Thermally burned resistor at 9v DC jack...

[induction]

Regarding the IC...it's a weird IC, there are two indicators on it...there's a little circle you can't really see up at the top of it, so I'm using that to orient the IC.  It was the same the last time I built this, but with the circle up top, it's oriented correctly.  I can switch it around and see what happens though!  

It's definitely upside down. The notch is what tells you where the top is.

[KazooMan]

I think he has the 9V and ground leads removed for the picture.

The IC is definitely rotated 180 degrees.  (Oops, Induction posted while I was typing - at least the three of us agree!).

Pins 4 and 11 on the IC are V+ and V- respectively.  Rotating the chip as it is installed has the polarity backwards.  It reverses the polarity on all four sections of the chip.  Hopefully the smoke hasn't gone out of the chip as well.

[slacker]

If IC1 got 9 Volts connected to it whilst backwards then it's dead, if there was something else causing a short, preventing it seeing any Voltage then it might be OK. For now I'd assume you've killed it and replace it before doing any more trouble shooting.

[KazooMan]

I looked at the pics of the board (downloaded them so I could blow them up).  I didn't see any obvious solder bridges, but they can be hard to see at times.  

Your easiest solution may to get a new piece of board and move the components over one at a time.  Sometimes when you have been trying a lot of fixes on a board such as reflowing connections, scraping to remove any tiny solder bridges, etc. It gets to the point where you are better off starting over.  The final pedal will probably be more robust and have fewer problems down the road.

I would recommend using a lot less solder.  With Vero you only need enough to establish the electrical connection to the strip.  That will provide more than adequate mechanical strength as well.  Your board looks more like what one would do with simple perf board where you need to run a bead of solder between pads to form the connection.  Please don't take offense, I am just trying to offer some advice.

[Jdansti]

I think he has the 9V and ground leads removed for the picture.

The IC is definitely rotated 180 degrees.  (Oops, Induction posted while I was typing - at least the three of us agree!).

Pins 4 and 11 on the IC are V+ and V- respectively.  Rotating the chip as it is installed has the polarity backwards.  It reverses the polarity on all four sections of the chip.  Hopefully the smoke hasn't gone out of the chip as well.

Thanks-missed the part about the wires being removed.

+1 on the chip.

[canman]

Hmmm...luckily I've got a few spare tl074's lying around!  I'll hook up some power and see if that fixes it.  Is it safe to say the other chip is fried, or did the 47ohm resistor take the hit instead of the tl074?  I know I could just flip it around and check, this is more for my own understanding of how circuits work.

I will post and let you guys know what happens in a few mins...

[IvIark]

I agree, the Vero layouts may be handy, but they do NOTHING for helping someone learn about how something works

Since when has that been the point of them?  It's paint by numbers nothing more, nothing less.  And the schematics aren't my property to share, but as noted in various places on the blog, 99% of them can be found on FSB.  If that's not good enough for some, then I'm more than happy to give them a 100% refund.

[IvIark]

I can't see where your supply is connecting, the hole next to the 47R is empty?

[KazooMan]

Re:  IvIark

Yes.  In his post with the pics he noted that he had disconnected the supply.  You can see the solder in the appropriate hole.  

Re. Canman

A plausible scenario is that when you installed the chip backwards and applied the 9V it fried the chip and in its final death throes a path to ground for the 9V was created.  You might want to check the IC to see if there is now a short (or low resistance) connection between pins 4 and 11.

Hopefully a new IC, installed correctly will have you back in business.  

[canman]

Well, I installed a new IC, correctly oriented this time...no extreme heat at the power input 

I am going to hook it all up and see if I can get it going, thanks a ton for the help everyone.  I will be sure to let you know if it fires up or not...   

[GibsonGM]

I agree, the Vero layouts may be handy, but they do NOTHING for helping someone learn about how something works

Since when has that been the point of them?  It's paint by numbers nothing more, nothing less.  And the schematics aren't my property to share, but as noted in various places on the blog, 99% of them can be found on FSB.  If that's not good enough for some, then I'm more than happy to give them a 100% refund.

Yes, it is paint by numbers, and then a lot of time helping someone figure out where it went wrong, and no resource for the more experienced person to be able to easily help them.  Yeah, someone can go hunting for it, if they want to take the time.  Maybe that should go in the debugging thread: "link to a schematic".  I dunno.   

The point of this FORUM has been to help people learn, historically, but there's always room for those who just want to tinker, sure.   Just that we're seeing more Vero's and less actual schemas, which contain the real data...

No offense intended, opinions are like, well...you know.  Everybody's got one.
It's nice that you'd do the leg work to 're-create' an otherwise unavailable effect, don't get me wrong.  I just don't like Vero layouts.  I'm sure I'm not the only one.  And there are 1,000's that do.

>>  Canman, hope it works for you! This is all a learning process that everyone goes thru - you're doing fine. 

