Bogus Schematics on the net.......?

[petemoore]

  I've seen a couple Duzey's posted, stuff that's like 'off limits'...somebody posted a schematic of a certain 'unattainable/desirable' 2Q Fuzz, and the Facto is there were obvious 'errors', to me and others at least, someone attempted the build, a waste of time and board...
  If it's something new, and you don't know about it's validity, just let someone else figure out if it has 'misnomers', or complete bunk...rare is the occasion of 'bunko schems'...just check it over or wait a day or two and it'll get sorted out.

[gez]

EPE.......Everyday Practical Electronics???

Yeah, but more like Errors, p*ssing errors!!

[StephenGiles]

What about this then?
http://img.photobucket.com/albums/v517/uncle_boko/EHface.jpg

!!!

[Torchy]

So far I have accumulated seven (7) schematics for the Brown Source. I built all of them. None of them work. I have tried, a friend has tried, to modify the most productive schematic. It boosts, the tone control works, it aint no fuzz. I changed the schem to the usual diode clipper. Now fuzzes but doesnt sound anything like the original.

All this without being able to open up an original ... this is the fifth pedal I have tried to "remotely" RE and my faith in web schematics is rapidly dwindling.

[markm]

Well, not to celebrate anyone's misfortune, I at least feel better knowing I am not alone in this!

Oh c'mon you guys!  If it's on the Internet, it has to be true....

It *is* a golden day when you can methodically trace through a schematic that is wrong, know what's wrong, why it's wrong, and then proceed to make corrections and get it to work as advertised.  That's only happened to me a couple of times, but i was glowing the rest of the day from it.

Oh how I look forward to that day.
I hope I'm around long enough for it to happen! 

[phaeton]

Well, not to celebrate anyone's misfortune, I at least feel better knowing I am not alone in this!

Oh c'mon you guys!  If it's on the Internet, it has to be true....

It *is* a golden day when you can methodically trace through a schematic that is wrong, know what's wrong, why it's wrong, and then proceed to make corrections and get it to work as advertised.  That's only happened to me a couple of times, but i was glowing the rest of the day from it.

Oh how I look forward to that day.
I hope I'm around long enough for it to happen! 

Just so you know, these circuits weren't complicated by any means.  One was a single-transistor fuzz, another was a tremolo that was easily divided into a 555 flasher and a 741 boost.  They were designed by a friend of mine.  The fuzz circuit had a biasing problem.  I think he meant for it to be 'misbiased' so it would clip, but the way he has it setup the transistor was biased "off".  This was the first circuit I ever soldered together, over a year ago.  I came back to it a few months ago and that's when I figured it out.  I keep emailing and PMing him to share notes and invite him here, but he's been swooped up into a whirlwind romance with some pretty latino girl that he works with.  Doesn't have any time for me, or DIY stuff.

He knows what he's doing when making circuits, I just think that either SPICE or CircuitMaker lied to him.  He's got a pile of tube amps that he's built, some of which are pretty nice.  Maybe if we all visit his homepage, he'll wake up and pop in:

http://geocities.com/teleman28056/projects.html

[amz-fx]

There are lots of bad schematics on the net...  the bad Rat schematic is one that comes to mind.   It will never work as drawn but is copied and posted on numerous sites and never seems to die.

Another example...   there is a guy with a big schematic site that rips off artwork from everyone in the DiY hobby...  he had one of my designs on his site and I asked him to take it down and to please just link to the original on my pages.   He took it down....  then a few days later he reposted it  in a version that he had redrawn.  In the process, he made a mistake on the drawing and now there is a bogus version circulating that won't work!   

-Jack

[George Giblet]

>The schematics I've found from reliable sources, that I have done layouts from and that are quote "verified", always seem to fire right up! I'm beginning to think there are more "uncertain" schems kicking around the net than actual real working ones.

I don't think you can judge the accuracy of a schematic from such comments.  A nieve tracer may not make any such comments, have the unit in front of them but generates a totally unworkable schematic and layout; there's many examples of this.   Alternatively an experienced tracer may add a note relating to uncertainties when the schematic may well be correct.   Many manufacturer's schematics are wrong.  There's also schematics and layouts people put up for circuits that have never been built.  The conclusion is you can't tell anything about accuracy, even if it appears to work, and even if it sounds close to the original.

