Take your Genesis audio to the next level - The Mega Amp 2.0 is here!

Sweet, I look forward to trying it out.

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Originally Posted by Ace

I might as well take the opportunity to make one thing very clear. I didn't mention this with your original Mega Amp PCB, Helder, but this time, I'm serious. This will go for anybody who wants to make their own boards. Unless you are given explicit permission to alter the design by doing things such as replace electrolytic capacitors with ceramics (itself a VERY bad idea in audio amps and I can't understand why manufacturers did this in the first place in actual products like the last Genesis hardware revisions and even PC sound cards), you're free to do so for your own personal designs, but DO NOT put those into production designs. The 22uF output capacitors, in particular, are really bothersome. 220uF has been chosen on purpose to keep bass levels as high as possible without being overbearing; by using 22uF, you're creating a more significant high-pass filter and killing off some of the bass the Mega Amp would normally deliver.
So please, to anyone wanting to make Mega Amp 2.0 PCBs, don't design a circuit to sell with changes I do not approve of. If I find such a design, you will be asked to pull it from sale until you redesign your board with the proper components.

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Hi Ace,

first of all, thanks to you and villahed94 for this (another) amazing project, it's awesome!

Secondly, I'd like to make my own PCB design, for me and my friends.
Can I use your new schematics, without (obviously) making any changes?
If yes, can I use tantalum capacitors?
Or is it better the electrolytic ones?

Thanks for all! :)

I am personally unfamiliar with tantalums, so all I can say is experiment. I'm not fond of them due to their tendencies to short out when they fail (had an Intel Socket 4 motherboard with a shorted tantalum on its -12V rail), but I really don't know how they would affect the sound.

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Originally Posted by CGQuarterly

Will anyone be offering an installation service for these? I don't lack the ability, but I do lack the time. But it would be nice to have this amp in the Genesis that I use to capture footage for my show.

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Im willing to do some of the installations, I have not done this mod before, but it doesn't look to bad. So after I get one and install it :) I can do it for others.

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Originally Posted by Ace

I am personally unfamiliar with tantalums, so all I can say is experiment. I'm not fond of them due to their tendencies to short out when they fail (had an Intel Socket 4 motherboard with a shorted tantalum on its -12V rail), but I really don't know how they would affect the sound.

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Thanks for the reply.
I decided to use electrolytic capacitors.
This is my prototype Mini board, I hope you like it:
https://oshpark.com/shared_projects/qT8V05gy

https://644db4de3505c40a0444-327723b...a1c09bc252.png

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Originally Posted by zeruel85

Thanks for the reply.
I decided to use electrolytic capacitors.
This is my prototype Mini board, I hope you like it:
https://oshpark.com/shared_projects/L0RtRWMq

https://644db4de3505c40a0444-327723b...a1c09bc252.png

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Where is the other IC? On both schematics there are 2 Opamps and I only see one on your board.

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Originally Posted by Helder

Where is the other IC? On both schematics there are 2 Opamps and I only see one on your board.

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Me and my friends are not interested in the mono output, that's why I decided to omit the second IC (TL072).
The only difference from Ace's schematics is the 0.1uF decoupling capacitor (C16) for U1 (TDA1308).

May I suggest adding an extra 10uF capacitor for 5V filtering? Just to be safe, I prefer to add at least one electrolytic capacitor to any add-on boards for a console.

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Originally Posted by Ace

May I suggest adding an extra 10uF capacitor for 5V filtering? Just to be safe, I prefer to add at least one electrolytic capacitor to any add-on boards for a console.

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I switched to 2x tantalum capacitors for decoupling 5V and non-inverting input lines, because there wasn't enough space for another electrolytic cap.
Here's the result:
https://oshpark.com/shared_projects/cLhLtWV3

https://644db4de3505c40a0444-327723b...4c7c8915b2.png

Can't say I'm too thrilled about the use of tantalums for power filtering, particularly due to their tendency to short out when they fail. What I can suggest is to use a smaller footprint for your 220uF output capacitors (those seriously look oversized) and replace the twin tantalums with a single small electrolytic 10uF capacitor.

Hey Ace, mind if I design a PCB to sell as a DIY kit through Console5?

Under the condition that you do not alter the circuit without my consent, you can make some DIY kits to sell. I wanted to do that myself, but the PCBs I kept coming up with were too big for my liking.

Did you think of reducing PCB size by re-purposing existing components on the mainboard?
Also there's a lot of wasted space. Traces could be cut and new components be places there.

So I got my prototypes in and the sound is great but I need to record some audio files with ceramic and tantalum and electrolytics so I can compare what can best be substituted and with what. Do you guys have any good games that have great tracks to test the audio on? I've used Contra Hard Corps and Gunstar Heroes but I'm open to suggestions and maybe a particular track that I can test?

Perhaps Streets of Rage 2? I recommend testing with bass-heavy games, especially if you want to hear the difference between various different output capacitor values.