Help please with SHO Clone! :)

[Les Paul Lover]

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.

Dwarf measurement is all important in pedal building. It makes the difference between strong and stout fuzz and weedy ones. Either that or my spellchecker corrected farad without my permission......

Good DMM regardless I think though. It's a Mercury EM890G. I found one place selling them on the net, but Couldn't manage to copy link on my phone. In any case, it was £20 + postage online, so £18 from local shop makes me feel all warm and fuzzy inside.

[Les Paul Lover]

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.

I thought that was the case. The pot lug 1 & 2 are linked. I'm obviously no expert -  . I have contacted the kit seller who reckoned the readings On the BS170 should be 3v, 6v & 0v.

I will try replacing it tomorrow if my son allows me some free time. I'll make sure I'll heat sink it, because I redo didn't do it 1st time around......!!!!

I sure hope to have it sorted soon!

[Les Paul Lover]

And thanks to you all for the informations and ideas, I really appreciate it.

I've learnt more messing up that build than I would have otherwise, and it's very interesting.

One last thing I didn't quite get please.... Is it normal to net read any voltage on the ground side of the circuit? I'm thinking D2, takes 6.2v, but with mo readings On the ground side - I would have expected to read 6.2v there too?

[duck_arse]

stout fuzz? no, thanks.

the ground side of the circuit is ground, 0V, (-), earth, it has "no potential". it is the reference point from which we measure. it doesn't matter if positive earth or negative earth. any point connected to earth will, should, MUST read 0Volts difference to any other point grounded. so all those "GND" points across the bottom of the circuit are electrically the same, short-circuited to each other, common.

so, put your black meter lead on any one of those marked points, and leave it there for all your measures. measure to the junction of D1 and D2, and it will read the same voltage as across the R1//R2 junction, because they are the same point, all joined. note that voltage.

measure to the top of D1, which is "common" to the 9V, (+), B+, supply, Vcc line. subtract the voltage you noted above, and that is the voltage across D1. do the same at the R2//R3 junction, which will give you the drain voltage, as the three points are again, common. common to each other, not common to all the other commons I've noted.

and that only leaves the pin3 of the pot, the source voltage. now you've collected the whole set, and they should be sane, if not correct. if you read anything higher than your V+, there is something amiss in your method.

(at the input terminal, the end of C1 "has no reference", and will float to whatever voltage is nearby. this is why we use depopp resistors, to reference the whole circuit to something, which we often call ground. at the output the larger cap has its end "pulled to ground", so it can't float, and should also measure 0V because no current is flowing through the [good] capacitor.) I hope some of this clarifies.

[Les Paul Lover]

stout fuzz? no, thanks.

the ground side of the circuit is ground, 0V, (-), earth, it has "no potential". it is the reference point from which we measure. it doesn't matter if positive earth or negative earth. any point connected to earth will, should, MUST read 0Volts difference to any other point grounded. so all those "GND" points across the bottom of the circuit are electrically the same, short-circuited to each other, common.

so, put your black meter lead on any one of those marked points, and leave it there for all your measures. measure to the junction of D1 and D2, and it will read the same voltage as across the R1//R2 junction, because they are the same point, all joined. note that voltage.

measure to the top of D1, which is "common" to the 9V, (+), B+, supply, Vcc line. subtract the voltage you noted above, and that is the voltage across D1. do the same at the R2//R3 junction, which will give you the drain voltage, as the three points are again, common. common to each other, not common to all the other commons I've noted.

and that only leaves the pin3 of the pot, the source voltage. now you've collected the whole set, and they should be sane, if not correct. if you read anything higher than your V+, there is something amiss in your method.

(at the input terminal, the end of C1 "has no reference", and will float to whatever voltage is nearby. this is why we use depopp resistors, to reference the whole circuit to something, which we often call ground. at the output the larger cap has its end "pulled to ground", so it can't float, and should also measure 0V because no current is flowing through the [good] capacitor.) I hope some of this clarifies.

Thanks a lot!!!!!!

I've learnt a lot through my failings, and that I'd thanks to you and the other people who have tried to help me!

I'm very thankful!



