Discussion of AC mains isolation transformers

[austinpop]

3 hours ago, lmitche said:

How strange!  Maybe you have a bad one.  Both here, and at a friend's, two EMOsystems ITs or Baaskes in series make a huge difference in both Win10 PC's and uRendu setups.

 

That may well be. A local CA'er @limniscate is getting an SOtM ISO-CAT6 isolator, so if I get s chance to borrow it, I'll see if that makes a difference.

[austinpop]

5 hours ago, Cornan said:

 

Both the built-in server and the control point needs to be OpenHome compliant for it to work. With OpenHome you will be required to fill in the Tidal account (username & password) in the control point app and not in the server. It will however communicate via the server to get various info, but it is already logged in via the control point AFAIK.

There is a difference in sq between various OpenHome control point. BubbleDS Next souds best IMO, but lately LightningDS is closing in.

 

4 hours ago, mozes said:

@austinpop can you try Tidal with Bubble DS Next streaming to Jplaystreamer? If you haven't tried this approach, I highly recommend that you check it.

This is without doubt the best way Tidal sounds in my system. 

 

Since this probably OT for this thread, let's discuss this in a PM. I don't really understand this configuration. I must be missing something.

 

Will shoot you some questions this evening.

[Cornan]

45 minutes ago, austinpop said:

 

 

Since this probably OT for this thread, let's discuss this in a PM. I don't really understand this configuration. I must be missing something.

 

Will shoot you some questions this evening.

 

Just send me a pm and I will answer in the best of my knowledge! ? AFAIK OpenHome is based on UPnP and works together with UPnP, but with some improvement. It stores the playlist on the control point. This is very obvious when you look at how much cache it consumes compared to a UPnP control point.This means that gapless playback is supported and also less data to pull from the source (cloud content).

[zilch0md]

On 6/1/2017 at 7:27 AM, Duke40 said:

 

TL:DR  I'm not sure if it is floating secondary or grounded secondary, though I do wish I knew.

 

[snip]

 

 

To determine whether an IT has a grounded-neutral or floating-neutral secondary...

 

1) With a load applied to the output of the IT, unplug the IT's input from the mains, so that the load will de-energize the IT.

 

2) Using a multimeter at the unplugged, de-energized output of your IT, test the continuity between the safety ground and neutral. 

 

3) If your meter reads "OPEN", your IT has a floating-neutral secondary (not shorted to the safety ground).

 

    If your meter reads "SHORT", your IT has a grounded-neutral secondary (shorted to the safety ground).

 

[Cornan]

35 minutes ago, zilch0md said:

 

To determine whether an IT has a grounded-neutral or floating-neutral secondary...

 

1) With a load applied to the output of the IT, unplug the IT's input from the mains, so that the load will de-energize the IT.

 

2) Using a multimeter at the unplugged, de-energized output of your IT, test the continuity between the safety ground and neutral. 

 

3) If your meter reads "OPEN", your IT has a floating-neutral secondary (not shorted to the safety ground).

 

    If your meter reads "SHORT", your IT has a grounded-neutral secondary (shorted to the safety ground).

 

 

Great to see you around here Mike! ?

Thanks for sharing how to figure out if the IT is floating or not. I know you'll been using ITs in your setup before I knew they even existed! ?

[joelha]

If this question has been asked already, I apologize, but a searching this thread for an answer would be tough.

 

I'm currently using a Topaz Ultra Isolation device for my front end devices and love it by the way.

 

My power amps are on a completely isolated circuit.

 

Also, because my amps are located in my basement (they're attached to the ceiling directly beneath my speakers) the run of power cords to a single isolation device would be quite long.

 

Even an isolation device for my amps alone, set between my amps, would call for a power cord run of several feet each.

 

So my questions are:

 

1. If my amps are on their own circuit, do I still want to plug them and my front end devices together into one isolation device?

 

2. If the answer to "1." is no, do I want an isolation device set between my amps even though the amps are on their own circuit?

 

3. Finally, does having to run a longer run of power cord (6'-7' between amps and probably 30' from my furthest amp to my front end) mitigate the benefit of using an isolation device?

