DIY Reverb: collected resources

[deadastronaut]

+1... cool.

[slacker]

That sounds great Merlin.

[merlinb]

Merlin, this is so good that it deserves it's own thread rather than be buried in this thread.

Thanks Rick! It will get one when it's in a box of its very own!

[sugonidamaso]

Hello,
Kindly check my work regarding the wiring and all. It seems that there is no power when I switch it on. I used the spdt footswitch on my wah. I already checked for some solder bridges et. al. I used the round dc jack(hope i get it right-offboard wiring ala tonepad) . Here are some of the pics:
http://i1225.photobucket.com/albums/ee389/sugonidamaso/Reverb/IMG_6628.jpg
http://i1225.photobucket.com/albums/ee389/sugonidamaso/Reverb/IMG_6626.jpg
http://i1225.photobucket.com/albums/ee389/sugonidamaso/Reverb/IMG_6623.jpg
Something wrong on my wiring? I also use the NE5532 instead of TL072-is it ok? And yes the 10ufNP is too big. Any difference regarding the polarized ones? Thanks in advance!

[merlinb]

I used the round dc jack(hope i get it right-offboard wiring ala tonepad) .

You don't need the green wire going to your DC jack, you can remove it. Brown wire should go to the biggest tab on the jack; blue wire should go to the tab furthest from the big tab (can't tell if you've done this from your photos). This is assuming you are using a centre-negative power pack.

 Have you measured any voltages anywhere? (It is always a good idea to check for power before installing any ICs)

What are the brown wires I can see dangling off your audio jacks? I don't think you need those...

I also use the NE5532 instead of TL072-is it ok?

That's OK

And yes the 10ufNP is too big. Any difference regarding the polarized ones? Thanks in advance!

The two 10uF non-polar caps can be any value down to about 1uF, so if you can find anything smaller in that range then go for it (plastic/cermaic/electrolytic all are fine). Polarised caps should not be used, however.

I already checked for some solder bridges et. al.

It is a little messy, so keep checking!

[sugonidamaso]

Thank you for your reply. I will check on my power supply. Sorry,I have a limited knowledge in electronics(beginner-I rely more on layout-majority of my builds are ) Where do I measure? What setting on my DMM? Brown ones are those from the sleeve of both jacks(sorry I have no baypass sound either-must check! ). What's your recommended value regarding the non-polarized ones? Must/Will check again. :icon_redface:Thank you!

[merlinb]

Sorry I have a limited knowledge when it comes to this one(beginner). Where do I measure?(I rely more on picture layout(majority of my build) )

You don't need to know the circuit inside-out to do this! Just check the data sheet for the chip you're looking at, and then measure between the +ve and -ve pins on the IC socket. For example, check that you get 9V (actually about 8.4V) when measuring between:
Dual Opamp: Pin 8 and 4

And check that you get 5V between:
PT2399: Pin 1 and 3

(General tip: Lots of ICs use diagonal-opposite pins for power, so that's a good place to start even if you know nothing about the chip in front you).

Thank you for this one! What would be your recommended value please?

Anything, it really doesn't matter. Any values from 1uF upwards will pass all audio frequencies. I only used 10uF because I had a bunch. Just go to RadioShack or whatever, and find a few small-size caps that are non-polar.

[sugonidamaso]

Hi. I manage to measure both PT2399 Pin 1&3 by 4.97v. I got 0.1mv to 0 on opamp. I also changed it to tl072 (from my newly built echobase) same reading.

[merlinb]

I got 0.1mv to 0 on opamp.

Well there's a clue. In your photo:
http://i1225.photobucket.com/albums/ee389/sugonidamaso/Reverb/IMG_6626.jpg
The trace running down the very edge of the right side of the board (which carries the 9V supply) looks like it may be broken- check for continuity?

[sugonidamaso]

Yes I did check for continuity post etch. Is the ground/outside border be connected to each other?
http://i81.photobucket.com/albums/j207/merlinblencowe/Equinox%20Reverb/reverbpcb.jpg
I mean on the left side.

Here's mine:
http://i1225.photobucket.com/albums/ee389/sugonidamaso/Reverb/IMG_6626-1.jpg

Thanks!

