Not a Small Undertaking

This will be part one in a series on this amp. So...let's get started.

In early 2013, I was commissioned by local genius guitarist, Luke Polipnick, to build an nice, warm tube amp. Up to that point I had trained myself in all of the electronic skills needed to make the amp, as well as the woodworking that would be needed for the cabinet, on separate projects. This amp was the first opportunity to put of all those skills together.

Initially, this amp was supposed to be based on a Fender Princeton Reverb, only slightly larger and with a few modifications. Once Luke and I started talking about what he wanted, it became clear that the Princeton Reverb should be more of a basis for the sound of the amp, and not much else. With that goal in mind, I drafted a schematic and got to work. 

One of the biggest factors in the PR sound was a type of phase inverter called the Cathodyne. The Princeton Reverb was one of the only amps made by Fender to use this method of phase inversion. The Cathodyne gave those amps a unique tone that has become very sought after. 

By the final modification to the amp, the circuit had strayed far from the original, with a Bassman style input stage, and a Super Reverb to fill in the blanks. Though, I can't be giving out all my trade secrets so easily.

Here's some pictures of the build progress:

 All the parts are in!

 All the wiring is done at this point. This took about 6 hours and 100 feet of wire to complete.

These pictures need some explanation. In order to save costs on modern expensive transformers, we agreed to buy a vintage Hammond L100 amplifier chassis and remove the transformers for use on the new amp. These vintage Hammond transformers were some of the highest quality of their day, not to mention their wonderful tone. The second picture is a 60 watt transformer made by the good people at ClassicTone. The amp actually has two switchable output transformers: a 35 watt Hammond and the 60 watt CT. Each transformer has a distinct sound. The 35 watt Hammond has a more earthy tone with rich saturation. The 60 watt CT is solid and clean, yet it still retains the warm tone of the amp.

Hey There, Stranger

Its been quite a while since I last posted, but for good reason. In September 2013, my good ol' guitar shop that I was working for closed its doors. form that, I was forced to transition my shop from the store into my own home. This ended up being a good move, as business is still good and my projects are still raging. Most things have stabilized, so I finally have some time to start writing again. New posts should be coming soon.

Behold... Omnibus

Here is the first real design that I developed and produced from 100% original designs. I'm proud of that.

Basically, its a very versatile boost, overdrive, and distortion. I sadly won't be able to go into huge technical detail because it really is still at least partially under development. Only getting better the more I tailor it.

At first, it was a pretty simplistic idea. Just a distortion that had a knob to blend different diodes in and out for the clipping section. Whee... big deal, eh? It was called the Signor Trogdor. Signor being Mister in Italian, (unless I'm wrong..) which I used simply because it sounded pretty cool. Trogdor being a reference to a certain dragon that was thought up by the geniuses over at Homestarrunner.com

Then I added the Type switch and changed a whole bunch of values to get everything sounding good. The original was in the hands of a local guitar player (who now lives in NY) for quite some time. I got good feed back from him on the general tone, but it wasn't ready yet.

Back to the bench for a full make over.

A new board, box, a bunch of different parts, and a bit of acid and some time made this hip little beast.



Renamed the Omnibus, this is the best sounding version so far. Those funky looking symbols on the pedal are letters that I designed to spell-
O M N
 I  B U S

The guitarist I built this for (different guy than before) really dug this version so much that he made it his signature sound, which is a real nice touch. The basic design for this will live for quite a while before I make any major changes.



The nice thing about having a good sounding pedal, is that I reason to make them in bulk. Right now, its only four at a time, but thats better than none! Four more of these, with a custom knob set, paint job, and possibly a knob layout change for each of them. I love nerding out to this sort of stuff.

I'll get pictures up of the four new pedals once they're done, but this is all I really want to get out now, so the rest will be for another post. Bottom line, this thing sounds effin' great.

The Armadillo

I'm trying to keep this run of posts going on my earlier projects, so lets move on.

After the talkbox, I decided it was time to move on to something more useful and complex. It just so happened that my 8th grade science project was going to be coming up soon, so I saw the chance and took it.

I had an old phaser pedal that I thought sounded pretty cool, and found a schematic, and went to work. The first approach I tried was with two bread boards and a whole mess of wires. Three tries later, and still nothing. Great.

