Quality of different 3PDT Switchs

Started by eddie_bowers, July 27, 2010, 01:33:53 PM

Previous topic - Next topic

eddie_bowers

I had been buying the more expensive ones (the ones marked CLIFF) at Pedal Parts Plus, but decided to go with the cheaper version since it looks exactly the same.

The first problem I noticed is that it appears to cause a more audible Pop when switched.
Then I noticed that even in bypass mode, the LED has a very faint glow as if the switch is still passing a tiny bit of current to it when disconnected (it IS wired correctly).
Anyone else had this problem?
I guess you get what you pay for.

-Eddie

tiges_ tendres

I use those cheaper switches.

No pops, no odd led dimming or glow in bypass.  That's not to say there might not be bad ones. 

From tour post, you seem to have based your findings on one switch.  Have you had this problem occur on multiple switches?
Try a little tenderness.

eddie_bowers

I confess, yes I based this on one switch.  Before I try putting another one from that batch in I just wanted to know if that was normal.
I hope not because I have about 10 of these.

Steve Mavronis

#3
I have my LED position like this and no faint lighting when it is in bypass mode: Cliff 3PDT Ground Pole -> Red LED -> 2.2K Resistor -> DC Jack Positive Lug

I have no pops either because I'm grounding the PCB input to the switch ground pole when in bypass mode.
Guitar > Neo-Classic 741 Overdrive > Boss NS2 Noise Suppressor > DOD BiFET Boost 410 > VHT Special 6 Ultra Combo Amp Input > Amp Send > MXR Carbon Copy Analog Delay > Boss RC3 Loop Station > Amp Return

Mark Hammer

The problem with switches is far more often soldering technique, and the application of too much heat, than the switch itself.

Take one of the problematic switches, gently pry up the tabs (just bend them 10-15 degrees), and separate the top and bottom halves, making sure all the pieces inside don't get lost.

Inside, you will see 2 (if DPDT), or 3 (if 3PDT) "banana-shaped" pieces that are the movable contacts which get shifted from one position to the other each time you step on the switch.  You will find they have some grease on them.  When people apply too much heat for too long, this grease liquifies inside the switch and flows over the contacts, creating all sorts of issues.  In some cases, the amount of grease applied may be just right, and in others there is too much.  If you clean the grease off these contacts, place them back inside, and close up the switch again (with no parts left over!), the switch will often function flawlessly.

It MAY be the case that cheaper switches have poorer quality control over how much grease get dabbed inside, or how precisely it gets dabbed, but the basic mechanism inside is the same for all stompswitches.

eddie_bowers


trjones1

I've noticed a difference between different types, but nothing that affects sound like more popping or something.  The Cliff ones seem to be just a little smoother in their action than the anonymous ones.  The click they make is also a bit quieter, but I'm talking about the acoustic click that it's making, not clicking in the signal path.  If everything is properly grounded and pulled down I've never had popping problems. 

I've also never found reliability to be a problem in any of the 3pdt switches.  I've probably installed 50 or 60 of them in different things I've made and only had maybe 1 or 2 ever fail.

skiraly017

This debate pops up every now and then but it's always good to read other people's thoughts and opinions. I've used just about everyone's 3PDT and my favorites were some very old Cliff ones that had a lighter blue body with a dull finish but as far as new production ones, the 3PDT's offered by a company called Run Run were very good. Unfortunately Run Run wants a minimum order of 1000 pieces.
"Why do things that happen to stupid people keep happening to me?" - Homer Simpson

Mark Hammer

Yes, let me differentiate between user-correctable sources of electronic failure, and feel.  ALL stompswitches may be subject to failure by grease-flow, but that doesn't mean that some don't feel more solid to you, or yield with the amount of pressure you prefer.  There ARE reasons to have preferences.

skiraly017

Quote from: Mark Hammer on July 27, 2010, 09:27:26 PM
Yes, let me differentiate between user-correctable sources of electronic failure, and feel.  ALL stompswitches may be subject to failure by grease-flow, but that doesn't mean that some don't feel more solid to you, or yield with the amount of pressure you prefer.  There ARE reasons to have preferences.

Jumping out of the 3PDT arena, the Carling DPDT are the bee's knees. They just "feel" right.  :icon_lol:
"Why do things that happen to stupid people keep happening to me?" - Homer Simpson

darron

i started a thread similarly not very long ago:

http://www.diystompboxes.com/smfforum/index.php?topic=85667.0

i wish carling made a 3pdt.....
Blood, Sweat & Flux. Pedals made with lasers and real wires!

zombiwoof

Quote from: skiraly017 on July 27, 2010, 09:43:23 PM
Quote from: Mark Hammer on July 27, 2010, 09:27:26 PM
Yes, let me differentiate between user-correctable sources of electronic failure, and feel.  ALL stompswitches may be subject to failure by grease-flow, but that doesn't mean that some don't feel more solid to you, or yield with the amount of pressure you prefer.  There ARE reasons to have preferences.

Jumping out of the 3PDT arena, the Carling DPDT are the bee's knees. They just "feel" right.  :icon_lol:

I just found out recently that the Carling 741 DPDT switch is still available, and it's cheaper than the other one everybody uses.  The 741 is the version with the lugs radiating in an X-pattern out of the bottom, like the old Arrow switches.  No one ever talks about this switch, so I didn't know it even was made any more.  I'm going to get a couple to try them out.  I thinjk I found them at Mouser, but maybe it was Digikey.

Al

eddie_bowers

Swapped the switch yesterday, and now all is good.  All Pops are gone as well as the LED issue.
I opened the "bad" switch up and there was a little grease on the underside of the white plastic part where the actual contacts are (is that normal).

Mark Hammer

Yes.  It is normal to have grease i there.  It is NOT normal to find a layer of it on the rocker contacts themselves.

What I do it take a Q-tip and clean out the little area where the rocker contacts sit, and wipe down the rocker contacts themselves.  Then I apply some Stabilant (www.stabilant.com) to the points where the inside portion of the solder lug and the rocker contact would meet, and place the rocker contacts back in.

caress

i've found all 3pdts to be more-or-less the same.  never tried the white ones, so i can't comment on them... but i've tried cliff as well as the other blue 3pdts from 5 or 6 different suppliers.  any differences were negligible in my opinion...

amptramp

One question with DPDT or 3PDT switches would be: how close to simultaneous is the switching?  If one section transfers before another, what effect does it have on the circuit?  What is the effect of early transfer going one way or the other?  If the difference is one millisecond, you can get a pulse with harmonics at 500 Hz and all integer multiples above that.  The effect can be due to the height of the contacts or the shape of the rockers.  It is important to determine the effect for all possible permutations and combinations because you could run into the situation where the prototype of an effect is built with a switch with one characteristic but your production run is built from a different lot and behaves differently.

Hides-His-Eyes

could anyone do that test with an oscilloscope and time it?