 

Sorry for the long message, but hopefully the answers will benefit others besides me.

 

Thanks in advance for anyone who can help me out.

 

Joel

[Speedskater]

What is an isolation device?

What is an isolation circuit?

By that I mean, how are the Hot, Neutral and Safety Ground/Protective Earth connected?

In the case of an isolation transformer, is it:

A portable corded transformer?

Or a permanent hard wired transformer?

[asdf1000]

13 hours ago, joelha said:

Thanks in advance for anyone who can help me out.

 

Joel

 

Hi Joel,

 

From what I learnt (and I asked a lot of the dumb questions at the beginning of this thread so I've learnt a lot from John S) the recommendation was to have a single power strip with all your devices plugged into that single power strip. Preferably that single powerstrip would have no filtering between it's outlets and no surge protection.

 

And then that same single powerstrip is plugged into a high isolation transformer (Topaz, Elgar, Eaton etc) or power conditioner.

 

I think having separate high isolation transformers between the devices was not recommended and the same with having different components on different circuits - if it can be avoided.

 

Somebody please correct me if I'm wrong.

 

Cheers! Sean

 

[asdf1000]

On 10/20/2016 at 5:40 PM, JohnSwenson said:

My recommendation is to use a simple power strip with NO filtering or surge suppression, the Topaz does it much better than what will come in almost any power strip. I plug EVERYTHING into thepower strip. This dramatically cuts down on the impedance between boxes, significantly lowering noise generated by leakage loops.

 

John's recommendation quoted above, from early on in this thread.

 

It's a very worthwhile read if you have time on a weekend. So much learning for me. There are so many tips from John.

[joelha]

Thanks a lot for the reply, Em2016.

 

The variable here is having the amps on an isolated circuit.

 

Otherwise, I know I would need to put the amps on the same isolation device.

 

But with the amps on their own circuit (and with nothing else on that circuit), I'm wondering if the amps still have to be on the same isolation device as the front end.

 

Joel

[asdf1000]

7 hours ago, joelha said:

But with the amps on their own circuit (and with nothing else on that circuit), I'm wondering if the amps still have to be on the same isolation device as the front end.

 

Joel

 

My mistake Joel. I have to defer to the electrical guru's here unfortunately. I'm not sure how the amps on one circuit could share the same Topaz iso transformer with front end devices that are on another circuit? 

 

Apologies if I got that wrong :-(

 

Hopefully someone else can help

 

[Daudio]

23 hours ago, joelha said:

So my questions are:

...

 

Until someone more knowledgable comes along, I have a few throughts for you.

 

I think you would be Ok using 2 isolation xformers, 1 for the front end, and 1 for the amps.  What I would try and do is to have the AC lines about the same length and gauge between the Iso tranny and the back of your gear (IEC input).

The point is to try and minimize leakage loop currents, by making the AC wire impedences as equal as possible between each component. So, similar Iso trans, similar cable runs, power strips, and even power cords (if possible). You still might have a little leakage between the front end and amps, but probably too small to worry about.

 

Could you hook up everything to the one Iso xformr, piled on the floor temporarly, just to see if it makes a difference for you ?

 

[joelha]

Hey Daudio,

 

Thanks very much for the reply and suggestions.

 

My current front-end transformer can't handle my amps let alone my amps plus front end.

 

That's why I've been considering getting a larger transformer but I'd hate to do it as an experiment.

 

Thanks again. I'll welcome any additional thoughts from others as well.

 

Joel

[Speedskater]

How many power amplifiers on one Topaz transformer, depends on the size of the amps and of  the transformer.

It's best not to load a transformer anywhere near it's rating, but most audiophiles don't push their big amps hard.

Home theater buffs on the other hand push their amps to the limit.

[Speedskater]

11 hours ago, Daudio said:

Until someone more knowledgable comes along, I have a few throughts for you.

I think you would be Ok using 2 isolation xformers, 1 for the front end, and 1 for the amps.  What I would try and do is to have the AC lines about the same length and gauge between the Iso tranny and the back of your gear (IEC input).

