# Topaz Low-Capacitance Isolation Transformers - for Affordably Clean Power



## zilch0md (Aug 27, 2017)

Have you been looking for a very effective, yet affordable solution for removing common-mode and normal-mode noise from your AC mains?  How about a way to prevent noise from being injected back into the mains from your audio components' power supplies?  How about a way to prevent ground loops between components and to discourage leakage currents?  How about a way to remove any DC offset that might be coming in from the mains?  And how about surge protection?

Several Head-Fi members are already aware of some other forums where people have done a lot of trailblazing with the use of *"Series 30"* *Topaz Ultra-Isolator Isolation Transformers*, such as those shown in the following PDF.

Note that only the *"Series 30" *models offer a *0.0005 pF* inter-winding capacitance, which yields -146 dB attenuation of common-mode noise.

Other "Ultra-Isolator" models have higher capacitance ratings, with less noise attenuation.

http://www.pacificparts.com/vends/mge/images/t1.pdf

Here's my *Topaz Ultra-Isolator 91095-32*, rated at 120V, 50/60 Hz, 500VA, with a low inter-winding capacitance of only *0.0005 pF* (recently purchased used, on eBay):




Though long obsolete, the Topaz Ultra-Isolator "-31" and "-32" models ("30 Series") are readily available on the used market, at various VA ratings, as shown in the PDF at the link, above.

They are unique in that, unlike many other Isolation Transformers, including the Tripp-Lite is500, is1000, or is1800, which are still in production, the *Topaz Ultra-Isolator* *-31* and *-32* transformers have extremely low inter-winding capacitance, which equates to being far superior at removing common-mode noise from the treble frequencies.

The following page, shows additional specs and some interesting performance curves, for the exact same transformers, re-branded under the Daitron logo.

http://daitronglobal.com/products/power/power-supply-transformer.html

*Greater than 146 dB (attenuation) throughout the audible spectrum, up to 20kHz, equates to a 20,000,000-to-1 reduction of common-mode noise.  They also provide 65 dB (1780:1) reduction of normal-mode noise.  *

John Swenson (of Uptone Audio) attributes their ability to remove power line noise from the higher audio frequencies to the very low inter-winding capacitance of these "30 Series" Ultra-Isolator transformers (per several posts he has made at www.computeraudiophile.com).

This first chart shows that below 20 kHz, the attenuation of common-mode noise is even greater than -146 dB, going below  -150 dB, at audio frequencies as high as 8000 Hz.





Source:  http://daitronglobal.com/products/power/power-supply-transformer.html

I'll add a follow-up later, but here's a (revised) guide to my current setup for power conditioning, using the Topaz 19095-32, pictured above, as well as some B&K Precision 1604A isolation transformers (currently in production), which play a different role in removing common-mode noise, as well as preventing any "backwash" noise (especially from DACs and any component having a SMPS, from getting back onto the mains to pollute other components).





More later...

Mike

*UPDATED* this post on 27 Aug 2017, to withdraw my prior, misleading contention that isolation transformers with Floating-Neutral Secondaries attenuate Normal-Mode noise, instead of Common-Mode noise. After a great deal of research, I'm now convinced that Floating the Neutral of the Secondary neither prevents Common-Mode noise reduction, nor allows Normal-Mode noise reduction.  *In short:  All isolation transformers attenuate Common-Mode noise, whether the Secondary's Neutral is Floating or Grounded. * (Keep reading.)


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## zilch0md (Aug 27, 2017)

Prior to reading John Swenson's posts about the need for a low inter-winding capacitance, I had been very content with the lowering of my noise floor, as had with a modern Tripp-Lite is500 isolation transformer.  But John pointed out that, unless the transformer is designed for low capacitance, as with these obsolete Topaz Ultra-Isolator transformers, common-mode noise that comes in from your mains will not be attenuated very well above 400 Hz.

I had assumed that sticking with the Tripp-Lite is500 was OK, however, because I've got a TRIAC dimmer switch in the dining room of my house, that when set to at about 50% of full brightness, generates enough noise for me to _audibly _raise my noise floor, when listening to unprotected, AC-powered Head-Fi gear that's plugged directly into the wall outlet.  Inserting the Tripp-Lite is500 isolation transformer between the wall outlet and my AC-powered gear, was _audibly _lowering my noise floor, with that dimmer switch set to 50%.  So...  I was justifiably content, but erroneously concluded, "My noise floor can't get any lower than this, the Tripp-Lite is doing a great job!"  Nope.  It was doing only a mediocre job!

*That's the insidious thing about noise:  You don't know it's there, until you get rid of it!  *

With several people reporting that these old Topaz Ultra-Isolator transformers were opening up their soundstage, with more detail and separation in the treble, and with the encouragement of a friend, I decided to give the *Topaz 19095-32* a try (pictured above), replacing my nearly two-year-old Tripp-Lite is500.

