Vulcan Rat Creation

[jfrabat]

I don't think there is a 100p in this... do you mean the 47p? That one is not important.

Check the transistor pin outs. Maybe they're backwards?

Yeah, I am missing the 47 pF cap (sorry)...  I have to check the whole layout; I also need to check it against the right diagram. I just noticed I used the failed experiment as a base.  I just finished building it last night, but was too tired to check it.  I will get to it tonight.  It is not that complicated of a design, so I just have to go over it.  I am sure I will get it working without many issues.

[Kipper4]

Check the breadboard voltages.
My breadboard for example needs a jumper from one half of the power rails to the other.
Well IT could be?

[Kipper4]

See here

Breadboard power rail jumper https://imgur.com/a/iSk0w

[jfrabat]

I do have the Jumpers...  on the left side of the pic you can see them (red and black).

[Ben Lyman]

even the experimental one will work, I just didn't like it much.

check that each power rails are connected horizontally as well. Some boards have a break in the center

[duck_arse]

See here

Breadboard power rail jumper https://imgur.com/a/iSk0w

kipper - see that nest of transistors top right corner of yer BB? get in the habit of sticking them in so the pins are all shorting, so 90^o turned from shown. when/if you happen to stick a mosfet in, it will then be protected from static damage.

[jfrabat]

Well, I got home last night and decided to start from scratch.  So I pulled everything off the breadboard, put the schematics back on the screen, and realized MAYBE it was not working because I connected the guitar to the output and the amp to the input...  Of course I realized this AFTER I took everything off the breadboard!  Anyway, I started putting it in the breadboard again, but I did not finish (took the wife to the movies instead; that's a kind of important project as well!  ).  I can't work on it tonight, but I'll finish it tomorrow and take it for a spin.  Well see how it goes...

[Ben Lyman]

...connected the guitar to the output and the amp to the input...  Of course I realized this AFTER I took everything off the breadboard...

Good! This is the kind of stuff that speeds up the learning process!
It didn't kill you so obviously, it just made you stronger 

[jfrabat]

Something like that... Now I am debating if I BB this one or the Deep Blue Delay...  I want to do both, but dont have enough breadboard space!  LOL!

[Ben Lyman]

definitely do both but remember:
You can live without delay but you can't live without distortion!   

That delay is a bit more complex than the Vulcan but all things considered, they are both pretty simple

[jfrabat]

I am getting frustrated, to be honest...  I got home late, and decided to take a crack at the Deep Blue Delay.  Got it on the breadboard, but could not get it to work.  That means my last 3 tries have been fails!  I got a little angel all boxed up, but no chorus effect.  I built the vulcan rat, but could not get it to work (out of stupidity, yes, but still!), and now the delay!  I do have my own overdrive (I call it the Screechy Cat), and it sounds pretty good, but I wanted something more aggressive (which is why I wanted to do the vulcan rat, and still will).  I am just PO's that all the latest tries have been for naught!

I think on the VR, I will skip the breadboard and design a point to point layout and go straight to the box!

Felipe

[jfrabat]

Got it back on the breadboard.  It's AMAZING how much better it sounds when you connect the amp to the output and the guitar to the input!     I did have a couple of resistors wrong (I think it was a 2.2K I used instead of a 2.2M) that I corrected.  Also had to steal a couple of 223 capacitors from the Deep Blue Delay, but since that one is not yet working, it dont really matter...

I really like the sound, so I'm gonna to a Point to Point layout and put it in a box.  Nice compliment for my Screechy Cat!



Nice way to get my morale back up!  I also got a real PCB for my little angel build, so that will also turn out well soon (I HOPE!)!

Felipe

[Ben Lyman]

congrats! I'm glad you didn't give up. Did you add the crunch box presence control?

[jfrabat]

No, right now it is straight out of the schematic.  I'll play with it now that I have a working prototype.

Sent from my EVA-L19 using Tapatalk

[bluebunny]

It's AMAZING how much better it sounds when you connect the amp to the output and the guitar to the input!   

LOL!  Been there, done that...   

Glad you're making progress.   

[jfrabat]

I am in the process of moving it from the BB to a perforated board and boxing it up...  I got everything soldered up (NOT my prettiest job!) on the perforated board, but I am missing 47 ohm resistor for the voltage protection circuit.  I also need to make the holes in the box and solder a couple of jumpers to the diodes (which I placed in the board instead of the switch).  Tomorrow I'll make the holes in the box, and wire up the stomp switch and jacks.  I'll have to go Monday to the store for the resistor.  Already checked for continuity, and I did not find any shorts or other issues.

[Ben Lyman]

Cool. the 47r is for filtering purposes, it works in conjunction with the 100uF to create a low pass filter... cuts the noise but passes the volts to the effect. If you don't have a 47r you can still get away with anything close, maybe up to 100r at the most? I don't know for sure what is the most you can use, hopefully someone will tell us soon, maybe you can go as big as a 1K?

The 1N5817 diode is the actual protector.

[jfrabat]

I have 100R if that will work...

[Ben Lyman]

ya, 100r is fine, use that

[jfrabat]

Wired everything up, but screwed up somewhere, cause now it's not working (and it did on the BB).  Have to go over it now, but will do it later...  I am tired of working on pedals this weekend!  Actually working on 2 at the same time!