Tycobrahe Parapedal Vero

[daverdave]

How do, I've just done a layout for the tycobrahe parapedal. I'm pretty new to making layout so I was hoping someone could look it over for me, see if there are any obvious mistakes. I used the schematic off geofex for it, but changed the values of the 2 68nf caps to 47nf.

I know it's pretty messy but I think it should work, but I ain't positive.

[daverdave]

sorry not sure if that worked properly, here's the link, I think?!

http://img230.imageshack.us/img230/6803/tycobraheparapedalveroab9.gif

[daverdave]

Lord, already realised I didn't even add the output! Sorry it is pretty sloppy.

[guilds100]

I think the ground and 9v on the chips are reversed



didnt see the -9v   

[daverdave]

It's positive ground, have I wired the power correctly?!

[Gila_Crisis]

yes to original one is positive ground. to make it negative ground, you only need to turn around the diode and the 2 electroitic caps?

[daverdave]

So the power's wired right? I'll have a glance over the layout tonight and might build it if I have time, hopefully it'll work.

[daverdave]

Right, I looked over the layout and noticed a mistake after the 2nd half of the 2nd opamp. I've corrected it though. It looks like it will work to me, but I'm not sure about the power, can anyone tell me if I've hooked the power up correctly? (to the opamps)

[Gila_Crisis]

didi you already built it?

[daverdave]

Not sure yet, I'm gonna build it tonight, I'm just not sure if I've wired the power to the opamps correctly. I'm tring to find a suitable dual ganged pot as well, I emailed chicago iron and they recommended an ALPS 100k dual volume pot, they said it isn't very important what value of pot is used. Not sure if that's right or not, they said they use a 10k with a 220 ohm resistor across it.

[Hanglow]

Cheeky bastards tried to flog me one of their custom made ones for $25 when I asked them 

[Branimir]

In what kind of casing will you fit it? Usual cryb*by or?

[daverdave]

Yeah, I've got an empty vox enclosure, it's easily fit in it. I'll try it tomorrow, see if it works.

[Gila_Crisis]

and, does it works?

[daverdave]

Sorry for the late reply, been a bit busy.
No it doesn't work, not sure if it's my dodgy soldering or the layout, but I'll have a good look.

Anyon see anything wrong with the layout?

[daverdave]

One thing is I'm getting a very high resistance across the diode, about 1.6M

Not sure if that's supposed to happen or not. Any replies would be greatly appreciated, I'm very new at doing layouts.

[daverdave]

Right, I noticed what I'd done wrong, well one thing at least. I hadn't supplied -9v to pin-4 on the opamps. I've adapted the layout and changed my build, however it still doesn't work. I'm getting a slightly distorted signal through the circuit but no filter.

Here's the new layout.

[alteredsounds]

I replied to you 'elsewhere' but just to point out that you have one 10nf cap too many and the 47nf are 68nf, there is also a .001pf right on the output on the original, couple resistors are a little off too.  I've started doing a layout and will post it 2morrow work permitting.

[daverdave]

I've changed the value of the 47nf caps to 68nf on the layout. I'm gussing that the second 10nf cap in the feedback loop of the 4th opamp is one too many, is that right? The only thing is both schematics (the geofex and the other one) have 100nf caps on the output, and they have the cap in the feedback loop (the other scheme states it as 1nf I think).

he photos you post only have the 4 caps though, I'm not sure if the values are the reason it's not working though.

[clsnacky]

It should work with 47nf or 68nf caps.  Awesome pedal BTW.  Hope you get it working.