Amp Project Fail/Win

A while back I purchased a lot of the parts needed for a Ruby Amp project.  This is a little 1/2 watt solid state amp. I started to put it together and then got side tracked. One of the things I’ve been trying to do this year is finish up all my little guitar projects I have collected over the years instead of getting more projects.  This is a difficult mind set to change. I am always on the hunt for new projects. And new projects usually consist of trying to get something for really cheap that needs a little help.

So I spent a big chunk of Saturday and a portion of Sunday putting together my Ruby Amp. On Saturday night I had everything wired up. The LED light would come on when I put a batter in or plugged in a power supply (yup, I went all out and added a an LED indicator light, on/off switch, and headphone line out to the schematic).  But I didn’t get any sound at all. Not even a bad hum.

I went over everything that evening and realized I had left out a two jumper wires on my perf board.  Got those on and I had hum!  No actual guitar sound, but at least it was humming. So I put it to bed and relaxed.

On Sunday I went over everything again. It is all there. But I started messing with where the ground wires all go.  Then I moved the wires for the LED light. The gain and the volume all impact the hum. The switch turns it off an on. The LED light functions with the switch (it was always on before).  But no guitar amplification.

I am not very technically minded. I cannot read the schematic very well and have mainly relied on pictures of other people’s boards online.  Maybe, if I’m free for a long period of time, I’ll draw up my own blue print of the Ruby Amp with the mods I added.  Of course, it won’t be a very popular blue print if it is for an amp that doesn’t actually amplify a guitar…

My whole goal for doing this (besides living that DIY spirit and being a “maker”) was to have a little amp on my work bench for when I’m working on a guitar out there.  In the same spirit I also got two junk amps from my local guitar shop.  One was the Raven RG100 that I turned into my 2×12 speaker cabinet.  The other is a sparkly red vinyl Kustom practice amp with a little 6 inch speaker.  Neither worked. I figured the Kustom could become a speaker cabinet or could house the Ruby amp I was building.

As I was working on my Ruby amp project I pulled out the Kustom for a distraction. I took it apart and found that the only obvious problem was broken input jack.  But replacing that is usually very easy. There must be something more to it because it was thrown away. But I had the right type of jack from the Raven and I just had to swap it with the broken one in the Kustom, so why not?  Today, in about 20 minutes, I swapped the broken jack in the Kustom for the jack in the Raven.  I plugged in a guitar and got sweet guitar amplification!

I could not believe it. It was so simple. And after I had spent so much time on my Ruby amp.  I will admit that the electronics board on the Kustom would not come all the way out. It was tricky to get my soldering iron in there and not damage anything else. I’m sure that the guitar tech at my local guitar shop told the customer that the cost of the professional repair would exceed the value of the amp… so it got junked to me… and I am much less valuable than a professional repair.

So I now have a little amp on my work bench just like I wanted. And what is the moral of this long tale?  Look around for alternate solutions before you dive into one of your DIY projects.  I could’ve spent 20 minutes on the broken amps and spent the rest of the day playing the guitar.

I’m sure someday I’ll come back to my Ruby amp.  It will be cool to say I, an inept DIY-er, made an amp.  But for now, I’ll just enjoy the Kustom on my work bench and worry about what I ruined on my Ruby amp later!


3 thoughts on “Amp Project Fail/Win

  1. I don’t know about you, but for me, part of the joy of being a maker is not giving up when it gets a bit tough. Learning a new skill, applying it, and then overcoming the initial challenge is where the pleasure lies.

    Now when it comes to troubleshooting a schematic, even if you have trouble reading them, I found the secret to be checking the things that the schematic say should be connected to each other. I set my multimeter to “ohms” and then probe at either end of the line on the schematic. So if resistor R1 is connected to capacitor C2, say, touch the probes to the relevant legs of the components and the resistance between them should be zero.

    The other common mistake (which I still make) is that some capacitors have polarity: it makes a difference which way round they are. Double check you’ve got them the right way round.

    Also worth checking you’ve got the battery connected the right way round too. I made that mistake the year before last and it took me hours to track down.

    Good luck!

    • Perhaps my blog entry was a bit harsh. I was certainly frustrated when I wrote it. You are right that making things includes not giving up, but there has to be some balance. I did all the things you described over the weekend and started to feel guilty about how much time I was spending on this Ruby amp project and not with my family or playing the guitar or doing any of the million other things that we often spend our time as people living in “1st world” countries.
      I think what I was trying to get across is the need to be aware of where and how we are spending our time. Making things is fantastic! It is a great use of time, but it does require time. I will track down the problems with my Ruby amp project and I will get it to work, but it will not be this week…probably next week.
      I think a better analogy may be guitar amps. We as guitarists could spend lots of money getting an assortment of tube amps for each sound we want or we could go with a modeling amp. Sometimes the modeling amp works just fine for most of our purposes and sometimes it is great to learn about tube amps and dialing in that “pure” tone we hear in our heads. Sometimes it would be better to dial in that tube amp then spend all our time on the million iterations of effects and models available in a modeling amp.
      But there is a time and place for everything. This weekend I was just realizing that I did not have the time or place in the near future to do what it will take to fix my Ruby amp project. My ego and desire for a small practice amp were satiated with the fixing the Kustom amp. My guilt and other life demands were hit a little too hard with the time I had spent on the Ruby amp project.
      I will come back to this project and I will make it work. I just need to remember to do so on my terms in a responsible manner.

      Sorry this is a bit of a downer comment. Don’t mean to rain on anyone’s parade. Big thanks to DAMacLeod and his comment. A great reminder to not give up and ways to approach an unfinished project in a reasonable and smart manner. Thanks!

  2. Pingback: pedal projects | Confessions of a Wanna Be Guitar Player

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