With that approach ditched, I started making a PCB layout for this thing. that took three tries and help from a local tech (the same one I worked with for a few months) to get the pedal all working. Honestly, after 5 months of work on it, it actually sounded really good and looked cool too. I took third at my school's science fair, and second at the districts fair, which is very good considering that it didn't really follow most of the guidelines. Nobody likes to follow rules, right?

This is the final pedal. The Armadillo, the name branded on all my other gear, was my first finished pedal. Get it? Armbrust. Armadillo. Close enough.
 Its almost 3" high, so its not really realistic to have it on a pedalboard, but hey, it sounds great.

Beacuse of the original Dilla's size, I was prompted to build another similar one down the line a bit. It actually sounds better, has better reliability, and is roadworthy. I expanded the controls too, just for a bit more versatility. I called it the Lil' Dilla.

A month or two after I built the Lil' Dilla, my dad and I decided to do a 'Great Phaser Shootout'. Clever, eh?

In order of awesomeness and how each of them sound: The Armadillo, 90's Phase 90, Lil' Dilla (a *very* close second), 70's script Phase 90. Im happy with those results.

I really should have started with something less complex, but what's the fun with that? The model of learning by taking way huge of a bite has defined how I approach projects now.

.......and I've got this weird obsession with phasers now.......

The First

Let's take it all the way back to my first real endeavor into the musical electronics world, way back in September 2010.

I first started out with a small battery powered practice amp (Danelectro, I believe) that I had gutted to use on this. The whole reason that I had though to do this was off of one youtube video. it layed out  simplistic talkbox, and I just took it and did my best to hack through getting it working.

Eventually, it turned into this-

Pretty awesome, huh?

The craziest thing is that it actually worked, and quite well too. As one can see, duct tape went to good use in almost everything in this project. I wish I had made some sort of demo of it, because this picture is all I have left of it. It has fallen apart and ceased to work recently, which is not surprising at all.

All my goofing in this sort of thing was suddenly given direction.

Preview of What is to Come

It has been a while since I have posted, so I figured it was due.

Now that summer is here, I have more time to build, design, and do repairs (to support the other two). This is a nice break from having to balance schoolwork and building, especially now that things are picking up in most aspects of my life.

I have several projects in the works that are all running in parallel to one another. Here's some summaries of 'em.

The first one I have yet to finish is an amp for an awesome local guitar player, who initially prompted me to start this blog. It was first supposed to be based around a Fender Princeton Reverb built into a head. Then it became made out of vintage Hammond Organ transformers (not to be confused with the new Hammond Mfg. transformers, which are awesome in their own right). Then it became 6L6 capable, with dual switchable transformers. Then a pine cabinet combo with a Weber Neo 15" speaker. There were a lot of other electrical changes, but I'll save that for later...

Another amp build is one that is a sort of test bed for future amps. The owner of the guitar store I tech at had told me about his intentions of starting a small, simplistic, and interesting amp line. I just took it and ran. I have never built something by intentionally blindly diving into a design. Nothing but research and selecting tubes for use went into the design. This one should be fun.

A local trumpet cat had recruited my skills to build a studio grade compressor for him. It was sold as a pre-made PCB and electrical parts for it. He also took it upon himself to source the case, meters, and optoisolators, which took quite a load off my back. Some of those are dang hard to find. Its mostly done, just waiting on a hardware order for now.

I have too many ideas floating around to write down them all, so I'll save those thoughts for a later post.

I'm still really looking forward to getting all this awesome stuff posted.

Getting Started With This

I'm trying to get a site going where I can post projects, products, interesting ideas, and or course the occasional rant.


But first, a little history.


My name is Dain Armbrust, I am 16 years old at this point. I have played bass for almost 7 years now, and have been building amps, pedals, instruments, and other musical paraphernalia for about 3. Any knowledge that I have on these subjects has come from either the wonderful world that is internet forums, blogs, and articles, or from the help of my family and other mentors. I am currently holding down an amp repair tech job at a local guitar store, and loving every minute of it.


Ultimately, I hope to get an abundance of awesome and/or amazing things posted on this site for the world to see.