Ok so I'm building on a breadboard for the first time and ib done 3 vero builds now but never really learned a whole lot about schematics in the process. So I decided to go back to the basics that I skipped. However I'm stuck and although I'm going to continue trying to figure it out for myself. O know it can take awhile to get a reply sometimes depending on time zones and all that other good stuff. If you could take a look at this schematic and the pictures of my breadboard and just POSSIBLY see where I messed up. Could be multiple places but I really think it's either around the pots or the clipping section I made my mistake, the latter of the two being the more probable cause I think. Also I know that 4 100pf caps in parallel isn't ideal lol. The leads however are really slim and actually fit in there with no problem. So I know it looks like I probably just jammed them in there but I made sure I was careful.
(http://i1305.photobucket.com/albums/s548/jessebelanger1988/Mobile%20Uploads/image_zpslsyfg4fh.jpeg)
(http://i1305.photobucket.com/albums/s548/jessebelanger1988/Mobile%20Uploads/image_zpsvnncplse.jpeg)
(http://i1305.photobucket.com/albums/s548/jessebelanger1988/Mobile%20Uploads/image_zps0obgt5k2.gif)
(http://i1305.photobucket.com/albums/s548/jessebelanger1988/Mobile%20Uploads/image_zpsdi38vxxj.jpg)
I use a bc109b as well instead of a 2n3904. Didn't even check the pin out to be honest so I'm going to try it with the right component there. Other then that the only sub I made was I didn't have a 12k resistor so I put a 15,3k in parallel also a tl071 opamp
Is that a TL071, or TL072 in the picture? Hard to tell. Beat me to it.
What exactly is not going on here?
So sorry I had caught that just before reading your question and updated the substitutions. It's a TL071 I can see how this is going to teach me a lot more then just building from a layout. However I'm sure I'm going to make some pretty dumb mistakes at first.
Quote from: digi2t on June 14, 2016, 11:00:48 AM
Is that a TL071, or TL072 in the picture? Hard to tell.
does the IC have anything connected to its pin 6?
hahahaha wow. Ok I'll fix that and let you know what happens guys.
Ok so I added the pin 6 to the second 1uf Wima cap by jumper and still nothing
I can't see the connections to the "feedback string", let's call it, either. a quick test would be to poke a 100k resistor across the top of the IC from pin 2 to pin 6. see if you get any output.
next we want the voltages on pins 2, 3, 4, 6 and 7.
[edit :] or just link the "25" tie to the pin 6.
Just a quick observation, with some breadboards the rails the run length ways for +/- sometimes need jumpers to connect the next set together, the solid red and blue lines suggest they are internally connected but this is not always the case. Check with a meter that these are connected as you may not be getting any power to the required parts.
Ok I'm going to try this now. Also I checked the bus rails and there connected the entire length of the board but thanks for the tip. For future reference I'm sure it will come in handy
Quote from: duck_arse on June 14, 2016, 11:47:42 AM
I can't see the connections to the "feedback string", let's call it, either. a quick test would be to poke a 100k resistor across the top of the IC from pin 2 to pin 6. see if you get any output.
next we want the voltages on pins 2, 3, 4, 6 and 7.
[edit :] or just link the "25" tie to the pin 6.
Is there any specific reason for Dirt Switch to be a DPDT..??
Something definitely looks wrong with the way you have Pins 2 and 6 connected to the IC. From the pictures, it looks like you are missing several connections to the key component "chains."
If I were you, I would trace those connections and make adjustments.
Quote from: antonis on June 14, 2016, 12:47:41 PM
Is there any specific reason for Dirt Switch to be a DPDT..??
I think it would be a better set up using a SPDT to short out R6, less likely to cause noise on switching. But obviously that has nothing to do with the circuit not working.
regarding the original problem, I may have missed it but I can't see where the problem is described, ie have you no sound at all ? or is something else not working the way you expect ?
