Mike R's mini amp

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. ironic

The unit works great. In fact I want one for myself.

Pics and  a schematic of the completed unit are coming soon.

Phono preamp

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.

Completed my first cmoy amp.

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 the low cost. this opamp costs $.77 compared to 4-7 dollars for one of the recommended chips.

The sound quality is serperb at general listening volumns. bass is very responsive and tight and the highs are clear but not overpowering. Adding a voltage divider to the input really helped with the noise problems I had with the headbanger amp.  Overall a very good sound that is a little better that the headbanger amp.