ckng 0 Report post Posted August 31, 2003 Hi, Just built a META42 with OPA2132PA op-amp, Elna Starget power supply caps and generic 1% resistors. On its own, it already sounded pretty good on AKG271 Studio. I am also only using some junk cable to connect to the RCA connectors and Neutrik 1/4" headphone socket. Will be adding the JFET cascade to bias the thing into Class A next. Just wondering what kind of improvements will I get if I use higher quality resistors, etc? How about stacking the buffers? Will the differences readily audible? Anyone else built their own META42? Regards CK Share this post Link to post Share on other sites
Firefox 0 Report post Posted September 1, 2003 The resistors don't really change the sound much. The circuit simply isn't simple enough for the resistors to colour the sound. Stacking buffers would give the amp more control of the sound. Chances are you'd get tighter bass. Going from 1 to 2 buffers per channel is good. 2 to 4 is not so noticable. Above that would be a waste of good money. Note that you need enough reserve capacitance for the buffers as well. Share this post Link to post Share on other sites
ckng 0 Report post Posted September 1, 2003 Thanks firefox. Another question, what would be a good wire to use to hook up the PCB to the input and output jacks? Regards CK Share this post Link to post Share on other sites
Firefox 0 Report post Posted September 1, 2003 Any teflon insulated copper/ silver wire will do. It's not so critical especially when the length of hookup wire is short. Share this post Link to post Share on other sites
Rameish 0 Report post Posted September 2, 2003 Congrats. IMO sound changes to the META 42 circuit/design are most evident with op-amps. That is find an op-amp that mates well with your headphone and taste. AD8620 is an okay op-amp but is not the bee's knees. OPA 627 or 637 are much better though have that typical slightly veiled BB sound. Increasing buffer from 2 per channel to 4 isn't really gonna help much but it's the last 1-2%. Also spend your money on a DIY linear regulated power supply. Frankly I prefer Silmic over Starget. You might wanna try something other than Wima "reds" also. Good luck and have fun. Share this post Link to post Share on other sites
fishball79 0 Report post Posted September 2, 2003 I'd suggest avoiding silver plated copper hookup wires (save for nordost but why would you want to cut it up!?). Especially the belden teflon insulated one. Its cheap but bright sounding... Share this post Link to post Share on other sites
ckng 0 Report post Posted September 2, 2003 Thanks guys! Where's a good place to get reasonably good hookup wire? LHS? Regards CK Share this post Link to post Share on other sites
ckng 0 Report post Posted September 6, 2003 Shucks, brought back a Cambridge Soundworks 15V regular power supply from office, forgot to check polarity, hooked it up and I think I fried the TLE2426. Didn't implement reverse voltage protection. The virtual ground is now at +Vcc I think. Hope my buffers and the op-amp are still ok. Regards CK Share this post Link to post Share on other sites
