2. vintage
  3. 163060-142670

To re-cap or not to re-cap? That is the question

I've got some very fine 1980s vintage equipment I love and don't want to replace. Recently, I was able to locate a company that repaired the drivers in my ailing speakers; I'd auditioned half a dozen excellent speakers in my home in anticipation of needing to replace my Teslas, and none pleased me as much. The amplifier has been serviced by a local audio engineer I trust--but he describes himself as a "recovering audiophile," and may not be the right person to ask what I want to ask here. Namely: should I have the capacitors in the amp, and perhaps also in the speakers' crossovers, replaced? Is there any other service protocol I should consider?

On the principle "don't fix it if it ain't broke," I'm inclined to leave well enough alone. I don't notice any audible deficit. But perhaps the system could sound even better?

Your sage advice will be appreciated.
snilf

Showing 3 responses by erik_squires

erik_squires
16,592 posts
 
Hi @elliottbnewcombjr

The issue with amps, and this varies a lot, is how much damage you can do if the electrolytic caps blow out.

With a preamp for instance, there's usually no more than +- 15V inside. At most you would blow a voltage regulator.

With an amplifier, with +- 60V or more, and high current, you can blow an entire amplifier board.  Maybe more important for solid state than tubes.

So, like Clint Eastwood's Dirty Harry, you have to ask yourself, "Do you feel lucky, punk?"

I have also consistently read from many that these upgrades are often quite beneficial sounding.
erik_squires
16,592 posts
 
You can replace the main caps fairly easily, but you may have a scattering of smaller power supply caps on the amp boards.  Usually 50 to 75uF or so. Those can like caps should be replaced at the same time.

Honestly, wet (electrolytic) caps in the 1980's were pretty crappy compared to the modern varieties.  Much more inductance and ESR than the average cap today, so you can improve upon the power delivery  and lower the noise a little by doing them too.
erik_squires
16,592 posts
 
Speaker: Film caps in speakers can last forever unless over stressed.  The electrolytic caps, if any, are what dries out. Consider replacing with Axon film caps, if you can compensate for ESR changes. Replacing tweeter/mid caps can change the character of a speaker, so I do suggest you leave that alone unless you have good help.

Amp: With an amp of 1980's, you've had a good 40 years with the original power supply caps, all electrolytics. If you replace them now it will sound better, and you'll greatly reduce the chance of burning up the rest of it.

Best,

Erik
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