First DIY solid state

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Guess what, Ebay links now die as soon as you post them. i.e. we can only guess what you refer to.
It's usually OK to use the very basic Chinese kits offered for peanuts everywhere on Ebay, so long as you remember you'll need a Power supply board and some quality fat caps like Panasonic THSA type as well as the power amplifier board(s).
Mounting hardware like suitable heatsinks of about 1-1.5 degrees/W rating for each amp. Then bolts, nuts, washers, lockwashers and spacers of at least 6mm length would be useful too, as would heatsink paste - the insulating variety. To get very good quality sound, it's likely you'll need a little more circuitry to drive a volume pot (preamp) and keep the match to amplifier buffered with a good low impedance source of perhaps 200 - 2,000R. This is not often catered to or discussed in simple designs where you are left to your knowledge and skill to get the best from your basic device. They still need to be connected to input signals so best to get this right.

Much of the Ebay cost is in postage, so don't waste money skimping with cheapest possible junk designs. a litte more to have some more flexibility and possibly enhancements too.
 
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Just saw your Post Ian,

Below is what i was planning on buying for $9 delivered:

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Its my understanding that PCBs, are simply metal and board, so there cant be a huge difference between PCB's right? But i understand capacitors and other components are a different story.

Where should i buy the other more quality components from?
 
One thing to consider... While the China/eBay stuff may be less expensive and you may or may not get a good quality product with a good layout, purchasing from folks like ChipAmp supports those that support us and our hobby. There are a whole bunch of folks that take the time to help people and contribute to the forums and it would behoove us to support them and their businesses when we can.
Just my $0.02 for your consideration
 
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One thing to consider... While the China/eBay stuff may be less expensive and you may or may not get a good quality product with a good layout, purchasing from folks like ChipAmp supports those that support us and our hobby. There are a whole bunch of folks that take the time to help people and contribute to the forums and it would behoove us to support them and their businesses when we can.
Just my $0.02 for your consideration

+1
 
I understand that it is a very niche hobby and supporting the cause is a good thing to do, but paying 39AUD compared to 9AUD is simply a huge difference, and I cant seem to justify four times the cost for something that is very similar.

AndrewT I have looked at the post you mentioned and this is what of got out of it. In a simplified way:

When you build onto a standard ebay PCB you are getting a base model, just like a car, if you want options to make it more driveable such as cup holders or tinted windows you either need a new PCB or to modify the ebay one with suitable components.

If I do this, will the amp have all the compnents that the chipamp board can feature?

Cheers and sorry if I am frustrating you guys, please bear with me.
 
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I guess you'll pay your $9 plus post and you'll get $9 worth of basic boards to the basic app. notes. A circuit that works and one that works well is like the comparison of MP3 and Flac or 24bit /96kHz digital resolution. If you just want to make some noise for cheap then sure, go for cheapest. You will soon be replacing it as you discover the facts of audio amplification and the need to use better circuits and layouts to get the best quality sound from chipamps. The idea that there are just more bells & whilstles with better boards is seldom true with Chipamp DIY. Most designs will do much the same; some only just, others with excellence and that can be due to several factors, not the least of which is the layout of what is a very closely packed and highly noise sensitive arrangement of IC pins. Optimising that part of the PCB and leadin into an adequately spaced or grouped connection array is half the battle of successful Chipamp implementation and jamming it all together on a tiny PCB may be cheap but seldom makes a good start. Some Ebay designs are not far removed from just autorouted tracks, ensuring minimal board and copper use, and this is unlikely to wind up good.

As you ask if you can add full features by "adding onto" a basic board, that's an open ended question. We don't know the precise circuit or features you consider yet but to discuss this fully, the chipamp forum is the place to post. However, the circuit complexity is usually geared to quality expectations so if you want a full featured design, then start that way, with recognised quality boards and features. Patching parts onto a PCB is a sure fire way to introduce noise so I suggest not messing with them. Build as the PCB was intended unless you know a lot more than the designer about his work.

Still, its your choice and its not wrong to start out basic but may I suggest you make allowances in your preparations for a more sophisticated affair when your interest is piqued by the basic attempt.
 
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Hmmm, so a definite no from everyone regarding going the cheap route.

That is fair enough as i understand that there are lots of details in circuit design that i dont understand such as loop area etc.

I may aswell get the whole kit from chipamp then to combine postage. I have to ask a stupid question though. There are two kits listed: one for two mono channels and one for two stereo channels. I thought that the listening style was determined by the Pre-Amp and not the amplifier itself, and that the two channels were individually connected to a pre amp and then this outputs as stereo, mono or surround. Is this not the case?

EDIT/PS: Mihkus your picture is ******* creepy, its like something from a nightmare :O
 
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This is the manual with explanatory notes for Kits on offer.

You will not find this level of documentation and explanation with Ebay kits and it will become an important part of your satisfaction in building it right - first time, if you follow closely.

I assume you are querying why anyone would build 2 mono kits rather than a stereo, if I have got the gist of your question right. It is common in high end gear, to build amplifiers in so-called dual-mono construction, with separate transformers and power supply circuits for each channel and thus force cross-talk down to unnoticeable levels, since there are esentially 2 separate mono amplifiers in the one case. This is a great plan, of course but will not be necessary for your first build where a stereo pair will be fine and can be upgraded by doubling just the power supply later, which you should have plenty of room for in your 2U case, if you think that will make significant improvement. Opinions are often divided on this but some guys just think that more is better in everything they do. Maybe. ;)

Chipamps are such simple designs that builders lavish all manner of refinements on them that are usually reserved for high-end products that none of us can (or will) afford. There are other reasons such as needing 5 channels for a 5.1 HT amplifier or a mono one for a small subwoofer etc. There are boards then, to suit most if not all likely needs.
 
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Dual Mono - 1 amplifier board and one power supply board for each channel. For stereo you need two, therefore a Dual Mono kit
Stereo - 2 amplifier boards, one for each channel and one power supply board to supply power to both boards. For stereo this will give you both channels.

I think Ian said everything you need for some idea of why offer both. The stereo kit is less costly to build due to only one power supply.
 
So is this a correct statement?

You can individually provide pre-amplification to two Mono channels and have them play in stereo, however you cannot have a stereo pair fed mono sound without there being crosstalk?

And is this also correct?

A mono amplifier with 23 (this is just a random number) channels have 23 transformers?

And one last question, do I get to solder the components onto the boards with the kits from chipamp or are they pre-made?

Thanks everybody
 
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