Help please with SHO Clone! :)

[Les Paul Lover]

Hi All,



I hope you can help me solve my problem – I've built a SHO clone with this kit:

http://pedalparts.co.uk/wp-content/uploads/2012/10/Boner.pdf





It worked at 1st test (the footswitch isn't wired yet), but not at the 2nd testing a few days later.
I did try to see how it would fit in the enclosure in the meantime, and did wiggle the pot a bit.

Now all I get is a very weak signal with the pot all the way down, and the signal gets weaker as the pot is turned up. 
The bypass is fine, I get full signal through to the amp when the pedal isn't powered.


I've since reflowed all solder points, with no change, and have taken the following readings.
I don't get any volt readings on anything going to ground or the pot, not sure if that is normal or not?

I hope you guys can help – so frustrating to know that it isn't working anymore!!!!

Thank you!


R1
6.2v
0v

R2
6.2v
6.2v

R3
9.5v
6.2v


R4
0v
0v

D1
9.5v
6.2v

D2
0v
6.2v

C1
6.2v
0v

C2
6.2v
0v

Q1
3.1v
6.2v
6.2v

[garfo]

If you have a solder pump, remove those solders.They look really bad.Resolder everything properly.It looks like you have big solder lumps and you could have cold spots.Also check if you have accidentaly lifted up any trace on the circuit, if you have just make a jumper in the place it occured.

[bufferz]

hang in there

[mth5044]

I can't open a PDF at work called Boner. 

[gjcamann]

Make sure you don't have your input/output jacks mixed up. I do that all the time.
I second cleaning up the solder. Make sure your iron is clean when you do this too to keep the crud off your joints. Also, make sure you've making good contact with the pad when you solder so it gets hot and the solder sticks to it. You'll get the hang of it soon enough.

[Les Paul Lover]

If you have a solder pump, remove those solders.They look really bad.Resolder everything properly.It looks like you have big solder lumps and you could have cold spots.Also check if you have accidentaly lifted up any trace on the circuit, if you have just make a jumper in the place it occured.

You're quite right, not the most pristine soldering there...!!!
That's why I was soooooo relieved when it worked during my 1st test!

And then disappointed after the 2nd test!!!

I don't have a solder pump, but have touched up all solder joints since that picture!

[Les Paul Lover]

I can't open a PDF at work called Boner. 

Eh, eh, eh!!!

[Les Paul Lover]

Make sure you don't have your input/output jacks mixed up. I do that all the time.
I second cleaning up the solder. Make sure your iron is clean when you do this too to keep the crud off your joints. Also, make sure you've making good contact with the pad when you solder so it gets hot and the solder sticks to it. You'll get the hang of it soon enough.

Sadly it isn't the input jacks....

[Les Paul Lover]

So here's my cleaned up soldering.


I would have a few questions.

Is it normal for all voltage readings going to ground to be 0v?

Is it normal to not read any voltage in the in leg if C1 and out leg of C2?


Is R4 affecting the circuit at all, considering it's going straight to ground?

How do I check if the 5k pot us working?




And thank you for your replies and the welcome, much appreciated!

[Kipper4]

R4 is an anti pop resistor and probably has some bearing on the output impedance.
C1and C2 are input and output decoupling caps .
R1 and R2 form a voltage divider to bias the MOSFETs gate To half the 9v power supply.
How do you check if the pot works?
With the circuit powered down put the multi meter probes on the middle and one of the outer lugs with the meter set to ohms setting. Then with your third hand turn t
He pot and watch the resistance change on the DDM (digital multi meter)
I hope I'm right on at least some of this and I hope it helps
Rich

[Les Paul Lover]

R4 is an anti pop resistor and probably has some bearing on the output impedance.
C1and C2 are input and output decoupling caps .
R1 and R2 form a voltage divider to bias the MOSFETs gate To half the 9v power supply.
How do you check if the pot works?
With the circuit powered down put the multi meter probes on the middle and one of the outer lugs with the meter set to ohms setting. Then with your third hand turn t
He pot and watch the resistance change on the DDM (digital multi meter)
I hope I'm right on at least some of this and I hope it helps
Rich

Thanks a lot!

Will check the pot tonight using my 3rd hand - quite glad I decided to grow one!

SO I assume it's normal not to see any voltage on the guitar in and amp out side of the caps?
And normal not to read any voltage on anything going to ground?

