Shockingly Funny - Lefty Does Electronics!

I have never put the time I should into electronics so I’m just a minor tinkerer.  I got re-excited about it recently and have started burning myself with a soldering iron more regularly lately.

I’ve always wanted to steal design a tube guitar amp and build it.  I was nearly successful a little while back and decided I needed to recreate my success (or at least some variation of it).

For those of you technically inclined folks following along at home, my first target is a very low powered amp, on the order of a Fender Champ (12AX7 –> 6V6).  I found a Vox AC-4 schematic and attempted to modify it by omitting the vibrato so it would just be EF86 –> 6BQ5.  It took some time and a lot of patience on the part of someone who knows more than I do but it worked(!)

I’m not sure why but it got put on the back burner and I wound up tearing it apart.  I recently tried to rebuild it, to no avail.  Just for fun, I went back to a modified Champ circuit (lotsa gain and a solid state rectifier).

The Build Gods are clearly not smiling upon me these days.  Below is part of my story….

So I built a small amp and it flatly refused to function.  I redid the output section and it still retained the most amazing S/N ratio, in that there was no signal OR noise.

I’m trying a different method these days.  I put in a few hours, then stop right before the chassis becomes airborne.  It seems like a very wise thing to do (and entirely out of character for me).

So I came back the next day and started troubleshooting.  A-HA! I think I have this brand new disorder that’s so new it doesn’t have a name yet.  It’s some weird combination of ADD and dyslexia.  Once again I had reversed my tube socket numbering.  For the life of me, I have a ton of trouble getting this right and it’s frustrating as hell.  Mind you, I have no trouble at all remembering each and every jumper wire, where it goes, and what it’s doing.

The amp will definitely never work if one doesn’t hook the plate to the output transformer.  So I did.  The right output transformer this time.   The amp obliged me by continuing its steadfast refusal to function.  Time for more troubleshooting on a different day.

So the Different Day arrived and I sat down with an (allegedly) fresh head.   A-HA! I went again.  This time it’s not working because there’s no voltage.  Well, not entirely.  There was no voltage because I forgot to hook the negative lead for the meter back up.  It’s not talented enough to read an accurate value with only one lead and I’m not talented enough to remember the 2nd lead.

It has already been suggested that I need a smarter meter.

In case I was bored, I turned to locate some parts and the amp did a triple gainer with whipped cream onto my lap.  This was all the more interesting because although I did unplug it, I hadn’t discharged the caps yet (400 volts).

Yet another great thing about tube circuitry is its tolerance.  Even when *I* can tolerate it no longer, it keeps running.  It keeps running in spite of my repeated attempts to stop it from running, via shorting things out and making all sorts of `interesting’ bzzzzt noises.

In fact, the only noise the amp has made so far is the bzzzzt noise it makes when things keep shorting out against other things.

I’m thinking the concept of waiting for a different day before troubleshooting is nowhere near as wise as it sounded (these things rarely are).  I could have produced the same result by continuing to scream at it all night long.  It’s even possible that I might have fixed it (yeah, right).

Just sharing my pain in hopes of provoking a smile elsewhere.