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EMI Circuit/Component Saturation

I've just been made aware that if components are left powered on for prolonged periods i.e. days-months they can become "saturated" - which in turn degrades performance.

The saturation may even extend to IC's and SC'c (so I'm told).

Personally I leave my system on 24/7 - NAIM actually recommends leaving their gear on and since I have a NAIM amp I adopted their "norm" for everything

Anyhow - I tried a few things to see what the impact might be.
1. Turned off my DAC + V-Link for an evening - left the amp powered on
- next day the system sounded significantly more lively and brighter with an extension to the high frequencies

2. Then I turned both Amp and DAC/V-link off for the evening
- next day the sound was as good as in #1 above, but I would not say that there were any further improvements to the sound.

I'm currently allowing my phono stage to Saturate before I can test that.

Since EMI saturation is more of an issue with very high frequencies, such as those used in digital sources I figure this explains why the digital side of my rig appeared to be affected more than the analogue-only amp.

I also think it has a lot to do with component quality and design e.g.

- I would assume the NAIM amp was affected less due to the fact it's design to be left powered on and as such is probably designed to better handle EMI saturation issues.

- whereas my DAC, which is more budget oriented, is probably not really designed to cope with EMI saturation issues

FYI: with my Bifrost DAC + V-link I noticed the highs starting to tail-off after being powered on for 4 days and after 6 days there appeared to be no further degradation.

So if you leave your components powered on for extended periods try this simple test and see if it makes any difference.

Costs nothing to try :-)
williewonka
williewonka OP
3,082 posts
 
Kijanki - I was actually informed about this effect by an audio designer with over 30 years of experience.

Having had a formal education in electrical engineering, I can understand how this effect may occur, simply because there are many electrical components that rely on EM saturation in order to operate e.g. transformers and inductors are the most common.

But many other components can exhibit traits similar to these components when subject to very high frequencies, which effectively alters their overall impedance.

In fact, I read a few articles on the web specific to digital circuit design that highlights these problems before placing my OP.

The effect is most noticeable when extremely high frequencies are in play, such as with digital music reproduction.

As stated in my OP, it was most noticeable with my digital components and hardly at all with my "analogue only" amp.

Perhaps one of our more learned Audiogon brethren can provide mode details?

What I do know - what I heard :-)

Regards...
lustformusic
68 posts
 
If you read your own post your system benefited only when you re-booted your Dac as they are a type of computer.
I realised this some years ago, also interesting to read similar in Jim Smith's book Get Better Sound.
kijanki's avatar
kijanki
4,432 posts
 
Williwonka, Saturation in magnetics occur when increasing magnetic field cannot increase magnetization anymore (magnetic flux limit). In 99% of cases magnetics are designed to stay below saturation levels. In addition saturation might depend on temperature but it is not a function of time.

Overall impedance of circuits is not "altered" by high frequencies. Their impedance is different at different frequencies, but again - it isn't function of time.

I don't question your experience but rather suggest that reason can be different including temperature or changes in ambient electrical noise.
williewonka OP
3,082 posts
 
Kijanki - I have neither the educational background or the desire to delve into the "root cause" and your thoughts on this topic may well be correct.

I was simply passing on what I had heard and since it came form a "credible source" and I found it to be beneficial, I thought other members might like to be aware of yet another intriguing facet of this insane hobby.

Lustformusic - The amp did not reveal any benefits that I can tell, but it is designed to be left powered on - a well known NAIM trait, so I figure the design combats this phenomena somehow.

I still have to test my analogue phono stage, which may or may not benefit from "rebooting"

I'll keep you posted :-)

Cheers
williewonka OP
3,082 posts
 
So I allowed the phono stage to remain powered on for around 10 days - the Digital components only took 6 days to saturate, so I figured give it a little extra.

I played 3-4 select tracks that I frequently listened to 2-3 times each to become familiar with the sound.

I then powered down the phono stage only and allowed it to completely drain for about 2 hours

I then powered up the phono stage and allowed 30-40 minutes for the electronics to warm up and power supply to stabilize.

On replay of the same tracks there was a discernible improvement in the high-en extension and the details and crispness of the upper frequencies could easily be heard.

Although the improvements in the phono stage were not quite to the same degree as those I had observed with the digital components, they were still very noticeable.

When I look at my observations pertaining to each component it is quite apparent significant improvements can be attributed to powering them down.

So that's what I will be doing going forward

Regards...
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