Need help with Multiplex + Daughterboard build

[Knut Koupee]

Hello!

I finally got around to wiring up a Multiplex I've had populated for a while and ran into some problems.

I'm trying to build one very similar to this one here:
http://www.madbeanpedals.com/forum/index.php?topic=6567.0

Mine looks like this so far:
https://lh6.googleusercontent.com/-VaOqqeHkvsU/UXyqwC-spoI/AAAAAAAADC8/cOHho1C_lMM/w1347-h898/IMG_4482.JPG

What is happening:

-Bypassed, my guitar signal comes through clean

-When I plug power in the modulation LED lights up solid and stays that way. Changing from delay 1, off, or delay 2 does not have any effect.

-When engaged, the power LED comes on.

-At no point to I hear any guitar signal when engaged.

-Engaged I get a very loud constant BZZZZZZ noise, even with the amp volume turned all the way down. This noise can go away if I tilt the enclosure around to various positions. It seems like if I have the enclosure flat, no noise. Once I turn it on its side or flip it over - noise. The noise also seems to be slightly different on its side, and then loudest flipped.

-I held down the "detune" for about 20-30 seconds with no LED light coming on. I haven't calibrated this yet, and the trim is turned fully CCW.


Some errors I made:

-I have the in jack wired to the out on the 3pdt pcb, and the out to the in on the 3pdt pcb.

-I wired the modulation daughterboard ground and power directly to the dc jack. I probably should have wired them to the 3pdt pcb 



I'm guessing something somewhere is touching something it shouldn't be when titled, or perhaps there is a bad connection. I'm pretty confident in my multiplex component soldering, I'm guessing the issue is somewhere in the daughterboard or the other connections to the jacks and so on.

Any suggestions would be most welcome.

Thanks!

[gtr2]

Did you test anything before you put it in the enclosure?  I'm assuming not 

Rocking before boxing is a necessity with this build.  I've built about 10+ of the MP and I still test before boxing.  There are many ways to make errors on big builds.

Are you placing your in and out jacks according to how you made you're wiring error while testing?

If not, it will bypass properly when off, but emit no sound when on.

It sounds like you have a couple problems, so you need to systematically fix your issues starting with getting the multiplex working, then the tape momentary circuit, and then worry about the modulation after that.

What are your voltages on all the IC's of the Multiplex?

You'd also be wise to track your signal with a audio probe.  Starting at the input of the Multiplex and work through the circuit.

If you don't have one, it's easy to build one.

http://diy-fever.com/misc/audio-probe/

The detune won't work without calibrating, but get the MP working first

Leave the modulation in the off position for now.

It's next to impossible to follow your wiring but if you get us your voltages and follow through with an audio probe telling us what you found it will be easier for us to help.

Josh

[Knut Koupee]

Thanks for the response

The only way I have to test it would be to wire it up before putting it in the enclosure, and I wanted to try and use amounts of wire that wouldn't be too short so in the enclosure it went.  I don't own a breadboard right now if you mean to test it with one of those.

I plugged my in and out correctly if thats what you mean - I do have them backwards from the traditional side on the enclosure right now (doh).

How do I check the voltages of my ICs? I saw this post: http://www.madbeanpedals.com/forum/index.php?topic=902.0  and it looks like I use a multimeter and connect to ground and to each pin on the ic's?

I haven't used a audio probe before, I'll check out that link you posted.

It sounds like I'll have to pull it out of the enclosure regardless, once I do I'll take some pics to see if that makes it easier to check with the wiring. If you can explain how best to check the voltages I'd be happy to provide.

Thanks!

[gtr2]

This is a testing rig tutorial that Jacob did.  You do not need a breadboard and building one like this or similar is extremely helpful and not complicated.  It's pretty much a necessity IMO.

http://www.madbeanpedals.com/forum/index.php?topic=1140.0

To check the IC voltages just put your multimeter on VDC and place the black probe on a ground point and the red probe on the each of the IC pins.  You can check the data sheets for the pin numbering.  They follow the same numbering method but looking at datasheets is good practice.

http://www.ti.com/lit/ds/symlink/tl072.pdf
http://www.datasheetcatalog.org/datasheet/PrincetonTechnologyCorporation/mXyzsyzt.pdf

Just list your voltages by pin number. (and also put which IC, ex IC3)

Don't start pulling it out of the enclosure yet, there are many things you can test while it's still in the enclosure.  Definitely build an audio probe and check your voltages first.

