Experience with power conditioners?

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1 hour ago, gmgraves said:

First of all, I don't know where you get the idea that I "live in a world where everything is perfectly designed..." Secondly, I have neither stated nor implied that "amps can always draw current instantaneously - no matter what impedance is seen by the amp's power supply". What I did say was that in a properly designed amplifier, instantaneous current delivery from the mains is simply not all that important, but steady current delivery is all that important.

 

And I agree that this is a useless discussion. I am not interested in pursuing this.

 

Yes, the current delivery capability of an amplifier PSU has to do with its output impedance -- this is generally dependent on caps & ESR. Well designed power supplies may have input chokes (google input choke filter power supply) which expressly limits the inrush current. The concept of instantaneous current delivery having to do with power "conditioning" is generally very misguided.

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1 hour ago, cjf said:

Do you happen to have any measurements that you've done yourself your willing to share with the peanut gallery on this miracle $60 "Medical Grade" ISO Transformer?

 

Use of isolation transformers is very well established. This has nothing to do with "instantaneous current delivery" rather reduction in leakage current (among the other things). Generally the interwinding capacitance is specified by e.g. Topaz. Mine have 0.0005 pF  giving common mode noise attenuation > 100 dB =>

https://books.google.com/books?id=OtXLBQAAQBAJ&pg=PA217&lpg=PA217&dq=0.0005+pf+capacitance+transformer&source=bl&ots=wf6fxXGSYf&sig=Vnm-U1csYZOIbOkd-OkuMjXrqxI&hl=en&sa=X&ved=0ahUKEwj45Mjl7ZvVAhUEZCYKHQrYAfIQ6AEIJDAB#v=onepage&q=0.0005 pf capacitance transformer&f=false

https://coefs.uncc.edu/mnoras/files/2013/03/Transformer-and-Inductor-Design-Handbook_Chapter_17.pdf

 

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14 hours ago, fas42 said:

The amount of energy needed to drive speakers with music having heavy bass content overwhelms the ability of the mains-transformer-smoothing caps to maintain delivery - the voltage rails sag, and modulate, badly; parts of the supply circuit ring with very high frequency rubbish.

This would be readily apparent in THD measurements. If your SPICE model shows "high frequency rubbish" then you probably need better snubbers. DIYAudio has endless discussions on amplifier design and a subforum on power supply design -- if you post your SPICE model there folks would help you out.

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11 hours ago, Speedskater said:

While I haven't checked, the new price may be well over $1000 US.

Yeah I'd like to reiterate that @gmgraves score of a 60lb trf for $60 is a great deal --- anything under $2/lb is --- that's used surplus of course  --- I have a too large collection of the 0.0005 pF Topaz that I've been acquiring on eBay -- you need to look for low shipping prices also. There's a guy in Indiana who's been slowly unloading some.  My wife is mystified as to why these superheavy boxes keep arriving from Indiana. These industrial isolation units can be wired balanced and/or floating but you need to know exactly what you are doing to avoid danger.

If you'd like a premade ready to go unit I highly recommend the Equi-tech "Q" also very very heavy but waay more than $60  

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20 hours ago, kennyb123 said:

Are you telling me that if I intentionally place a high impedance and highly reactive load between the amp's power supply and the wall outlet - this won't impact in any way the amp's ability to draw current quickly?

It might not -- typically there are many miles/km & many Trf between power plant and your amp. By   Thevenin's Theorem:  adding or removing a slight impedance at the end of a long chain has minimal if any effect. The way to actually reduce output impedance is, once convert to DC add low ESR output capacitance -- one can also use active measures such as high bandwidth capacitance multipliers.

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48 minutes ago, Middy said:

I know opinions and passions can get the better of us but the Question remains from @pam1975 For some solid advice.

 

The advice to use an isolation transformer was very solid and reasonable.

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22 minutes ago, cjf said:

Is it possible that the $3K Torus is not as good as the $60 unit? That I cant answer, but I sure hope not.

I don't think it's about which transformer is better rather what sound good to you in your system -- It's not fair to test components in different systems with different listeners and draw conclusions about the components. I'd predict that the 100lb transformer is perfectly excellent

 

You could start doing doing a bunch of measurements if you wanted to track down with some degree of validity or else just do what sounds best  

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9 minutes ago, fas42 said:

Audio power amplifiers are the real meat of the AC power problem in most audio situations - because they demand transient, heavy spikes of current from the mains supply to feed the typical power supply smoothing caps; other audio components have requirements far less grunty, they're relatively benign.

 

This isn't true. As I mentioned above:

 

1) what about an input choke filtered power supply? How do "transient, heavy spikes of current" make it through the choke?

2) What about constant current sourced amplifiers? How would they work? Do you heard of a "cascode"?

The whole point of a "typical power supply smoothing cap" is that it is the supply current that is smoothed with respect to amplifier draw.

3) What about shunt supplies? They are also designed to supply "instantaneous spikes" of current without drawing such spikes from the mains AC.

I could go further on and on, but start by addressing the three examples

 

9 minutes ago, fas42 said:

 

Just imagine you had a very heavy duty light dimmer, driving some high wattage lamps in your room - do you think that a normal stereo would be completely impervious to any interference from that?

 

Really?

Let's start with a few very simple questions:

1) what is current in amps that the lamps use?

2) what is the maximal current in amps that the ampifiers draw? 

3) how many amps is the circuit rated for

4) at any point does a fuse blow?

 

C'mon