tag:blogger.com,1999:blog-65417175017669228302024-10-06T23:16:04.628-07:00Unknownnoreply@blogger.comBlogger18125tag:blogger.com,1999:blog-6541717501766922830.post-12405769934229056942012-04-03T08:11:00.000-07:002012-04-03T08:11:17.479-07:00

I built this Oberon guitar amplifier for my brother's birthday present. My brother is a bassist and like most guitarist he likes to play his acoustic bass at the beach with his buddies. His bass however is overpowered by acoustic guitars. He wanted a portable amp that would be loud and easy to carry around. I settled on a mini keg as they are durable and easy to acquire. Bells Oberon spelled the

Unknownnoreply@blogger.com6tag:blogger.com,1999:blog-6541717501766922830.post-39862107429783862692012-03-24T22:19:00.000-07:002012-03-24T22:19:56.753-07:00

How to get advmame on the rasberry pi. I found a tip about using advmame instead of xmame and decided it was worth a try. advmame has an awesome configure script that takes all the work out of editing makefiles. It also runs a lot faster. First you will need to have some sort of rasberry pi simulator I went with this method. RPi on Virtual Box As before Use the following command to ensure

Unknownnoreply@blogger.com21tag:blogger.com,1999:blog-6541717501766922830.post-11829976672020782412012-03-20T21:30:00.001-07:002012-03-24T22:30:40.807-07:00

How to get mame on the rasberry pi. Full size screen shot Please note that it is easier to get advmame up and running. check out my guide here. First you will need to have some sort of rasberry pi simulator I went with this method. RPi on Virtual Box Here are my pre patched files makefile.unix unix.mak Lets get started. Use the following command to ensure your running on the arm kernal

Unknownnoreply@blogger.com11tag:blogger.com,1999:blog-6541717501766922830.post-794332257083064522012-01-10T14:04:00.000-08:002012-01-10T14:04:04.194-08:00

Just another amp build. nothing special about the circuit. the Power supply on the other hand is a different story. I picked up a little iphone speaker box from the dollar store that took only one aa battery. after tearing it apart i found a little opamp and a buckboost converter. the converter takes 1.5volts from the battery and turns it into 5volts that the op amp requires. So for 1 dollar I

Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-6541717501766922830.post-79488369054351408962012-01-10T13:47:00.000-08:002012-01-10T13:47:37.496-08:00

I'm sure there are those out there like me, that have a ton of usb charging cables. In my case theres my phone, my girlfriend's iphone, my tablet, her nook, and my camera. Thats 5 different devices using 3 different types of cables. On top of that the iphone wont respond to all usb chargers.It seems Apple will take every step to try and insure that you only use their chargers if your not using a

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-90161127369257300912012-01-02T21:51:00.000-08:002012-01-02T21:51:44.648-08:00

I recently had an xbox given to me. The only problem no video cable. I decided to see If I could hook it up to a computer monitor. The older 360s have the capability to output rgb vga video signals. One simply has to connect the correct pins on the video connector to a db15 connector. I used some old hard drive ribbon cable to make the connections. I added a pin socket to the cable to so I could

Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-6541717501766922830.post-55784165164034166402012-01-02T00:54:00.000-08:002012-01-02T00:54:41.361-08:00

After some experiments I concluded that the radioshacks version of the lm386 is extreamly noisy. lm386 .7watt and 1 watt versions from digikey are far better sounding and seem to eliminate the white noise that can be heard from the radio shack equivelent.

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-24624083386474114132012-01-02T00:32:00.000-08:002012-01-02T00:32:45.943-08:00

Getting this working on the device seemed to be alot bigger of a problem then I would of liked. After trying to follow the guide layed out here. I ended up formating the flash and not writting the new data. The nand patch file provided by the megaupload link at the bottom didnt match the internal nand found in my tablet. Knowing that if I powered off the

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-63187612032192930582011-01-07T08:41:00.000-08:002012-01-02T00:49:08.452-08:00

My current thoughts on the portable amplifier is to incorporate inverter technology to enable the use of 2 AA batteries instead of 2 9volts. The change should allow for better battery life and cheaper operation. This will also open up the possibility of using USB as a power source to make a cheap but High fidelity sound card. Two chips that I have looked into so far include the LT1073 and

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-36064643662864501672011-01-07T08:34:00.000-08:002012-01-02T00:49:08.438-08:00

Unfortunately I have yet to get the super hard on to function correctly. Perhaps a different MOSFET is in order.

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-71610134584318047532010-04-05T19:30:00.000-07:002012-01-02T00:49:08.423-08:00

http://analogguru.an.ohost.de/193/schematics/Zvex_SHO.gifThis was a pretty simple build. I got all of the parts except the stomp switch from digikey. I etch a custom pcb using the toner transfer method. The toner transfered perfectly from some glossy magazine print. pics coming soon.

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-59848796301661838642010-04-05T19:13:00.000-07:002012-01-02T00:49:08.217-08:00

I finally figured out where the distortion problem was coming from. I simply failed to take into account the bias on the output of the chip.

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-13401921058282171072010-02-20T22:12:00.000-08:002012-01-02T00:49:08.407-08:00

Well after several failed attempts at adding distortion to a simple lm386 amplifier I finally succeeded. Simply adding a switch that changes the first stage of the amp from a gain of 20 to 200 did the trick. I would of thought that adding distortion to an opamp based unit would have been easy. ironicThe unit works great. In fact I want one for myself.Pics and  a schematic of the completed unit

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-25518587266664911692010-02-18T12:59:00.000-08:002012-01-02T00:49:08.393-08:00

Ive been looking into making a preamp for my dads jukebox. The current amp setup is very tinny at higher volumes. As it turns there is a special filter for phonographs that is called an riaa filter. Record companies use this filter to help vinyl records last longer and increase fidelity.This leads me to conclude that it may simly be a matter of capitors in the filter section of the jukebox.

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-3614704646768451492010-02-17T20:23:00.000-08:002012-01-02T00:49:08.380-08:00

Construction of the amp went well although I do have some complaints about the general performance of the amp. First off the amp needs two 9 volt batteries. second the amp distorts at higher volmunms. I understant these problems are related to the tl072 opamp that I had used. In the future I may try a transistor half bridge on the output of each channel to get better performance well maintaining

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-44098980196605921542010-02-13T11:17:00.000-08:002012-01-02T00:49:08.365-08:00

Here are some pictures of the first model.The Circuit is based on on the Headbanger amp project. Newer models will be based on the standard Cmoy style amp. Cmoy should be Superior in sound quality to the headbanger amp and has fewer parts. The reason I started with the headbanger amp was the availability of parts locally (read radio shack).The exception to the switch in circuit design will be

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-1029881345943572852010-02-10T19:41:00.000-08:002012-01-02T00:49:08.349-08:00

I am making several cmoy style headphone amplifiers. Including a special one for mike Robinson that will work as a guitar to headphone practice amp with internal distortion. more to come later including schems and pictures

Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-6541717501766922830.post-75327842819966686992010-02-10T19:01:00.000-08:002012-01-02T00:49:08.333-08:00

So I dont have to pay for hosting :)

Unknownnoreply@blogger.com0