Can someone point me to Graingers post on burning in caps external from gear?

[Pfenning]

I was reading the forum a couple days ago, and saw Graingers post on burning in caps (especially teflons) before installing them into gear. I just saw it a few days ago, and now I can't find it again. If someone could post a link to it, that would be very helpful. Thanks.

Pfenning

[Adrian]

I don't have the link but I captured information regarding this process.

Basically, you can use the speaker terminals of any amplifier.  The amp must be capable of powering a 4 - 8 ohm load.
This will work for non-polarized Film caps but not sure if I would try to burn in electrolytic caps because they are polarized.

You connect the capacitor leads to the speaker terminals BUT you must have the circuit under load (not just the capacitor).

The load that I have used is a 5 ohm resistance in series with the capacitor.  Because 10 ohm resistors are fairly easy to find I paralleled two 10 ohm resistors and then connected them in a series circuit with the capacitor.

For example, if you want to burn in the capacitor for 200 hours you will need to have a constant signal (CD on repeat or streaming signal from your computer as an input to the amp) for about 8 days straight (24/7).

The signal can be set with the source feeding speakers at a volume at or slightly above normal listening level.  Note the volume pot setting.  Disconnect the speakers and then connect the capacitor(s) with their 5 ohm load to the speaker terminals.  Start the input to the amp and set the volume to the level you noted earlier.

You obviously won't hear anything because you have disconnected the speakers but the signal from the amp will be going through the capacitors.

I would recommend using a solid state amp for this so you can save "tube" life when you really want it.  I built a gainclone amp specifically for this purpose.  When I am not burning in caps I am using it listen to music from my computer via a Modi DAC.

Hope this helps.

[mcandmar]

You obviously won't hear anything because you have disconnected the speakers but the signal from the amp will be going through the capacitors.

You might be surprised.  I know if i play a test tone into my S.E.X. amp connected to a dummy load i can hear the tone, never did figure out if it was the output iron or caps, but its certainly audible.

[Pfenning]

Thanks for the reply. I think I am set now.

Pfenning