Nichion is already a better quality cap. This is suitable for power needs.
For the audio circuit cap, you may wish to acquire a BlackGate model that is reviewed as "warm sounding" because that is beneficial.
That would be the 22uf or 33uf or 47uf in the audio signal circuit--that is listed as "optional" in most chipamp kit instructions.
It isn't really optional--it protects your speakers by preventing DC output.
Since this behavior varies between individual chip samples (manufacturing variance), then preventing the behavior is the way to get stereo (both chips match performance) that matches per left and right.
Other weird sounds:
There are four resistors in the usual kit's audio signal.
These are usually blue.
If they're tan/beige color, count yourself lucky and skip to the next paragraph.
Two of them will have values between 680 ohms, 1k, or 2k.
Its time to play "spot the plonker." You can remove some weird sounds by changing those two (or all of them) to the tan colored resistors.
Tan resistors with a Gold stripe is 5% carbon (good), and carbon has a "smoothing" effect on non-audio noises.
That's helpful to LM3886 so that it doesn't amplify the hetrodyne on digital sources (possible source of the weird sound you describe).
The fifth resistor that you'll see on most kits is the mute switch resistor.
*Check these components with a multimeter to insure that you have exactly the same values per left and right for stereo.
Steel wool and flux:
You can swipe the soldering iron across a bit of steel wool so that the tip is brilliantly shiny--each time before soldering an audio connection.
A tiny bit of flux is very helpful to insure a good, solid connection at a solder joint. This insures that there won't be any mysterious static.
Application of flux, and a tiny bit more solder, onto existing solder joints, can correct them.
Optional components:
Some of the kits don't contain speaker output zobels. That's not okay. Absence of the zobel would make the amp quirky about speaker cable choices.
Alternatively, you can use 0.1uf miniature polyester (cheap sort) directly across the speaker terminals. That does a similar job. It can work in addition to an onboard zobel.
This optional output filter components prevent weird behaviors by decreasing transmission/amplification of non-audio signals, such as ultrasonic hetrodyne cascades. And, preventing the problem makes lower listening fatigue.
My own LM3886 kit amplifiers had six choices that were all capable of amplifying non audio signals. All of them did exactly that. Not only was the amp exhausted so that it wasn't powerful to amplify audio
but it also sounded weird.
This had been advertised as "extra detail." But, none of it was an audio signal--it was noise, mostly in ultrasonics that hetrodyned to divide and then cascade (by octaves) down into the audio bandwidth. I am unsure whether the components themselves created the noise or whether the extra non-audio labor had partially set off the Spike protection.
Most females and most younger men would hear a painful "screeching treble" coloration; however, most adult men would not perceive this.
Purposeful clipping:
Another cause of a weird sound is the Spike power-limiter's purposeful clipping. It is especially aggressive in LM3886.
The LM3875T and LM1875 are less likely to engage Spike.
It doesn't switch on/off, but rather it is a variable effect that engages slowly at first with a hint of raspy sound.
Inappropriate thermal management is the most widely documented way to set off Spike. Do plan your thermal management carefully.
Amplifying non-audio signals
is the most common way to set off Spike; however, that one is a bit mysterious because most adult males cannot hear it partially engaged.
Not only does the noise cause harm to women, children, and pets, but it also gives the amplifier an unnecessary workout and sets off Spike--long before advertised power output is reached.
More useful power=more power:
My mod, in the link above, is a brute force way to restrict the amplifier to audio signals. That increases its useful power output.
The filter capacitor listed (in the link, post 1403686) is for full range (floorstander) speakers. However, bookshelf speakers could use a smaller value like 3.3uf (30hz speakers) or 2.2uf (40hz speakers) or 1uf (65hz speakers). Of course, its not necessary to have the amplifier labor so greatly to produce bass notes that won't come out of the speakers.
Just like cutting the treble bandwidth (down to the audio spectrum) makes less amplifier efforts and increases the useful power. . . so, at your option, you can cut the bass bandwidth to correspond to your speakers, which also makes less amplifier work and increases the useful power.
Increasing the useful power by restricting the amplifier to audio signals--avoids setting off the weird noises of Spike protection.
Whatever name you choose to give to the sound of Spike protection, well, that's up to you. I chose to call it a screech.
Does this explain my reference to Spike's audiable effects?
Does this explain why you would want good thermal management?
Thermals:
At the minimum, that's a heat spreader, a cool air intake, and a hot air output--like any other hard working computer chip.
If you'd like to get one hot without paying dearly through loss of quality, then try LM1875 (very hot) or LM3875 (similar, but cooler). In particular, LM3875TF (isolated) can probably work with a "just bolt it somewhere to the case" approach. Although, I'd still like to see a large metal washer + thermal paste on the outside (probably bottom) of the aluminum case, and with air intake holes around it.
This creates a situation whereby hot air is underneath cool air--it won't stay that way. It quickly moves so that the hot air goes up, thus creating a nonstop breeze.
The common 2x3 inch $1 TO220 /w 90deg fins heatsink is prethreaded for screw mounting onto a PCB board.
This heatsink is small, but, if it is screwed to the bottom of an aluminum enclosure, with air holes underneath it, (and/or the top with air holes above it) then it can be mighty--because the case makes it bigger.
I use those to cool my Thompson's (for music), and high-power-hacked LM1875's which are both quite the challenge indeed. Of course, I put thermal paste between any metal parts that serve heatsink.
Passive Heatsink:
A smaller bit of thick and thermally conductive material that is thermally connected to progressively larger and thinner (or less conductive) materials until, at last, air is able to conduct the heat away. For computers, its a small copper plate that's bolted or glued to a large aluminum fin. For laptops, this large aluminum fin is thermally connected to and bolted to the bottom of the enclosure, which also has a vent at this point. Sound familiar?
That's all I've got for now except. . . do see the link (above post) for more clues on how to prevent amplification of non-audio signals--which is an additional way to keep the chip cool and boost its useful output.
Cheerio!
