Uglyface 555 chip

ildar · September 19, 2006, 10:26:40 PM

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?

$uperpuma · September 19, 2006, 10:58:10 PM

The Schematic on Tim Escobedo's site specifies that it must be a CMOS...

oldrocker · 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.

ildar · September 20, 2006, 11:13:44 AM

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?

Tim Escobedo · September 20, 2006, 11:30:14 AM

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.

ildar · September 20, 2006, 11:39:40 AM

Thank you. I just needed a definitive "USE THE CMOS, STUPID!"

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.

$uperpuma · September 20, 2006, 11:55:30 AM

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

the original schematic of what is now called 'The Atari Punk Console' is in there

Fun Stuff!

Noplasticrobots · September 20, 2006, 02:25:58 PM

Rat Shack even sells the CMOS 555 so you shouldn't have a whole lot problems getting one in a hurry even.

mongo · September 20, 2006, 03:56:02 PM

The Hitachi HA17555 is a CMOS version of the 555??? Thanks!

Andy

oldrocker · 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.

ildar · September 21, 2006, 04:51:34 PM

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.

birt · September 21, 2006, 05:49:41 PM

mine didn't work with a NE555 but works very well with a TLC555

Ge_Whiz · September 21, 2006, 05:54:54 PM

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.

Paul Perry (Frostwave) · September 22, 2006, 10:03:17 AM

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...

RDV · September 22, 2006, 10:37:56 AM

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

$uperpuma · September 22, 2006, 11:12:48 AM

4k posts RDV....congrats..

oldrocker · 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. 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?

ildar · September 22, 2006, 08:51:22 PM

TI is sending me some free CMOS chips, 4 or 5 I think. oldrocker, if you can wait I'll send you one.

Paul Perry (Frostwave) · September 22, 2006, 09:19:48 PM

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.

oldrocker · September 22, 2006, 09:52:43 PM

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

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Uglyface 555 chip

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