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When to use/how to choose a power conditioner

Phorize

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#1
Hi all,

I have a question about the use
of mains power conditioners. Put simply, I’d like to understand the problems that they can address, the features one should look for in a conditioner/what constitutes a well engineered conditioner and any recommendations on particular products.

Behind my question lies a problem, namely that I have an audible, constant lower mid band hum emitting from the headphone (but not the speakers) output of my new amp. I suspect it is down to some local condition with my mains, as i had the same precise problem with another restored vintage amp by the same designer. Anyway, I’m not going to start randomly buying equipment until I’ve diagnosed the problem, and the designer has been extremely helpful offered to help me trouble shoot this issue. The amp has been fully tested and there are no obvious faults. I’m largely interested in understanding the general issues around mains power and amplification.
 

Wombat

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#2
1. Once you have clearly established that your mains is the problem.

2. Having established 1., above, use a credible product and follow their instructions.

Note: The mains are rarely the problem.
 

Speedskater

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#3
Remember that 'power conditioner' is an undefined term. It could mean almost any combination of the following.

a) Noise filter - a low-pass EMI/RFI filter.
b) Surge protector - although it's better to have surge protection at the home's service entrance.
c) UPS - note that many UPS's are not really UPS's!
d) Line voltage adjuster.
e) Balanced power transformer.
f) Isolated power transformer.
g) DC blockers.
h) Regenerators (PSAudio)
i) Power Factor Correction
j) I forget? But I think that there are more.

But in any case most hi-fi setups don't need one.
 

maty

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#4
Hi all,

I have a question about the use
of mains power conditioners. Put simply, I’d like to understand the problems that they can address, the features one should look for in a conditioner/what constitutes a well engineered conditioner and any recommendations on particular products.

Behind my question lies a problem, namely that I have an audible, constant lower mid band hum emitting from the headphone (but not the speakers) output of my new amp. I suspect it is down to some local condition with my mains, as i had the same precise problem with another restored vintage amp by the same designer. Anyway, I’m not going to start randomly buying equipment until I’ve diagnosed the problem, and the designer has been extremely helpful offered to help me trouble shoot this issue. The amp has been fully tested and there are no obvious faults. I’m largely interested in understanding the general issues around mains power and amplification.
Try first in other house != mains.
 

Cahudson42

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#5
with another restored vintage amp by the same designe
Restored vintage amp?

Yes - try it elsewhere..

2. Have some friends try their equipment at your place
3. Consider the problem is in the vintage amp
 

solderdude

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#8
Behind my question lies a problem, namely that I have an audible, constant lower mid band hum emitting from the headphone (but not the speakers) output of my new amp. I suspect it is down to some local condition with my mains, as i had the same precise problem with another restored vintage amp by the same designer. Anyway, I’m not going to start randomly buying equipment until I’ve diagnosed the problem, and the designer has been extremely helpful offered to help me trouble shoot this issue. The amp has been fully tested and there are no obvious faults. I’m largely interested in understanding the general issues around mains power and amplification.
What I read from this is that you have an amplifier that has speaker and headphone out and you have an audible hum from the headphone out but not from the speakers.

Questions
1: with your ear next to the speaker can you hear hum ?
2: which headphone and and amplifier are you using ?
3: when using the headphone do you have a really small usable volpot range ?
4: With the amplifier connected to nothing else (but the headphone and mains) and the vol. pot turned down fully.. is there a hum ?

Most hum problems are NOT caused by ground loops.
I don't think any power conditioners* (see post speedskater) will solve anything here.
 
OP
P

Phorize

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Thread Starter #9
1. Once you have clearly established that your mains is the problem.

2. Having established 1., above, use a credible product and follow their instructions.

Note: The mains are rarely the problem.
Thanks for your reply. Can you comment or signpost me some good information on how power sunderstand that noise can impact on spdif output for example, or current fluctuations can affect turntable speed stability, but when it comes to an amplifier, aside from ground loop, what theoretical issues can arise fro
 
OP
P

Phorize

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Thread Starter #10
What I read from this is that you have an amplifier that has speaker and headphone out and you have an audible hum from the headphone out but not from the speakers.

Questions
1: with your ear next to the speaker can you hear hum ?
2: which headphone and and amplifier are you using ?
3: when using the headphone do you have a really small usable volpot range ?
4: With the amplifier connected to nothing else (but the headphone and mains) and the vol. pot turned down fully.. is there a hum ?

