Please help, Marshall SupaFuzz + LPB

[KerryF]

Ok, so I have built a bunch of things with no problem.  Now, I just finished my Marshall SupaFuzz, which is working great, but I decided to add an ElectroHarmnoics LPB Volume Boost to the pedal.  Its seperate and all, but after I finished both, I was going to connect them in the same enclosure.  Well, I just tested it, totally seperate from the SupaFuzz, and it is sortof working.  The sound goes through and all, but theres no boost.  All there is, is a loud click when I press the bypass switch, and if I switch pickup positions.  Can someone please let me know any problems they can think of?  I used the 2N5088 first, then a few others, but they all sounded the same.  I am using a socket for the transistor, but I had problems with the socket not working for the Germanium Transistors in the SupaFuzz, but when I took it out it worked.  Maybe I should take the socket out, but any other help?

Thanks, Kerry.

[burnt fingers]

I think this thread addreses that problem.

http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=14a8570a6bf69bef60252854827ed7a3&topic=29816.0

[Peter Snowberg]

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Please title your post with an accurate title for faster service and for ease of reference by others in the future. Thank you.

[petemoore]

IIUC you're attempting to debug an LPB.
  Sockets wirings can be tested with a DMM, find where the socket pin is to be connected and test with 'beep mode' for continuity to all points it is supposed to be connected, and NoN-continuity to adjacent socket pins...or anything else that is not shown as connected to that node on the schematic.
  For Debugs, "DEBUGGING..what to do when it doesn't work" is at your disposal for developing debugging chops.
  Can someone please let me know any problems they can think of?
  Oh yes...100's of them..if not more.
  Here's two:
  Misbiased transistor
  Misconnection
  "Extra connection"
  whoops that's three, but I add: any possible combination of these three, + a few others, x10.
  Your DMM can help isolate the problem, if not the audio probe will help.
  Ok, so I have built a bunch of things with no problem.  Now, I just finished my Marshall SupaFuzz, which is working great, but I decided to add an ElectroHarmnoics LPB Volume Boost to the pedal.
  I would go about the debugging...one circuit at a time, actually, one gain stage at a time in this case.
  I only rely on 'sounds cool' to determine if a circuit is working properly when I know exactly how the circuit works [by having tried another known working copy], I always subject them to the debugging process, at least the voltage readings [when it's boosting or passing the right amount of signal...ie I don't need to use the audio probe to find a signal loss], to verify all the biases are within operational parameters.
 
 

[KerryF]

^-I have gone through most debuging I think, and everything seems fine.

Also, I tested this, by itself.  Not through the SupaFuzz at all.  Totally seperate.

[KerryF]

So I just looked at the Debugging thread, and nothing seems to be wrong with it.  The SupaFuzz works great but the LPB doesnt.  And like I said, they arent connected yet, still running seperate and I am testing the LPB by itself with the guitar->LPB->amp.

I am thinking it may be the socket, because like I said, when I built the SupaFuzz with sockets for the transistors, it didnt work, and then when I took them out, and put the transistors right into the circuit, it worked great.

[Peter Snowberg]

Measure the voltages.

[petemoore]

  So I just looked at the Debugging thread, and nothing seems to be wrong with it.
 I looked and couldn't find anything wrong with 'it' either.
 Except 'it' isn't working, simply because of application failure.
 I am thinking it may be the sockets.
 Why? Re-read the above posts and you'll see this is a waste of time, verify Via DMM whether connections are made.
 re-read the degubbing thread and present your findings in the manner dexcribed.
 Then there's a very good chance We'll be able to fix the LPB.  
 Otherwise, yes it could be the sockets, or anything else.
 
 
 
 

[KerryF]

Ok so I just put it together on my Breadboard and it worked perfectly.  I just scraped the first LPB and started fresh so hopefully it will work this time...

[KerryF]

Ok so I finished the new LPB on the veroboard, exactly how I did it on the breadboard that worked.  It doesnt work on the veroboard though for some reason.  Its actually quiter rather than louder.  So I built the LPB twice on veroboard (didnt work), and once on breadboard (worked).

Also, I tested the Marshall SupaFuzz again and it wont work.  I changed nothing, and it worked about a week ago.  I have no idea what is going wrong here.  Its really strange...  I built the ColorSound ToneBender with the same layout, and it worked and still works great.  The SupaFuzz worked now doesnt work for some reason...

[burnt fingers]

Measure the voltages.

Help us, Help you.  You can give a man a fish and he eats for a day, you can teach him to fish and he'll never go hungry again.

[petemoore]

Ok so I finished the new LPB on the veroboard, exactly how I did it on the breadboard that worked.  It doesnt work on the veroboard though for some reason.  Its actually quiter rather than louder.  So I built the LPB twice on veroboard (didnt work), and once on breadboard (worked).
  I think if you repeat this enough times, like rolling dice and Murphy's law, the breadboard and vero chances of success will equal out.
  Buggin while you go...I used to measure every resistor just prior to it's installation.
  I haven't heard mention of a DMM.
These allow being able to work on getting a circuit debugged with any effeciency.

[KerryF]

yea... well i dont really have a DMM yet.  how much does a simple but working one cost?

[captntasty]

This is not just me being a jerk...  You MUST have a DMM!  I am by all standards pretty much a noob, but found out very quickly that building pedals without a DMM is like driving a car without a steering wheel - you might be able to go fast but in only one direction!  Sooner or later you'll hit a wall!  I've seen them for as little as $5 for the most basic, $15-$20 will get you pretty much everything you need.  If you can afford components to build, you can afford a DMM.

[phaeton]

Yes, a Digital Multi Meter is an absolute must, and the bonus is that you can buy one 'good enough' for stupidcheap.  You can also spend hundreds of dollars on one but for stompbox stuff you don't really need anything fancy.  Like captntasty said- $5-$20 would get you rolling, and you can find them in your local Wal-Mart, K-Mart, Sears, RadioShack, etc.

Most of them measure the 3 important things:  Voltage, Resistance, Current.  Some have a continuity test which is very handy, but you can also build a simple continuity tester yourself if you had to.  Autoranging is a nice feature, and I think it's pretty much become standard- get it if you can in your price range, but don't sweat it so much if you can't.

Not harping on you- just telling you how it is.  As you're seeing, you can build stuff without one, but when something doesn't work there is very little you can do to figure out why.  Schematics on the web can be wrong. Components can be out of spec.  Several components can be on the fringes of their tolerance all in one direction and cross a tipping point.

Instead of building a failed circuit again and hoping for the best, you can poke around for 10 minutes or so with a DMM and replace/adjust the one or two components that are causing trouble.

Good luck.

[KerryF]

Sounds great man.  I already have a continuity tester which is VERY helpful so I guess I will have to get one of these.