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How ToSoldering a Dunlop volume pot?

Posted: 7 Mar 2007 10:55 am
by Ernie Pollock
someone on the forum mentioned a while back that you could use those 470K hot potz, part #EGB-24A, well I got one, but the little pins on the back of the vol pot will not hold solder? I have tried filing them & cleaning them up so the would, but they will not hold regular solder that I have use for years. What is the secret of solding the wires on the volume pedal to these pots. In the dunlop vol pedals they have a little clip on that pushs into the pins, I have not found anything like that that we could use to make them work in other volume pedals. NEED YOUR HELP IF YOU KNOW HOW, LET ME KNOW
shoot me an email

Ernie Pollock
301-264-4172

Posted: 7 Mar 2007 11:00 am
by Greg Cutshaw
Ernie,

See here (last pic in 3rd row) to see a Dunlop pot that I soldered to. I used ordinary electrical flux solder and it seemed to solder easily with no external flux applied. Is yours like this one?

Greg

Posted: 7 Mar 2007 12:01 pm
by Morton Kellas
Greg, thank you for all the information you post on the forum. We appreciate it.

GREG

Posted: 7 Mar 2007 2:00 pm
by Don LaCourse
greg would you or any one have a wire diagram for a neck selector switch, i put one on my bud and no matter how i wire it , it has both necks on , forward- middle or reverse. what is best toggle swicth for a sho-bud. thanks for any help. don.

Dunlop Pot

Posted: 7 Mar 2007 2:13 pm
by Dick Sexton
Ernie,
I just received and installed a Dunlop pot, same one as you. I have an old Ernie Ball pedal that also has the push on "Quick Disconnect Clips" that push on the tabs on the Allen Bradley type pots. This is what I did and it worked like a champ. First, I removed the old pot from the pedal then using a pair of needle nose pliers, I folded the clips/contacts on the old pot back and forth until they broke off right at the old pot. Then, using a pair of side cutters, or as sometimes called, dikes. I made a cut into each of the clips length wise at the old pot end, then with a Dremal tool made each of these cuts just large enough to slip over each of the tabs/posts on the New Dunlop Pot. I positioned the tabs so that I could get the "Quick Disconnect Clips" on each without interference, then using the pliers, I crimped the tabs into place on each of the little posts. This done I used a good electronics solder, 60/40 and soldered the tabs onto the posts using a 150 Watt Weller soldering gun. It gets hot enough to easly flow the solder. I thought about and should have taken a picture of the pot before I put it back into my pedal, but I did not. I "will" do this for you though, if you want to. Send me the Dunlop Pot along with the old pot, I'll do this mod and get the pot back to you as quick as the mail. No Charge. Just e-mail me for my address. Ernie, be advised though, you can get these pots TO HOT and can cause heat related internal damage. I don't like the idea of soldering/resoldering the wire directly to the pot, the wire can wick the heat away from the connection requiring more heat to make the connection then would be required by my method. And not much room to heat sink. Of course, this is just my openion. Also, I think these Dunlops are the current super pots of the industry. Mine has worked flawlessly. Dick S.

Need more info...

Posted: 7 Mar 2007 2:35 pm
by Donny Hinson
Ernie, what kind of soldering iron are you using? Have you tried some different solder? (Too small an iron, or solder with no flux, a common problem sometimes with some "new" solder, will definitely cause problems. If your solder doesn't smoke when you melt it, there's no flux.) Filing terminals is not a good practice! Solder terminals are almost always either gold-plated or tinned. Filing will remove these coatings, and actually make soldering more difficult.

Posted: 7 Mar 2007 5:32 pm
by Jim Sliff
NEVER use a soldering gun around guitars or amps. They toss out too much heat and can cause all sorts of magnetic problems. Absolutely verboten by 99% of the techs on the planet.

But you do need a 60watt or so iron, And sanding is not right - first, use a little acetone to remove oils, or you're sanding the oils into the metal, making it worse. Solvent clean, then hit it with a drop of vinegar (an acid), then flux it, then heat it (not the wire or solder), flow the solder onto the pot and add the wire.

It's not easy, and expect to burn a few pots up learning how as you do your first 10 or so.

