Popping Small Clone

[piltdownman]

I know this has been addressed before, but I have an old EHX Small Clone (in the big box) that pops crazy loud when you engage it.  I couldn't find a specific article on the site with it.  Would this be fixed with a resistor from the AC to ground?

Thanks

[IvIark]

You could probably do with adding pulldown resistors to the input and output.  Add a 1M resistor from input wire to ground, 100K resistor from output wire to ground.  

[piltdownman]

Thanks, as always.  I'll try that tonight.

[inefficiency]

Is this a good fix for any pedal that has a "pop" when you engage it?

[IvIark]

Not any pedal, but any that has an input and/or output cap with no fixed path to ground.  Most pedals don't need an output pulldown resistor because the volume pot does the same thing, but an input will usually benefit from it because the first component after the input wire is often a cap and with no path to ground and charge in the cap can remain there until turned on, which then causes the pop.  I do include a pulldown resistor in the vast majority of my layouts though, if you want to check just see if I have put a 1M resistor somewhere along the input wire row and the ground row.

But sometimes LEDs can cause popping too which requires another fix, and some stomps will pop no matter what you do for some reason, it may be one of the contacts making slightly before the other.

[inefficiency]

ah, I see.

Just asking because I plugged my em-drive in today and my buddy was using it for some fairly serious boostage. When he stomped it on there was a bit of a pop. Kinda wondering if it's the cheap switch although I've never had a problem with them before. I heard it can also be something to do with the LED.

Or more than likely the result of hitting the front end of an amp with a ridiculous jump in signal strength.

[inefficiency]

Oh and for these pulldown resistors (if the layout doesn't have em) could you just wire the 1M from the tip lug on the jack socket straight to the sleeve one? Do the same on the output with a 100k?

Probably not as neat as having it on-board, but I'd say it's probably the most secure alternative.

[IvIark]

No that wouldn't work because the switch would mechanically separate the pulldown resistor and the circuit's input cap and so exactly the same thing would happen when you stomped on.  On top of that it would also add (a) resistor(s) permanently between your effect signal path and ground which is always a no no.

The pulldown resistor works because it always gives current in the cap a path to ground, no matter whether when on or in bypass.  Without it the current is discharged when the effect is turned on which causes the pop.

If you have used the blog's offboard wiring for the stomp switch, then you can do it by soldering a 1M resistor between lug 5 (input wire to board) and 2, 3 or 6 (ground), and if one is required at the output, then also a 100K resistor between lug 7 (output wire from board) and 2, 3 or 6 (ground).

[inefficiency]

Ah, smart. That makes sense now.

So is the 1M resistor on your Em-Drive compact layout the pulldown resistor?

EDIT: oh shit, thats a 2M - guess not!

[IvIark]

2M would be fine for a pulldown resistor, I tend to use 1M if I'm adding it myself or the value used in the original if it has one, and I've done them up to 10M.  But the 2M in the EM Drive is a bias resistor for the transistor and so no it doesn't have one.  You don't think adding it to the stomp is the best way in that case though because the Gain pot is in between the stomp and input cap, so I think you'd be better adding it from the Gain 1 & 2 connection on the board and ground.  You may be able to add it to the layout as it is by using the hole above the collector and going down at an angle to one of the free holes on the bottom row (compact layout), or if you haven't built it yet, add an extra column to fit it in.  Or alternatively solder a 1M resistor directly to the Gain 1 & 2 linked lugs and the other side to the back of the pot which will ground it.

[inefficiency]

Yeah I had another look at the layout after posting and realised it doesn't have one. I need to look more carefully :p

Well, it's already built and it's in a 1590A. Despite the tiny side of the board, it's still pretty fiddly. I also used the little 9mm pots that looks like they're meant for pcb mounting and stuck them both to a piece of vero for ease of connecting stuff to them.

The DC jack is right beside the pots though and with everything being so tight in there anyway, I'll be able to find something to ground to.

Cheers again for the help Mark and sorry for hijacking the thread slightly!

[inefficiency]

Is this what you meant with adding the extra row, Mark?



I had to use Photoshop because I can't figure out the DIY layout creator. Every time I put certain components on, they're the wrong size. A resistor will be standing instead of lying flat unless I use like 6 rows or something silly like that and whenever I put down a transistor, the inner leg of it sits between rows. All the sizes are just screwed.

[rocket88]

inefficiency - i think mark meant to add another column. but that makes sense to me since the input into the circuit comes from the gain. i don't think you need to have a 2M for the pulldown, 1M should be enough. looks good to me man.

[inefficiency]

That IS another column. Columns run vertically whilst rows are horizontal.

Yeah, 1M will be enough, but I used Photoshop and just copied and pasted the one that's already there and didn't bother changing it to a 1M. From my understanding I don't think it really matters what it is. I guess just use whatever you have.

EDIT: To add on to this. If anyone could make a post with some basics of using the DIY Layout software, that would be great because I'm not having much joy with it.

[rocket88]

look at my posts, mark and induction helped walk me through a layout and gave me some great help. i'll try to find it and post a link to it. what they sad was super helpful and i made some analogies that made some basic concepts stick in my head.

btw, yes columns are up and down and include parts of different copper strips, while rows are side to side and contain a single strip of copper.

[IvIark]

Yes that looks good to me.  I can't help much with the latest version of DIYLC, I use V2 exclusively because it's just what I'm used to now and I didn't like V3 as much.

[inefficiency]

Cool. I'll have a look!

Cheers fellas.

[Dogbrainz]

I recently discussed the same problem with BYOC chat regarding a popping footswich noise on my Chorus pedal build.

I was told it's probably the input resistor needs re-soldering or replacing.
I asked if it may be the input capacitor, as I had heard this can also cause popping.
They said if fixing or replacing the input resistor doesn't work, try doing the same for the input capacitor

[induction]

inefficiency wrote

II can't figure out the DIY layout creator. Every time I put certain components on, they're the wrong size. A resistor will be standing instead of lying flat unless I use like 6 rows or something silly like that and whenever I put down a transistor, the inner leg of it sits between rows. All the sizes are just screwed.

After any component is created, you can double-click it to open the component editor. This lets you choose sizes, colors, change names, values, etc. I like to make the components in my layouts match the size and color that I actually use in the build, in case I need to use the layout for reference later.

After you make a layout that has all the components the way you like them, you can save the file to the templates folder and use it as a starting point for new projects so you don't have to mess around so much in the future.

[inefficiency]

Yeah, I got there in the end!

The templates thing I didn't have figured out, but I'll get on that this evening.

Cheers!