Vulcan Rat Creation

[jfrabat]

Little late for the 2n2...  It is already soldered in.  I thought that cap only served for avoiding hiss and noise from reaching the output?  Guess I was wrong, though...

[jfrabat]

Reversed 2 pots that were working backwards (I will later replace the B1M for a C1M when they arrive), and included some diodes:



2 germaniums in series and one BAT46 on the reverse direction.

Put the second coat of paint on the enclosure today.  I also need a 2P2T switch to wire the diode LED indicator for the diodes, but that will likely happen in january...

I will post again once the pedal is finished.  Tha ks again to all of you for helping me with this project!

[jfrabat]

Well, I know I said I would not post until it was finished, but what can I say; I am excited it's working!  So sue me if you mind me sharing!  LOL!

Here's the enclosure so far (knobs and other stuff are only for reference):



I still need to clear coat it and put all the guts in...

Oh, and here is a test without and then with the clipping diodes.  I recorded this straight from the DAW, and had to adjust volume so that it was at the same level (Audacity compressor).

https://drive.google.com/open?id=0B88Re3K-59SycVdoSTAzbzVwU1E

[duck_arse]

... I am excited it's working! ....

I still need to ..... put all the guts in...

this. most important. do not forget.

[jfrabat]

this. most important. do not forget.

Yeah, it is kind of important, isn't it?  [emoji1]

I have been using it without the box all weekend, though...

[Ben Lyman]

Very cool, love the graphic

[jfrabat]

Not yet finished, but...



Still have to:
1. Buy the missing knob
2. Cut the pots so that the knobs do not stick upwards
3. Wire the wall dc conector
4. Solder the signal wire on the stump switch I broke installing this
5. Eventuallu change the sitch to a 2P one so that I can wire an LED for it and install that as well.

But so far, so good!

[jfrabat]

Got the broken cables wired up (one from the diode module had also broken), and put the knobs in place.  And like Anakin Skywalker said, "IT'S WORKING!".  I have not yet connected the wall plug, as I need to find how to connect it (have not done it in my other pedals either!, but basically that's the only thing missing... Well and changing the switch to a 2P2T so that I can wire an extra LED to indicate the diodes are working...  But that I'll do in January after I come back from my trip!  Here's a picture next to my other pedals:



From those, the Little Angel is waiting a new PT2399 (it's not yet working), and the Ultimate Overdrive I do not really like all that much (it works, but to be honest, I do not think it is working right, as the sound does not change at all when I switch on and off the different diodes).  The Screechy Cat and the Vulcan Rat, on the other hand, are working just fine (actually, without the diodes, the Vulcan Rat sounds similar to the Screechy Cat, but the Cat cleans up faster as you turn the guitar volume down).  And a Tremolo just got started...

Thanks to all on here for helping getting this pedal to work!  Merry Xmas and Happy New Years to all!

Felipe

[Ben Lyman]

Looking good Felipe. You can also run the red clipping LED from its place with some wires and move it right into your LED bezel. Then when you throw the switch to activate the clipping diodes the red LED will glow on and off when you play your guitar.  It's a cool visual effect

[jfrabat]

Well, that's not a bad idea... I'll have to throw a LED into the diode board, though, as I do not have one.  Maybe I will take out the Germanium ones and replace them with a red LED.  But I will do that in January as well; I got to pack!  I am leaving tomorrow!

[jfrabat]

Don't ask me what I did, because I woke up at 2AM yesterday, took a flight home, and in the afternoon (not wanting to sleep because when I do sleep during the day, I have trouble sleeping at night, and I had to work today!), I decided to add the LED to the pedal.  Of course, now it is not working (no sound coming through even when bypassing).  My guess is either a wire came loose in one of the jacks or there is a short somewhere (most likely, it's hitting the case).  I will have to look into it tonight (or tomorrow night, depending on how tired I get home!).  But it is frustrating how delicate this pedal has turned out  and I blame the stiff wires, which break rather easily.  Luckily, I already have on hand new multistrand 24 gauge wire in different colors that I bought on Mammoth Electronics for my next project, and although I do not like them as much as the ones I got from guitarpedalparts.com (those were a bit stiffer, making them easier to work with), these are much more resistant to both heat and movement than what I was working with.

[jfrabat]

Found ONE of the culprits...  The signal wire broke off the switch.  Now bypass is working fine, but I am now getting a lot of noise from the circuit (which I did not have before).  There is another loose wire somewhere for sure, as the circuit works sporadically if I move the board around...  I just have to sit down and find it.

[jfrabat]

The wires I used have proven to be a REAL PITA!  They are VERY fragile. 

