Vero newboe problem

[jetblackelectrics]

Hi guys

I have some newbie questions about building on vero.

It is my maiden voyage and i thought i would start of on easy level and build a JHS little Black buffer. I have build i few handfuls of succesfull kits, so i am not completely new to soldering and pedal building.

I build the circuit from tagboard, but when i plug it in my testrig all i hear is a loud synth-like tone on the first one which kind of drains out when i touch the back of the vero, and nothing on the second circuit.

I checked the layout and it matches the tagboard one.

Any ideas what i am doing wrong? Anything i do when building kits on pcb that cant be done on vero. I am afraid that i am missing something obvious.

Thanks in advance and please bear with me. Looking forward to posting build reports when it works


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[jjanssen1]

Whould it be possible for you to post some pictures of the board and the layout your using
Cheers
Joshua

[jetblackelectrics]

Yes of course. I'll post when i get home in a few hours


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[muddyfox]

I've found that with vero, at least 90% of all errors is solder bridges. "Knife the gaps" is the regular mantra in all vero-related conversations so do run a scalpel between all the copper traces and make sure your cuts are actually all the way through (worth checking with a dmm right after you cut them all).

And yes, pictures help immensly. 

[jetblackelectrics]

[jetblackelectrics]

I have knifed the gaps :-)

Suspected problems:
Oxidation?
I have used a TL072IP. Musikding was out of TL072 but they had the same description.

[muddyfox]

Oxidation shouldn't be a problem as any flux in the solder wire probably cleaned that up sufficiently.
IC substitution is fine.

I'll go and take a look at your pictures. Being at work, doesn't help the task any. 

EDIT: unless you're really good at soldering, it pays to socket your ICs, if for no other reason then to eliminate the possibility of heat damage while soldering. Do you have an audio probe to trace the signal?
Also, those gaps don't look particularly knifed. You really need to dig in.

[alanp]

What's the stray strand of wire around the Ground pad?

I'm not hugely keen on having 9V and Ground so damn close, especially with a technique as error-prone as vero. (I'm more keen on perf.)

If this is your first build, I would STRONGLY recommend getting a fabbed, simple as hell board (can't think of any offhand, JMK has a boost-buff simple board IIRC).

[jetblackelectrics]

I'm gonna knife em good! :-)
I have built Jakobs basic testrig with the probe, but i haven't had any luck using it.

Its my first verobuild, but i am hoping to make it work. The stray wire is just a stray wire im cutting off right now :-)

[midwayfair]

Don't guess if you've done the cuts properly. Use your multimeter's continuity setting.

Post voltages on all pins of the op amp. The pictures help, but we still need that.

[GermanCdn]

Looks like a solder bridge under the LED pad to the ground pad (top RH corner of the board in the pic), which would in turn ground out your 470R resistor, which is linked to your 2M2 resistor and your IC pin 8.  All kinds of badness could result from that.

[davent]

Looks like another stray wire in the bottom left corner of the top photo and on the  backside photo looks like another solder bridge in the top left corner. And i'm a strong advocate for using different coloured wires for different purposes, makes it so much easier to keep track of things and sort things when trying to sort out  problems.

[AntKnee]

Looks like a bridge from power to ground, top left corner of solder side photo.

[jetblackelectrics]

Hi again

I got the circuit working on my testrig. I am ashamed to say that i was my testrig that was faulty.

But now i am confused about the wiring when i put it in the box.
Input to input
Output to output
Board gnd to dc jack ground
Board 9v to dc jack
Board led to led + and led - to where?

I dont have a footswitch.

I am sorry for my level of incompetence :-)

[davent]

The -ve lead of the LED just needs to be connected to ground... as long as there is a current limiting resistor (clr) between the LED and the +ve  connection. If there's no clr for the positive side you'll need a clr between the LED -ve lead and the ground connection.

dave