SONY CDX CA900 Signal Line Capacitor Upgrade

Continuing from my post here, this Sony HU CDX CA900 make me surprised how good is the sound quality compares to others favorite brand such as Pioneer. As usual, I always want to make a simple upgrade especially on the signal line capacitor. This parts will give more impact in upgrade sound quality. Now is time to dismantle this head unit and no worries about this brand new head unit with the seal on it will be break by myself for this upgrade purpose.

Before doing this upgrade, let me show the schematic of this head unit. I get it by download online.

In this first step, I only change the line output capacitor that connected from DSP IC to power amplifier IC. There is only 2 capacitor on it which I more concerning to the front channel. You can do for another 2 capacitor upgrade for rear channel, but I don't think that is necessary for me.

The more I learn this schematic and compares to the Pioneer DEH-P8850MP, I can conclude why this Sony sound better. The signal path is simple compares to the Pioneer which so many converter in the signal line that, of course affect to the end result of the sound.

The schematic also show the components placement. In this case I only change the two blue circle above which the same code with the schematic. The others three bellow is for AUX IN capacitor upgrade which in this moment I am not doing anything on it. Maybe next time.

Opening this unit is easy. Less than a minute, all components are dismantled.

I inspect the components layout, PCB quality, and components itself and I can say they are all top of the notch design and quality.

But not for this signal line electrolytic capacitor which is only a standard quality, basically for multi purpose electronic use. That is the one that I will upgrade!

The actual capacitor value is 4,7uF, Rubicon brand and I change them to Elna Silmic II which I know very well for its sound quality. The value is increase to 10 uF due to my lack of stock of the based value.

The good point of increasing the value of this capacitor is effecting in the overall dynamic of the sound.

Before and after soldering the new capacitor. The board traces are easily break up.

The good things about Elna Silmic II is the small size. It is just like the standard capacitor. So no worries for re-fitting the others components to fit it in, especially the CD driver unit.

And this is the result of this simple upgrade.
I can tell that this upgrade do so much improvement in the sound quality. At the first time, before the new capacitor break-in, sound pretty harsh with boomy bass. This is typical brand new capacitor sounds like. But after a few days with approx 2 hours play everyday, the sound changes a lot. Definitely the mid sector is a king. The high frequency is more open and smooth, the bass is more focus.

I can only say, wow... How much difference I got for only doing this simple upgrade. Worth to for every pennies I spent with this kind of result.

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