*The difference made by going to a transformer with an extremely low inter-winding capacity was immediately discernible, most especially in the treble frequencies - just as John Swenson has reiterated*.  It was a real slap in the face, with my having stubbornly stuck to using my Tripp-Lite is500 for so long, but in the end, I'm very happy with the decision to get the Topaz, of course.

Now, the decays last much longer, as their energy descends towards a noise floor that is much deeper. The topology of the recording space becomes more tangible with those low-volume echoes and reverberations that can make everything sound more natural and less "reproduced."  Micro details that were buried in the hash previously, are now revealed, better than ever.
*
It really makes me wonder just how much lower the noise floor could possibly go.  *

At this point, I believe its lower than what I'm getting from battery-powered portable gear, but that's probably just the difference in detail offered by my best desktop DAC  (the Oppo Sonica DAC) and my best portable DAC (Oppo HA-2) - which is significant. If I could power my Sonica DAC with a DC battery pack, it would be a fair comparison.   Still, even when I use a portable amp with the Sonica DAC, I can hear the noise floor _drop_ when I power the DAC with the Topaz Ultra-Isolator 19095-32 instead of with the Tripp-Lite is500.

Note that, all along, for over a year now, I've also been using the *B&K Precision 1604A* isolation transformers, placed _in between_ the Tripp-Lite is500 and my AC-powered digital components.  I am continuing to do so, having replaced the Tripp-Lite with the Topaz.

So, the AC power reaches my DAC (and a DC power supply that provides 7.5V to an Uptone Audio UDB Regen), through this chain, but the DAC and the DC power supply, each have their own B&K PRecision 1604A transformers (see the chart above):

*120V Wall Outlet > APC LE1200 Voltage Regulator, set to 107V > Topaz 19095-32 > B&K Precision 1604A*



https://www.amazon.com/Precision-1604A-Single-Isolation-Transformer/dp/B000LDLF3M


_Grounded-neutral_ isolation transformers (i.e. Topaz and Tripp-Lite) and _floating-neutral_ isolation transformers (B&K Precision and some models of Hammond Mfg.) differ significantly, as shown in this diagram:



 

*UPDATED *on 27 Aug 2017:  The graphic, above, has been revised to correct my former, _incorrect_ assertion that isolation transformers with Floating-Neutral secondaries attenuate Normal-Mode instead of Common-Mode noise.

If you were only going to buy one isolation transformer, get a low-capacitance Topaz Ultra-Isolator, selecting one that supplies at least _twice_ the VA (volt-amperes) as the total of all of the loads you intend to power.  Note that 500 VA is very roughly equivalent to 500 Watts (but only for purely resistive, non-reactive loads, blah, blah, blah...)

Again, refer to the linked PDF in the first post, to research the Topaz model number you need for the gear you intend to use and remember that for power amps (for speakers) you don't want to cut yourself short on selecting a big transformer. The load of an entire headphone system, on the other hand, can easily be handled with 500VA, typically.  If in doubt, looking at the power specs of each component, you can always try measuring the load of each component, in VA or in Watts, while operating, by inserting a *Kill-A-Watt* between the power cord of the component and the wall outlet.

https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU

Note, also, that some of the Topaz Ultra-Isolators (model numbers ending with "-32") come with ready-to-use power plugs on the Primary side and power outlets on the Secondary side of the transformer, while others (the "-31" models) are meant to be hard-wired, with only conduit punchouts and recessed screw terminals.  Note, too, that even my small, 500VA model, weighs 24 lbs.  The larger ones get to be quite heavy (and expensive).

Back to discussing the chart, immediately above.  John Swenson earnestly contends that there's no difference in common-mode noise attenuation between isolation transformers that have a grounded-neutral secondary (i.e. the Topaz Ultra-Isolators) and those which have a floating-neutral secondary (i.e. the B&K Precision 1604A) - at least not any differences that can be solely attributed to the the presence or absence of that shunt between the neutral side of the secondary and the safety ground.  To be fair, I will add that he even proposed a test that can be performed with an oscilloscope, to show that attenuation of *common-mode noise (voltage transients or spikes that occur between Ground and Neutral or between Ground and Hot)* would be just as effective in a floating-neutral isolation transformer as in a grounded-neutral isolation transformer.

Please understand that my respect for John Swenson is immeasurable and let's not forget that he's a very accomplished EE, responsible for some very popular, state-of-the-art designs, but on this point, his contention is up against a large consensus of opinion I've seen in many other writings about isolation transformers and, in the end, it doesn't really matter whether a floating-neutral transformer can, as John says, reduce common-mode noise just as well as a grounded-neutral transformer, as long as you are using both, in series, as I do.

