Technical/electronics/capacitor question, for you pedal makers...

[bakerster135]

So I've been messing around a bit with the TK421 that I got back from Tom (COG). Have replaced the op-amp with an LM308N, which went in fine, but I had a bit of a job getting the 30pf compensation capacitor (ceramic) in there...

It's now in the socket securely, but a bit of the ceramic coating flaked off at the top of the legs/below the round bit when I was putting it in!

I assume this is ok, and will not affect the performance of the cap, but I just wanted to check with you guys!

Can provide pics of necessary, but if anyone in the know could let me know, that'd be great!

Cheers,
Al

[Woodinblack]

Thats almost certainly fine, the stuff round the legs is prone to coming off. But I looked up [font="helvetica, arial, sans-serif"][color="#282828"]TK421 on google, and apparently that is the designation of one of the storm troopers stationed on the first death star, so that might cause you problems later.[/color][/font]

[bakerster135]

Thanks, that's put my mind at rest! Darth Vader's my dad, so I should be fine on the other count too! :-)

[flyfisher]

I agree and wouldn't worry about a little bit of the capacitor material breaking off, as long as it really is only at the base near the wire legs.

As a point of interest though, the use of sockets is generally discouraged in electronic assemblies for all sorts of reasons, especially if the design/performance/stability is critical. I'd guess this is not too important with an audio device but a socket will add some additional capacitance to the circuitry - only a tiny amount, say a few picofarads, but since you're using a 30pf capacitor then the socket could easily be contributing around 10% of the capacitor value. Not necessarily a problem, of course, but when experimenting with component changes it's sometimes helpful to understand what's really going on in the circuitry.

As for the Storm Troopers - you're on your own there!