If you are having problems with your build I would not point the finger.  Just put up the schematic and layout and let people on the group help you get it working.  If enough eyes go over it any errors on the schematic or layout can be picked up.  You can of course make build errors and if you blame the schematic you might not try hard getting the unit to work when in fact it could be made to work.

Something to think about.

[markm]

There's also schematics and layouts people put up for circuits that have never been built. 

This is what I was getting at in my original post.

>The schematics I've found from reliable sources, that I have done layouts from and that are quote "verified", always seem to fire right up! I'm beginning to think there are more "uncertain" schems kicking around the net than actual real working ones.

I don't think you can judge the accuracy of a schematic from such comments. 

Not passing judgement at all.
Just a generalized statement and coincidence maybe?
I don't know. It is strange though isn't it?

If you are having problems with your build I would not point the finger. 

GIVE "the finger" maybe but, I wouldn't point!! 

Just put up the schematic and layout and let people on the group help you get it working.  If enough eyes go over it any errors on the schematic or layout can be picked up.  You can of course make build errors and if you blame the schematic you might not try hard getting the unit to work when in fact it could be made to work.

Ya know, I've been there and done that and you're right, there is loads of help here. I have had a few project issues worked out here for the better and problems solved too. That said, my original post was a generalized statement. When I typed that post out I had no idea I would even remotely get anyone's panties bunched up over it.
I have to agree with what you were trying to convey and that is, there are schematics that are posted that are unverified.
in some cases, alot of schematics posted that are not verified.
Those for the most part, are what I have been messing with as of late. I am a newbie at reading schems and doing layouts but I'm learning everyday.
Thanks for your advice. 

[StephenGiles]

http://img.photobucket.com/albums/v517/uncle_boko/EHface.jpg

No comments??

[markm]

Would I be wrong to say this is not an "authentic" EH schematic?

[nelson]

Would I be wrong to say this is not an "authentic" EH schematic?

There is no EH pedal with that name. That I am aware of.

[StephenGiles]

It just proves my point that circuits can be altered easily in Paint!

[markm]

Now who would post something like that on the internet? 
Isn't the net supposed to be like Pleasantville or Mayberry? 
Thanks for the point there Stephen, very well done.

[lvs]

A small anecdote about a very small circuit. Actually, the schematic is not "bogus", it's rather "official".

Some time ago I became interested in using a dual blend pot in a passive guitar circuit. Before buying one I did a simple spice simulation of the parallel blender circuit depicted at the Stewmac site. I got results that raised questions about what resistance taper it takes to hear a continuous change while turning the pot. A passive circuit like this, with each pickup seeing a load that's even lower than it's own resistance, would require a different pot resistance taper than an active one using buffers.

Lindy Fralin had figured out that actually a reverse log tapered pot works well for blending in a pickup in a passive circuit, for hearing a continuous change. My simulation appeared to agree with that and a simple test with a single log pot also. So, to make Stewmac's passive blending circuit work right, I assumed their blend pot had to be dual reverse log. But wait, on the same page they also have a stereo circuit with the same pot, where each pickup drives a separate channel. That's where (forward) log tapered pots are appropriate rather than reverse ones.

Those two circuits using the same pot, a bit funny. In one circuit, blend pot resistances should be tapering off towards the middle detent, and in the other, towards the outside positions. I mailed Stewmac but the guy at the other end didn't seem to understand the problem. (Not entirely his fault I guess - I'm not so good at explaining things in English. If you are reading this... still awake?)

I decided to ask the question at a guitar electronics forum. A Member Of Good Standard and a Moderator jumped in, so that should guarantee getting to the point... well...

<edit : copy of that conversation deleted >

Eventually I just had to find out for myself. I know now that Stewmac's parallel blender circuit is something I never gonna install. There's a lack of gradual control. Their stereo circuit will work ok.

It's valuable to me to try to understand the things I plan to build, respect other people's expertise but also question it, and not believe something just because it's there.