Capacitors, especially electrolytics, degrade over time so it is likely a combination of both.
Question: Is it possible it actually sounds better or am I just glad to have it home again?
Ok, but on a more serious note, my 16 year old amp crapped out. The place I took it to for a repair job seemed completely legit and replaced 16 caps. The unit sounds better than ever. Question: Is it possible it actually sounds better or am I just glad to have it home again?
I remember an AES study, many years ago, that looked at the mechanical issues in film caps. They had some fancy laser interferometer equipment or some such to measure vibrations of a quality film coupling cap due to magnetostriction and electrostriction. They could prove that indeed, as some frequencies and levels the cap body did start to vibrate but the excursions measured were at the molecule size level. Not something I would expect to muck up my listening.
OTOH, some boutique crossover caps apparently are loosely wound and exposed to high currents and they could be singing.
What can be measured and what are the typical sonic symptoms of degraded or bad caps in various parts of audio circuits?
Is the speed (rate) of charge and discharge of caps variable between types? Does that affect audio performance?
What's the expert view on preemptive replacement of power supply caps? Some manufacturers have a nice little earner going with this.Deteriorating capacitors can have varying effects on amplifiers depending on where in the circuit they are and what function they provide.
What's the expert view on preemptive replacement of power supply caps? Some manufacturers have a nice little earner going with this.
For people without the skills to check, what should they do? Pay someone to check every ten years, some other length of time, or just leave it till something seems off?Only replace if clearly not up to spec.
For people without the skills to check, what should they do? Pay someone to check every ten years, some other length of time, or just leave it till something seems off?
For people without the skills to check, what should they do? Pay someone to check every ten years, some other length of time, or just leave it till something seems off?
You may never notice "seems off", because it'll happen so gradually. Unfortunately, properly checking capacitor performance means removing them from the circuit, which depending on the equipment can be quite invasive, or as simple as removing some wire connections. It's more likely the former with solid state electronics.
A bit of both. Deteriorating capacitors can have varying effects on amplifiers depending on where in the circuit they are and what function they provide.
When I returned the amp to operation I did think it sounded better then it had previously - not better than when I purchased it ( although it is hard to remember exactly what it sounded like 25 years ago ) so the new caps returned it to working as designed, but not better than original.
No doubt that replacing badly deteriorated caps will make the amp once again measure to factory spec or better. The reality of the amp actually sounding better will be highly dependent on how bad the old caps actually were and how much improvement the new ones made in tech performance.Just as a deteriorated cap will measure and sound different in some instance, so too new caps with different construction and quality, will also measure and may also sound different.
What is a serious influence here is bias. If you spend the $ and do all the work to get that amp percolating like new, your expectation bias and (near) human brain is going to make you hear a huge improvement in the sound no matter the reality. Win Win Win.
Happens all the time even if there is no change. Your mind works differently when you attempt to listen carefully for differences. In doing so, it hears more detail, air, etc. These were always there but ignored.How about when I replaced some coupling caps with a different type, hoping to prove it makes no difference, but instead, got a big surprise?
Happens all the time even if there is no change. Your mind works differently when you attempt to listen carefully for differences. In doing so, it hears more detail, air, etc. These were always there but ignored.
Do the test blind and you will fail to hear the same difference because then, you don't know if something has, or has not changed. Make sure you test 10 times and see if you get 8 right. If it is big surprise, you better get 10 out of 10 right....