*Note that now, after a LOT of reading, I am in complete agreement with John Swenson's position, and thus, I'm having to go back and edit many posts in which I've mislead readers.  (The truth will set you free!)*

We both agree the grounded-neutral secondary of the Topaz transformers is eliminating common-mode noise - that which is most harmful to our gear, in addition to being the most audible at consistently raising the noise floor.  And in the case of the Topaz Ultra-Isolators, where the attenuation is 20,000,000:1 or better, right out to the end of the audible spectrum at 20kHz, thanks to their low capacitance, there's hardly any justification for seeking _even more_ attenuation of common-mode noise by adding another transformer, in series.

But for careful examination of my first chart (in the first post, above), you might now be asking yourself why I would bother with inserting the B&K Precision 1604A  floating-neutral transformers in between the Topaz and my digital components.  Answer: Not only is there a consensus of [absolutely incorrect] writers who say floating-neutral transformers provide a 1000:1 attenuation of any remaining _normal-mode noise_ coming from upstream [not true] - but I'm sure even John Swenson would agree that *isolation transformers with floating-neutral secondaries can prevent "backwash" noise, which can emanate from the power supply of each component), from polluting other components that are plugged into the Topaz that resides upstream.  They can also prevent ground loops.  *[These latter claims for transformers with floating-neutral secondaries are true.]

And as many people like to say, when it's all said and done, *it's what I hear (or don't hear) *which convinces me that there's no point in worrying about whether or not common-mode noise is attenuated by floating-neutral transformers just as well as with grounded-neutral transformers.  *I prefer the sound of the Topaz + B&K transformers, in series, supplying power to my Sonica DAC, to what I hear with only the Topaz* - and I have the peace of mind of knowing that nothing else which is plugged into the Topaz can be polluted by any noise coming back from the Sonica DAC (or from the AC-powered DC power supply that I use to power an Uptone Audio USB Regen, plugged into the USB input of the DAC).

See the first chart, in the first post, above, for additional details, such as not using a surge protecting or circuit-breaker equipped power strip to give yourself more outlets on the output of the Topaz.  As John Swenson has written, you want a simple power strip with as little wire between outlets and as short a cord as possible coming from the Topaz.  By plugging all of your components into that one power strip, the impedance between components can be kept low, which helps to reduce leakage currents.  (I hope I'm getting that correctly.)

Mike


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## zilch0md

By the way, for those in countries with 240V power...

The _Terminal style models_  of the Topaz Ultra-Isolator models are rated for 120 or 240, and have screw terminals that can be wired to the appropriate style of outlets - but please seek the advice of a skilled electrician (or hire one, outright) to do this work.

See the PDF at the link provided in the first post:  http://www.pacificparts.com/vends/mge/images/t1.pdf


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## winders

I have my Topaz 91002-31 (2.5kVA, .0005pf) wired to provide balanced power (60 volts to Hot and Neutral relative to Ground). You might want to discuss the advantages of balanced power. The noise floor is supposed to be lowered even more (increase in dynamic range of 16dB to 20dB). Also, this Topaz had an audible hum that went away once wired for balanced power and it runs cooler.


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## zilch0md (Aug 20, 2017)

Hi Winders,

Thanks for joining in!   I'd heard that some of the terminal-style Topaz Ultra-Isolators allow you to "center-tap" the Secondary, to very effectively create a balanced transformer, but mind doesn't allow that and I'm reluctant to experiment with balanced power - perhaps unjustifiably.  One thing I've heard for sure is that you don't want to plug any kind of lamp or other appliance into the outlet of a balanced power transformer, if the switch for that lamp or appliance is a SPDT switch vs. a DPDT switch.  In other words, if the switch only interrupts power on one side, the appliance will still see power coming in from the other half of the transformer.

Keep in mind that nearly every load we might ever plug into a balanced power transformer was not designed for balanced power.  So, it would be best to just unplug the component from a balanced power transformer rather than using its own power switch to turn it off.  Better still would be to install a DPDT switch between the balanced power transformer and the appliance.

I'm curious about your having referenced some source that says the noise floor is lowered even more (16 to 20 dB), but I'm content with the -146 dB attenuation had with my "unbalanced" transformer.  

Update:

I found this article on the topic of balanced power.  Keep in mind that in the UK, whenever they talk about an "isolation transformer," one can assume they are talking about a a 1:1 transformer that has a floating-neutral secondary.  Just watch any YouTube video on isolation transformers, where the speaker has a British accent, and you'll see that they equate "isolation" with floating-neutral secondaries and they refer to grounded-neutral secondary transformers as something primarily seen in America.

Sorry about this long .jpg file, but I created it as a means of annotating the article that can otherwise be found at the link provided.  (Open it in a new tab, then enlarge it.)



Source:  http://www.soundonsound.com/sound-advice/crosstalk-readers-writes

Quoting pp. 20-21 of http://www.surgex.com/pdf/PowerGround.pdf



> NEC 647, which defines the requirements for balanced power systems, places some important restrictions on both their installation and use.
> 
> 1. Conductors must be sized so that the IR drop does not exceed 1% of the line voltage under a load equal to 50% of the branch circuit current rating, and so that the combined IR drop of the feeders and the branch circuit wiring does not exceed 2%.
> 
> ...