Ok something is way off. The only pins doing anything are pin 2(0.6v) and 3(.2v
Correction I was using a new multi meter and I probably messed up somehow. I used my old one and I'm getting
1,.15v 2,4.5v 3,4v 4,.15 5,4.6 6,4.6 7,9.3 8,0
Literally only used it because the article that goes with this schematic says to use it . I know I can use SPDT but I only have a couple and I didn't understand there was a benefit to it. Also I only have on off on switches so i used a 100k in bottom row the wires attack( connect **) from the middle two lugs to the breadboard and then the 510k on the top 2 lugs. Sorry for not giving any details as to what's wrong. There's literally just no output signal at all. When I touch the tip of the cord the plugs into my guitar I get no noise at all
Quote from: Ice-9 on June 14, 2016, 01:07:32 PM
Quote from: antonis on June 14, 2016, 12:47:41 PM
Is there any specific reason for Dirt Switch to be a DPDT..??
I think it would be a better set up using a SPDT to short out R6, less likely to cause noise on switching. But obviously that has nothing to do with the circuit not working.
regarding the original problem, I may have missed it but I can't see where the problem is described, ie have you no sound at all ? or is something else not working the way you expect ?
I'd go through it section by section get each bit working before going on to the next bit.
Start with the power section top left on the schematic, build that, check you have 9 volts where it says V+ and 4.5 volts where it says vb. There's no point going any further until you do.
Then build everything up to the right had side of C3, check your voltages again. 9 volts on the collector of the transistor and about 4.5 volts on the other two pins. Connect your output jack tip to the right hand side of C3 and play guitar through it, should sound the same as plugging straight into your amp.
Then build the rest of it, check you have the right voltages on the opamp, 9 volts on pin 7, 0 on pin 4 and about 4.5 on 2,3 and 6.
Hopefully that will get it working and at least you'll have more of an idea where the problem is if it doesn't.
I made a mistake with my new multimeter. There's new voltage readings posted. I'm so sorry I just bought the other one and I really need to take a little time and get familiar with it. As there new to me to begin with
C9.5v b0v E0. So my problem should be with the transistor right? I swapped it for the correct part as well so I'll check I put it back right.
1,.15v 2,4.5v 3,4v 4,.15 5,4.6 6,4.6 7,9.3 8,0
I'll keep trying for awhile then I'll just move onto something else and come back to this one. Thanks for all the help guys
Quote from: slacker on June 14, 2016, 01:46:43 PM
I'd go through it section by section get each bit working before going on to the next bit.
Start with the power section top left on the schematic, build that, check you have 9 volts where it says V+ and 4.5 volts where it says vb. There's no point going any further until you do.
Then build everything up to the right had side of C3, check your voltages again. 9 volts on the collector of the transistor and about 4.5 volts on the other two pins. Connect your output jack tip to the right hand side of C3 and play guitar through it, should sound the same as plugging straight into your amp.
Then build the rest of it, check you have the right voltages on the opamp, 9 volts on pin 7, 0 on pin 4 and about 4.5 on 2,3 and 6.
Hopefully that will get it working and at least you'll have more of an idea where the problem is if it doesn't.
This is good advice.
build a small section, test its volts?, test with guitar?, repeat.
? where applicable
Where does IC1 Pin 2 connect to D1, D2, D3, and C4?
You need to check your routing like I mentioned above.
My two bits...
Strip the board and start from scratch. Looks like you're herding cats now. Print up the schematic anew, and grab yourself a highlighter too. Start at the input of the schematic, with each component or jumper you place, double check that each end is connected to the proper spot, and then highlight it on the schematic. Use different color highlighters for different sections if it will help keep things organized. Once everything is highlighted across the schematic, you should be good to go.
It's easy to get lost on a breadboard, especially with a circuit that has duplicate sections, such as a Big Muff. When I tried breadboarding the first time, I found it easy to get lost, or miss connections. Highlighting the schematic as you go I find keeps me on track. Especially so when you need to take a break part way through.
My eyes don't help me but, maybe, you've done a "noob" mistake.. :icon_wink:
Up right on your breadboard is build the Vb - BJT circuit on second pair of 5 columns but it's isnt jumpered on the first one..
(except the BJT Collector..)