--------------

I removed the BS170. I was glad I kept all the component's trimmed leg, they came in really handy to reopen the pcb soldered up holes.

And the BS170 was the culprit, I had fried it. I was very pleased to hear it work again! That boost is VERY Powerful, even at the lowest setting!

Now.... I need to finish painting the enclosure, and wire the switch and diode!!!! All very exciting!!!!

[peterg]

I'm glad it's working! Sorry to hear about the loss of your BS170 though.

[Les Paul Lover]

I'm glad it's working! Sorry to hear about the loss of your BS170 though.

Yes it was a bitter sweet moment.

This BS170 looked to have a promising future, but it was tragicaly cut short. Knowing that I'm the cause of it didn't help.
We had full service and burial, the eulogy was very touching.

I recovered after a whisky and plugging in the working SHO clone. That thing is ace.




I will make sure to post the completed pedal once done!

[duck_arse]

shame it's already buried, I wanted you to measure its gnomes.

[Les Paul Lover]

shame it's already buried, I wanted you to measure its gnomes.

Are they important to Fuzzes? I thought it was the dwarves..... I'm confused!!!!!     

[Les Paul Lover]

Now that I've debugged it, I kept on going with the project, with the aim to get it in the box ASAP. I thought I'd post my updates to you.



I have done a neat teamplate to paint my 1st box, and decide to have a go with it......

- 1st try: painted quite liberally, paint flowed everywhere underneath the template. right mess. I considered myself lucky to be able to sand it off and save myself a full repaint.

- 2nd try: using a thinner brush and little paint, I manage to get a clean but weak outline. It's when I passed over it again that I did the damage.... My hand isn't steady enough with a brush, and it looked like a tremor line. I had to pass over and over it again, resulting in it being as thick as it is now. (see pic below for entertainment value)

It is now absolutely obvious that I was deluded in thinking I could pull that off. Let me repeat it: I can't draw fir Sh!t. Seriously, if your life was depending on a drawing, let your dog do it and ignore me.

Anyway..... Pic for your entertainment....

[/quote]


I've decided to keep it as is anyway. This SHO clone was a learning prjoect, and it sure has been one. I've learnt lots. And lots. And some of my limitations.....

Where it is frustrating, it's that I wanted to paint a whale outline on the blue box for my reverb. I'm not quite so sure I can pull it off now.....

[duck_arse]

I rekon the bustier looks fine as is, and plenny others hereabouts would agree, I'm sure. if you're using a stencil, you're better off spraying over it instead of brushing. a shaving brush. from the 2$ shop. cut the end off square/flat. stick down yr stencil of a whale, v. lightly load up the brush w/ some paint, white? and then dab dab dab (jab jab jab?) around the outline. remove stencil - there it is. something, anyway.

I'm sure of lots of stuff tonight. I'm sure my eyes aren't good enuff for stencil cutting any more. you might think of adding some more paint to the bustier, to add texture to the under-curves (you know the ones).

I'm just about to start painting boxes, I've bent my prototype today, gotta start measure cut sand drill bend. then I'll need some paint techniques - so many to choose from ......

[Les Paul Lover]

I rekon the bustier looks fine as is, and plenny others hereabouts would agree, I'm sure. if you're using a stencil, you're better off spraying over it instead of brushing. a shaving brush. from the 2$ shop. cut the end off square/flat. stick down yr stencil of a whale, v. lightly load up the brush w/ some paint, white? and then dab dab dab (jab jab jab?) around the outline. remove stencil - there it is. something, anyway.

I'm sure of lots of stuff tonight. I'm sure my eyes aren't good enuff for stencil cutting any more. you might think of adding some more paint to the bustier, to add texture to the under-curves (you know the ones).

I'm just about to start painting boxes, I've bent my prototype today, gotta start measure cut sand drill bend. then I'll need some paint techniques - so many to choose from ......

I'm getting used to my drawing - it's just quite different from the nice neat thin lines it was meant to be.......   

I've decided I'm going to go ahead and try for the whale too. I may try slightly differently though, not with a stencil but rather a shape to lay on the pedal and keep there.

Yeah, I think I'm gonna add another layer to the breast area, but I will clear coat it too, bbecause that's another thing i want to learn to do.