Going to read about decoupling capacitors now....

[LucifersTrip]

Q1
3.1v
6.2v
6.2v

if the voltages are the same, it means those points are shorted (connected)...and they shouldn't be.

[peterg]

Fuzz Skull - Lugs 1 and 2 and connected on the schematic. The pot is a acts as a variable resistor.

Les Paul -  It looks like you soldered Q1 directly to the board instead of using a socket. You may have fried it with all the soldering. Also using the power jack as your central grounding point isn't the best approach. The tabs on it are pretty flimsy and could have come loose. You are better off using one of the audio jacks. Connect the board, power jack and second audio jack to it.

[Kipper4]

yer the transistor might be blown.
When soldering transistors directly to a board it's a good idea/practice to heat sink the leg you are soldering in.
I use a pair of long nose pliers with an elastic band round the grip ( to clamp the pliers nose to the leg. this can help hold it in place as well) and put it around the leg im about to solder in (componant side). it dissipate the heat from the soldering action and protects the transistor somewhat.
did you check for solder bridges too?

the solder looks a bit blobby around the transistor. you can use the heat sink method and remove some of the solder with a solder pump.
failing that pm me your address and i'll send you a new transistor to try.
good luck
Rich

[Kipper4]

yer its quite normal not to see DC voltages in the audio path since the guitar signal is AC.
the decoupling caps i talked about earlier are there to stop DC getting into the circuit.

[Les Paul Lover]

R4 is an anti pop resistor and probably has some bearing on the output impedance.
C1and C2 are input and output decoupling caps .
R1 and R2 form a voltage divider to bias the MOSFETs gate To half the 9v power supply.
How do you check if the pot works?
With the circuit powered down put the multi meter probes on the middle and one of the outer lugs with the meter set to ohms setting. Then with your third hand turn t
He pot and watch the resistance change on the DDM (digital multi meter)
I hope I'm right on at least some of this and I hope it helps
Rich

Ok, had some time last night and got to check to pot over.

Reading we're fine at the holes before the lugs, however I was getting any reading on the soldered lugs. I resoldered them, and am now getting good readings there.... However, the circuit isn't working still.

Since the diodes are ok, the caps seem fine too, resistors are hard to mess up with.... I believe my next port of cal is replacing the transistor BS170.

[Les Paul Lover]

Fuzz Skull - Lugs 1 and 2 and connected on the schematic. The pot is a acts as a variable resistor.

Les Paul -  It looks like you soldered Q1 directly to the board instead of using a socket. You may have fried it with all the soldering. Also using the power jack as your central grounding point isn't the best approach. The tabs on it are pretty flimsy and could have come loose. You are better off using one of the audio jacks. Connect the board, power jack and second audio jack to it.

Thanks for the tip!!
I'll have to unsolder the ground and energy supply once I fully wire it in the box, I will foreground it to the inpout or output Jack then!

[Les Paul Lover]

yer the transistor might be blown.
When soldering transistors directly to a board it's a good idea/practice to heat sink the leg you are soldering in.
I use a pair of long nose pliers with an elastic band round the grip ( to clamp the pliers nose to the leg. this can help hold it in place as well) and put it around the leg im about to solder in (componant side). it dissipate the heat from the soldering action and protects the transistor somewhat.
did you check for solder bridges too?

the solder looks a bit blobby around the transistor. you can use the heat sink method and remove some of the solder with a solder pump.
failing that pm me your address and i'll send you a new transistor to try.
good luck
Rich

Thank you so much for the offer! Very kind of you! I have actually bought a spare one a couple of weeks ago knowing I'd struggle to get one if needed ( I happened to be near an excellent independent electrical shop), REALLY cheap too! Got a great multimeter there for not much - I think £18, the does diodes, V AC/DC, Ohms, dwarfs, temperature and hfe.

Also got a helping hand for £4 which I thought was very good too. They sell the thin solar by the meter too  .... £0.35/m.... I could go on and On! You wonder how they make a living!

[duck_arse]

Got a great multimeter there for not much - I think £18, the does diodes, V AC/DC, Ohms, dwarfs, temperature and hfe.

can we, err, see, this  meter? not much call for the dwarfs range, but interesting.

[peterg]

Fuzz Skull - Lugs 1 and 2 and connected on the schematic. The pot is a acts as a variable resistor.

totally misread Fuzz Skull's comment. Q1 should have 3 different voltages as he points out.