
mine didn't work with a NE555 but works very well with a TLC555 ;)
There are some significant differences between the specs and performance of the 555 and the CMOS 7555 - see the data sheets. A significant proportion of 7555 circuits will not work with the 555.
Linear CMOS chips seem to vary more between manufacturer, than most chips do.
The CMOS 555 can vary quite a bit (not usually a problem for 'standard' circuits).
Another chip I have had trouble with, is the 4046 phase locked loop. If you are ever making a batch of something with 4046s, stick with whatever is in the prototype, or at least check if the other brand will work!
It's the old problem of using chips in places they wern't expected to go...
Mine worked with a non-CMOS version 555 but worked very badly compared to the real thing.
The Crash Sync works fine with a regular 555 though I believe.
RDV
4k posts RDV....congrats.. :)
When I looked at the chip diagram for the TLC and LM chip from Radio Shack they were virtually the same. The pinouts were the same like trigger,comparator,reset, output and ground. Where and what is the CMOS part? I didn't pick up the TLC chip today like I planned so I was wondering how the LM555 works different from TLC555. Does anyone know?
TI is sending me some free CMOS chips, 4 or 5 I think. oldrocker, if you can wait I'll send you one.
Quote from: oldrocker on September 22, 2006, 08:19:52 PM
When I looked at the chip diagram for the TLC and LM chip from Radio Shack they were virtually the same. The pinouts were the same like trigger,comparator,reset, output and ground.
Certainly, the pinouts are the same, and the block diagram is the same..... but things like the risetime and impedance of outputs, peak current draw at switchover, current draw, maximum and minimum operating voltage can all vary. usually it doesn't matter, someimes it does. (hence the common recommendation on the forum to use 7555 or other cmos for lfo generators in fx to minimise noise on the power rail).
Ther bottom line is this.. if someone says that they made a circuit using a particular brand of chip, and I make it with a different one, it might work OK. But if it doesn't, the first thing I do, is try using the chip that they recommended. Then, if it still doesn't work, at least I know that I made a mistake.
Thanks Paul that clears things up for me. I've come to the conclusion that since I don't know what an UglyFace is supposed to sound like then maybe what I have isn't what I think it is. So even though I thought it was working right it's only because I'm settling for what I have and not what I'm supposed to have. If that make sense. I will go out and get a CMOS version 555 chip in the morning.
Has anyone tried the mods found below? And if so what do you think?
http://www.webdevils.com/stompbox/index.php?d=21&m=06&y=06
I did the mix-mod... it works, ok... but the signal never gets completely clean..its still overdriven when the mix is all the way couter-clockwise... I only put it on my latest one because the guy will be using it with keyboards and may want to bring the effect in and out on the fly...
Well I replaced the LM555 chip with the TLC555 chip and I hear no difference. It works the same and sounds the same to me. It's no big deal but I just wanted to let people know that if you can only find a LM555 chip for your UglyFace it will work. If there is a difference it's so slight believe me you won't notice. I know this may be hard to believe but I actually found a Rat Shack employee who knew electronics. He was the one I bought the first LM555 chip from and he asked me if I was working on the same circuit. I told him I was and he said there shouldn't be any noticable difference between the LM555 IC or the TLC555 IC and I guess he was right. So I can only assume the LM is CMOS.
Quote from: oldrocker on September 23, 2006, 05:54:13 PM
So I can only assume the LM is CMOS.
Instead of assuming why not get the facts from the datasheet. ;) In this case the LM555 is
not CMOS according to my quick read through.
http://www.national.com/ds/LM/LM555.pdf
The TLC555 is CMOS.
You probably just found a 555 with the right specs to fit the circuit's needs but I would not count on the consistency based on Tim's comments.
Andrew
Oh, OK I see. I guess this CMOS chip just through me for a loop. Well I've got a lot to learn about these. I keep forgetting that specs with some components can vary a lot. Oh well I left the CMOS IC in there since that's what it's supposed to have. I guess I was lucky with that LM chip I had in there. I can always use it to build another Crash Sync. I know Tim knows what his stuff. I hope he doesn't think I was trying to prove him wrong or anything I was just confused at the why this chip worked. I get it now. Sorry for all the confusion on my part.