Question about caps in vintage power monoblocks


If a pair of vintage power monoblocks (produced in mid 80s) was kept in storage for the last 15 years or so with less than 100 hours of use - would the capacitors continue to deteriorate while in storage at about the same rate as if one was continuing to use them or would the damage/drying of the caps slowed down/stopped once they were put in storage?

973d1792 912c 40b1 bb6b 180d352536d4chattaudio
Definitely deteriorate and in general if I was taking amps out of 15 years in storage, I would have a tech check them over. At the very least use a variac to get them slowly up to voltage don't just plug them in and flip the switch.
Thanks, jond!

Make and model make a difference too, and what part of the 1980s?  Remember, there were recessions then, two in fact, and many manufacturers cut corners to stay in business.  The brand of the cap is important....quality is quality, the bottom line.

You do not state if this is tube or solid state, that makes a difference.  Yes, bring it up slowly to 1/3, then 2/3, then full is a proper way, but not necessarily if it is transistor.

My suggestion is replace the fuse with 1/2 amp rating, speakers attached, no input.  If transistor bring up over 15 to 20 minutes to power, if the fuse pops, then the caps may have shorted.  If tube, bring up over a longer period, may be 3 to 4 hours.

hi Chattaudio,

The electrolytics are what will eventually dry up. Not being used will help them last longer, but if you have a 30 yo piece of gear, it is time to seriously think about re-capping them no matter what.

Also, the modern electrolytic produced since the 80s are just a lot better, smaller, cheaper. I've heard from several that they feel their gear sounds much better after re-capping.


Some say not using the amp makes it age faster...
Thanks for your replies, folks!  The pair of monoblocks in question is Denon POA-6600.  Denon is not a brand known to cut corners, at least not back then.  Specifications suggest that at least at the time of their release these monoblocks were dang close to state of the art:

Power output: 250W into 8Ω (mono)

Frequency response: 20Hz to 20kHz

Total harmonic distortion: 0.002%

Input sensitivity: 1V

Signal to noise ratio: 123dB

Speaker load impedance: 4Ω to 16Ω

Dimensions: 310 x 207 x 456mm

Weight: 15.6kg

We'll see how they sound when they arrive.  I will update this post later!