THE ORRONOCO AUDIO DIY

I do some improvement from my last project  here  by changing the capacitor to this paper in oil capacitor type. With this upgrade, the instrument detail, depth of sound stage and the vocal are dramatically improved. This is also one of my favorite capacitor for signal application.

In this post, I will share my building process of LM3875 Gainclone amplifier. If I compares with LM1875 or LM3886, this LM3875 is the most simple amplifier to build with only few parts needed. This LM3875 also has the best S/N ratio compares to the others. For this simple circuit, I prefer to do it by point-to-point connection . The benefit compare using a printed board is the purer signal transfer. I always using high quality parts that I believe the leads from those components are better in materials compares to the PCB traces. So let's do it.

For most people, building any electronic circuit would be convince by buying or making a board or a PCB. I used to be like that until I experience that doing point-to-point circuit is more fun. First, I free to use any case I want that not limited to the board design and second, the layout could be limitless. Including this B1 buffer pre-amp is the most simple circuit design by Nelson Pass. The sound produce is neutral yet doesn't need much components in it.

Every end of the year, I don't know why I am always make a new amplifier. Maybe the hot season already left behind and the chill wind blowing in the morning refreshing my mind. I have more energy to build something like this one, the compact F5 amplifier. Right now I am using the PCB for the very first time since 12 years ago. This F5 amplifier is pretty simple and point-to-point is not difficult to make. But I already had this PCB on hand, not using it will be a waste. The PCB quality are very good, although I found some mark on the fet is wrong but overall this is the best PCB I can get from my local forum member. I also check the best possible placement for the final transistor. I guess this is the final layout. Then I will put the final Transistor attach to the heat sink. Surface of the heatsink need to be clean before installing the fet on it. By doing this will improve the heat transfer. I still have a CPU thermal paste from my previous PC projec...

Last week I do review  here  this finest amplifier and when there is a chance for me to install in my car. I can't wait any longer to experience the sound quaity from this mighty amplifier.

The input and output plugs will be install now. As usual, I using almost all components from the original case, except for the input RCA jack. I am using CMC RCA which become my favorite choice.

I have heard that someone could hear the difference in audio quality by changing one resistor to another brand. Perhaps it is true! Actual condition from inside a resistor is more complex then just saying it is a passive component that have only a resistance. The resistors lead quality and the carbon or metal film quality really determined on how the resistor behave in the audio system. Maybe that condition will effect at the final result which is the sound itself.

Having the compact case like  this , I speed up my amplifier project to be starting soon. I look around what amp can I make with this kind of case and the result is will be no other than the F5 amplifier from Nelson Pass. It is class A, 2-stages amp, and running hot. Although this is not the typical big F5 amp cases, hopefully the heat is not an issue.

Finding hi quality amplifier case is a pain. Most of them are imported from China. Actually they are good aluminium case but in my opinion, they are overpriced. Plus I should consider the shipping cost which makes the price tag increase like a rocket. On the other side, there also a local cheap case that I would not even dare to touch it. It is ugly and build quality is pathetic. So what is the solution? I could tell by using the used amplifier case. You need to find the most flat surface case for easy components mounting. In this case I will use the amplifier case from David Hafler XL-280.

I can say that I am quite lucky to have this 25 years old Magnat Classic 400. It is my car amplifier back in early 2000. This is a 4 channel car amplifier that rated pure 50 watt per channel, not top of the line product from Magnat and it is quite affordable at that time. But despite it is affordable, the build quality for this amplifier is top notch. I can say this is the finest amplifier for the money that no any other product could match.