A Passionate Apathy » projects

Altoid Amp – ‘A curiously loud little amp’

howie73 — Sat, 07 Jun 2008 01:22:51 +0000

I am starting to build a few more pedals and I needed a small amp that I could keep on the desk just to test the functionality of the circuit as I complete it. I used a schematic from runoffgroove.com called the ruby and installed everything in a metal Altoids can.

Its a 1/2 watt amp powered by 9 volts. It has a volume and a gain knob that allows it to go from very clean to quite crunchy. I plugged this into my single 12″ weber silver bell and was very surpised by the sound. Its no tube amp, but the sound is very good…. and loud. With an overdrive pedal in front of it, the guitar could easily be heard throughout the house. With the gain turned up about 30% the amp goes into a light overdrive that is very touch sensitive. Above that and great harmonics start punching through. Here is a picture next to a standard size Boss pedal.

Crate VC-508 transformation

howie73 — Wed, 16 Apr 2008 20:25:43 +0000

Eric Beeman gave me his crate tube amp to modify into something a little more palatable(the black amp in the first pic). The parameters were low cost, small, and light weight. He wanted to get a warmer clean sound out of it as well as a more usable overdriven sound. Beside that he gave me free reign.

I looked up mods for the amp online. I found a good resource at guitarnutz.com. One of the problems with this crate amp is that it has a solid state pre-amp before the first pre-amp tube. When you turn up the gain, the solid state section would overdrive before the tube. This results in a harsh buzzy overdrive. The guitarnutz page had instructions on how to fix this.

I removed and replaced a few capacitors and resistors, re-routed some wiring and added a pot to control the drive of the power tube. I also rewired the tone control to work like a normal one instead of the ‘mid scoop’ it actually controlled.

As part of the fix we needed to get a 12AY7 pre-amp tube instead of a 12AX7. This tube has lower gain properties and will not overdrive the next stage int he amp as much. Since we needed a new tube anyway, I ordered that one and a new el84 tube from Dave’s tubes. I got JJ brand tubes which are generally considered good solid dependable tubes.

The next part of the eqation was a new speaker. 12″ speakers are very common for guitar and could definitely give some improved warmth over the stock 6″. Since price was a factor, we went with a Weber signature series. It has a ceramic magnet for a little better low end and an overall warm voicing.

Now for the cabinet a small size was necessary. I used baltic birch for the construction and a semi closed back to tighten up some of the low end. (This speaker does not like closed back)

After an attempt at staining the cab for a natural finish, I decided tolex would be a better option….

The result is great. While the speaker still needs to break in, it produces much warmer tones. The overdrive in the amp is very pleasant and highly controllable via the two gain controls. When the speaker settles in I think this will be a very good amp for the money.

first guitar pedal from scratch

howie73 — Fri, 11 Apr 2008 01:45:59 +0000

My past few pedals have all been based on a kit that I buy. It comes bundled with all the components I need as well as a PCB board that determines where all the components go.

This pedal I built from scratch. I saw a schematic and layout online and built it based on that. I bought all the capacitors, resistors, pots, switches and wire. Its a step forward in my learning of electronics.

The pedal is called the ‘Highway 89′. It is an overdrive pedal loosly based on the Dr Z route 66 pre-amp. The first thing I did was wire it all up so that I could debug any problems that may arise. So all the pots and jacks are just hanging out attached to wires.

Once I made sure all was OK I drilled out the enclosure I bought. To do this I put masking tape over the paint of the enclosure. I then used a punch to create dimples to center the drill bit. I then drilled a pilot hole and proceeded to make it larger with a step bit.

The next step was to secure all the pots, switches, led, jacks, and power supply in the enclosure.

Finally I installed the circuit board and did all the off board wring in the enclosure.

My first impressions of the pedal are good. It is a very high gain pedal, but with the guitar volume down a little it really produced some good haronics along with a rich midrange hump for a very fat and grainy sound. After I play it for a while I may make a few modifications to it, but it works great for me now. All I need now are some knobs for it.

Another guitar pedal

howie73 — Tue, 11 Mar 2008 04:11:34 +0000

I think I need to start a new blog just for my guitar projects….. The last pedal I built was a great start. The sound with my setup just didn’t make me say, ‘wow!’. So I advertised it on The Gear Page and sold it. After I had sold it I had another member of the board ask me if I could build him one, so of course I could not say no.

I started with the same kit, a marshall blues breaker. Then after researching some mods on the net I added three switches. One switch was ‘Gain’, where I used LED’s and diodes to give some additional clipping options for slightly different distiortion sounds. The second switch was a ‘Fat’ switch which slightly boosted the lows. The third switch was a ‘Mid Boost’ which progressively added back mids to the notorious mid scooped marshall sound.

So, I continue my quest to understand all these electronic components…. I still have a long way to go.

I’ve got two more projects in process right now and one on the drawing board, so look for more in the future!

amppedal-006.jpg

amppedal-008.jpg

amppedal-010.jpg

Pedal…

howie73 — Fri, 04 Jan 2008 05:28:00 +0000

No, not the bicycle kind. The guitar kind….

I am the kind of person that loves building or improving things. I can almost never leave my cars alone, and prepping our race car is always fun. I have also built a high efficiency bass cabinet to go with my puny David Eden head as well as a sub to augment it.

So needless to say as I continue into the electric guitar realm I had to build my own pedal. I guess the word build may be a little stong here. Assemble is probably a better choice. I bought a kit from generalguitargadgets.com and started assembly yesterday.

The kit I got was the Marshall blues breaker. I chose it because I wanted a simple circuit to start with and I can always use another overdrive tone. It is a reproduction of the original pedal plus the added benefit of true bypass switching.