Here's another reference:


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## zilch0md (Sep 10, 2017)

Here's another PDF that may be of interest:

http://www.surplussales.com/Transformers/Pdfs/tp-91092-31_N.pdf

It has some interesting discussion about adding capacitors on the downstream side of a Topaz, as well as substituting the mains earth ground with one of your own making.  Scary.  

It also provides hookup instructions for the models that have terminal strips instead of ready-to-use, three-prong outlets.

UPDATE:  It also provides (poorly written?) instructions for how to set the jumpers on the -32 (terminal style) models.  Here are some helpful, related photos:





The jumpers seen in the photo above are different from those found in some models (below):





Wire can be used, instead, of course.


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## zilch0md (Aug 11, 2017)




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## uncola

I was just researching these.  Thx for the great info


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## zilch0md

Hi Uncola,

You're in for a treat.  Happy hunting and remember that you can search for a given model number under the Topaz, Daitron, MGE, or Eaton brands - check the specs before you buy, of course.


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## uncola

Kind of thinking of making a diy one.. from the antek 1.5KV dual 58V secondary for balanced power.. and atl hifi has a pcb for dc blocking and soft startup..


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## gregorio

zilch0md said:


> [1] Have you been looking for a very effective, yet affordable solution for removing common-mode and normal-mode noise from your AC mains?  [2] How about a way to prevent noise from being injected back into the mains from your audio components' power supplies? [3] How about a way to prevent ground loops between components and to discourage leakage currents? [4] How about a way to remove any DC offset that might be coming in from the mains?



1. No. That's something I would expect even a cheap, mass produced bit of audio kit to deal with, let alone an audiophile bit of kit!
2. No. That's something I would expect even a cheap, mass produced bit of audio kit to deal with, let alone an audiophile bit of kit!
3. No. That's something I would expect even a cheap, mass produced bit of audio kit to deal with, let alone an audiophile bit of kit!
4. No. That's something I would expect even a cheap, mass produced bit of audio kit to deal with, let alone an audiophile bit of kit!


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## uncola

hi gregorio I see from your profile you do a l a lot of pro audio stuff.  You might want to read zilch0md's questions more carefully, most of those things he mentions are almost never implemented in normal audio gear and some like ac leakage current was only recently known about and you need either a battery supply, dual bank supercap supply etc to remove..


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## zilch0md (Aug 12, 2017)

uncola said:


> Kind of thinking of making a diy one.. from the antek 1.5KV dual 58V secondary for balanced power.. and atl hifi has a pcb for dc blocking and soft startup..



You're a handier handyman than I am.  Even soldering a new fuse holder into my Topaz was challenging, for me.

Still, though I congratulate your DIY skills, please consider that my Tripp-Lite is500 isolation transformer doesn't clean up the treble frequencies _*anywhere near as well*_ as the Topaz 19095-32.  They are schematically _identical!  _The difference is in their construction, with the latter achieving the very low capacitance of 0.0005 pF.

In addition to John Swenson's "pot banging" on the need for this low inter-winding capacitance, when selecting an isolation transformer, there are some people posting to the same  Computeraudiophile threads who have bought Topaz models with higher capacitance (i.e. 0.005pF), then deciding to buy and compare a 0.0005pF version, only to _*readily*_ conclude they can hear the noise floor drop further still, in the higher frequencies.

*What we are observing, when we get the noise floor down this low, is that it is tilted, not flat! * It's easier to clean the lower frequencies, as evidenced by the first of four graphs, in my earlier post, above.


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## zilch0md (Aug 13, 2017)

Here's an amazingly _*relevant *_video, for those seeking a better understanding of the relationship between an isolation transformer's inter-winding capacitance and leakage currents:


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## zilch0md (Aug 27, 2017)

http://www.mastec.co.nz/JST/PK8.html

Quoting from the paragraph above:   "With all transformers, stray capacitance, called inter-winding capacitance, can exist between the windings.  *It is via this inter-winding capacitance that [incoming] high frequency [common-mode] noise [from the mains] can couple through to the secondary winding. *However, when a grounded [Faraday] shield is used to separate the primary and the secondary windings, the inter-winding capacitance is significantly reduced. This effectively increases the impedance (resistance) of the coupling path and therefore reduces the amount of high frequency [common-mode] noise that can couple through to the secondary winding."

*Thus, the lower the inter-winding capacitance, the greater the reduction of high frequency common-mode noise.*




http://www.mastec.co.nz/JST/PK8.html


Info about the sources of residential electrical noise:


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## zilch0md (Aug 25, 2017)

For the most passionate of students, here's a very well-written article, which, among other things, provides very succinct definitions of the different types of noise.

The author, Marc Dekenah, all but carves 11th and 12th Commandments in stone.

Paraphrasing...   Thou shall not use the term "Normal-Mode Noise," but rather "Differential Noise" and "Transverse Noise" is a superset of "Differential Noise;" they are not one-in-the-same.

