[Billy]

Checked all the resistor values all look correct apart from R10 and 11 (22K) which I can’t see using this for future reference

 

http://samstechlib.com/15924820/en/read/5_Band_Resistor_Color_Codes

 

All capacitor values look correct can’t see C4 and 8 values but they are correctly orientated C5 is within the range specified yours at 220N will allow more highs through

 

And R3 I think it is as you say not enough solder on it the secret to good soldering is to heat both the component leg and pad at the same time and allow the solder to flow nicely

 

With you being able to hear effect it definitely sounds like a bad connection somewhere once you’ve reflowed your solder hopefully it’ll work fine include the solder joints on the 3PDT switch where the switch lugs are soldered to the pcb IN and OUT (T) pads and those that go to the IN and OUT jack socket solder lugs reflow the joints on the IN and OUT jack socket solder lugs if you get good bypassed signal then those 3PDT lugs are OK also check that your cable jacks have a good connection to the jack socket tips when inserted.

 

Be very careful when reflowing the 3PDT switch lugs too much heat can damage the switch internally so again around 3 to 4 seconds allow it to cool then do the next one

 

Post a picture of the 3PDT switch so we can see the switch connections to the jack sockets and pcb IN and OUT

[Billy]

The test pedal is basically a pedal without a circuit in it that you can attach your newly populated pcb in, out, ground and power to

 

It saves you soldering your 3PDT in and out jacks and DC jack to your pcb prior to putting it in the enclosure

 

If it tests OK then doesn’t work when you wire it into your enclosure 9 times out of 10 you then know you’ve made a mistake with your offboard wiring to the 3PDT jacks DC jack etc

 

If it doesn’t work then with a test box with an integrated audio probe you can immediately start debugging as Barry says with the flick of a switch using the integrated audio probe

 

I have been working on an image showing how to make one from tagboard effects this one

 

http://tagboardeffects.blogspot.com/2014/09/test-box-20.html?m=1

 

I’ll get it finished when I get a minute and post it, it’s simply a visual of the above instructions

 

 

 

 

 

 

 

 

 

 

[Billy]

This is an interesting read

 

https://bogdan.nimblex.net/diy/2016/12/08/testing-charge-pump-ics.html

 

This guy tests a few different charge pumps but initially it explains briefly how it works with the internal CMOS switching, caps charging and inverting the voltage etc

 

Datasheets are of course great for any component usually giving circuit examples for what they can be used for but not always giving a clear explanation in laymans terms so I usually google to try to understand better for example I like to know what each pin function is

 

On the 7660S in particular the LV pin (pin 6) took me a while to figure out, when I used a 7660S to give me -3v for a Selmer Buzztone build in conjunction with a voltage regulator

 

It ended up oscillating with a loud squeal until I eventually figured out LV must be low voltage as soon as I grounded pin 6 the squeal disappeared of course if I hadn’t skimmed over the datasheet I’d have seen the circuit with LV going to a switch to ground but they are definitely not always 100% obvious or clear

 

Anyway I often breadboard one or two of the datasheet circuits it does help you to understand it’s functions especially if you do what I do and change external caps etc to see how it’s affected but you can waste a lot of time messing around haha

[Billy]

Hi Angelo

 

The first thing I notice is that you may have a few dry solder joints so firstly I would try carefully reflowing every solder joint

to do this simply hold your soldering iron tip on each joint for around 3 seconds or until the solder melts making sure you hold your tip on the component leg and pad at the same time to get a good connection remove your transistors from the sockets when reflowing

 

Some do look as if too much heat has been applied from your soldering iron what kind of soldering iron are you using?

 

Do you have bypass signal

 

You should also cut off as much of the component legs as possible on the solder side of the pcb this can cause short circuits if they come into contact with the bare metal of the enclosure, back of the pots etc

 

We need to clearly see all of the components on the pcb and where your wires connect to on the 3PDT in and out jacks and DC jack a picture like this below is ideal

 

With a picture like this we can begin checking the values and orientation of the components and ask for more pictures as required for example close ups of the jacks and so on

 

From your description of whats happening you may have more than one fault but it sounds like you have a dry solder joint causing a poor connection and high resistance to the signal flow

 

[Billy]

A 7660S can be used as a voltage inverter for positive ground circuits meaning you can use a normal +9v adaptor and daisy chain with standard negative ground pedals rather than use an uncommon positive ground adaptor the pumped up series integrates it into the circuit if you look at the power supply section in the schematics

 

The datasheet contains all the information and circuit examples for it’s uses

[Billy]

You need the CLR on the 3PDT board with your LED mounted on it Smitty  you may be lucky with the power not getting to the pcb and it might not have blown

 

Mount anything from around 1K to 4K7 depending on how bright you like it I’ve gone higher than 4K7 because I like them dull

 

Hopefully the DC jack is your only problem your build looks good to me

 

[Billy]

So just to recap and make sure I’m understanding correctly you’ve checked your adaptor (cord) which puts out +9v and when it’s plugged into the DC jack and you put your meter probes on the DC jack solder lugs you get no voltage? With your meter set to 20V DC

 

 

[Billy]