Josh

[Knut Koupee]

Ok, thanks for the links

Everything is still boxed up. I haven't made a audio probe yet.

I have the IC voltage info. I used a DT832, ground at the DC Jack. V~ 200 setting.

IC1 (TL072CN)
Pin8: 20.2
Pin7: 18.2
Pin6: 18.6-18.7
Pin5: 19.8
Pin4: 19.8
Pin3: 19.8
Pin2: 18.6-18.7
Pin1: 18

IC2 (PT2399)
Pin16: 18.7
Pin15: 18.7
Pin14: 18.7
Pin13: 18.7
Pin12: 18.7
Pin11: 18.7
Pin10: 18.7
Pin9: 18.7
Pin8: 18.7
Pin7: 18.7
Pin6: 18.9
Pin5: 18.6
Pin4: 19.8
Pin3: 19.8
Pin2: 19.6
Pin1: 19.7

IC3 (PT2399)
Pin16: 18.7
Pin15: 18.7
Pin14: 18.7
Pin13: 18.7
Pin12: 18.7
Pin11: 18.7
Pin10: 18.7
Pin9: 18.7
Pin8: 18.7
Pin7: 18.7
Pin6: 19
Pin5: 18.5-18.6
Pin4: 19.7-19.8
Pin3: 19.7-19.8
Pin2: 19.6
Pin1: 19.6-19.7



And on the modulation daughterboard the TL072 had:
IC1 (TL072CN)
Pin8: 20.2
Pin7: 18.4
Pin6: 8.8
Pin5: 5.6
Pin4: 0.0
Pin3: 8.8
Pin2: 1.9
Pin1: 15.8

And the H11F1 had:
(Pin next to the O notch on the left): 16.5 (Pin1 if using the TL072 numbering)
Pin below that: 17.3 (Pin2 if using the TL072 numbering)
Pin below that: 0 (Pin3 if using the TL072 numbering)

Pin Opposite the O notch): 19 (Pin8 if using the TL072 numbering)
below that: 18.5 (Pin7 if using the TL072 numbering)
below that: 19.7-19.8 (Pin6 if using the TL072 numbering)

[Parra]

that setting on the multimeter is for reading alternate currents (AC), and guitar pedals run on direct current (DC). you should set your multimeter in 20 V--- (it's like three dots with a line on top) to do the readings.

[Knut Koupee]

that setting on the multimeter is for reading alternate currents (AC), and guitar pedals run on direct current (DC). you should set your multimeter in 20 V--- (it's like three dots with a line on top) to do the readings.

thanks

Here are the values at V-20

IC1 (TL072CN)
Pin8: 9.52
Pin7: 8.80-8.81
Pin6: 8.90
Pin5: 9.43
Pin4: 9.40
Pin3: 9.43
Pin2: 8.90
Pin1: 8.74

IC2 (PT2399)
Pin16: 8.95
Pin15: 8.93
Pin14: 8.94
Pin13: 8.95
Pin12: 8.95
Pin11: 8.95
Pin10: 8.95
Pin9: 8.95
Pin8: 8.94
Pin7: 8.94
Pin6: 9.24
Pin5: 8.87
Pin4: 9.40
Pin3: 9.40
Pin2: 9.36
Pin1: 9.38

IC3 (PT2399)
Pin16: 8.95
Pin15: 8.93
Pin14: 8.94
Pin13: 8.95
Pin12: 8.95
Pin11: 8.95
Pin10: 8.95
Pin9: 8.95
Pin8: 8.94
Pin7: 8.94
Pin6: 9.24
Pin5: 8.87
Pin4: 9.40
Pin3: 9.40
Pin2: 9.36-9.37
Pin1: 9.38



