Thank you both. I bought a cheap hole-punch (Fiskars brand) at Officeworks and it works perfectly. I also viewed the video tutorial.  

Thanks for the quick responses. Fred, I see from your ebay ads that you're also in Australia. Any idea where I could find the model you use locally?   Thanks.

I've just built my first CMOY and am having trouble punching holes in an Altoids can to house it. I tried a steel hole punch and hammer, but the result was a bit messy. I bought a rotary hole punch on Ebay, but it is absolutely hopeless - no where near enough pressure to punch a hole in anything...

I tried the TL2426 and it fixed the problem - perfect voltage split between the audio channels. Two 9v batteries do sound a bit better than one, but the difference is fairly small. I think I'll stick with the single battery, though, in order to use my Altoids tins.   Thanks again for the...

Thank you Soymilk and nikongod!   It did not occur to me that wide variations in voltage through the rail splitter resistors were "normal" in amps not using a tle2426 (after all, the split looked good until an amp was plugged in). I was convinced the problem was somewhere else.   I tried...

Hi,   I bought a JDSLabs headphone amp awhile ago and thought it was great! I got interested and tried to build a CMOY amp according to Tangent's tutorial. Using an OPA2227PA (from the JDSLabs amp)  the sound is OK, although not quite as good. However, when I try an NE5532, TL072 or JRC4560D...