Can someone explain this wiring???

[brokenstarguitar]

I just built thing "Thing" from the attached layout and schematic. The pcb is etched and the 2SK30A I subbed with a J201. I wired it like I thought it should be but the 4558 got so hot. I now have a huge burn on my pointer finger  . The whole "Ground" and "Earth" got me so confused. Anyway, if someone can explain or even draw me something up I would GREATLY appreciate it. Thanks guys!!!

[ubersam]

Looks like they're using the chassis ground symbol for ground and the half-darkened signal ground symbol for 1/2 Vcc or Vref, see the two 10K in series from +V (arrow pointing up) with a 100uF connected in the middle junction. At least that's how I interpret it.

[knutolai]

hope this helps

[antonis]

I think that a DC isolating capacitor should be placed in series with 47k resistor..

[duck_arse]

the j201 is "end gate", the k30a is "centre gate". did you do the leg twist?

[brokenstarguitar]

the j201 is "end gate", the k30a is "centre gate". did you do the leg twist?

Yea. I put a socket there so I can put the k30a in when they arrive. Now what are they referring to by "006P" near the power supply? I also have this picture that was in the build doc, unfortunately the doc is in Chinese so that wont help much. What I don't get is it seems the "Positive is going to the "Negative" on the DC jack.

[ubersam]

Now what are they referring to by "006P" near the power supply?

006P = PP3 = typical 9V battery

[brokenstarguitar]

Now what are they referring to by "006P" near the power supply?

006P = PP3 = typical 9V battery

OH, ok. What about the + going to the negative of the DC jack?

[ubersam]

Now what are they referring to by "006P" near the power supply?

006P = PP3 = typical 9V battery

OH, ok. What about the + going to the negative of the DC jack?

That's probably not going to the negative lug of the jack but rather to the "no plug inserted" lug. It's a way of disengaging the battery when an adapter is plugged in.  The internal contact of that lug  is normally in contact with the positive lug when there is no dc plugged into the jack. Once you insert a dc plug, the contact is broken and the battery is effectively disconnected from the circuit.

This should help: http://www.generalguitargadgets.com/pdf/ggg_sw_dcjack.pdf

[brokenstarguitar]

This should help: http://www.generalguitargadgets.com/pdf/ggg_sw_dcjack.pdf
[/quote]

That wiring diagram is totally different than the schematic and layout I posted. I've attached another picture so you can understand better. Its basically wired with a positive tip, and I have no idea here.

[hymenoptera]

You should wire the PSU the way you want. If they show "tip hot" but you want to wire it "tip negative" then do it your way instead.

[ubersam]

That wiring diagram is totally different than the schematic and layout I posted. I've attached another picture so you can understand better. Its basically wired with a positive tip, and I have no idea here.

I was going by recollection as I couldn't see the pictures at work. Our network was blocking photobucket. Anyway, now I see the schematic indicates that the dc jack is wired center pin positive. I haven't seen many pedals that use center pin positive dc jack wiring, mostly center pin negative. Shouldn't be a problem though as long as your ac adapter is also center positive. On that picture you posted, the image on the right shows the same wiring as the pdf I linked to, and is center pin negative. The image on the left though, tells a different story. It's wired as you said, center pin positive, and it is using the no contact switch of the dc jack to disconnect the battery's negative when a dc plug is inserted. Why they did it that way, no clue. Perhaps they're unfamiliar with what is common practice for us, center pin negative. Another thing that is bothering me is how they are using the chassis to pass ground from supply to the board, not the way I'd do it.

[brokenstarguitar]

That wiring diagram is totally different than the schematic and layout I posted. I've attached another picture so you can understand better. Its basically wired with a positive tip, and I have no idea here.

I was going by recollection as I couldn't see the pictures at work. Our network was blocking photobucket. Anyway, now I see the schematic indicates that the dc jack is wired center pin positive. I haven't seen many pedals that use center pin positive dc jack wiring, mostly center pin negative. Shouldn't be a problem though as long as your ac adapter is also center positive. On that picture you posted, the image on the right shows the same wiring as the pdf I linked to, and is center pin negative. The image on the left though, tells a different story. It's wired as you said, center pin positive, and it is using the no contact switch of the dc jack to disconnect the battery's negative when a dc plug is inserted. Why they did it that way, no clue. Perhaps they're unfamiliar with what is common practice for us, center pin negative. Another thing that is bothering me is how they are using the chassis to pass ground from supply to the board, not the way I'd do it.