OK it’s difficult to see even when I zoom into the photo it looks like you have 2 red wires from the DC jack one to the main pcb +9v and the other to the 3PDT board +9v

 

If you have power going into the DC jack and not beyond then I’d reflow the solder joints on the DC jack I can’t see if any of the wires are touching I’m assuming not that’d be a dead short usually causing the wires to heat up so you’d definitely notice it! If you’re not getting power on the DC jack lugs make sure you’re using a centre negative adaptor and continuity check that ground is the centre pin on your DC jack

 

it does look like you have a lot of solder on the DC jack lugs so as I say reflow making sure you get a good flow and remove any excess solder sometimes even if it looks shiny on the outside with excess solder it can be dry on the inside making a bad connection

Continuity check from your DC jack lugs to the +9v pads making sure you have a good connection make sure its the lugs and pads you continuity check and not the ends of the wires same for your ground connection and conversely make sure nothings connecting that shouldn’t be

[Billy]

Do you get 9v on the DC jack with the adaptor plugged in

[Billy]

Can’t see your DC jack clearly but main +9v should go to the outer power lug with the middle one being for battery power as I say can’t see if your power is going to the middle if so change to the outer one

[Billy]

Hard to believe

What a massive loss to us all

Pete was an absolute gentleman always willing to guide and help everyone always coming up with great innovative ideas I used to enjoy our little competitive bits of banter trying to answer support issues first he usually left me in his wake

He was an absolute  top guy and definitely made it feel like a little community

I’m gonna miss Pete nothing was too much for him I’m truly saddened that our ever present friend isn’t going to grace us with his vast knowledge, humour and selflessness I hope his family are OK and Pete is off to a much better place where he deserves to be

RIP mate catch you later

[Billy]

Well done on getting it working, it does get easier!

 

You have learned a lot which will be good for your next pedal build

 

As Barry said read the guides a lot is answered in the guides and they’re written with the beginner in mind with links for more information

 

And definitely make an audio probe and a test pedal it makes fault finding much easier and much faster

 

I look forward to seeing your completed pedal

[Billy]

Great glad it’s working the transistor voltages don’t have to be exactly the same a few mV won’t make a massive difference

 

To check resistance on your potentiometer measure resistance between the two outer lugs 1 and 3 but remember they have a + or – 20% tolerance so may not be exactly 2K

 

You will get 0v between the middle and 1 outer lug the middle and other outer lug will give you a resistance reading, turn the potentiometer shaft the other way and they’ll be opposite

 

If you are getting 0v between the same lugs turned both ways then the potentiometer may be faulty

 

There is information on how they work in the beginners guide to effects pedal components

 

24K won’t make much difference to a 22K resistor for R4 that is why your transistor voltages are slightly different Q2 collector with more resistance giving you 1.70 instead of 2.3v if it sounds good just leave it

 

[Billy]

If your initial measurements were reversed then you’d have 5.82v on the emitter of Q1

 

Take Q1 out of its socket and check the 3 socket holes don’t have continuity with each other

 

Weird measurements sometimes indicate no path to ground so check Q1 emitter has continuity with ground if not reflow the socket solder joint and re check  making sure the 3 socket holes don’t have continuity with each other

[Billy]

All of your components look to be of the correct value the only one I can’t see clearly is R4 (22K) the colour bands should be

red, red, black, red, brown

 

Looking at the schematic and comparing your transistor voltages to what they should be I suspect you may possibly have a solder bridge or poor solder connection giving you your strange readings

 

Q1 Collector and Q2 Base should have the same voltage being directly connected to each other after R3 (51K) looking at your readings I think they do 1.75v

 

I think your voltages have Q1 and Q2’s Emitter and Collector the wrong way around and what you have as the Emitter is actually the Collector and visa versa your empty socket readings would make more sense that way

 

Q1 Emitter is only connected to ground and the fact you have 5.82v? there again makes me suspect a solder bridge / poor connection somewhere, continuity check Q1s Emitter to ground

 

Check Q1 Collector has continuity with Q2 Base

 

Check each transistor empty socket making sure that each of the 3 socket holes do not have continuity and double check the solder joints on the sockets

 

Check that R3 left side nearest the IN pad has continuity with Q1 Collector ( in red dots below on the pcb image)

 

This will give us an idea of where there could be a bridge or bad connection

 

 

Just for info 2N3904 pinout

 

[Billy]

R8 is the CLR current limiting resistor for the LED 1K8 would be bright 3K3 not as bright you can use any value from 1K to 4K7 depending on how bright you want it

 

I’m at work at the moment so can’t have a good look I would suggest you make an audio probe see the guides link on the homepage for how to build and use one

 

This method will cut your fault finding from hours to minutes a great tool to have and cheap to make

[Billy]

OK so if I understand correctly you have your yellow wire from the 3PDT going to the ring connection on the one I drew the red line on? The IN jack socket? the ring is the shorter of the 2 catches

 

If that’s the case that wire needs to go to the tip solder lug

You’ve traced the 3PDT / jack connections  in effects mode you want to do it in bypass mode, lug 1 of the 3PDT in your picture would be bottom right because it’s upside down

[Author]

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