[linuxworks]

just a public service reminder:

for those that choose to use the (cough cough) buyable part as a buffer instead of the burr-brown 'we don't stock that' chip) on things like the pimeta amp - 2 things you need to remember to do:

1) lift pin 5 before soldering. I'm not a fan of fully cutting it off (in case you pick the wrong pin and realize later your goof) and lifting it is enough to keep it out of harm's way while you solder the other pins.

2) leave out the 200ohm resistor (R11 on tangent's schematics).

I believe his instructions do mention #2 but not #1.

here's a link to some discussion:

http://www.head-fi.org/forums/f6/pos.../index354.html

here are some of my shots of what I'm talking about:

just posting this in one thread for easy reference

.bl

 

[rds]

Quote:

...on things like the pimeta amp - 2 things you need to remember to do:

Just to clarify that these tips are specifically for the Pimeta and not necessarily for other amps using the buf634

 

[error401]

I'd still clip the extra lead off after testing the amp.

 

[linuxworks]

Quote:

Originally Posted by error401 /img/forum/go_quote.gif I'd still clip the extra lead off after testing the amp.

you mean, once the chips are soldered in and verified working?

yes, I agree, then its safe

but can the pin be snipped off safely once the chip is soldered that close to the board? I guess so - but is it worth the effort?

I have 2 pimetas now and I really can't tell the audible diff between the 2 buffer types. I'm glad there's an alternative that's almost a direct drop-in for the very hard-to-find 'normal' part.

.bl

 

[error401]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif yes, I agree, then its safe but can the pin be snipped off safely once the chip is soldered that close to the board?

Not difficult at all with a quality pair of cutters, or even a sharp knife. Is it worth it? No, not really. It's not even really necessary to lift it on the PIMETA since the pads don't connect to anything. It's just one of those little neatness things I guess.

 

[tangent]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif I believe his instructions do mention #2 but not #1.

Yes, sorry. I didn't realize when I wrote that that there were traces making shortcuts through the buffers' pin 5 in a few places. The BUF634 doesn't use that pin, so it's harmless with that chip, but not with the LMH6321.