I can't even build a tube reamer!

[GreenEye]

I told myself I wasn't going to post my tube reamer failure, but I find some relief in crying on my stompbox brothers' (and the one sister's) shoulders.

All I know is I spent many an hour on this damn thing this weekend, and it ain't working.  My voltmeter may as well be a rock with wires, I can't figure that thing out either.   :oops:

I think I've got a grounding issue, and perhaps some sloppy soldering around the IC socket.

The weird part was, I switched the tip and ring connections of the input jack for shits and giggles, and oddly, I got somewhat of a distorted signal, but it wasn't behaving very nicely.

I'll figure it out eventually, but if anyone built it already and had a particular BUG they worked out with this one - let me know what it was, perhaps I made the same mistake.

[Fret Wire]

Well, if you want to start from the beginning, remove all the offboard wiring. Hook up the +9v and ground to your battery, and measure the IC pin voltages. Post them here. Then we'll see if the problem is on your board, or the offboard (jack & pot) wiring.

[petemoore]

Voltmeter..I'd have to recommend a cheep decent DMM for easier problem finding. My voltmeter's gone unreliable before. with it's readings as reference, it's difficult to spot the problem.
 When things look messy by an IC chip under the board, I test continuity [beep mode of DMM] between pins 1 and 2, 2 and 3, 3 and 4...5 and 6 etc. to see if two are connected [rarely should they be].
  I check to see if the battery's shorting.
  Check all grounds.
  Take pin voltages
  Usually I find the problem
  Then do the 'thumb' probe...my thumb connected like an audio injector...starting from the output, testing to see if I lose the 'buzz' sound..I find loss of signal often using this method [touching the shank of a small screwdriver to my thumb and...] wiper of output pot, signal input to output pot, Opamp output/capacitor...etc working my way back [right to left] through the signal path on the schematic/on the circuit  board with amp connected.
 See if you can locate where in the schematic/and circuit board you're losing the signal.

[GreenEye]

Pete: So everything should make a buzz/pop when I touch it, IF everything is hooked up correctly?

Fret Wire: I thought I'd post some values on my op amp pins before I go ripping out all the off-board wires.  This is how I did it: with the black lead from my multi-meter connected to the ring of the input jack, where the negative battery is going, and the red lead on the following pins, I get:

(looking at top of board, starting at the upper left of the IC and going down), in Volts
1. 9.44
2. 8.60
3. 4.80
4. 9.47

(now from top of right side, going down):
8. 0.00
7. 9.56
6. 8.97
5. 9.44

Maybe the big goose egg on #5 means something, but then again, it's not connected to anything.  [This is with the battery reading at 9.56 alone]

[GreenEye]

After looking at the value on pin #3, I should make a confession.  I made the following "mod" to the connection from the input cap to pin #3, which at the time I didn't think would matter (maybe it F-ed it all up though).  It seemed like the same thing to me, I just extended the lead from the cap to the resistor and then up to the pin (in green).  Instead of putting a jumper from the cap to #3 (redlined out).

[Fret Wire]

IC: top left (red dot) down:
     1
     2
     3
     4

Top right down:
     8
     7
     6
     5

Post those again in the right order. What IC did you use? I'll dig out my reamer and check my voltages.

[jimbob]

I built this one--great build--Its simple enough that if it dont start right up ill try a few things--if i cant figure it out i just re-build it..Thats just how i do it though..Smarter folks actually figure it out..

[GreenEye]

Fixed the pin order above.

First, I tried a "741 operational" from Circuit Specialists (their Part No. MC1741CP1).  Then I popped in one I had gotten from Small Bear (which corresponds to the values in this thread), which was a LM741.

Thanks!

[Fret Wire]

I checked mine - battery 9.44v

1. 0
2. 4.65
3. 4.24
4. 0
5. 0
6. 4.68
7. 9.41
8. 0

Even though that's my actual unit, the voltages would be similar with any single IC ckt of this type. Here's the voltages of GGG's Dist. +, which uses a 741, connected in the same manner:
http://www.generalguitargadgets.com/diagrams/dist_ic.gif

Pins 1, 5, & 8 are not connected. Pin 4 goes to ground. Pin 7 should be at full battery voltage, and pins 2 & 6 should be at half power supply voltage. Pin 3 should be slightly less than half supply voltage.

Your IC has a small circle or half circle molded into one end of the top of the chip. Check to make sure that you install that end to correspond with the red dot on the ROG perf layout. Your voltages are way off.

[Steve C]

After looking at the value on pin #3, I should make a confession.  I made the following "mod" to the connection from the input cap to pin #3, which at the time I didn't think would matter (maybe it F-ed it all up though).  It seemed like the same thing to me, I just extended the lead from the cap to the resistor and then up to the pin (in green).  Instead of putting a jumper from the cap to #3 (redlined out).

You were right in thinking that wouldn't make a difference, because the three points are still connected.  

If I read your previous post correctly you weren't sure how to use the volt meter so I'll say the following.  Make sure you meter is set to read voltage and put the Black lead on your ground or just the - side of the battery and while keeping that there, touch the red lead to each pin of your IC and note the reading on each pin, and see what you get.  The only pin that should be around nine volts would be pin 7.

[GreenEye]

Thanks to all for the input.  

For what it's worth, I think it's the old "too much solder" problem.  This was my first build with a Radio Shack "PC Board," which has all the little copper circles on the bottom.  Maybe it's not even intended for a guitar effect application?  The copper circles are so close together that it's nearly impossible for a newb to not bleed over to the adjacent ones.  I'm going to do this one over on perfboard with no copper!!!  :twisted:

Steve: regarding the meter, my biggest problem is figuring out how, in a working circuit, there's a reading on one side of some caps, but not the other side.  Some caps, though, show a reading on both sides.

