She’s big and bulky, but you can’t ask for too much when you’re dealing with pre-printed PC boards. The 22k resistor in the gain path makes for extremely high output (in terms of headphones). The 100k stereo potentiometer on the output side should make the noise floor a lot lower unless the knob is cranked. That’s what I was going for here since the application of this device will be mainly for when other loud instruments are being played in the room. A short trip to the electronics store should yield three more of these guys. After that, it’s onto the chassis.
This was my first attempt at building the circuit on the PC board. Unfortunately, I think I’m going to have to get a different board since this one isn’t quite big enough with two opamps. Soldering it is also a bitch considering it’s tiny and my iron tip isn’t as small as it should be.
The 1/8″ plug is the output soon to have a pot attached to it for volume control. I’ve been thinking about attaching an light meter to each channel, but I still need to know what the dimensions of the chassis will be before I jump that far into it.
Double the circuit for stereo. This is a breadboard representation of a single “channel.” Each channel will have its separate PCB with controls. This one lacks a volume pot, but the output was more than enough. 750mW after hooking up the gain path resulted in ripping the ear buds out of my ears in order to avoid total deafness. Sadly to say, I have about as much luck avoiding electrocution as I do cutting myself with knives. I’ll keep to the low voltages for a little while longer.
In my attempts to recently mod a Peavey Classic 30, I’ve been researching audio amplification like a demented mad scientist scheming to destroy the world. I’ve understood the conceptual model of amplification for a while, but I’ve never actually plunged into the crafting part of it before now. After changing out some tone caps, I couldn’t help but wonder how something like capacitance could actually affect the way the electrical signals are converted back into mechanical sound even though it’s pretty obvious.
A while ago I came across a schematic that included a simple 8-pin IC as the workhorse of the circuit. It’s called the LM386, and it’s got to have near a thousand uses judging by the amount of information about it. My cohorts and I have been toying with the idea of headphone sessions, a improvisational mixing session where the four of us write and play music while being conscious of the stereo field. This of course requires the purchase of a headphone amp. Why buy one when you can just build one.
I played with the LM386 for about five hours. It was mostly blind experimentation since I was just using parts I could pull off other dead devices. I had also purchased a shitload of resistors earlier in the day which I was also dying to play around with. I could only get it to sound clear enough at lower volumes through a .5 Watt speaker with a tear in the cone. It seems ample enough for headphones. I figure four dual PCBs with essentially 8 tiny amps attached to a pot on the jack should just very well do the trick. I’ll make a better effort to document as well.
Eventually, I was indeed able to stumble my way in the dark to Hotel Venecia without having to sleep outside. The next day I decided to attempt to make my way to Volcán Maderas, the smaller of the two volcanoes. I set out from Charco Verde on foot assuming that eventually a bus would swing by the road. I walked a good 10 kilometers before I found a bus stop along side the main road on Volcán Concepción.
Transportation on the island is extremely sparse at times due to the difficulty of maintaining running vehicles in such a remote location. According to Alvaro Molina, the owner of Hacienda Merida, buses have been subject to running out of gas completely from time to time. On Sunday, there is only one that makes its way around Maderas, and it only runs at 8:30AM.
After hoping off the bus and heading towards Santo Domingo (the halfway point on the isthmus between the two islands), I read a sign that said it would be another 4 kilometers just to the halfway mark. Luckily for me, a nice caballero by the name of Dolfo gave me a ride on the back of his motorcycle which cut a lot of walking time off my journey. I still had another 10-12 kilometers before reaching my destination point in Balgüe.
The beach at Santo Domingo is practically unrecognizable from its usual state. The water from Lake Nicaragua comes all the way up to the wall. In July of 2008, Hurricane Felix dropped a lot of rain over the Pacific coast of the country and more rains followed over the course of the year. Lake Nicaragua (or Lake Cocibolca as it used to be called) is a giant fresh water connected to the Caribbean Sea via Río San Juan and isn’t usually subjected to drastic changes in water level that I know (I don’t live there). The winds, however, were a nice change from the drier, hotter western side of the island, and it seemed a good place to stop and drink a beer before proceeding on down the road.
I arrived via the ferry that runs from San Jorge to Moyogalpa, the principal port town on the larger of the two islands. As I was heading over on the boat, I was looking at the map of the island trying to figure out where I would stay the night. The trip from Granada had taken quite a long while, and the ferry ride is an hour and half itself. By the time I actually was on the island, I had about an hour of daylight left.
I decided to make my way to the lagoon of Charco Verde which was supposed to be a fairly remote place. It wasn´t far from Moyogalpa, so I figured it would give me a chance to get into some real nature.
The bus dropped me off at Charco Verde, and I proceeded to head down the dusty road to where ever it lead. The sun was setting over the campos and the sound of unfamiliar birds could be heard in the trees. I walked a good half a kilometer before I ran into a man on a bike who had conveniently strapped a flashlight to his thick sweatband. He told me that the lagoon was flooded and that I’d need more than my boots to get through the water. I, in turn, asked him where the hospedaje was in which I intended on staying. He said that it was a good ways off and that I should go to Hotel Venecia which was very similar. He then showed me a short cut on a horse trail and said that I should use that to get me there before it was completely dark. The term “en recta” in Spanish means “stay straight.” Even though I knew this, I failed to stay straight which left me alone in the dark on an Island in a country where I had never been. I don’t think anything could have been more perfect at that moment.
Having landed at Managua’s International Airport, I’ve been fortunate enough to make my way to Masaya. My anxiety levels dropped about ten fold after a short walk around downtown even at night. Managua is bustling with rampant commercialism that’s next to impossible to escape… especially for someone completely out of place. I’ll throw up some pictures as soon as I get to a computer that allows it.