Build Your Own Clone Message Board

Yesterday morning before i went to work, i had to go meet some local «stoner» kids, so i brought a full array of boost and drives with me....

The kid was using a Sovtek MIG60 head ( ) and had tons of noise going on...really hearing some electricity cycle going on...

Just for fun..in case it would have been just the amp, i plugged a solid state crate amp they had there..........and it was the same thing..

Anyway we went on trying some pedals in there, one of the kids came over my place and really liked the «Germ Booster» i did when paired with the Onesie he bought me, so he wanted to try that setup again...

We plugged the Germ Booster, daisy chained with all the other pedals, using a One Spot power supply, the pedal worked pefectly as usual for maybe 5 minutes........and then BAM!! nothing......just a super quiet signal, opened the box...IC was hot as hell...

So today..i plugged the pedal in my rig, using a dc brick that is plugged in a Numark power conditionner, pedal worked great for 5 minutes and then.......BAM!! nothing....well...some little signal, unplugged the power jack..and it came back to normal, i will change the IC7660S that does the polar rev to make sure she does'nt fail on me..because i use that pedal on a regular basis...

Hehe...long story...lol, but is it possible that bad electricity could have make the IC defective?

Cheers!

Rej, I just checked a data sheet for the 7660S. Maximum supply voltage is 6v. I'd guess that running them at the 9.5-10v that most adaptors put out will kill them pretty quick.
I'd go with the MAX1044 (rated to 9v) or, my favorite, the TC1044S (which can handle 12v)

Hmmmm....there's something i don't understand now.........why are we able to use those as a charge pump? it's 9volt going to them?

What i use is a TC7660S, reffering to the datasheet with the manufacturer of those i use, it's rated for operation ranging from 1.5v to 12v.

Microchip TC7660S Datasheet:
http://www.datasheetcatalog.com/datashe ... 660S.shtml

And i realise that i've not written the good model in the first post.........damnit!

I use the ICL7660 rated at 10v if I don't use the TC1044 which is my fav too.

You can also stack the IC's. Literally. I don't know how much it will help but it's worked for me in the past. Cheers

Edit, cross posted.

Careful, AIC7660 is not the same as a TC7660 which is not the same as a TL7660 which is not the same as a LMC7660 which is not the same as the ICL7660. The AIC has a max input voltage as GA said, 6v. The others have max input voltages from 10v to 12v.

Unfortunately, IC7660S doesn't pull anything on Google. And by anything I mean a manufactures data sheet, so while the community may generically refer to them as IC7660S, that's not really enough to spec out a part because as you can see, similar part numbers yield very different parts. So, exactly what part is in your pedal; manufacturer and part number?

Have you measured voltage under no signal, signal, and fault conditions? That will tell you if it's this chip or not.

Voltage Readings:

DC Jack: 8.98

Bobtail:

1: 8.98
2: 8.58
3: 0
4: 7.27

5: 8.98
6: 8.36
7: 8.32
8: 7.26

Loaded:

1: 8.97
2: 8.97
3: 0
4: 8.42

5: 8.98
6: 8.42
7: 8.39
8: 0

Off the cuff (I've never played with these chips before, so standard issue disclaimers apply), here are some thoughts. Those readings seem odd, pins 1 and 8 are tied together in the Sunking schematic, so they should be the same.

Also, is pin 5 positive or negative? On the schem it says it should be negative. IMO, if it's positive, I'd say either the chip is toast, or something (fried op amp, IC2?) of lower impedance than the guts of the chip is pulling the pin to +9v. Does the charge pump get hot with IC2 pulled? If so, then the charge pump is dead. If not, then the TL072 is dead, and possibly taking the charge pump with it.

Not sure about the other pins, except for pin 3, and well, being that it's supposed to be grounded, that's a good reading which is encouraging.

D'oh, D'oh and re-D'oh.............maybe i have'nt been clear enough..i did'nt use the chip as a charge pump, but for polarity revere in a PNP circuits so i can daisy chain the pedal with all the others....

Pin5 is postive, well...on my multimeter....

these charge pumps need to protected with a zener diode to stop the voltage rising above their maximum rating. however I suggest you try the LT1054 - it is rated at 15 volts and is pin compatible with the 1044/7660
I really don't know why people haven't ditched the 1044/7660s in favour of the 1054s for that reason.

Its nearly pin compatible.

If you are using a 1044S/7660S with pins 1 and 8 connected together to raise the oscillator frequency out of audible range, then you need to break the connection between the pins if using a LT1054, power needs to go to pin 8 only.

The LT1054 is a much better part, 15V input, and much more current output.

Thanks for the tip Paul, i'll buy a couple one and try it out

So all i need to do is having a Zener that connect to the 9V+ and goes to ground?

you need a load resistor too so it goes..

Perfect! i have 9.1v zeners...going to be perfect!

Thanks!

no worries, let me know how it goes

Yup, i'll make a little vero layout with this and polarity protection on it aswell, could be usefull to integrate that to some finicky circuits...

Here's the link to the experiment, i have also tested it by plugging a 18v jack to the layout and it gives a reading +/- 9.3V when using a 9.1V zener.

So i think that it works great

Exactly what zener are you using? 8.6v isn't exactly common. Typical stuff (like a 9.1v, 1N4739A) is going to need 15v to work (last post at the moment): http://www.buildyourownclone.com/board/viewtopic.php?f=41&t=37887

Ok, assuming you haven't sorted this out already, according to your voltages (namely pin 5 being positive), your chip is toast, or there is an error on your board.

I was thinking you were using this in a Klone by one of your posts midway through the thread. Now I see what's going on

I'm so bored of people contradicting me.

here is the circuit I suggested in action, the left meter shows Vin and the right shows Vout

that's an 8v8 ZD by the way

If you specify all of the parameters, parts, etc, no one will contradict you. 8v8 ZD is not a part number, and specifics count as I pointed in my other post, so I'll ask again, specifically what zener are you using? Also, a pic doesn't really prove anything, if it did, I and every other engineer would be out of a job.

I'm more inclined to see what cleaver thing you came up with than prove you wrong, but if you don't provide sufficient info, no one can do that.

it's part number is 8v8, that is all it says along with the others I have with all their other voltage ratings stamped on them, if I were to take a guess it would be an RS part but I can't remember. but it's not important, it's a physical demonstration of a working circuit, you can stick whatever voltage z diode in there and it will do the same thing at a different voltage.
if the picture doesn't prove anything that clearly shows the input voltage going into my circuit and the output voltage
coming out of my circuit then there is nothing anyone can do to prove it via the internet.
I suggest that you do a little less math and just try things out, datasheets aren't that accurate, math is perfect world answers
which only should be taken as ball park.
contrary to what people tend to believe, I don't post helpful circuits to cause an argument, I post them because I use them to
stop the issues that I used to have and people still have so that people don't have them anymore.
all you achieve by coming on and burning down someone elses suggestion by stating mathematics that no one cares about and datasheet
figures is muddying the waters, it stops people even bothering to try anything to see if it works for them.

all I'm trying to do is stop someone blowing up their pedal again by using a method that I use to stop things that I make blowing up without them having to spend loads on a V regulator and hack it in.

You're funny. You should really quit trying to be an EE and do standup.