Let the reader be schooled. LOL

http://www.marcspages.co.uk/pq/3270.htm

Here's an index to several other topics - all, equally well-written and in-depth:

http://www.marcspages.co.uk/pq/0000.htm


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## zilch0md (Aug 14, 2017)

http://www.radio-electronics.com/articles/circuit-design/resolving-emi-common-mode-normal-146


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## zilch0md (Aug 28, 2017)

https://www.erico.com/catalog/literature/TNCR016.pdf

Here's some very compelling discussion regarding that PDF's statement that Isolation Transformers cannot attenuate Normal-Mode Noise (Differential-Mode Noise):

https://electronics.stackexchange.c...attenuation-for-differential-transients/92015

This has me doing some serious head-scratching, as the first reply to the poster's question makes so much sense to me.   

*UPDATE on 27 Aug 2017:*  I've concluded, through open inspection of my 19095-32, that the Topaz Ultra-Isolators achieve -65 dB of "DM" noise reduction (Differential-Mode or Normal-Mode or Transverse-Mode noise reduction), *not *through the use of Y-Caps at the input, an X-Cap across the output, and/or surge suppressing MOVs, either before or after the coils, but rather through the Faraday shield design, which is most likely a double or triple shield, with grounding of the shields done as shown in some of the graphics that follow in my subsequent posts, below.  I see no evidence of the Topaz 19095-32 using any caps or MOVs.


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## zilch0md (Aug 28, 2017)

More food for thought...   Check out the last diagram, which talks about introducing capacitors to reduce differential-mode noise:

www.murata.com/~/media/webrenewal/products/emc/emifil/knowhow/26to30.ashx

This ties into the previously linked PDF from Topaz, where they mentioned the use of capacitors to deal with "extreme transverse noise":

http://www.surplussales.com/Transformers/Pdfs/tp-91092-31_N.pdf

Note, too, that in this Topaz PDF, they mention how the Topaz Ultra-Isolators use "line noise suppressors designed to eliminate virtually all transverse-mode noise that results from common-mode noise on the Primary."

I think what it's saying is that the common-mode noise coming into the Primary gets converted to normal-mode noise coming out of the Secondary (which I've read in several places happens with all Isolation Transformers), but they deal with it by adding "line noise suppressors" - whatever those are - which would explain how the Topaz/MGE/Daitron ITs magically manage to offer -60 dB (1000:1) of NMNR, in addition to the -146 dB (20,000,000:1) CMNR - which is the only kind of NR you're supposed to be able to get from a 1:1 transformer that's equipped with a Faraday shield (and the lower the inter-winding capacitance, the greater the NR at higher frequencies.)

But what exactly are these "line noise suppressors" that Topaz is claiming as capable of doing -60 dB of Normal-Mode NR?

*UPDATE on 27 Aug 2017:*  Again, I've all but disassembled the windings of my 19095-32, but I don't see anything but wires coming out of the core - there are no caps, MOVs or other filter circuits, that I can see.


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## uncola

I've seen a lot of IEC inlets with built in emi/rfi noise reduction using uh.. I guess caps and resistor networks?  maybe it's that?   I have one but it's 6 amp max input so not good for a big iso transformer


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## foreverzer0

Wouldn't this be easier to find and cheaper (and looks better): http://emotiva.com/product/cmx-2/ http://emotiva.com/product/cmx-2/


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## zilch0md (Aug 28, 2017)

uncola said:


> I've seen a lot of IEC inlets with built in emi/rfi noise reduction using uh..* I guess caps* and resistor networks?  maybe it's that?   I have one but it's 6 amp max input so not good for a big iso transformer



Bingo!  I think you've guessed correctly!  Yesterday, I posted a comment, to an existing thread at electronics.stackexchange.com, and got this response from a guy named Tony Stewart, whose answers I find difficult to follow, but...


> CM = -146dB @ 100kHz , DM= -65dB @ 100kHz Considering attenuation for a Pi Filter at 100kHz, this means it has a good line filter included rated at 100kHz not 60 Hz. It is reasonable. Floating neutral ignores capacitive coupling of CM noise which does occur. . A CM choke and Pi filter Y caps are needed for CM Noise and X cap for DM noise. – Tony Stewart. EE since '75



I had referenced the MGE PDF (one of the first links I provided in this thread), where the 0.0005 pF models are claimed to offer -146 dB of Common-Mode noise reduction and -65 dB of Normal-Mode reduction.  This Tony Stewart fellow, uses the acronym "DM" for Differential-Mode.

I had also asked what influence is had on noise reduction, if any, by floating the neutral of the secondary instead of having a grounded neutral  secondary (the latter being what we have with the Topaz/MGE/Daitron transformers.)

