McMeat switch wiring on the pisotones site

Started by daverdave, February 18, 2008, 07:08:54 PM

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daverdave

I'm trying to make a Mcmeat, I'm using the switch diagrams on the pisotones site, does any one know if they are showing the wiring from the front or the back? As in, is it wired to A, B and C or A, D and C.
I know this sounds like a stiupid question but i'm going of the idea that you wire pots off diagrams going from 3-1.

axg20202

I'm about half way through my McMeat build, but have not got to the point of using these diagrams yet. However, from what I have read scanning the many old posts on the Mcmeat, the rotary switches in the diagrams are being shown with the solder lugs facing you (i.e. back view), but for some stupid reason, the pots have been drawn with the shafts facing you (i.e. front view). If you check the schematic you will confirm this.

daverdave

Thanks for the reply, think I've got some resoldering to do. I looked at the schematic and the rotary switches say 2A, 2B etc, but if the view is from the back then they'd be wired to D instead of B, and the intensity knob was labelled correctly on the pisotones site, apart from the wire from the switch, which was drawn to 3 instead of 1.

axg20202

Yep, others have mentioned that there are errors in these diagrams but I can't find posts that name all the errors/corrections. The owner should take the pics down TBH. If you check every connection against the schematic you'll be fine. Where they differ, go with the schematic. Seems these diagrams have given lots of people confusion. I might actually ignore them altogether when I do my interconnects and work them out as I go from the schematic only. Check twice, solder once. (a variation on my Father's very useful woodworking tip of "Measure twice, cut once"...

Good luck.

Andy.

daverdave

Cheers mate, I'll take a look at the schematic. Do you know if the jack wiring is correct?

axg20202

Don't know mate. I guess I'll find out. Can't be hard to figure out though if not - it's the usual affair for the in and out jacks and then a normalised switching jack arrangement for the fx loop.

daverdave

Well I'll see what happens, I'll post a report when I'm done, wouldn't mind hearing how yours turns out, thanks for the replies.
Dave

daverdave

just thought I'd let you know that the switches are wired with the shaft facing you not the lugs, so they're reversed on the layout, so are the pots, but a couple of the wires going to the pots in the switch diagrams are going to the wrong pot lugs.

lowstar

one of the expression jacks is not drawn right, but i forgot which one it was and how i did it. most people that built it don´t know because there´s hardly anybody using the decay-pedal-jack (i think it is that one).
btw there is absolutely no reason to take these pictures down, they provided lots of help for many people that built it and will do so in the future. the one or two errors are easily spotted while wiring it if you crosscheck against the schematic.

cheers,
lowstar
effects built counter: stopped counting at 100

daverdave

Thanks, I'll look out for the jack, most of the wiring is fine, but it's a bit confusing, I'm used to reading the pots from the back. Just takes a bit of investigation sometimes, the diagrams have helped alot though.

axg20202

Quote from: daverdave on February 20, 2008, 05:48:41 AM
just thought I'd let you know that the switches are wired with the shaft facing you not the lugs, so they're reversed on the layout, so are the pots, but a couple of the wires going to the pots in the switch diagrams are going to the wrong pot lugs.

Thanks for clarifying this. It's puzzling why someone would decide to draw it this way for the switches. I can see why one might to do this for the pots (I can imagine them sitting on the workbench, shafts up, when he drew the connections), but not the switches, which would have the connections obscured when sitting shaft up. Odd.

I'll be completing my Mcmeat this week so fingers (not wires) crossed.

daverdave

Right, finished it and it doesn't work. it passes signal with the blend knob turned all the way down, but get quieter when its turned up and there's no wah whatsoever.

Does any one know a few trouble shooting pointers related to this particular circuit, or is it just a case of working my way through?
It ain't pretty in there, I'm pretty sure I wired everything correctly.

AndyA

Did you wire up the indicator light? If it lights up then the VTLs are getting power. You can also audio probe the output of the VTL, should give you a nice wah sound if everything is going ok. My build messed up at first becuase one of the jumper wires from a pot was touching the input of one an opamp. Also, if you have the controls set a certain way no envelope will be created. The way to avoid this is to never turn the attack up higher than the decay.

lowstar

QuoteAlso, if you have the controls set a certain way no envelope will be created.
what the man said. when i built mine, i also thought at the start that i had made a mistake, but it was just the controls set in a wrong way. i don´t have mine with me right now so i can´t give you a foolproof setting, but if you google for the manual, it has some factory settings in there. a common mistake with this build is also that, if no fx send/return jacks are used, you have to put a jumper wire between two pads, and sometimes people forget to do that.

cheers,
lowstar
effects built counter: stopped counting at 100

daverdave

I'm getting an output from the vtls when the mode switch is set to the middle position, not on others, there is an output at the end as well without the wah sound though.. The green led only lights up when the trigger switch is set to down.

I must have made a blunder somwhere, Is it worth changing the ic's and seeing if that helps?

daverdave

Right, I'm getting sound through it, it's filtering but it's really reallt quiet. I used an audio probe at the vactrol outputs, I'm getting a wah but it gets quieter when I turn the blend pot up, also the bandwidth switch lets the full signal through when set to bandpass, the middle position, but there's no filtering, does anyone have any suggestions I could try. i've been tring to work throught the circuit, but I don't have that much experience.

I'm pretty sure my wiring is correct, I might have bitten off more than I can chew with this one.

BRingoC

This pedal is a "treat" of sorts, I think they called it the meatball because of all the wires running through it the board looks like a meatball sitting on top of a pile of spaghetti.  Anyways, if I were you, I would try to make a drawing of the switches and pots as you have them wired, then try to compare them to how they are on the other wiring diagrams you have.  The diagrams that are floating around are correct, they just are not that clear, I had trouble understanding the correct wiring when I made mine, for instance I had trouble understanding how the filter switch was supposed to be wired when I was reading the schematic, but later sorted it all out.   Stick with it and it will come together.  Also, try one pot or switch at a time, try to get that correct rather than trying all of them at once, maybe you have your pin orientation backwards on some and not others, etc.
Since when is 3/4 of the way up "cranked"?

daverdave

Thanks for the reply, I'll have a check tonight. I think it might be the wiring that's gone wrong. I checked the wiring for the range switch and I think it's correct, it's the mode switch that seems to be wrong, I'm getting a full signal with it set to the middle signal but there's no wah, but on the other 2 settings I get the wah, it's just really quiet.

axg20202

Quote from: BRingoC on February 24, 2008, 06:46:01 PM
The diagrams that are floating around are correct, they just are not that clear.

I could be wrong but I'm not convinced this is the case, assuming you are referring to the pisotones diagrams. I am at the point where my McMeat is ready to be boxed up. I did the wiring from the schematic and while doing so checked them against the Pisotones diagrams. There were several differences between the two and in these instances I went with the schematic. From what I can tell, the controls in my build work as they should. I'm pretty sure that if you ditch the diagrams and confirm all connections against the schematic instead, using the build PDF to confirm the location of all board connections, you will be golden.

daverdave

I did use the schematic for the switches, not sure I checked the mode switch though, so I could have miss wired it, are you using the same switches as the pisotones build? I used a 4p3t switch the mode switch, not too sure how to wire it but I'm assuming 1,2&3 are for A, 4,5&6 are for B etc..
I'll have a gander tonight, thanks for the replues guys.