[Govmnt_Lacky]

After looking at your etch I think I may see a problem...

One the right side of your board (in the picture), follow the run right next to the second "m" of 77mm going down.

The point where the trace appears like it did not transfer completely...... is it touching that solder point? According to the transfer, it SHOULD NOT.

Good Luck  

EDIT: Also, it looks like that same trace is making contact above the "77mm" spot wright where it bends over the edge of the 16-pin DIP.

[sugonidamaso]

Yes I did see that. There's a bypass signal/tone now. After I remove the ground connected on my spdt footswitch. It also appears that the opamp measured 9.14v. I'll look for something else.

[merlinb]

Yes I did check for continuity post etch.

I highlighted the 8.4V feed on your PCB. I circled the problem area in yellow (this is the bot Lacky was talking about too). If you have the correct 5V supply to the PT2399, then there MUST be voltage on the first part of this trace. But if its not getting down to the opamp then there MUST be a break in the trace. Are you CERTAIN that measuring between pins 4 and 8 gives you no voltage? Are you sure there is continuity between pin 4 and the ground plane (circled in green)?

Is the ground/outside border be connected to each other?
http://i81.photobucket.com/albums/j207/merlinblencowe/Equinox%20Reverb/reverbpcb.jpg
I mean on the left side.

No you don't need a connection there. If you follow the ground plane round the other side of the board you will see that those two points are still connected together 'the long way round'.

EDIT: I was typing when you replied.

After I remove the ground connected on my spdt footswitch.

Huh? Which ground?
Did you use a BC337 as in the schem, or did you sub a different transistor? (Which may have had a different pin out).

Oh yeah, you are plugging into the INPUT jack right? Easy to get mixed up when you're turning the board over and over! 

[Govmnt_Lacky]

Also check the area directly below and a bit to the right of where Merlin marked the photo with the "V' in 8.4V. That bend looks like it is making contact with the adjacent solder point.

You may want to go over the ENITE board and ensure there are no bridges due to a semi-good etch 

[merlinb]

OK, you say you have a bypass signal, which is a start. Here's something to try:

It looks like your main pot is wired backwards (so counterclockwise is maximum reverb). You can fix that later. For now, turn it fully CCW and then get a bit of wire or a small screwdriver or something, and use it to touch pin 16 on a PT2399 (try both). Make sure your skin is touching the wire as you do this. If the signal path is OK you should hear a reverberating pop in the speaker. Report with findings!

Also, I am looking at that footswitch and wondering if its wired correctly. OTOH, no matter how you wire it, you should get either the bypass OR effected sound in one position.

[sugonidamaso]

IT'S WORKING! It is the SWITCH(the foot switch from my wah-crybaby spdt)! How will I wire it? When I try to switch it off the whole effect shuts down-no bypass signal. Yes, the pot is the other way around.

[merlinb]

How will I wire it? When I try to switch it off the whole effect shuts down-no bypass signal.

The blue wire needs to go to the moving armature inside the switch (the pole), so that it gets connected to one of the green wires, depending on the way the switch is set.

You'll have to figure out which tab on the switch is the pole. Suggest you desolder it and use a continuity tester to figure it out (with a bit of common sense! )

[sugonidamaso]

How will I wire it? When I try to switch it off the whole effect shuts down-no bypass signal.

The blue wire needs to go to the moving armature inside the switch (the pole), so that it gets connected to one of the green wires, depending on the way the switch is set.

You'll have to figure out which tab on the switch is the pole. Suggest you desolder it and use a continuity tester to figure it out (with a bit of common sense! )

I don't have that one either Thank you dear sirs for your patience and understanding! You're great teachers!

[merlinb]

I don't have that one either Thank you dear sirs for your patience and understanding! You're great teachers!

Is it going yet? You're the only other person who has built it, so I'm keen to see it succeed...

[sugonidamaso]

Ooops! Based from my last post-YES! Thank you so much! My etching suck! I just used the glossy page of a magazine , the one you pointed out (trace problem) was the one I trace it with a marking pen. I ran out of PNP. So costly in here. To sum it up-thank you sir for making this one. I really needed it. Here's the link:
http://www.diystompboxes.com/smfforum/index.php?topic=93062.msg798611#msg798611