So, I have decided to redo the board.  I will also print a circuit board for it myself (I have done this twice, but I am happy enough with the results to try it here).  I am using the layout of the veroboard for the PCB, but it should look a bit cleaner.  I am also using stranded wire I got from Mammoth (I'l be honest, I liked the wire I got from guitarpedalparts.com better, as it was stiffer and thus easier to work with, but I ran out of that one, and I have 4 rolls of the Mammoth ones, so I will use them until the run out!).  I have not yet decided if I want to recicle parts or will just use new parts; I am leaning towards new ones just because of the hassle it will be to desolder the old board (unless I have any parts our of stock, of course!).  And I will keep the LED in the diode board, as I do want it lighting up when I use the effect. 

I'll post some pictures once it is done; it may be a while, though, as I am currently working on 4 pedals!  I have my Little Angel that I have yet to get to work (dry signal goes through, but no wet signal), I got an EA Tremolo I started while I waited for the new PT2399 of the Little Angel to arrive (similar error; dry signal works, but no tremolo effect), and I just got a Phaser PCB I bought (I will not start this one until the other 2 are working).

[jfrabat]

By the way, here's the PCB layout.  If anyone wants the PDF, drop me a PM and I will share it.

[jfrabat]

By the way, here's the PCB layout.  If anyone wants the PDF, drop me a PM and I will share it.

After building the pedal, I noticed that there are 2 holes missing.  No biggie, and the PDF is updated in case anyone wants it.  But just so you know.

Now, back to the pedal construction; I need help AGAIN! I finished building the pedal for the second time, but it's once again not working (I think I will keep my day job for now!).  I basically re-did the whole thing, so anything could be wrong.  I also added the wall DC jack, but that's not the issue (voltage is fine).  First, here are the pictures:



Here's a shot of most of the pedal (the 2 pots missing are behind the board).  Layout is almost exactly the same as before, as I am using the same box, stomp switch, and jacks.  Everything else is new (well almost; one pot is not).



Here are the pots.  Notice I kept away from the rivets this time around...



Here's a close up of the upper part of the rats nest... Ehrr, the pedal, I mean.



And the stomp switch and diode tray.





Here's the new board.  I checked continuity at all suspicious spots, and there is none where there should not be (at least I found none).  If you notice the cap and resistor that are slanted next to the LED and IN, it's becuase I drilled the wrong holes larger for the wiring.  But as far as circuit, it should not matter.  I also noticed while building that I did not use the 47 Ohm resistor as per the instructions; but since the old one had 100 Ohm resistor in place, I went with that. 

Now, I checked voltage at the input of the board, and that's working fine.  I also used the audio probe, and notice that the signal makes it to the board, but I loose it at Q1.  There is no amplification.  And I checked Q1, and it seems I soldered it the right way (please double check for me, but it seems that I did).  Also checked diode direction, and they seem to be fine (please double check as well).  And, as a result of past experiences, I also checked the resistors color codes, and I think they are all correct (please double check!).  Any other ideas?

Voltages are as follows:

Battery:
At Socket: 9.23V
At Board: 9.22V

Q1:
E: 2.03V
B: 2.76V
C: 2.04V

Q2:
E: 2.01V
B: 2.74V
C: 2.01V

Q3:
E: 1.99V
B: 2.71V
C: 1.99V

Compared to Ben's, these voltages are WAY off!

Just checked my volts, all are 2N5088 so maybe a little different.

Battery 9.4v

Q1
c 4.70
b 1.01
e 0.43

Q2
c 4.60
b 1.02
e 0.44

Q3
c 4.69
b 1.01
e 0.44

Any ideas?

[jfrabat]

Hi, guys; any ideas on what to check?  I went through it last night once again, but did not find anything.

[duck_arse]

jfra - are we still using this circuit? can you give us a parts overlay for your layout? each stage is, for some reason, doing the wrong thing the same way. it almost, almost looks like all your E and C are shorted together, and all your B are shorted, except the B-E voltage looks about right.

[Ben Lyman]

Filipe, did you get my PM? I thought it looks like r3 r9 & r12 might accidentally be 4K7 instead of 4M7 in your board

[jfrabat]

jfra - are we still using this circuit? can you give us a parts overlay for your layout? each stage is, for some reason, doing the wrong thing the same way. it almost, almost looks like all your E and C are shorted together, and all your B are shorted, except the B-E voltage looks about right.

Ben, yes, I am using that same layout.  But I think Ben hit the nail on the head!

Filipe, did you get my PM? I thought it looks like r3 r9 & r12 might accidentally be 4K7 instead of 4M7 in your board

Jesus Christ, you are right!  It is DEFINITELY a red band instead of a green one!

I can't believe I did not pick this up.  I was careful to read every resistor, test it with the MM, and then checked codes TWICE when troubleshooting!  And STILL I missed this!  I will replace them tonight.  Hopefully, that will get it to work!

Thanks a lot, Ben!

PS: No, I did not get the PM!

[Ben Lyman]

PS: No, I did not get the PM!

Oh wow, sorry you didn't get it a couple days ago. Anyway, I hope that solves it for you, keep us posted. I sent you a test PM just now to see if you get that one.
Good luck!