The kit comes with everything you need except tools. The schematics and layout are on the web. I actually soldered everything up, put it together and it worked on the first try! I was not expecting that.

One of these days I’ll pull it back apart and paint the enclosure, but before that I am already planning a few little modifications for it. The cool thing about

researching and assembling the pedal yourself is that in the process you learn a little bit about what is really going on in that circuit. So if you hear something you don’t like you can work at fixing that instead of just heading for a new pedal.

I’m sure this won’t be my last pedal, it was a blast! My goal is to work on more and more

difficult pedals and ultimately build my own small tube amp.

So if anyone is up for having a pedal built, let me know. I’ll work for chinese sweat shop wages….

Jan 1, 2008 – 6:30 am……

howie73 — Wed, 02 Jan 2008 03:56:00 +0000

With anticipation I pull up to my Dad’s house. It was cold this AM. I had made sure and put on my long underwear, beanie, sweatshirt, etc. He was already waiting so we hopped in his Jeep and headed out. What would the day hold? Would we find what we were looking for? This journey may be a prediction of our general successes for the rest of the year.

We were pretty sure we know where we were going, but we had not been there in almost a year. So as we turned off the freeway and made a couple of turns we began scanning the horizon for our destination.

The sun was till low in the sky so we had to squint to see as we drove along. My Dad spotted it first, “Turn in there!”

Following his direction I ended up in a parking lot with very few cars….. We had beat the crowd. A big plus for us. We got out of the jeep into the crisp cold of the morning. The back hatch was lifted and we pulled out our gear. Everything got locked up and we headed for the main gate.

We signed in, got our hands stamped and proceeded through the turnstyle.

Here is were the real journey began. Hundreds if not thousands of cars in front of us waiting to be the donor of some needed and necessary part….. Yes we were at the Junkyard….

If you are a gearhead, keep reading. If you are not….

We came to find a big part for his jeep. Now skip to the end…….

The goal for the day was to find a rear axle for his Jeep. Not just any old axle, and actually not even a jeep axle, but a ford 8.8 out of a 95 or newer ford explorer. And today was not any old day at the junkyard either. Today was 1/2 off day!

Rear axles in most Jeep cherokees are usually a dana 35 or a chrystler 8.25. Neither of these axle are very strong and even if upgraded have flaws that cannot be worked around. When building a 4×4 capable vehicle with bigger tires you need axle strength, both in the axles themselves as well as the ring and pinion and the housing. The ford 8.8 out of a newer explorer provides much bigger axles (31 spline) a bigger ring gear and a much more stout housing.

Along with these advantages it has the same bolt pattern for the wheels, it is the right width for the cherokee and comes with disk brakes instead of drums.

We did not go up unprepared. We had sent a scout ahead of time to see if we had a chance to find one of these elusive beasts….. (actually we just knew a guy that had gone up a couple of days before and asked him to look for us). We thought our chances were good. He had seen at least 2 of the newer explorers with the rear ends in tact.

The yard is organized by section so all our look would be confined to a smaller area than the whole yard. On our initial scan we found at least 5 or so potential cars. We checked for completeness and then picked the one with the lowest mileage.

With tools in hand we began the extraction process. In no time at all we had everything loose and it was ready to pull out. We made sure that we had all the little accessory bolts, brake lines, calipers etc and then hauled it out to the road about 30 feet away. This junkyard has a big forklift that drives around and pickes stuff up for you. So he came by and picked up the axle to take up to the front for us.

Once it was paid for, we put it in the back of the jeep and headed for home. Now there is still quite a bit of fab work to do to get it ready for the jeep, but it well definitely provide a good building block for his jeep build up.

I know we may be the black sheep, but for this part of the Lumsden clan, it was a great start to the new year.

And for those of you who read this whole commentary and are sitting there thinking, “I can’t beleive I just read this whole thing about going to a stupid junkyard.” well…. hahahaha

The pedalboard

howie73 — Tue, 27 Nov 2007 00:32:00 +0000

I just thought I would share my most recent little project. Now that I am becoming an ‘official’ electric guitar player I have a few pedals that I run in front of my amp. At this point I only have 3, but it is still cumbersome to transport them in my backpack without getting all scratched up.

I decided it was time to make a pedalboard. For those of you who are not familiar with guitar pedalboards, they are just mechanisms to keep guitar pedals secure and organized.

Traci and I were out on a saturday morning hitting the yard sales and I found an older suitcase that I thought would be a cool platform to build from. I brought it home and realized that for my whopping 3 pedals, it was just too big right now.

I was talking to my mom and dad about the project and they said they had an old suitcase I could use. Turns out it was my great grandma Marie’s. I would guess it is from the 50’s. This was a much smaller suitcase and would work great for my project.

I set up the suitcase, now guitar pedal board, so that the lid is the bottom. I built a platform to raise the pedals up above the edge of the lid and covered it in carpet. I use velcro on the bottom of my pedals to hold them in place on the carpet.

In the other half of the suitcase I knew I was going to have a little extra room so I built a hinged door with a gate latch that I can open and close. This provides a great place to store cords, music, etc. I then attached foam to the door so that when the two pieces are together, the foam gently holds the pedal down on the carpet.

On the outside I had to cut and remove the pins that hinged the two pieces together. I then added two more latches to that side that are similar to the originals. With judicious use of the wire wheel along with brown and black spray paint I was able to get a pretty good vintage/rusty look to match the other hardware on the case. (In this picture it is actually upside down, feet sticking up.)

So now I have a good pedal board that will allow for a little bit of expansion (maybe 3 or so more pedals with the right wiring) and is different than anyone elses…..