Seppuku Space Fuzz - Breadboard layout Debug

[digitalzombie]

Hi all. I like to breadboard circuits before I build them. I found a schematic and verified strip board layout for this pedal, so I decided to build a breadboard template in DIYLC. I think I'm going to make this a regular thing.

Anyway, I'm fairly certain my BB layout matches the schematic, but I'm still learning and I'm not getting any sound at the output. Would you mind please looking at this layout against the schematic and let me know if anything looks like I have it wired up wrong?

https://imgur.com/a/94sNN

I should note the only liberties I took in the design was replacing C3, C6 (parallel 33nF) with a single 68nF, and for R6 I didn't have a 560K so the layout shows a 100K and 460K in series (I actually only had a 470K and wrote 460K here by mistake).

[digitalzombie]

I found some possible errors are Q2. There was an unnecessary link connecting the 68nF to my "R6" (the resistor's in series to simulate the 560K). Figured it would be easier to just bridge the C & B of Q2 with R6 instead of that single space link connecting C & B since that 68nF is already connecting to B. Also, that same link connecting C to B might be causing DC to go to Q2 B through the 10K resistor. Not sure if this would be causing that issue.

http://imgur.com/Ns8IT2X


I made some tweaks to address this, so let me know if V3 here looks better. I'll try it out and test that I haven't fried Q2. Will report back. Thanks.

http://imgur.com/Z6hfBcH

[Fast Pistoleros]

very cool man, post the final breadboard picture for us when your done, thank you!

[digitalzombie]

If it works with the v3 layout above I sure will. I'd like to start making it a thing. Everyone loves to share vero and pcb layouts, no one seems to offer up breadboard layouts...

[nocentelli]

If it works with the v3 layout above I sure will. I'd like to start making it a thing. Everyone loves to share vero and pcb layouts, no one seems to offer up breadboard layouts...

Without wanting to imply any criticism, I would venture that pcb and vero layouts are valued and shared widely because they generally save you at least 20 minutes if you want to build your own pedal without doing your own layout. Breadboarding a circuit from a schematic takes the same amount of time as breadboarding from a breadboard layout. That's not to say breadboard layouts are worthless, I'm sure they could be useful as a way to help people learn how to breadboard, but smallbear and other diy learning resource sites have other simple circuits layed out step-by-step, and once you've done a couple and learned the mechanics of how a breadboard works the learning benefits come from translating schematics into physical form.

[duck_arse]

dz - I applaud your effort at diagramming the bb. I think all nocentelli's points are valid, but I also think there should be bb layouts on offer.

dz, your circuit diagram does not show a connection from R1 to positive supply, is this correct? also, re your layout, don't link up - along -over - across and across just to get V+ to pin 6 of the LM386, link it straight across from the IC to the supply rail! (I didn't look the whole circuit/layout.)

[digitalzombie]

V+in is going to e1, and R1 connects a1 to supply rail. Is this incorrect? And re: pin 6, what's wrong exactly with doing it the way I did? I suppose I could jumper the 9v rails and it would be easier that way.

nocentelli, I hear what you're saying, but I think you're coming from a very experienced perspective, whereas I'm coming from a very inexperienced perspective. Having said that, I'd be willing to wager that there are more people that visit here that are wanting to learn vs already know what they're doing. I've done a couple of Steve smallbear's bb tutorials and that's what inspired me. Honestly, putting stuff out on the bb is what really started to make things click for me. If you think bb-ing from a layout takes just as long as breadboarding from a schematic, I'd love to share my current project, the Deluxe Pitch Pirate schematic with you

[nocentelli]

...I'm not getting any sound at the output.
https://imgur.com/a/94sNN

dz, your circuit diagram does not show a connection from R1 to positive supply, is this correct?

Q1 has no connection to the +9v power supply rail. The sustain lug 1 and the 10k from the Q1

[digitalzombie]

...I'm not getting any sound at the output.
https://imgur.com/a/94sNN

dz, your circuit diagram does not show a connection from R1 to positive supply, is this correct?

Q1 has no connection to the +9v power supply rail. The sustain lug 1 and the 10k from the Q1

I thought that was weird, but check the schematic. http://m.imgur.com/Z6hfBcH

I'm not seeing a direct connection between Q1 & +9v, unless you count where R2 bridges across from pin6, which I'm pretty sure is what I've got going on here. Please correct me if I'm wrong.