And on the modulation daughterboard the TL072 had:
Pin8: 9.52-9.53
Pin7: 8.71
Pin6: 4.56-4.57
Pin5: 3.81
Pin4: 0.00
Pin3: 4.56-4.57
Pin2: 0.00
Pin1: 7.54

And the H11F1 had:
(Pin next to the O notch on the left): 7.91 (Pin1 if using the TL072 numbering)
Pin below that: 8.44 (Pin2 if using the TL072 numbering)
Pin below that: 0.00 (Pin3 if using the TL072 numbering)

Pin Opposite the O notch): 9.23 (Pin8 if using the TL072 numbering)
below that: 8.84 (Pin7 if using the TL072 numbering)
below that: 9.40 (Pin6 if using the TL072 numbering)

[gtr2]

I still do not think your measuring correctly.

Those measurements are far to consistent with each other.

Josh

[Knut Koupee]

I still do not think your measuring correctly.

Those measurements are far to consistent with each other.

Josh

I'm using this:
http://img.b2bage.com/photo/product29/517654/big-dt832-digital-multimeter.jpg

Set 3 clicks to the left of off (the 20 setting under the V section with the straight line and 3 dots below it).

Black cable plugged in COM, Red in V(ohm symbol)mA.

Black lead touches the ground solder lug on the DC jack, red lead touches the pin on the IC.

Am I doing anything wrong? 

[Knut Koupee]

Here is a quick youtube vid showing IC3 pins 1-16 in order and how I'm checking the pins

http://www.youtube.com/watch?v=LRt2r4rQF2Q&feature=youtu.be

[gtr2]

hmm.. it looks right how you're doing it but the voltages are not right for most of your pins.  You are showing power at the ground pins on all the IC's.  That's the first red flag.  You also should be at 5V on pin 1 of the pt2399's.  A lot of the others are incorrect too.

What are you reading at the 9V pad and the G pad on the Multiplex board?

Josh

[Knut Koupee]

What are you reading at the 9V pad and the G pad on the Multiplex board?

Hi Josh,

9V - 9.52
G - 9.46

o_O

[gtr2]

The ground pad should be 0.0V

Somewhere you have something incorrectly wired or a solder bridge.

You've likely destroyed all the IC's and the regulator as well...

The good thing is they look like they are all socketed 

You're going to have to pull out the board and investigate.

Josh

[Knut Koupee]

The ground pad should be 0.0V

Somewhere you have something incorrectly wired or a solder bridge.

You've likely destroyed all the IC's and the regulator as well...

The good thing is they look like they are all socketed 

You're going to have to pull out the board and investigate.

Josh

Oy

Here are some unboxed pics, please let me know if you see anything, either in the wiring or solder connections. If you need different angles/close ups I'd be happy to provide.

https://lh3.googleusercontent.com/-QIhSyJ1acsw/UYg-LmJz-WI/AAAAAAAADE0/ypkOcRGmggs/w1347-h898/IMG_4662.JPG

https://lh4.googleusercontent.com/-fgXvu9cmuC0/UYg-TFECbWI/AAAAAAAADE8/vwANx7oZxhM/w1347-h898/IMG_4666.JPG

https://lh5.googleusercontent.com/-rzs5Ljbga1s/UYg-eyt4fxI/AAAAAAAADFE/H_j2b9xhT8g/w1347-h898/IMG_4668.JPG

https://lh3.googleusercontent.com/--Gt6KY9_4XA/UYg-gVsgdFI/AAAAAAAADFM/MiyB4VBGxw0/w1347-h898/IMG_4669.JPG

https://lh4.googleusercontent.com/-1GeeU5ODQ64/UYg-hFUqGsI/AAAAAAAADFU/Xon28PvKG30/w1347-h898/IMG_4671.JPG

https://lh6.googleusercontent.com/-6GNCZS2WAxk/UYg-hwbReGI/AAAAAAAADFc/bWI-FsV30mo/w1347-h898/IMG_4675.JPG

[gtr2]

I don't really see much from the pics.  Your going to have to do some investigation and see if you have any solder bridges etc..

Josh