The point is to try and minimize leakage loop currents, by making the AC wire impedences as equal as possible between each component. So, similar Iso trans, similar cable runs, power strips, and even power cords (if possible). You still might have a little leakage between the front end and amps, but probably too small to worry about.

Could you hook up everything to the one Iso xformr, piled on the floor temporarly, just to see if it makes a difference for you ?

I have read the idea of having all the AC Safety Grounds equal lengths.  But different components won't have the same leakage currents (not in frequency, phase or amplitude) so you can nothing by this extra work.  Even identical amps, unless they are playing a mono signal won't have the same leakage currents.

 

I would try to reduce the lengths of the Safety Grounds from component to component.

[Daudio]

1 hour ago, Speedskater said:

I have read the idea of...

 

Still waiting for someone more knowledgeable to come along. Till then could you refrain from muddying the waters with your idle speculation ?  TIA

 

[lmitche]

6 hours ago, Daudio said:

 

Still waiting for someone more knowledgeable to come along. Till then could you refrain from muddying the waters with your idle speculation ?  TIA

 

Wow, great way to make friends and influence people. I'm impressed!

 

While we are waiting, maybe you can tell us what this quote from John Swenson means:

 

 "I plug EVERYTHING into the power strip."

[joelha]

You're right to reference that quote, Imitche.

 

My only question is whether having amps on a completely separate circuit provides an exception to that statement.

 

Joel

[lmitche]

2 minutes ago, joelha said:

You're right to reference that quote, Imitche.

 

My only question is whether having amps on a completely separate circuit provides an exception to that statement.

 

Joel

Nope, everything means everything.  

[joelha]

Thanks Imitche.

 

Just to be clear, you know this to be the case yourself or you're interpreting John Swenson's message to include amps on a separate circuit?

 

Joel

[Speedskater]

6 hours ago, Daudio said:

 

Still waiting for someone more knowledgeable to come along. Till then could you refrain from muddying the waters with your idle speculation ?  TIA

 

True, I'm not an expert. For expert knowledge, you might read the papers and books of the real experts.

Experts like:

Ralph Morrison

Henry Ott

Neil Muncy (RIP)

Jim Brown

Bill Whitlock

[Daudio]

32 minutes ago, lmitche said:

Wow, great way to make friends and influence people. I'm impressed!

 

You follow that characters posts for a while, and come back and tell me if you think I was off base !

 

 

33 minutes ago, lmitche said:

While we are waiting, maybe you can tell us what this quote from John Swenson means:

 

 "I plug EVERYTHING into the power strip."

 

It means the optimal configuration. But when the 'optimal' meets the real world, things get more difficult. And, as an engineer, John understands this.

 

'Real world' in this case is a pair of amps in the basement. You got a better idea ?

 

[lmitche]

Joel, well both really.  I reached the same conclusion experimentally here, read John's post confirming the superiority of the design, and then followed the success of the same on Jud's system, and been reading about the success of many others on CA.

 

The logic is to limit the impedance between devices.  As devices, including amps,  are all connected at both the AC and interconnect level, having an amp on a second isolation transformer almost guarantees an impedance mis-match.

[lmitche]

7 minutes ago, Daudio said:

 

You follow that characters posts for a while, and come back and tell me if you think I was off base !

 

 

 

It means the optimal configuration. But when the 'optimal' meets the real world, things get more difficult. And, as an engineer, John understands this.

 

'Real world' in this case is a pair of amps in the basement. You got a better idea ?

 

Well, I guess you have to go with a sub-optimal solution, or use galvanic isolation further up the chain to create two separate isolation zones. (I have 3 GI zones). Is your DAC and preamp in the basement as well?

[Daudio]

8 minutes ago, lmitche said:

Is your DAC and preamp in the basement as well?

 

Not mine, @joelha's system. But I'm pretty sure the answer is no.

 

https://www.computeraudiophile.com/forums/topic/29662-discussion-of-ac-mains-isolation-transformers-started-wposts-moved-from-quotlps-1-troubleshootingquot-thread/?do=findComment&comment=674375