[nocentelli]

Yes, it's wrong. The connection from +9v to the collector resistor and lug 1 of the sustain control has been omitted, but the transistor will not pass signal without it. moonsun has that connection in his perfboard drawing of the trace of the original pedal, you can see there are two 10k resistors connected to the +9v supply that snakes under the 386 chip and connects pin 6 as it goes: http://bit.ly/21qgvrt

...but moonsun obviously neglected to draw that connection into the schematic you have copied on to your breadboard layout, and he also didn't draw in the other 10k resistor that is connected from +9v to lug 1 the sustain pot to stop it cutting off the input all together at the minimum setting.

[Fast Pistoleros]

If it works with the v3 layout above I sure will. I'd like to start making it a thing. Everyone loves to share vero and pcb layouts, no one seems to offer up breadboard layouts...

I try to bread board a lot, I am getting better lol
nice to have some done to just go in and start modding or messing with !

[digitalzombie]

Yes, it's wrong. The connection from +9v to the collector resistor and lug 1 of the sustain control has been omitted, but the transistor will not pass signal without it. moonsun has that connection in his perfboard drawing of the trace of the original pedal, you can see there are two 10k resistors connected to the +9v supply that snakes under the 386 chip and connects pin 6 as it goes: http://bit.ly/21qgvrt

...but moonsun obviously neglected to draw that connection into the schematic you have copied on to your breadboard layout, and he also didn't draw in the other 10k resistor that is connected from +9v to lug 1 the sustain pot to stop it cutting off the input all together at the minimum setting.

Man, I'm super confused. Because to me it looks like I have that connection you're speaking of. Look at the left side of my v2 edits picture I posted earlier where I highlighted the 9v+ path in red. http://imgur.com/Ns8IT2X

I mean, am I nuts, or is 9v+ getting to the Collector of Q1 in my breadboard layout, because it looks like it is.

And... I mean I'm not going to say it sounds like a stock model because I don't have one to compare it to, but v3 of my BB layout seems to work even though you're telling me it shouldn't pass signal past Q1.

Sorry for the crap playing. I hadn't even had my first cup of coffee when I recorded this an hour ago.

[nocentelli]

Man, I'm super confused. Because to me it looks like I have that connection you're speaking of. Look at the left side of my v2 edits picture I posted earlier where I highlighted the 9v+ path in red. http://imgur.com/Ns8IT2X

I mean, am I nuts, or is 9v+ getting to the Collector of Q1 in my breadboard layout, because it looks like it is.

No, my apologies, I somehow only checked out your first layout and failed to spot you had it sorted in the "v3" layout (http://imgur.com/Ns8IT2X) - Sorry for any confusion.

Demo sound great - super nasty.

On a more general note, I would advise running +9v and 0v down both sets of rails (top and bottom) so you don't need numerous links jumping the power and ground across the board and left and right in addition to signal-carrying jumpers running left to right, and instead bring a jumper down from above, or up from below so you can service the power and ground needs of both sides of the board in a way that is neater and easier to trouble-shoot by eye.

Also, it is IMO much better to place resistors, capacitors, diodes etc that connect transistor or IC pins to ground or +9v actually connecting from the pin direct to the rail, rather than to a point within the 5-hole matrix that is connected to the rail via a jumper: That is, place the biasing resistors at 90 degrees to the signal flow, just like on a schematic. The whole point of having power and ground rails that run the length of the breadboard is that multiple components can all hang off a single line making hooking it up easier and quicker; If you're jumpering the power or ground from spot to spot within the board, you may as well not have a rail and do it all point-to-point. If you look at a schematic, it is set out almost exactly like a breadboard, with the +9v rail running across the top, and the ground rail running along the bottom. I'd just advise having both ground and power at the top and bottom, so you have more options for running components in the most simple manner with the minimum of jumpers.

[duck_arse]

people, my humble apologies! it was me what was wrong. there is a collector to supply resistor, R2 (Ver. 03 post), but that part of the circuit is drawn so badly as to obsure it from, seemingly, all of us, with just the slightest misdirection (from me, again, sorry).

I did go over the whole circuit and layout (again, Ver. 03), and found no other errors. I would advise adding an electro of at least 220uF between V+ and ground, after the supply 100R, as bypass for the 386.

and the reason for a link straight to a buss is so you can then forget about it. stick the IC into the board, wire the link to V+ and the link to ground, done. one problem you won't have. again, as nocentelli says, parts going V+ or ground should go straight there. if you hapen to go up- over- around- down and back in links, with 3 components connecting along the way, and then lift one of those ups- or backs-, your problem propagates thu the layout.

so, when are we going to start the breadboard races?