So I have a Zeropoint SDX that I had the runaway oscillation problem. Turns out I ordered a wrong momentary from Tayda, a normally open rather than a normally closed, so I ordered a normally closed switch from small bear... that's odd same problem...hmmm it just so happened that I pressed the replacement switch and played with the feedback knob and the issue went away and the feedback knob was very useable. So I checked the continuity on the two switches, both were the same... It just so happened I ordered another nc momentary from Lawrence over at BLMS, so I checked continuity on his nc momentary, none unless I pressed the button....So I guess what I am saying and asking you to do is check your nc momentary you got from small bear and make sure it is an nc instead of an no in case they shipped you the wrong momentary also.
Thanks for posting this! I recently bought a momentary at a local electronics shop and did not even think about whether it is closed or open! I will have to test it before I finish my SDX. Also, did you contact Steve about the mistake? I'm certain they will send you a replacement...
Nope I didn't contact him, to me it's not a huge deal,just been pullng my hair out over this build first one issue then another and FINALLY it's done! yaay!!! How would you go about contacting Steve?
Tayda does have the DPDT momentary stomps. They are kinda convenient because one side is normally on and the other is normally off, so you can choose which one you need. The SPDT is probably the same, but I haven't got any to test and they don't have docs up for that one.
Quote from: RobA on June 26, 2013, 03:05:42 AM
Tayda does have the DPDT momentary stomps. They are kinda convenient because one side is normally on and the other is normally off, so you can choose which one you need. The SPDT is probably the same, but I haven't got any to test and they don't have docs up for that one.
Well that's cool, the only one I was able to find at Tayda was the normally open one, at the time anyway.
Quote from: jimilee on June 26, 2013, 02:42:01 AM
Nope I didn't contact him, to me it's not a huge deal,just been pullng my hair out over this build first one issue then another and FINALLY it's done! yaay!!! How would you go about contacting Steve?
There is an email address on the website. I'm not sure if he is the one responding all the time but someone will take care of you. I would open a line of communication and maybe see if they will throw one in on your next order or give you some credit if you no longer need it. Every time I have asked a vendor to just throw it in my next order they end up sending it immediately, but if your not in need of the part now it's worth a shot. No need for them to pay unnecessary shipping costs!
Quote from: Stomptown on June 26, 2013, 03:35:10 AM
Quote from: jimilee on June 26, 2013, 02:42:01 AM
Nope I didn't contact him, to me it's not a huge deal,just been pullng my hair out over this build first one issue then another and FINALLY it's done! yaay!!! How would you go about contacting Steve?
There is an email address on the website. I'm not sure if he is the one responding all the time but someone will take care of you. I would open a line of communication and maybe see if they will throw one in on your next order or give you some credit if you no longer need it. Every time I have asked a vendor to just throw it in my next order they end up sending it immediately, but if your not in need of the part now it's worth a shot. No need for them to pay unnecessary shipping costs!
Right, I didn't want them to have to ship unnecessarily but I will order again, so that's a great idea.
In the meantime you'll have to find a project to put that normally open switch to good use! ;D
Smallbear sent me an old-style belton brick, and an email to them cleared it ALL up with no worries :)
To clarify, not so much a Bad switch from sb as it was a Mislabelled switch, then... (the switch itself was good, just the wrong one!)
Quote from: jimilee on June 26, 2013, 03:07:26 AM
...
Well that's cool, the only one I was able to find at Tayda was the normally open one, at the time anyway.
I have no idea when they got them in. I got them in my order from the latest coupon. They feel a bit wimpy and they click. I'm not sure which I like better feel wise yet, the DPDT or the SPST.
Jimi, you got the switch you ordered from Smallbear and the wrong switch from Tayda. You also just ordered the wrong switch from BLMS.
Normally open = shunted, only connects when you press the button.
Normally closed = always connected, shunts when you press the button.
In the ZPSDX, the switch connects two lugs of the feedback pot when you press the switch. The right switch is a normally open. Otherwise, those two lugs will always be connected and you'll be feeding back.
Edit: I have some normally open Carling copies. I'll give you one if you need it.
^yep
Quote from: midwayfair on June 26, 2013, 12:53:02 PM
Jimi, you got the switch you ordered from Smallbear and the wrong switch from Tayda. You also just ordered the wrong switch from BLMS.
Normally open = shunted, only connects when you press the button.
Normally closed = always connected, shunts when you press the button.
In the ZPSDX, the switch connects two lugs of the feedback pot when you press the switch. The right switch is a normally open. Otherwise, those two lugs will always be connected and you'll be feeding back.
Edit: I have some normally open Carling copies. I'll give you one if you need it.
According to the Bom it's a normally off momentary switch,and I bought 2 normally open momentary switches which caused it to oscillate out of control.
So, if I understand this right, off == open, right?
The Tayda SPST I have is a press to connect contacts type, which should be a normally open then.
This should be the right switch for the build, correct?
Maybe Tayda has multiple of these mixed up?
I used the Tayda SPST momentary (normally open) with my ZPDX and it worked without a hitch. That is the sort of "L" shaped one for $1.99.
I see there are some 2PDT and 1PDT momentary switches, but I don't have experience with them.
Chad
Normally off = normally open.
