CHASM REVERB

[deadastronaut]

Nice, what about a drill template for the delay and trem?  

Ahhh, forgot, there is no pro pcb for the delay. Perhaps some day???

trem template is done..

[3dsmatt]

I have a problem. I wonder if anyone can help.

I've built two pedals and the circuits have worked fine outside the enclosure but as soon as the jacks touch the enclosure the signal cuts out.

As I said , I've had the exact same problem with two DIY builds.

As you can imagine, I have no idea when it comes to electronics but I imagine there is a grounding issue, ye ?

BTW. I live in Spain, I don't know whether that makes a difference.

Matt.

[samhay]

Any chance you are using a metal DC jack? As pedals live in an alternative 'negative tip' world, these won't work and you end up grounding your V+.

[deadastronaut]

+1...

Just answered your email.

[deadastronaut]

just for the record:
matts problem was a tip pos supply...

[aishabag23]

How would I wire the OSC to a footswitch instead of a toggle? Do you think it would be more fun to have it be a momentary switch or latching? I can't decide 

I'm also slightly confused about how to wire the main on/off footswitch as well... I was thinking about using a little Millenium Bypass daughter board for the LED. Does anyone have a fairly straight-forward way to explain? I'm fairly new to all of this, so please excuse my noob questions. Thanks so much (in advance)!

Btw, I'm using v. 2.4 PCB (04/15/14)

[deadastronaut]

@aiesha..,, give me a bit and ill knock up a drawing ok....

[deadastronaut]

here ya go..



you could use a momentary or latching for the osc..,

connect 2 lugs on a dpdt  (red)

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[aishabag23]

Thank you, man! I really appreciate it. 

[aishabag23]

Btw, since there are pads for both foot switch and toggle... Would it be possible to connect both a toggle and the momentary switch? Or does one cancel the other out?

[deadastronaut]

i would think they would cancel out..

[SnoopKatt]

Rob,

This project was a lot of fun and I'm glad you're happy with the boards.  Thanks for letting me in on the fun!

Well, I'm not the best photographer, but this is a little tease of how the boards look populated.

This is my first etched enclosure and I still need to work out the kinks, but I wasn't going to trash the enclosure because of a few pits.  Gives it character, right?

Anyway, this is how she looks.

Cheers,
George

Quick question: I populated the PCB and I'm about to solder in the pots. However, I noticed that they have metal on them, and it would be a bad idea to do that without anything in between the back of the pot and the board! What do you guys use to isolate the two?

[vigilante397]

Quick question: I populated the PCB and I'm about to solder in the pots. However, I noticed that they have metal on them, and it would be a bad idea to do that without anything in between the back of the pot and the board! What do you guys use to isolate the two?

EDIT: Re-read the question. It shouldn't be an issue if the back of the pots touch the board as the board has a solder mask, so as long as they aren't actually touching any leads it shouldn't be a problem. Another option is to get pots that have "pot condoms" on them that prevent any contact.

[deadastronaut]

the toggle switch generally acts as a spacer too...

and like nathan said, pots with those plastic condoms are cool..

if your really worried about it touching though, and you haven't got condom pots

slip a strip of non conductive stuff behind there...ive used cut up vinyl cd covers, old tupperware tub cut up..

or a bit of packing foam.  but really the toggle should leave an adequate gap..

[SnoopKatt]

Cool, I just gotta drill the holes and fit them. Thanks! My other pots have those condoms, but the 22k didn't :/

[deadastronaut]

Cool, your fine then...

[zedsnotdead]

Hello people!

I built a Chasm using Robs PCB, and I think it's working... I mean, is acting strange, but I get a nice reverb out of it....
What happens is this: when the MIX pot is about 75% to 100% CW, the dry signal is attenuated and the processed signal takes over more and more... that's normal. But it's lags behind the input signal for about 100ms, I reckon.

Here is a demo of what is happening:

I checked all the soldering, all the values of each position. They are ok.
Then I probed the signal and I found that the signal is OK until it hits on Beltons. It's output (pins 5 and 6) is a lagged signal, regarding the input.

Then I measured the voltages, and these are the results:

Voltages measured with
- circuit powered ON on footswitch
- OSC Off
- All pots @ max

V+: 9.17v
Va: 4.94v
Vb: 3.33v
Vc: 6.65v

Note: "~" means oscillating reading

Q1
D: 3.33v
G: 0.12v
S: 3.32v

Q2
D: 3.34v
G: -0.33v ~
S: 3.20v ~

Q3
D: 6.65v
G: 3.31v
S: 2.00v ~

IC1
1: 3.34v
2: 3.34v
3: 3.03v
4: 0v
5: 3.34v
6: 3.47v ~
7: 3.47v ~
8: 6.65v

IC2
1: 3.34v
2: 3.34v
3: 3.34v
4: 0v
5: 3.34v
6: 3.34v
7: 3.34v ~
8: 6.65v

Belton BTDR2H-L
1: 4.93v
2: 0v
3: 3.34v
4: 0v
5: 3.35v ~
6: 3.34v ~

I think something's wrong, but the only thing I can think of is that it's caused by a faulty brick.
But really, im not sure. Could you guys help me out??

thank you!!!

[samhay]

^when the MIX pot is about 75% to 100% CW, the dry signal is attenuated and the processed signal takes over more and more... that's normal.
Correct

^But it's lags behind the input signal for about 100ms, I reckon.
Also normal. That's what the brick sounds like without the dry signal mixed back in.

If you don't like it, add a 4k7 - 10k resistor in series with lug 3 of the mix pot, or replace the mix pot with a log 10k pot so that this only happens at the very extreme.

Edit - lug 3, not 1 of the mix pot (Fixed).

[zedsnotdead]

Thank you samhay!!!

So everything is working as it should.

Just out of curiosity, whan I was probbing I noticed that after R9 (and on pin 6 of IC2) there was no sound/signal, but on IC2 pin 7 (output) I got signal again.
Although this must be correct, could you be so kind and explain why that is happening?

Tks

[zedsnotdead]

If you don't like it, add a 4k7 - 10k resistor in series with lug 1 of the mix pot, or replace the mix pot with a log 10k pot so that this only happens at the very extreme.

lug 1? not lug 3?