Posted: 7 Mar 2007 6:37 pm
by Lee Jeffriess
I have done a couple of these pots with a Radio Shack 100 watt gun, which is probably not a good idea, absoulutly no problems.
These conductive plastic pots are the future, I have just hit two years with one, thats even better than quality American made Mil spec carbon track pots. (remember those?)
Lee

thanks:

Posted: 8 Mar 2007 4:59 am
by Ernie Pollock
Maybe my soldering pencils is just not hot enough, I will have try that solder one of you guys mentioned below. I will make another attempt at this, I have never had a problem soldering before, but will admit, I am more of a picker than a solderer!!

Thanks to all

Ernie

Posted: 8 Mar 2007 6:08 am
by Dave Little
I have a couple of these new Dunlop pots but haven't had the time to get into installing them yet. Looking at the little posts, they have a head on them - like a small brad. I would think that there is a clip on connector somewhere thats made just for these posts. No?
Dave Little

Posted: 8 Mar 2007 8:08 am
by Mike Wheeler
The posts on that pot are solder posts. The indentations are for wrapping a wire around them before soldering...to get a good mechanical connection.

Ernie - You just need 60/40, Tin/Lead, solder...nothing special there. But you will need a soldering iron that has some staying power. In other words, once you touch the iron to the wire, terminal, and solder, the solder has to melt and flow freely. Some small pencil type irons can't maintain the necessary temperature long enough. They "cool off" too quickly, causing a bad joint. That sounds like what's happening to you.

I'd suggest a full sized 50 or 60 watt iron, with a conical tip (like a sharp pencil).

Posted: 8 Mar 2007 6:21 pm
by James Cann
It's not easy, and expect to burn a few pots up learning how as you do your first 10 or so.
Well, at $20-$30 per, we're gettin' right up there, aren't we! Well, why not, since we don't seem to balk at any of the other relative expenses of our beloved hobby!

Posted: 9 Mar 2007 10:59 am
by Olli Haavisto
Go to an electronics store and take the pot with you. I`m sure (?) you`ll find connectors that fit over the pins on the pot. Like the connectors for the cartridge on a turntable , only bigger. Solder those to the leads and you`ll never have to solder again when changing the pot !

Posted: 9 Mar 2007 7:35 pm
by Michael Dene
Olli,
yep, except there's precious little room to spare inside an Emmons pedal to accomodate a plug of any sort ... just enough to solder the wires!
Don't get me wrong, the Dunlop Pot I got fom Tom B. is still going strong ... just very little room to play with.
Michael :)

Posted: 10 Mar 2007 3:22 am
by John Daugherty
Ernie, Looks like you got more advice than you bargained for. Let me assure you that the magnetic field of your soldering gun will not damage the volume pedal. Just don't allow the gun to get hot enough to damage something. If we had to keep magnetic fields away from amplifiers, we would have to get rid of the speaker, coils and transformers. The secret to soldering is: heat the surface of the metal first. When the metal is hot enough, it will melt the solder and the solder will flow. As already mentioned, you should use 60/40 rosin core solder. You probably know that solder will not stick to brass or aluminum. I have never seen a pot terminal made from these materials.

Posted: 10 Mar 2007 9:18 am
by Jim Sliff
John's point needs to be reinforced - you have to heat the SURFACE, not the wire or just melt solder and let it drip. And on pots, that takes a big iron. I actually have an old 80-watt that I use only for pots - it's far too hot for other soldering and will cook sensitive parts - which is another good point: if you can, clamp needlenose pliers onto wire between the part your soldering and the solder point, especially with things like transistors and diodes - it acts as a heat sink and keeps you from destroying the part.
Solder those to the leads and you`ll never have to solder again when changing the pot !
Personally, I disagree with using removable connectors. I don't even like the ones on speakers, and remove them on everything except vintage amps where originality is important.

Those connectors only make contact on a limited basis, and are highly susceptible to corrosion (especially when the connector and lug are different metals). They are also not a solid connection, and can be knocked loose in transit. For a statinary irtem like a stereo amp they might be OK (except for the corrosion problem), but for something like a guitar amp - bad idea.

Posted: 15 Mar 2007 4:59 am
by Donny Hinson
You probably know that solder will not stick to brass or aluminum. I have never seen a pot terminal made from these materials.
Actually, brass is the most widely-used and preferred material for the terminals on switches, pots, and other lug-type components. Of course, it's usually pre-tinned by hot dipping. But still, soldering to brass with just about any soft solder is quite easy because it's mostly copper in composition. (Most all water valves used in copper piping systems are made of brass.)

Aluminum, because it oxidizes so quickly, is quite difficult to solder unless special techniques and solder are used, or unless it's been electroplated first.