Author Topic: Making an RGB amp  (Read 1369 times)

soop

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Re: Making an RGB amp
« Reply #15 on: May 24, 2011, 05:04:37 AM »
I was talking to a friend about something similar, and he said "you can print PCBs now".  I quickly looked up making PCBs after I saw your thing, but I'd assumed you'd fabricated the board yourself.  I see that it's possible, but it's out of my level.  If you had it made that answers my question just fine.

What I'm thinking now, is that compared to gtsamours it's obviously using smaller components, but I'm thinking it could have been layed out a little neater.  gtsamours looks a lot more economical.  Could be wrong here, but I think that's the case.  It seems to share more connections, and aside from the end connections, it seems to be symetrical vertically and horizontally. [edit] sorry, that's just because yours amplifies more things.  If you recreated gtsamours as a double sided board, it would be tiny.

If this is the case, it should be possible to create a compact, double sided board that takes up hardly any space.  Can anyone else see that?  The problem with the full size components would be that the extra depth would cancel out the decreased width, but with your tiny components, it would be a massive saving in area without an increase in volume.
« Last Edit: May 24, 2011, 05:06:59 AM by soop »

Charlie

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Re: Making an RGB amp
« Reply #16 on: May 24, 2011, 06:46:08 AM »
Sorry, still not sure what your goal is.

If you want to make the "worlds smallest(?) RGB amp" only , it would fit onto a PCB about 1" square, but you might need to put parts on both sides.
--OR--
if you want to make the "worlds smallest(?) video amp" only, well... it would fit onto a PCB about 1" square, but you might need to put parts on both sides.
--OR--
etc, etc.

Point is, obviously if you remove those functions you don't want, you get smaller!  But my specific goal is the EPROM emulation, so I need socket space...which lends itself nicely to the daughterboard concept I mentioned previously.  And in that case, it makes no sense to design for a fixture to go INSIDE the console (DUH).  But that makes me ask....if RGB is your target, aren't there a number of RGB amps already around here?  And aren't they pretty small already?

Or do you have some other intent?

Charlie

gtsamour

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Re: Making an RGB amp
« Reply #17 on: May 24, 2011, 10:54:38 AM »
soop, from your words I understand that you just want to make an amplifier to fit in a console or something, same as me.

Trust me when I say that the one I made fits just fine inside most PCE consoles. The only exception being the Core II and probably the white PCE, these consoles are so small that i doubt you could ever find something that could fit in there.

My amplifier is symetrical and compacted in a way that it takes the less possible space using these components which I may add cost next to nothing.

I have installed this very design of the amplifier to four PCE consoles and it works like a charm each and every time.
« Last Edit: May 24, 2011, 10:56:56 AM by gtsamour »

soop

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Re: Making an RGB amp
« Reply #18 on: May 24, 2011, 11:21:36 AM »
soop, from your words I understand that you just want to make an amplifier to fit in a console or something, same as me.

Trust me when I say that the one I made fits just fine inside most PCE consoles. The only exception being the Core II and probably the white PCE, these consoles are so small that i doubt you could ever find something that could fit in there.

My amplifier is symetrical and compacted in a way that it takes the less possible space using these components which I may add cost next to nothing.

I have installed this very design of the amplifier to four PCE consoles and it works like a charm each and every time.

Yes, this is my aim, sorry if that wasn't clear to everyone.  My aim is to make an RGB amp that fits into a Core unit.  I already have the parts already, though it's disheartening that you haven't managed to fit it into the same unit I aim for. I would have thought that the space saved by removing the RF unit on the PCE would have worked :/

@Charlie, I have no idea about the amps out there, I've only just started learning about this.  Do you know of an AMP that could fit into a PCE?  If you could provide a link, I'd apreciate it.

[edit] completely missed the explanation of the daughterboard, yeah, I just want to make an RGB amp, plain and simple, inside a PCE
« Last Edit: May 24, 2011, 11:25:18 AM by soop »

Charlie

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Re: Making an RGB amp
« Reply #19 on: May 24, 2011, 12:55:20 PM »
Don't know about a CORE unit, but if you simply want a really small RGB unit, there is a schematic someplace here of a simple unit showing 4 transistors.  If you use SMT components and tantalum caps, it should easily fit on a one inch square board.  Since I don't know the abilities of each and every TG unit (I only have a TG-16 and a DUO), I'd first check to see if that same transistor-based circuit actually works on the target unit before making the final PCB.  Next question is, how much room do you actually have in the target unit?  As I said, I am not familiar with the various units, but I'd think that each one should certainly fit a PCB that small --- wouldn't it?

Maybe a better approach would be, tell me how much room you actually have for a PCB (in three dimensions if possible), and I'll see what kind of board will do the job?  Or maybe a picture of the inside of a unit, and we'll see what kind of irregular shaped PCB will fit.  Of course, there is still the matter of installing the connectors, unless you'll accept a cable through a hole someplace.