I wouldn't wire it this way either, that's what got me confused. I guess my question now is, how do I wire it negative tip? I wired it as I normally would and got nothing... The difference I seen in the schematic and the board layout is the 33uf electro right below the 567 connecting the positive and ground. Should I remove it and wire it as normal or what? I just want to get this thing running. Btw, I appreciate your help.

[hymenoptera]

Another thing that is bothering me is how they are using the chassis to pass ground from supply to the board, not the way I'd do it.

I was going to say that diagram was missing a ground wire, but now I see that they're relying on chassis to carry ground between the in/out jacks. Yeah, there should deff be an extra wire running between the in and out jack sleeve lugs. Good looking out.

[ubersam]

I wouldn't wire it this way either, that's what got me confused. I guess my question now is, how do I wire it negative tip? I wired it as I normally would and got nothing... The difference I seen in the schematic and the board layout is the 33uf electro right below the 567 connecting the positive and ground. Should I remove it and wire it as normal or what? I just want to get this thing running. Btw, I appreciate your help.

The board is laid out correctly as far as I can tell, no need to flip the 33u cap if it's already + to + and - to -. The diagram/schem shows to wire the dc jack as center positive but the positive lead from the dc jack still goes to + on the board and the negative lead still connects to the board's ground. If you used a center positive adapter, everything would have been ok. But, If you plugged in a center negative supply while you had the dc jack wired center positive, then you would have reverse powered the circuit. You would have burned some things out. That would explain the hot 4558, in which case I would suspect that it is dead. And that would explain why you're still not getting any sounds even after you reversed the dc jack wiring. Swap the 4558 out and see if you get sound out. But before powering up, it might be a good idea to double check with a multimeter that the board ground is connected to the center pin of the DC jack and all 9V connections are connected to the + of the DC jack.

On a related note, here's how I'd wire it: https://www.dropbox.com/s/9afz3n8n2bidmct/IMG_0908.JPG?dl=0

[brokenstarguitar]

I wouldn't wire it this way either, that's what got me confused. I guess my question now is, how do I wire it negative tip? I wired it as I normally would and got nothing... The difference I seen in the schematic and the board layout is the 33uf electro right below the 567 connecting the positive and ground. Should I remove it and wire it as normal or what? I just want to get this thing running. Btw, I appreciate your help.

The board is laid out correctly as far as I can tell, no need to flip the 33u cap if it's already + to + and - to -. The diagram/schem shows to wire the dc jack as center positive but the positive lead from the dc jack still goes to + on the board and the negative lead still connects to the board's ground. If you used a center positive adapter, everything would have been ok. But, If you plugged in a center negative supply while you had the dc jack wired center positive, then you would have reverse powered the circuit. You would have burned some things out. That would explain the hot 4558, in which case I would suspect that it is dead. And that would explain why you're still not getting any sounds even after you reversed the dc jack wiring. Swap the 4558 out and see if you get sound out. But before powering up, it might be a good idea to double check with a multimeter that the board ground is connected to the center pin of the DC jack and all 9V connections are connected to the + of the DC jack.

On a related note, here's how I'd wire it: https://www.dropbox.com/s/9afz3n8n2bidmct/IMG_0908.JPG?dl=0

I did swap the 4558 when it burned me, lol. Anyway to move on. I wired it with your wiring diagram and remembered when I breadboarded a similar 567 layout awhile back that I had to send the 9v directly to pin 4, not through the resistor. So I removed the 100k resistor from the power rail to pin 4 and put a jumper in. Now it works, sort of. I hear the Ring mod, the volume works, the mix control works, and the toggle works.

My issue now is the volume is really low. I tried a 100k pot instead of the 10k but it didn't help. Any advice?

[ubersam]

Try swapping out the 10K resistor in the feedback loop of the 2nd opamp stage with a 22K. That should turn that stage to an amplifier with a voltage gain of 3.2, roughly 10db. That might be enough to bump up the volume. If not, try a 33K, keep going up until you reach the desired output volume without clipping.

[brokenstarguitar]

It seems to be working like it should with the exception of a high pitch whine. hmmmm..... Possibly the nature of the 567 though. I appreciate your help. Thanks!!!

[brokenstarguitar]

What about adding a LFO? How would I wire it? I have a Tremulus LFO board sitting here that's left from a previous build. The one wire from the LDR goes to the Smooth pot and the other to pin 7 of the 4558 on the Tremulus. Here's a layout for the LFO board. Thanks!!

[mth5044]

...what do you want to modulate with the LFO?