Second, I’ll state that my opinions are just that - my opinions. These have been formed by the experience of which I’m about to write and are in no way definitive; rather just the observations of guy who chose a relatively complex design for a first build and is trying to document that.
Last point before diving in is a little background. Been playing since 1981 when I got my first guitar at 12. Never had decent gear until the last 10 or so years. Always “made do” with whatever was at hand. I have absolutely no background in electronics and spent my entire professional life in what I consider a non-technical but disciplined and physical personnl-centric line of work where attention to detail and accountability were cultural tenets. This taught me the value of fully understanding a problem, thinking through approaches and solutions, then deliberately planning and executing - all of which proved invaluable in this project.
So you’re interested in a Dumble-type amp, but don’t have the dough to invest in one of the originals?
No problem, you have choices! Here are a few that I considered:
1. Purchase one of the many well-made and great sounding “tribute” models from one of the pro-builders on this board. There are about a half dozen builders on TAG that can send the circuit of your choice along pretty quickly (or direct you to the retailer that can), and chances are you won’t be disappointed. From what I can tell, all are very knowledgeable guys that I would trust to deliver a high quality product if I were to go down that road. Wasn’t the answer for me because I wanted specific tweaks, to learn something, and to spread a lower cost over time as finances permitted (retired = lots of time, not lots of $).
2. Purchase one of the mass-produced copies from Asia (and marketed by a few larger US brands & retailers) and learn through modding one of those into something I wanted. Wasn’t my answer either for a few reasons: poor iron to start with, confusing/strange implementation of circuits & designs, lower quality components - all culminating in greater time, effort, aggravation, and cost to create what I wanted. Read about those in “discussion” and you’ll understand.
3. Find a reputable kit form ODS. The well established kit makers didn’t have any readily available when I started my research, otherwise I may have jumped on that because I was unfamiliar with knowing how to order all the parts that make an amp. In kit form - that’s figured out for you. In the end, I’m glad I had to learn how to speak “Mouser”!
4. Dig in to this board (both “files” and “discussion” sections as well as the “technical discussion” at minimum) and learn the basic differences between the circuits and generations. The “Search” function is your best resource. Look at the layouts and BOMs in the files section and get an idea of what you’re looking for; then begin planning your project. Here’s some points to consider:
- Decide what you want to build and stick with it. Stay as close to the layout as possible and use the layout as well as any BOMs for the model to develop your parts list and ordering schedule. Figure out if you’re building or buying your boards. That in itself is a huge learning experience and there are plenty of resources to build or buy here. It’s not a complicated way to start learning. You’re just punching holes and staking eyelets based on the plans you’ll find in “files”.
- Search for build threads and read them front to back. Search for historical data from some of those that have crossed paths with original Dumbles and HAD himself (there seems like quite a few on this board). Their collective memory, experience, and anecdotal information puts the build threads and layouts in context. Reading and re-reading their archived conversations will train you to understand what you’re looking at and help your project make sense . You will refer back to them often if you want success.
- Chassis and transformers are the biggest expenses. Cabs are as well, but that’s at the last step. You need a chassis to start, then the iron, then the furniture - so budget accordingly. A lot can be done with just the chassis and boards (and a Mouser order).
- Learn the Mouser website; it’ll help you buy the right stuff the first time. Read the data sheets with “where the part is going/how it’s being used” in mind. You’ll still end up with a bunch of stuff you don’t need because you ordered wrong - but luckily resistors and caps and the smaller stuff are relatively inexpensive. You’ll also have to buy from other sources (AES, Mojotone etc.), but Mouser, DigiKey, and the other electronics suppliers have much of what you need. I’d suggest developing an inventory management system of some sort so that you don’t re-order unnecessarily and so you know what you have on hand when you’re planning your work.
- Once you have boards and a chassis and the basics (caps, resistors, wire) take a look at what you have and start with what you think you can handle. I started with my drill press and Martin Manning’s excellent board construction plans to try and learn the major parts of the circuit separately through making my own boards. Made my own eyelet staking tool as well. Watched some YouTube vids on eyelet and turret board construction and adapted what I saw to the project at hand, and it all worked out.
- Ever heard of how you eat an elephant? The answer is “in small bites”. This applies here. Once you get going, focus on the small sub-task at hand and read up on it here (and anywhere else you can find info). Once you can think your way through the steps, take a small bite. I made a lot of notes every time I’d start something. I’d start by listing the desired end result, materials needed, what I knew to do and what I needed to figure out. A bit of an exercise in itself, but it helped me get organized and gave me the confidence to start the next piece. Work in this deliberate manner and you’ll be amazed how much you learn and how quickly you get going. Quit for the day or evening when you start making mistakes. It’s easy to get lost in this stuff if you’re unfamiliar with it. Go slow and do it correctly the first time. It pays off in the end.
- Most importantly, ask questions here. The wealth of info and experience is staggering. Hopefully I don’t need to say it - but I will: be polite and try to form your question as specifically as possible. It can be difficult to be specific when unfamiliar with electronics, but sometimes leading with “this is what I’m trying to do and this is where I’m stuck” can get the ball rolling. Understand that everyone here has a life outside the interweb and don’t expect instantaneous responses. If you present yourself genuinely, someone will respond. Given my experience - I’d bet on it.
I can’t say enough about the great folks here and how generous they’ve been with helping me - and I’m sure they will be for you as well. Good luck!
Now on to build #2…