Charlie

gtsamour

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Re: Making an RGB amp
« Reply #20 on: May 24, 2011, 06:05:58 PM »
Well soop, the Core II i have doesn't have an RF unit to make space by removing (probably only the Core I has one). The Core II produces composite signal. Probably if my amplifier was constructed with tiny components it would be able to fit inside but that would probably require PCB designing and production that I'm not able to do. So I had to go with the external amp solution as you can see in my link above, which isn't bad at all because the amp is relatively small.

The problem resides only in these very small consoles (white PCE and Core). On SuperGrafx, TurboGrafx-16 and  the DUO there is plenty of space, no problems there.

Charlie:
The cosnole soop is reffering looks something like this on the inside http://www.pcenginefx.com/forums/index.php?topic=9379.0

The simple "just transistors" solution is easy and could probably fit even in the scart but I read somewhere that it can damage the console itself. The rest of the components in the diagram are there for a reason... something to do with regulating impedance if im not mistaken.

Also... all kinds of PCE consoles produce the same output RGB signals so the isn't an issue of the amplifier being suitable for one and not suitable for another. One amp works on all.
« Last Edit: May 24, 2011, 06:17:48 PM by gtsamour »

SuperDeadite

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Re: Making an RGB amp
« Reply #21 on: May 25, 2011, 12:53:51 AM »
Here's the amp I use.  Absolutely tiny and works wonderfully. :)

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soop

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Re: Making an RGB amp
« Reply #22 on: May 25, 2011, 03:22:44 AM »
That one looks really nice too. Is that a custome PCB?  What are the chips? Are you using those instead of transistors?

SuperDeadite

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Re: Making an RGB amp
« Reply #23 on: May 25, 2011, 03:29:53 AM »
They are DIY kits I buy from a Japanese website.  The pcb is factory made,
I only had to solder in the parts.  It uses IC amps, no transistors.  The
"new N64" amp on gamesx is an exact clone of this circuit.
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gtsamour

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Re: Making an RGB amp
« Reply #24 on: May 25, 2011, 03:47:57 AM »
Price and link please....

SuperDeadite

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Re: Making an RGB amp
« Reply #25 on: May 25, 2011, 03:54:27 AM »
About $25 with today's exchange rate.  They will only ship to Japanese addresses though.
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gtsamour

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Re: Making an RGB amp
« Reply #26 on: May 25, 2011, 04:37:06 AM »
Hmmm, i think its too expensive. I'll keep making my own amps...

Charlie

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Re: Making an RGB amp
« Reply #27 on: May 25, 2011, 08:32:46 AM »
There are a number of RGB amp threads here, some for op-amps and some for transistors.  In them, the various pros and cons are discussed, including the op-amp type and impedance issues.  (I'm too lazy to find them now, but they ARE here).  I remember specifically that I was the one who guessed what op-amp was actually being used before that info was even published.

$25 is not too much to spend for a pre-fabricated PCB, especially if you consider that the PCB kit is probably a high-volume (= low cost per board) item; the Expansion Interface board I show here, given that it is low-volume (can't get much lower than one!), cost about $150, plus my time in design and component install.  But given, as I said, that both the op-amp circuit and the transistor circuit are available here, just use one of the prototype houses that will make the PCB for $9.99, buy the parts, and build it!

So, anyone want to do some research and determine what size PCB you actually could install in whatever unit, preferably in all three dimensions?  Then let's see what circuitry will fit on it. (Hmm, don't forget you need cable connectors some place!)

Charlie


soop

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Re: Making an RGB amp
« Reply #28 on: May 25, 2011, 10:35:43 AM »
There are a number of RGB amp threads here, some for op-amps and some for transistors.  In them, the various pros and cons are discussed, including the op-amp type and impedance issues.  (I'm too lazy to find them now, but they ARE here).  I remember specifically that I was the one who guessed what op-amp was actually being used before that info was even published.

$25 is not too much to spend for a pre-fabricated PCB, especially if you consider that the PCB kit is probably a high-volume (= low cost per board) item; the Expansion Interface board I show here, given that it is low-volume (can't get much lower than one!), cost about $150, plus my time in design and component install.  But given, as I said, that both the op-amp circuit and the transistor circuit are available here, just use one of the prototype houses that will make the PCB for $9.99, buy the parts, and build it!

So, anyone want to do some research and determine what size PCB you actually could install in whatever unit, preferably in all three dimensions?  Then let's see what circuitry will fit on it. (Hmm, don't forget you need cable connectors some place!)

Charlie



It's a valid point.  Let me see what I can come up with.

soop

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Re: Making an RGB amp
« Reply #29 on: May 27, 2011, 04:55:45 AM »
Although my mini breadboards still haven't arrived, I'm beginning to think that they're wrong for the job anyway, but I also have a bunch of those hole ones coming too.

I've been thinking, and I reckon if I do a double-sided amp, I can get it down to an area of 4x5 holes, which is pretty small, with the power running through the middle, and the ground jumpered from the corners.



It should be like that, but mirrored on the other side.  Can't see why that wouldn't work at the moment (apart from perhaps the size of the components), but any comments?