If it ain't broke, don't fix it?

[OMGCat!]

What would the result of this drying out of fluid be on the performance? I'm still leaning towards using "as is" for two reasons. Restoring is a hassle for me (I would likely damage it and not sure where to look for tech people) and the NAD is way better than the entry level I upgraded from. Sonic improvements no matter how subtle is what matters to me most so the NAD is still very satisfying compared to my old amp. However I do borderline obsess about optimal performance from my system. If I decide I really want the work done, I guess I'll learn to do it myself. In the event of a screw up, at least I would have learned a few things about one of my hobbies (and there are much more expensive amps out there waiting to be screwed up) The engineering and how an amp's components "communicate" with each other and perform their functions is a mystery to be uncovered.

It really depends on the circuit design, how bad the cap has gotten, where in the circuit it is, etc. I've had amps with a bunch of caps at half value that didn't sound much different (if at all) with all new ones in place but an amp with one bad filter cap that's throwing 60 cycle hum and you're definitely going to know.

 

[krimney]

I am currently sitting in the same boat. I recently bought a receiver that is 15+ yrs old. This model has a few known issues and the one I bought was apparently not functioning 100%. Many of the user selected settings were set to max levels which may have contributed to it's performance. So far for me it has performed satisfactorily for me. As it is a very complex unit with CPU controlled stuff and lots of different boards( HT gear) I will likely just listen to it as long as it works and if it causes problems then deal with it. If I give it to a tech, (very few have worked on these things) I am guessing once he is into it, then problems will arise.

 

[merlynski]

Run it.

26 years is past guaranteed cap performance life but that means they may not be performing to spec.

36 years? 50/50. a recap isn't dumb but is it worth it?

46 years? A recap would certainly make it work better.

A failed cap is not a Chernobyl event. Usually the sound gets lousy and/or you get random pops.
You may lose sound but it won't burn up or catch on fire or throw pieces and parts around.

I guess 90% of 70s vintage (40+ years old) is being used with factory caps and pleasing owners.
They probably don't sound as good as they could, but they work.

Unless it is a Tantalum Cap, one of their fail modes is: short out, heat, smoke, flame on. I have seen it many times.

 

[sj.brodie]

If you become a subscriber (upper right corner in the home page), for $25.00 per year you will have access to BT (Barter Town) where members buy, sell and trade equpment (among other things). Some newer, some vintage. Often, the vintage equipment has been rebuilt and/or recapped.

As to your NAD, if it works good now and you're happy with it, why not just keep it til it dies. Could be several years. On the other hand, that rabbit hole is inviting.

Just letting you know I’ve subscribed. Hoping to eventually find a creek 4330 or similar in BT. I’m curious how creek would perform against my NAD.

 

[slimecity]

Dont know if its already been said or not but there is a lot to be said for preventative maintenance on replacing several troublemaker components. these include the Hitachi 2SC458 "shed" profile tranny, the VD1212 double diodes and the black flag caps. There isnt much debate about replacing these outright as they will fail and cause some damage when they do.

Theres also the old ceramic flying saucer transistors - common in older sansui gear - these get noisy and fail with age and IMO my amps have always benefitted from replacing these for sonics & reliability. Plus, I have a soft spot for the old Leak Delta/Stereo 30 and 70 amplifiers, and am currently working on my 4th unit. These all have several BC118, 119 trannies at the input stage to the preamp boards - in the units I have seen, these ALWAYS fail at some stage - guaranteed.

 

[Markoneswift]

To add to what my friend @slimecity is saying, I too am working on a vintage amp right now - a Leak Delta 30 to be precise. It sounded fine after I bought it and replaced a fuse. Upon investigation however, the main power supply smoothing cap was toasted. This wasn't obvious because that cap is mounted upside down in a clamp. I pulled it and found a puddle of dried gunk under it, along with a large blister in the plastic top cover which released a lot of gas once pierced. The other three smaller caps all had those same blisters so clearly all needed replacement.

I guess what I'm saying is, it wasn't broken in the sense of not working at all, but similar to a badly running car it needed attention to core components. Age is absolutely a factor and I used to be firmly in the camp of leave it alone if it works. After going through this little Leak amp though, it's clear to me that gear of this age WILL need some kind of attention to make it run optimally, rather than just work.

 

[Blue Shadow]

@slimecity spell check on your blag (blaque) flag caps...ah black flag...Done! THX

The advantage to using an old working unit as you decide to do some work on it is that you will have an idea of how you like it and it's sound. Then go in and swap the tired but not worn out (it still worked) parts and enjoy the fruits of your labor with a sonic change. Just buying and diving in seems more an electronics refresh hobby not an audio hobby. Nothing wrong with that, though.

 

[Eastham]

If you're gonna keep it for a while re-cap it, that's what I've done with my favorites along with known troublesome transistors. Unless you're not confident in replacing components, then it's probably best to let sleeping dogs lay or buy a cheap unit to experiment with first. My $0.02 And for what it's worth a re-cap certainly makes a decent difference to my young ears, especially the main filter's, reduces a lot of the mid bass boom.