[ADS]

I diagrammed out an amp and powersupply that I am planning on building (Alltogether, parts are going to be around $60, not including wallwart). Will this design work?

 

[guzzler]

yep, it will work... you might like to consider putting some smaller film caps paralleled with the big (and comparitivly slow)2200uF elcos to provide better transient response... but no, looks a good first amp!

g

 

[ADS]

Ok, I've changed the design a little bit. The power supply caps are going to be 25V Panasonic FCs and the DC protection cap is going to be a Panasonic polypropylene. From what I understand of electronics, I think this amp is going to sound d*mn fine for the price ($48 at digikey without enclosure, volume nob, or RCA jacks)

. Anybody have any comments on the design or things I could improve? I want to fit this onto this protoboard, here, so space is a little tight (even though it is a home amp). Does anybody have an unfilled bmp of the above protoboard I could use to plan the layout? This is the same one tangent uses for his cmoy tutorial, so somebody must have it.

 

[bralack42]

Attached is a photohopping of an empty RadioShack 276-0150, as shown in Tangent's CMoy tutorial. It's not perfect quality, but it'll work for laying things out.

 

[stereth]

I've used that protoboard for several projects. I tend to take a piece of graph paper. I draw the outline, 17x25, with notches on the corners. For the traces, I either draw with pen on the back of the paper, or just sketch lines at the top and bottom of the pattern. Then I place the components on the board as I draw them. Use pencil.

 

[faehntim]

I posted a photoshop layout of this protoboard for download, in case you want to use it. It's near the bottom of the page in the link. You can just use layers and slide the parts around to figure out how you want your layout.

Link

 

[ADS]

Thanks for all your help! I have one question remaining before I start ordering parts, is the 100 ohm resistor after the Opamp a good idea? I read in the meta42 tutorial that it is supposed to reduce ringing, but I'm thinking it may increase output impedence too. Should I leave it in? Lastly, are there any tweaks/additions you would recommend to increase audio quality? I'm getting excited about building this thing.

Slightly updated schematic below:

 

[guzzler]

you could make the amp into a multiloop topology as per the META42 schematic (2 more resistors per channel)...

no need for the bandwidth pin to be connected in the power supply, just a waste of current

the resistor between the op-amp and the buffer doesn't affect the impedance at all as it is "hidden" behind the buffer for want of a better explanation!

g

 

[ADS]

Just order the parts, here's the final version. It's basically a non-multiloop meta42 with BUF634 buffers instead of the normal EL2001s. I might make it multiloop a little later and see if I can hear the difference. Is the difference really that great? I understand the principal behind it (Although the article by Jung doesn't seem to exist anymore so I'm not really sure I have it right), and it doesn't seem that it should really make that much of a difference.