My interpretation of his response is that first, it's "reasonable" for the Topaz transformers to claim both -146 dB of CM and -65 dB of DM noise reduction, but the DM NR can happen *only* by way of "a good line filter included rated at 100kHz not 60 Hz" - which is basically his interpretation of the MGE PDF's use of the phrase "line noise suppressors."

He goes on to add, somewhat cryptically for my thick-headedness, to say that a floating neutral [at the secondary] "ignores capacitive coupling of the CM noise."

Which begs the question:  What does he mean by "*ignores*?"  Is he saying that a floating-neutral Secondary, in and of itself, will *remove* all CM noise that manages to pass from the Primary to the Secondary by way of capacitive coupling?  We know (I know) that the whole purpose of the Faraday shield is to combat that capacitive coupling of CM noise, some of which still gets through, of course, even if your inter-winding capacitance is as low as 0.0005 pF.  But...  What exactly does he mean when he says "a floating-neutral secondary *ignores* capacitive coupling of the CM noise?"   I have to conclude that there would be no need for Faraday shields in a 1:1 transformer, if all you had to do is cut the ground from the Secondary's neutral - to remove CM noise that comes into the secondary, and since we don't see any such products out there, "*ignores*" does not mean "*removes*."

So what exactly does he mean by "a floating-neutral secondary *ignores* capacitive coupling of the CM noise?"

Unfortunately, they have an extraordinary policy at electronics.stackexchange.com, that prohibits the asking or questions beyond whatever question was posted by the OP of any thread!  Give me a break!  That's counterproductive!  You can't have an expanding discussion.  I was told I have to post any related questions, as brand new threads.  As yet, I've not bothered to start a thread with the title: "What does Tony Stewart mean when he says, 'a floating-neutral secondary *ignores* capacitive coupling of the CM noise?' "   LOL

He does go on, however, to say:  "A CM choke and Pi filter Y caps are needed for CM Noise and X cap for DM noise,"  which reminded me of the Topaz Installation Instructions, previously mentioned, above:





THAT is what Tony Stewart calls an "X-cap" - it straddles the output (Line and Neutral) of the secondary - to deal with Normal-Mode/Differential-Mode/Transverse-Mode noise, but apparently, the Topaz/MGE/Daitron transformers _already have _some kind of X-cap in place to deal with transverse-mode noise.  The PDF I've referenced above is suggesting that an _additional _X-caps can be added to deal with the "Special Noise Problem" of  "_Extreme_ Transverse-Mode Noise."

*UPDATE on 27 Aug 2017:*  No - they don't already have any kind of internal Y-Caps or X-Caps!  In fact, if you read the first sentence in the graphic immediately above, it says:

*"Topaz Ultra-Isolator line noise suppressors are effective in removing both types of noise."*​
The context of this sentence suggests that the entire product (the whole transformer) is a "*line noise suppressor"* - not just some circuit within the product.  

Similarly, further down, it reads:

*"Topaz Ultra-Isolator line noise suppressors are designed to eliminate virtually all transverse-mode noise that results from common-mode noise on the primary."
*​Once again, the phrase *"line noise suppressors"* is obviously referring to the entire transformer, not to some unidentified components within the transformer.

Now read the part I had highlighted in yellow.  They're explaining how an optional X-Cap can be installed across the output of the Secondary, to deal with extreme transverse-noise coming into the Primary, from the mains.  This in itself, suggests that no caps are implemented in the design, as shipped.

Nope!  The Topaz units must be achieving their specified -65 dB of Normal-Mode noise reduction by way of a proprietary Faraday shield design.  (See my later posts, below.)


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## zilch0md (Aug 28, 2017)

I couldn't remember where I had seen the following diagram, but after a good deal of searching, I've found it again:



The entire article deserves examination...

http://www.murata.com/~/media/webrenewal/products/emc/emifil/knowhow/26to30.ashx

... but that last diagram clearly illustrates the difference between a Y-cap and an X-Cap, as mentioned by Tony Stewart.

Given that the 0.0005 pF Faraday shield of the Topaz transformer is already providing -146 dB of Common-Mode noise suppression, there's not much point in adding a Y-cap for additional Common-Mode noise attenuation, but...  the -65 dB attenuation of Normal-Mode noise, claimed by the Topaz/MGE/Daitron tranfsormers, must be accomplished through use of an X-Cap (that is already factory-installed, across the Secondary output).

*UPDATE 27 Aug 2017: * Nope!  I've looked. There are no caps inside the Topaz 19095-32, at either the Primary or after the Secondary. And, if there were, they wouldn't invite you to optionally install your own, as outlined in the instruction sheet, referenced in my previous post.


