Boss CE-2 build - no delayed signal

[fickpack]

Hi all,

I've been working on a Boss CE-2 clone from this schematic - https://tagboardeffects.blogspot.com/2014/06/boss-ce-2.html

I've got the thing assembled, but I'm not getting any chorus, just clean signal. When I switch to vibe mode (the modulated signal only) I get nothing, or sometimes squelchy or squealy sounds.
It should be noted that I've replaced some resistors I didn't have with a close value that I had on hand, or wired some in series to make a larger value. The ones I replaced are:

56k -> 33k+22k in series

220k -> 100k+100k+22k in series

339k -> 390k

56k -> 47k

330k -> 290k

Things I have tried:

-Replacing transistors and ICs
-Re-biasing with trimpot
-checking for solder bridges
-re-soldering joints I thought looked crappy
-audio probing it up (but am having a bit of trouble with this complex circuit, I'm not getting anything from Q2 even after re-soldering the socket and swapping the transistor)

And here are my voltages for the ICs:

JRC4558

(1) 5.75

(2) 5.77

(3) 5.75

(4) 0

(5) 7.57

(6) 5.75

(7) 5.75

(8 ) 5.75

TL072 (in place of TL022)

(1) 6.99

(2) 5.75

(3) 6.95

(4) 5.75

(5) 7.57

(6) 6.95

(7) 7.57

(8 ) 5.77

MN3101

(1) 7.58

(2) 7.58

(3) 5.77

(4) 5.8

(5) 5.8

(6) 5.82

(7) 7.56

(8 ) 5.9

MN3007

(1) 7.57

(2) 6.41

(3) 6.41

(4) 6.41

(5) 7.54

(6) 7.54

(7) 6.09

(8 ) 6.09

Where can I go to pinpoint the problem?

Thanks a ton in advance!

Here are some pics, I should mention that I'm doing the original version on the schematic page

Obviously, I'm still a beginner, so this isn't pretty. I realize that a lot of the soldering is atrocious (when I replaced a few components some of the copper strip came off the board so I bridged those gaps with resistor trimmings) but I have done my best to make sure there's no bridges or anything. If it's screwed up beyond repair, please don't hesitate to let me know lol

[patrick398]

Hey Fickpack,

First of all welcome to the forum, you have come to the right place.
Somebody who actually knows what they're talking about will be along in a moment but in the mean time, a couple of points.

It's worth baring in mind that the layouts you're working from are not schematics, they're verboard layouts. A schematic (here: https://www.electrosmash.com/images/tech/ce-2/boss-ce-2-schematic-parts.png) is a lot easier to follow, see what's going where, and understand a circuit even if you've never seen it before.
Vero layouts can be a bit trickier to decipher.

If i'm honest the bottom of that board does look a bit...charred. There's a fair few sections with quite hefty blobs of solder that are very dull and suspicious looking. That's almost certainly a cold solder and won't conduct or will conduct very badly.
There are numerous other joints which look a bit suspect but you've got voltages on all your chips so maybe it's not so bad.

Personally my first port of call would be to find out why you're getting 5.7ish volts on the power pins of those ICs where you should be seeing around 9v.
Can you measure the voltage at the battery/DC jack?

Being perfectly honest, if it were me, i'd start again. Carefully removing the components of value (ICs, trannies, regulators etc) but scrapping the rest.

Might be worth doing a few smaller circuits first too, just to get your soldering a little better. With a circuit as complex as this there are just so many variables and things to go wrong.

You may well be able to get this one firing though, i can be a tad impatient and like re-building when things go wrong but no doubt someone here can help you nurse this back to health.

Patrick

[bluebunny]

Welcome!

Further to what Patrick said, you don't have 0V anywhere other than your 4558.  I'd take out your chips and re-measure your voltages at the power pins (4 and 8 for the opamps) and also check continuity from your battery connections to everywhere that should be either 9V or 0V.  Let's get the power right first, then go looking for shorts and other stuff.

[duck_arse]

also welcome, and what they said. and this:

[antonis]

Welcome fickpack..!!

Nothing to add on above well said except that drawing a circled red arrow around IC's (as proposed by Stephen..) won't help a lot..!! 

[fickpack]

Thanks for the help/welcome all.

2 new developments:

1. I tried a different power supply and the pins that should be reading around 9v do read around 9v, so there's that

2. Per bluebunny's suggestions I measured the ground pins without the ic's socketed and for the 3007 and 3101 at least there is 0v in the socket pins where it should be. Why would they measure 0v when no ic is connected but not when they're socketed?

[thermionix]

Where did you get the MN3007 and MN3101?

[ElectricDruid]

I can see some places on the solder side of the board where it looks like there are little bits of solder in between the tracks. I'd run a narrow screwdriver blade up and down between the tracks to make sure there's nothing stuck in there shorting things out.

[ponce]

Where did you get the MN3007 and MN3101?

Last year I built the same pedal with a great help from few of the members here and it works perfectly. I got my chips from one electronic parts supplier here in Croatia. I guess It's their old stock. As I see, they still have some in their webshop. That said, after dozens of ones I got from China proved to be fake.

http://elmatis.hr/SearchResults.aspx?searchText=Mn3101

http://elmatis.hr/SearchResults.aspx?searchText=Mn3007

http://elmatis.hr/CompanyProfile.aspx

[Slowpoke101]

I do have to point out that this is a rather complex build and can be difficult to get to work correctly at the best of times. You really do need to improve your soldering but that will come with time, so let's see what can be done.

You have 0V on pin 4 of IC1 and with better power you now have a higher voltage on pin 8. Good. But 0V is still missing from the other ICs. Have a look at the following picture and carefully inspect (re-soldering would be good) the indicated connection points. One point is under IC4.



Somehow the 0V connection that goes under IC4 is not connected to the 0V lead of the battery. A faulty solder connection is the most likely suspect but carefully inspect the track under IC4 in case it has a hairline fracture or cut between the 0V link connection point and pin 3 of IC4.

Let us know how you go.

[ponce]

Above the mastermind of my success with the CS-2 build, himself. Greetings and all the best!

[fickpack]

Hey, thanks so much all, I've made progress!

I got the ICs from Small Bear, so I'm fairly certain my soldering is the problem lol

Slowpoke101, I re-did those joints and now all of the ICs are properly connected to ground according to my meter. Additionally, I'm now getting oscillations for sure--they're quiet, but if I turn up my amp and mess with the rate/depth knobs you can hear the throbbing changing with the knobs, so I'm headed in the right direction. Right now it just seems like noise is being oscillated (can't make out the signal in there) so I'll go back and see where the signal gets lost with my audio probe.

Again, thanks all, it's getting closer!

[thermionix]

I got the ICs from Small Bear

Good to go then.

I'll go back and see where the signal gets lost with my audio probe.

You are on the right track.  Good luck!