ezzo 0 Report post Posted August 15, 2007 Hi, Im quite new here. Im intending to make a diy amp. Prob a cmoy2 or pimeta design. 1) Does anyone know where can i get the PCB for either of them? 2)And what exactly is the difference btw a cmoy 2 and pimeta or others of the same complexity? Thanks! Share this post Link to post Share on other sites
1bit 0 Report post Posted August 15, 2007 oh, looks like you've already post your questions here, ezzo 1) for cmoy2, it seems the only source is jasonhanjk, tropicalrips is not selling them anymore. i'm also trying to get a few more pcb from jason and have sent him pm but so far no response. anyone knows other channels? pimeta pcbs can be bought from tangent http://tangentsoft.net/shop/ 2) well they are quite similar yet quite different lol they are both 3-channel amp design (if we can say so) pimeta uses a combination of opamp and buffer, the opamp to get voltage gain and buffer to supply current whereas cmoy2 uses jung's multiloop design putting two opamps (in 1 channel) to work in sort of "paralel" (not really in paralel in the true meaning, but nonetheless share the current load together) and doesn't use separate buffer. to create virtual ground, cmoy2 uses two resistors; whereas pimeta uses tle2426 ic (cost and pcb space savings for cmoy2) another difference (perhaps the most important) is that pimeta bias the opamps to work in class a mode by forcing to draw more quiescent current from them (probably will reduce battery life) another observation is that cmoy2 pcb is smaller and can fit in an altoids mint tin with a 9v battery. another thing, (but probably not verified) cmoy2 uses lm6171, a bipolar opamp as buffer for the ground channel. the chip might be the possible cause of nonstability (distortion) of the amp if the power (or ground) to that chip is not soldered properly. happy diy-ing Share this post Link to post Share on other sites
ezzo 0 Report post Posted August 17, 2007 Thanks 1bit. Well, looks like I'll have to stick to cmoy for now Share this post Link to post Share on other sites