----------



## zilch0md

Here's a question I posted to electronics.stackexchange.com, yesterday, where again, Tony Stewart responded, only to obfuscate things further still.  I really have a hard time following this guy:

https://electronics.stackexchange.c...ences-in-noise-reduction-will-a-floating-neut


----------



## zilch0md (Aug 20, 2017)

foreverzer0 said:


> Wouldn't this be easier to find and cheaper (and looks better): http://emotiva.com/product/cmx-2/ http://emotiva.com/product/cmx-2/



That's an interesting product.  It's certainly less expensive, smaller, lighter and easier to purchase than a used Topaz transformer, but I suspect it is _much_ better at normal-mode noise suppression (surge protection) than common-mode noise suppression - which is what the Topaz 0.0005 pF transformers do, like nothing else can.

If I had a Topaz that was making lots of acoustic noise, as some people have reported with theirs, I would definitely consider front-ending the humming Topaz transformer with this Emotiva product - specifically to elimate the DC offset on the mains power, that is attributed to transformer hum.

Transformers can also remove any DC offset before it reaches the load, but if the transformer is humming loudly (and running hot) due to DC offset, I'd rather block the DC offset with something like this Emotiva product, before the transformer sees it (instead of putting the transformer inside a foam-filled box, the way John Swenson does with his very noisy Topaz, so that he can enjoy listening to his music!)

Here's a paper on the subject of transformers creating acoustic noise.  DC offset and its sources are discussed:

http://www.idc-online.com/technical...MEASURING_ACOUSTIC_NOISE_EMITTED_BY_POWER.pdf


----------



## foreverzer0

zilch0md said:


> That's an interesting product.  It's certainly less expensive, smaller, lighter and easier to purchase than a used Topaz transformer, but I suspect it is _much_ better at normal-mode noise suppression (surge protection) than common-mode noise suppression - which is what the Topaz 0.0005 pF transformers do, like nothing else can.
> 
> If I had a Topaz that was making lots of acoustic noise, as some people have reported with theirs, I would definitely consider front-ending the humming Topaz transformer with this Emotiva product - specifically to elimate the DC offset on the mains power, that is attributed to transformer hum.
> 
> Transformers can also remove any DC offset before it reaches the load, but if the transformer is humming loudly (and running hot) due to DC offset, I'd rather block the DC offset with something like this Emotiva product, before the transformer sees it (instead of putting the transformer inside a foam-filled box, the way John Swenson does with his very noisy Topaz, so that he can enjoy listening to his music!)



Actually, if you take a closer look it's supposed to do both. They also have a 6 outlet that's only common mode line filter and specifically states the output is free of "high-frequency line noise" whereas the 2 outlet product I linked to before does this plus dc offset correction.


----------



## zilch0md

https://www.middleatlantic.com/-/me...-whitepaper-integratepowerintorack.ashx?la=en
https://www.middleatlantic.com/-/me...s/whitepapers/power-paper-addendum.ashx?la=en


----------



## zilch0md (Aug 20, 2017)

Yet more for the inquiring mind, from Texas Instruments:

http://educypedia.karadimov.info/library/slla057.pdf

And from another source:

http://www.mtecorp.com/pdfs/ProtectionofElectronics.pdf

Please suh, may I have some mo', suh?

http://www.pulseelectronics.com/download/3100/g019/pdf


----------



## zilch0md (Aug 28, 2017)

*UPDATE 27 Aug 2017: * I strongly suspect, but really can't tell by examining my partially disassembled Topaz 19095-32, that they were designed with a double Faraday shield - not shown in any of the examples in this graphic.

I can only conjecture that the first of two Faraday shields is connected to the Primary's Neutral - providing some Normal-Mode noise reduction.
I must also conjecture that second of two Faraday shields is connected to ground (as with most 1:1 isolation transformers).
I know from testing continuity between the outlet prongs that the Secondary's Neutral is grounded - which greatly reduces the probability, though still possible, that they have a third shield connected to Secondary's Neutral.  (What's the point, if you've already got a shield connected to ground, as is the Secondary's Neutral - unless, of course, doing so, somehow diverts just a little bit more Normal-Mode noise to Ground before it hits the Secondary's outputs?)


----------



## zilch0md (Aug 26, 2017)

Isolation transformers _*can*_ be designed to eliminate Normal-Mode noise in addition to Common-Mode noise, without using Y-Caps at the input and/or X-Caps at the output:



http://www.servostabilizerdelhi.net/isolation-transformers.html

 

http://www.mastec.co.nz/JST/PK8.html


----------



## zilch0md (Aug 27, 2017)

As an alternative to the B&K Precision 1604A, the* Hammond Manufacturing "171 Series"* offer both a grounded Faraday shield and a *floating-Neutral secondary*, in six models that range from only 100 VA to 1000 VA:












http://www.hammondmfg.com/171.htm

http://www.hammondmfg.com/pdf/5C_171.pdf


----------



## zilch0md

This article explains why the output voltage of a 1:1 transformer can vary, relative to the input voltage, with different loads:

http://www.ecmweb.com/basics/basics-transformer-voltage-regulation


----------



## zilch0md

Another excellent paper - one of my favorites, thus far:

www.aptsources.com/resources/pdf/Floating%20Output.pdf


----------



## knowhatimean

So.. Mike, are you still using those empty wooden thread spools between your equipment ?