Most hum problems are NOT caused by ground loops.
I don't think any power conditioners* (see post speedskater) will solve anything here.
1) no
2) audio technica ATH-MSR7G. I’d rather not name the amp company, they are a small outfit and are being very helpful; I’d feel like I was throwing them under a bus if I named them before they’d had a chance to address it. I’ve eliminated ground loop as a cause, the grounding of the headphone socket itself is of interest.
3)no, it’s normal
4)yes

Thanks for all of the replies above.
 

LuckyLuke575

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#11
I want to buy a power conditioner just so I can be fancy and show off to my non-audiophile friends :)
 

RayDunzl

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#13
My "power conditioner" is an Equitech 1.5Q balanced isolation transformer.

1572472702862.png


The raw A/C power here likes to make the transformers in my amps audibly groan, this stopped it.

The output AC floats around the earthed center tap of the secondary.

Hot and Neutral are at 60Vac (differential).

It also silenced all the other transformers in the rack, now only faintly audible by using a stethoscope on the enclosures.

I will be electrocuted by it at some point still in the future, according to urban legend and conspicuous and repeated warnings here at ASR. Let me add a pre-need Good bye, Farewell, and Ta-Ta.

Besides, if it's good enough for LIGO, who am I to demur.
 
Last edited:

solderdude

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#14
1) no
2) audio technica ATH-MSR7G. I’d rather not name the amp company, they are a small outfit and are being very helpful; I’d feel like I was throwing them under a bus if I named them before they’d had a chance to address it. I’ve eliminated ground loop as a cause, the grounding of the headphone socket itself is of interest.
3)no, it’s normal
4)yes

Thanks for all of the replies above.
It is possible the common connection on the headphone socket is connected to the wrong point.

question:
5) Is the amplifier balanced, as in does it use output transformers ?
6) Have you tried connecting the headphone directly to the speaker outputs (or via 100 Ohm resistors) ?
7) Do you know how the headphone plug is wired internally ?
 

gene_stl

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#15
Most installations do not really need a power conditioner. One thing they can be helpful for if selected carefully may be to help keep lighting bolts out of your equipment. Nothing will lightning proof your power grid but it can make things more lightning resistant. The Iron and coils of a nice Sola Topaz power conditioner (these need to be carefully selected so that the idle current and capacity are sized correctly) will increase isolation and lower the rise time of the power going into your gear. It will also stop lots of RFI and EMI such as added to the line by dimmers and SCRs.
Some of them (ie medical ones) can be fully isolated which may also be useful for controlling ground loops.

But mostly they are not necessary unless you have a very specific problem or live somewhere plagued by lightning strokes or surges.

If you do decide to get one, get a Sola which is the real professional deal. They have been the best brand for so long that there are literally tons of them available used. I have used them on many sensitive pieces of scientific gear.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=Sola+power+regulator&_sacat=0

Tripp Lite makes some good ones too. I myself would steer clear of audiophile ones. Speedskaters post above details most of their numerous possible functions.
 

LuckyLuke575

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#16
It's gonna have to be the several Shunyata Denali.
Ah man, I get anxious when I see 4 figure prices and black boxes that I don't understand... :D

I was hoping to get something branded as an electrical / hardware device, then pay less than $100 for it lol
 

ahofer

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#17
Ah man, I get anxious when I see 4 figure prices and black boxes that I don't understand... :D

I was hoping to get something branded as an electrical / hardware device, then pay less than $100 for it lol
For the avoidance of doubt, I think those high-priced power conditioners are ridiculous.
 

LuckyLuke575

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#18
For the avoidance of doubt, I think those high-priced power conditioners are ridiculous.
Clear. I'd really like to get a practical one that can optimize the power input, and also protect from surges and lightning etc but whenever I search for power conditioner on Amazon, I either get hair conditioners or toilet cleaning products.
 

gene_stl

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#19
Clear. I'd really like to get a practical one that can optimize the power input, and also protect from surges and lightning etc but whenever I search for power conditioner on Amazon, I either get hair conditioners or toilet cleaning products.
Search ebay and buy it used. Search the terms "Sola" "TrippLite" "Power Conditioner" and "Regulator"
No need to buy new. These things are immortal. Oops you are in Germany so you will have to buy a German made one but you still could find a good used one on ebay. German ElectroTechnical stuff is usually great, and overbuilt even more than American stuff.
 

trl

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#20
I'm adding https://www.audiosciencereview.com/...s/laptop-source-cheap-bad-power-supply.10401/ to this thread, just in case the info might be helpful for the OP. Basically, I was able to replicate PSU noise coming from laptop, then via the USB cable into my DAC, amplifiers, then speakers.

A passive EMI/RFI filter did nothing, but an isolation transformer did helped and the background noise added disappeared.
 

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