Remember a switch is OFF when the circuit is SHUNTED, i.e., not connected. The simplest place we find this is a light switch. When you turn the switch off, it breaks the connection and no current flows through the bulb.
Normally closed = normally on.
It's rare, but it's possible someone at Tayda mixed up the abbreviation "NO" for for "normally on." In fact, the "O" is probably the reason the words "closed" and "open" are used instead of "off" and "on".
According to the above, you bought a switch at Tayda called a "normally open" switch and discovered that the lugs were connected when the switch was NOT pressed. This indicates that it's a normally closed switch, and they made an error. You thought that you had ordered the wrong type of switch, so you ordered a normally CLOSED from Smallbear.
Quoteso I ordered a normally closed switch from small bear
Which worked the same as the Tayda switch.
Oh I get it, thank you, so then the one I bought from blms was mislabeled. But I like it better because I don't get the runaway oscillation and it works like the latest video of the zpsdx posted in the June section. So then that begs the question, do you think the BOM should be changed? Several builders were experiencing the runaway oscillation.
I use these: http://www.taydaelectronics.com/electromechanical/switches-key-pad/stomp-switch/2pdt-stomp-foot-pedal-switch-solder-lugs-2.html (http://www.taydaelectronics.com/electromechanical/switches-key-pad/stomp-switch/2pdt-stomp-foot-pedal-switch-solder-lugs-2.html)
They are a bit bulky but can be used as both normally open and normally closed, which is enough for me to have some in my parts bin. Plus, they look exactly the same on the outside as a 3PDT, which I like! I've seen some builds around here with two different footswitches side by side, something I would never do (no offence....)
Paul
Thanks Paul, I think I will grab a few in my next order. I have another zero point pcb to build plus these seem to be common in the things I like to build. Man this delay is awesome now that I got all the bugs worked out.
Quote from: jimilee on June 26, 2013, 05:10:11 PM
So then that begs the question, do you think the BOM should be changed?
What are you suggesting needs to be changed in the bill of materials? Certainly not the type of momentary (NO vs. NC)? The reason the switch does its thing in the first place is that as you turn up the feedback pot, the closer you get to 0 resistance between lugs 2 and 3 (and assuming the resistance to ground is >0), the less feedback is shunted to ground. Swapping the type of switch would in fact make it oscillate all the time above 0 on the feedback pot.
There is no situation in which a normally closed (normally "on") switch is the proper switch to use, and using it will not help if you are dissatisfied with the feedback pot without the switch connected. If you remove the switch entirely, the pedal should work exactly the same as when you are not pressing the switch. If that's not true, then you have something wrong.
The only truly useful change if you find feedback happening too
early is to use a log taper pot. It will spread out the range more. You can make it even more log-y by sticking a 12K or so from lug 1 to lug 2, and the resistance to ground will always be less (= less feedback).
However, if you're talking about taming what the
oscillation switch does, basically, controlling how quickly it permits oscillation, check my build reports for the Joshua Tree, Hamlet, and ZPSDX; I describe using a trimpot to dial in the oscillation exactly. Given that there's pretty much zero space (hah) left on the PCB, though, I wouldn't count on Brian adding that functionality to the stock design ...
It was just a question while I'm trying to figure it all out. With the switch reversed I am able to control the oscillation and now my build works exactly like the latest video that was posted. I don't pretend to suggest I know better than the BOM by any means, so please don't take it that way. I'm just trying to understand it all. Now mine doesn't oscillate out of control until I push the switch. One thing I like about this community is the freedom to exchange ideas. Thanks so much for your knowledge, I greatly appreciate you.
Quote from: jimilee on June 26, 2013, 05:48:33 PM
It was just a question while I'm trying to figure it all out. With the switch reversed I am able to control the oscillation and now my build works exactly like the latest video that was posted. I don't pretend to suggest I know better than the BOM by any means, so please don't take it that way. I'm just trying to understand it all. Now mine doesn't oscillate out of control until I push the switch. One thing I like about this community is the freedom to exchange ideas. Thanks so much for your knowledge, I greatly appreciate you.
I'm confused. I have a pretty solid feeling that the BLMS SPST and the Tayda SPST are the same switch (from looking at the two sites and having a Tayda version in hand). The Tayda switch is an off-(on), which should be the right one for the circuit.
Did you check the continuity of the BLMS before you put it in?
It would probably be good for the build doc to directly say what type of momentary is needed in the BOM. I know that it says it in the detailed instructions, but it would help to have it spelled out in the BOM.
Quote from: jimilee on June 26, 2013, 05:48:33 PM
It was just a question while I'm trying to figure it all out. With the switch reversed I am able to control the oscillation and now my build works exactly like the latest video that was posted. I don't pretend to suggest I know better than the BOM by any means, so please don't take it that way. I'm just trying to understand it all. Now mine doesn't oscillate out of control until I push the switch. One thing I like about this community is the freedom to exchange ideas. Thanks so much for your knowledge, I greatly appreciate you.
Jimi, I'm just trying to get you to think about how that part of the schematic/circuit works. I'm sorry if I sounded ... cantankerous.
No it's cool, I was being honest with you, and I do learn from you and I thank you for sharing your knowledge.