[petemoore]

Yupp, won't work with those voltage readings.
 Be certain the chip is the right way around...I've fried chips by installing them 180 degrees...pin 1 [indicated by the dot on the chip] should be at the left top, pin 4 at left bottom [4 is ground].

[petemoore]

I've been using one of those cheepo RS soldering irons with the pencil tip.
 I mount that in a brick hole, so I have an 'extra' hand for holding the solder, board, and part to be soldered in place on the board.
 When I twist the wire/lead 'just right, I can let go or hold it from atop the board so it stays put where I want it when soldering.
 I used to do circuits on a hardback book cover, paste the schematic right on the hardboard, then drill little holes and lace / solder the circuit in that, but since I got better at perfing [about 20 lbs of projects ago] I haven't had any problems...other than those of my making...no perf problems.

[Fret Wire]

Well, if you did have your IC orientated properly, then those voltages you posted are probably the result of solder pads touching on the IC pins. You did check your IC orientation, right?

The RS perf will work for pedals, you just have to be careful around the IC, and any jumpers that run off it. That's with any perfboard. Solder the IC first, then check with a magnifying glass to make sure no solder pads are touching. Then solder the jumpers and check again. Even better would be to solder the IC pins that have no jumpers first. Then, solder the other IC pins and their jumpers at the same time. You can use your DMM to check also that no IC pins are connected.

Then you're all set to do the rest of the ckt, which will be easier than the IC and it's jumpers.

You can still salvage what you have if you use soldering wick to remove some of the excess solder as well as an exacto knive to clean any touching pins.

[jimbob]

The RS perf is about all i use and it works about as good as anything else. When im done, i get a magnifying glass and a knife or something sharp (sometimes a dremmel w a rugged tip and clear a path between pads where theres not supposed to be anything. It works great for me that way but you really cant re-use the board later if you change your mind and want to recycle the board for something else.

[GreenEye]

I kicked that tube reamer's arse!!!    

I thought perhaps it was something in the circuit I wasn't seeing, like maybe I wasn't reading the cap or resistor values correctly.  So I breadboarded it, and it works like a charm.  My first breadboard too!  Whoo hoo!  I like it, and will be committing it to perf soon.

I think I'll be breadboarding most of the circuits I try from now on, to verify the parts and so I don't end up with a room full of effects I may not want.

[bwanasonic]

I much prefer the pad-per-hole perf. If you are flowing solder all over the place, you might need a finer iron tip and maybe less heat. As others posted, a magnifying glass and a pointed object or xacto blade are really handy for checking and fixing unintentional solder bridges.

Kerry M

[petemoore]

I use the 'scallop' of a half worn out RS pencil tip, and it works to eliminate solder bridges.
 I knock the blob off the hot tip by hitting the iron against something, then touch it to the one outside of where the solder bridges across two pads, just enogh to melt most of the glob onthe board, then hit that glob off the iron tip and repeat a couple times, never overheating the board.
 Then maybe I have to go to the  other side of the bridge glob and repeat steps 1&2, but angling the board so gravity [yes gravity does 'pull'...for those 'disbelievers' disregard such a suggestion, but don't sit under an apple tree].
 Because the solder won't stick to phelonic board, it will draw to the metals.
 Third hand or mounted iron [what I do] is recommended.
 Approach and retreat need to be accurate, I like to be able to rest my wrist on a fixed object when the board is about 1'' away from the iron tip, makes it much easeir to do accurate approaches and retreats of the tip to the pad/lead point.
  Right before you're about to solder a connection, clean/get the blob off the tip of the iron, then add just a touch fresh solder to the tip, apply the 'tinned' tip to the pad/lead [perfhole with wire and or OA socket lug pin in it], add a teeeny bit of fresh solder right where the tip and wire coming out of the padhole meet, then the copper pad and the wire should heat very quickly and by touch/touching little dabs of solder where you want them [about the time it takes you to retouch the solder to the heating metals, the metals should have just enough time to 'recover' heat]...see the solder will cool the tip, and especially the pad, especially if the added cold thermal mass of the solder is between the hot tip and the cooler portion of the solder joint ...1/16'' to 1/8''es away.
 Trick is get the metals just hot enough to 'grab' the solder without adding so much that you get 'overglobbed'.
 I find that clean freshly tinned tip of the iron conducts the heat more consistantly, and touching the solder a few times as I heat the metals to the point where the whole copper pad grabs solder makes it easy to get a nicely shaped connection and structural bonding.

[Lonestarjohnny]

Smart move Greeneye's, the breadboard lets you throw the circuit together in a hurry, takes time to make all those solder joint's,
Me, I like to perf, it's more fun than just throwing this stuff on a circuit board, and it look's soooo homemade, i get some pride out of this way, also when my bud's look at it and go, wow, you made it, sorta makes ya feel good ! :mrgreen:
congratulation's on getting it going, and
just take your time wireing in your switches and jack's,
Johnny

[GreenEye]

I appreciate all the input greatly.

I don't know if it's my technique or what, but the tips of my iron go "bad" after about 2 effects.  The tip becomes irregularly shaped, as if part of the metal has been worn away.  It ends up with a hook-like end, with only one side able to conduct heat efficiently.  I thought tips lasted longer than that.  Probably because it's a rad shack iron.  I'm not getting anymore stuff from them, it's all so unreliable.