u/OneTiger2586

Quite a bit of time has passed since then, but I decided to share my DIY project here after all.
I chose a somewhat unconventional amplifier design featuring inductive compensation. I was curious to hear how it would sound. There were challenges regarding high sensitivity to high-frequency interference, and the circuit was prone to oscillation.
The problem was resolved by connecting an active volume control; it turned out that the FET input stage does not tolerate being left open.
Once everything was up and running after debugging, I decided to put it all in a case, and then decided to add a spectrum analyzer for visual appeal.Once everything was up and running after debugging, I decided to put it all in a case, and then decided to add a spectrum analyzer for visual appeal.

Hello everyone I hope I haven't become too frequent)At one time, I was faced with the need to do something about the sound of the rear acoustics.The fact is that I do not plan to install a subwoofer in the foreseeable future, and to build the right stage, only the bass support of the front acoustic can be heard from behind.Therefore, there was a need to shut up the rear on medium and high frequencies.To solve this small problem, I had to make a small tweak in my Alpine CDA-9813 work radio.I removed the jumper resistors at the inputs of the rear channel and soldered to them a piece of signal cable with RCA plugs at the second end.This solution made it possible to connect the rear channel to any of the standard RCA jacks of the radio.Specifically, I connected the subwoofer to the output. Now, if you don't use the built-in crossover, the rear will play full lane as before. If you use a crossover, the subwoofer band will be played.

Greetings to all car audio enthusiasts!
Today is a special day for me. I finally received the package containing the faceplate for the 7878 model.
I’ve been wanting to find this rare Alpine model for a long time, but so far, I’ve only managed to find the faceplate in good condition. Just as I had hoped, the 7878 faceplate fit my 7877 unit perfectly.
I tidied up the faceplate a bit, and now I have two fully functional faceplates for my 7877—both in excellent condition but with different illumination colors.
Now, I definitely want to find the main unit for the 7878.

Hi everyone! I bought this set at a Japanese auction. They’re brand new and have never been installed. I’ve had my eye on this series for a long time. What can you tell me about the sound quality and what has your experience been like using them?