[canman]

OK, I got everything hooked up and I'm getting sound!  The bypass is, well...bypass, haha.  Works fine.  The boost portion of the circuit works wonderfully.  It's the main board again...when I turn up the gain all the way, and then turn the volume up, after a certain point all I get is a high pitched squeal.  Never encountered something like that before.  The sound I get before it starts to squeal is a fairly anemic sound as well, so something isn't quite right, obviously. 

The EQ works and sounds great...just gotta figure out where the squealing is coming from and how to fix it, haha. 

My initial reaction is that I wired up the pots backwards or something, because it only starts to squeal at one end of the taper.  And the gain and volume pots seem to interact with each other as far as the squeal goes so I'm not really sure which one is the problem.  How do you guys even start debugging something like this?  Where is the first place to look?

[GibsonGM]

Ouch! Ha ha - hey, at least it's kind of running, which says a lot!

Do you have an audio probe?  If not, I'd make one and try to trace your way thru, til you get to the bad area.   

For now, I'd say re-check all your pot wiring and be sure they're hooked up right.   What you're reporting isn't that odd, but I'd have to say it's not Supposed to do that!    Maybe another solder bridge, my friend...

[canman]

I don't have an audio probe, I really should make one though for sure.  At this point I just want to get this stupid thing up and running!!

I had the gain pot wired up backwards, but that didn't make a difference other than reversing the taper.  Does this sound like an offboard wiring issue or something on the board?

The pots I have don't have the plastic coating, is it possible they are shorting out because of the contact with the enclosure?

[IvIark]

The point of this FORUM has been to help people learn

And very good at doing so this site is too, that however isn't the point of mine.  Your preference is neither here nor there to be honest, people like what they like, no problem at all with that.  But I do the layouts for people who DO like vero layouts, and my only reason for posting here was to give my reason why schematics aren't posted along with the layouts.  I wouldn't do anything that may cause Google to drop the site, and so if they're not my intellectual property I'm not posting them unless I have permission.  End of story.  I would also hope that people using the site who would like to see a schematic are prepared to do enough for themselves to type the effect name in a search box at FSB, and sometimes I'm sent schematics anonymously and asked not to share them for a variety of reasons, and under those circumstances no one else will see them anyway.

Anyone who doesn't like the way I do things or who isn't prepared to do a little digging themselves are more than welcome to move along to the next site, although to be fair to the people who do use the site, it's not very often that I hear anyone complain about it, and when I have it's usually somewhere other than the blog and by people who don't like them anyway.

[IvIark]

OK, I got everything hooked up and I'm getting sound!  The bypass is, well...bypass, haha.  Works fine.  The boost portion of the circuit works wonderfully.  It's the main board again...when I turn up the gain all the way, and then turn the volume up, after a certain point all I get is a high pitched squeal.  Never encountered something like that before.  The sound I get before it starts to squeal is a fairly anemic sound as well, so something isn't quite right, obviously. 

The EQ works and sounds great...just gotta figure out where the squealing is coming from and how to fix it, haha. 

My initial reaction is that I wired up the pots backwards or something, because it only starts to squeal at one end of the taper.  And the gain and volume pots seem to interact with each other as far as the squeal goes so I'm not really sure which one is the problem.  How do you guys even start debugging something like this?  Where is the first place to look?

A lot of people have had squeal with this effect and I think it's just the nature of the high gain beast.  If you haven't boxed it then that will help a lot, but you may still get some oscillation afterwards.  The common cure seems to be short offboard wires and shielded wire for the input and output has really helped.  Check some of the comments in the blog thread.

[canman]

I love your layouts man!  I just suck at building this stuff, haha.  I'd love to learn more about schematics, I just don't have the time right now, so I glean what I can from the vero layouts.  

I've been reading some of the comments in the blog, I'm not sure if this is the typical squeal from a high gain pedal.  Even before it squeals, the distortion is tame...not has thick and heavy as it usually is.  I've built two of these before for friends and when I crank the gain on them I have some hum, but no squeal...it's like the last quarter of the taper, all guitar signal is gone and it's just squeal.  Very strange.

[IvIark]

Don't beat yourself up about it, you've done a decent job there looking at your pics.  I once debugged a Forest Green Compressor for quite some time before realising I hadn't plugged the IC in the socket, so we all make mistakes!

[canman]

I'm ok with making mistakes, but I want to at least know what mistake I made!  Haha!

The backwards IC...easy mistake to learn from.  Trying to locate on the board where I've gone/where I've screwed up the wiring...I'm pretty bad at that, haha.  I read through the blog for the TW, I didn't see much about oscillation, other than one or two posts...is there another area of the blog I should be looking?

[IvIark]

There's some posts about it in the blog's forum too and the FSB thread about oscillation, but I don't know where I saw the shielded wires mentioned.  So many forums and my aging brain can't cope