I'll bet you've even found a way to incorporate using them under these isolation transformers now ! (Sorry.... I haven't messed with anyone for a long time , It was time...He,he)!

On a serious note, I started using an Equi=Tech BPT years ago & I'm pretty sure that I'd be hard pressed to ever be able to enjoy listening to my music w/o it's benefits in front of my playback. The only drawback to it (& I do mean only) was it's price... Great thread !


----------



## zilch0md (Aug 31, 2017)

knowhatimean said:


> So.. Mike, are you still using those empty wooden thread spools between your equipment ?
> 
> I'll bet you've even found a way to incorporate using them under these isolation transformers now ! (Sorry.... I haven't messed with anyone for a long time , It was time...He,he)!
> 
> On a serious note, I started using an Equi=Tech BPT years ago & I'm pretty sure that I'd be hard pressed to ever be able to enjoy listening to my music w/o it's benefits in front of my playback. The only drawback to it (& I do mean only) was it's price... Great thread !



Hey!

Yes, I still use the wooden spools to separate my Metrum Acoustics stack from the Oppo HA-1 - to run cooler.   








I'm glad you're happy with the Equi=Tech BPT.  That's more than I can spend for power conditioning, but I don't doubt it does a great job.  They have a great reputation.


----------



## knowhatimean

zilch0md said:


> Hey!
> 
> Yes, I still use the wooden spools to separate my Metrum Acoustics stack from the Oppo HA-1 - to run cooler.
> 
> ...


I seem to recall ,& 'seeming' to recall is becoming more frequent than I care to admit, I probably mentioned that I was using the Equi=Tech to you way back in the 'Aurix' thread.

To be honest the cost of it (even though it was a used unit) was more than I should have spent. No regrets though & I find it very relevant & worthwhile that you have been suggesting
this technology to others.

"Keep on, Keeping on"
Steve


----------



## zilch0md

Thanks Steve!

I have to say, I'm not fully convinced on the subject of balanced power's advantages - in part because I've never given it a chance.  I do, however, know that several references suggest that it offers a a few more dB of common-mode noise reduction, beyond that offered when the secondary is grounded at the Neutral (unbalanced) vs. at a center-tap (balanced).

More on that and back to the discussion of Isolation Transformers...

On the heels of retracting my long-held, dogmatic position (i.e. my ignorant and arrogant position) regarding grounded vs. floating secondaries' affect on Common-Mode vs. Normal-Mode noise reduction, I feared there was a good possibility that I was _again_ leading readers astray as I stuck my neck out and posted the following response to abtr's question at ComputerAudiophile:

*Quoting my summary of just about everything learned, thus far:*



> Hi Abtr,
> 
> This is my current understanding, _eager for correction_, where appropriate...
> 
> ...



I've been apprehensively awaiting the correction I solicited at the top of that post - preferably from John Swenson or Superdad (Alex Crespi) of Uptone Audio, but today, I'm relieved to see Superdad's "Like" applied to that post.  It's a very welcome seal of approval (relief from my apprehension), even if I were the only person who could see it - just knowing that I have not, again, stuck my foot in my mouth, teaching above my understanding.  I'm still left wondering if Superdad hasn't withheld some minor objections, but I'll take it at face value.


----------



## zilch0md

Ok, news flash:  I've found that when using my OPPO Sonica DAC with a Metrum Acoustics Aurux headphone amp, the treble sounds noticeably cleaner when they are both plugged directly into the Topaz grounded-secondary transformer, having removed the B&K floating-secondary transformer (from the DAC).  Apparently, the difference in AC voltage was encouraging leakage currents. (The DAC, on the B&K, was seeing a higher voltage than the amp.)  Any "backwash" coming from the DAC (or ground loops) made possible in the absence of the floating-secondary IT on the DAC, are apparently inaudible, if they are an issue at all), relative to the audible leakage current noise, caused by unmatched supply voltages.

John Swenson has advocated plugging everything directly into the grounded-secondary Topaz (with low inter-winding pF rating), using a simple power strip, if necessary for more outlets, to reduce the impedance between each load.  This has turned out to be great advice for my Sonica DAC + Aurix amp, but I still prefer the lower noise floor I get for other combos, by inserting the floating-secondary transformer in between the Topaz and the DAC (and again, for other digital sources.)

Moral of the story:  YMMV!  Experiment!  But pay attention to the voltages when you put transformers in series.  It helps to have the APC LE1200 voltage regulator - I had to bump the setting up to 120V for the Topaz powering both the Sonica DAC and Aurix amp, after removing the B&K 1604A from the DAC.


----------



## uncola

the interwinding capacitance problem, I think I read newer balanced isolation transformers have a shield tied to ground in between the primary and secondary winding that prevents it.. so is it still necessary to get the topaz with low interwinding capacitance transformers?  I've ordered parts to put together my balanced isolation transformer but I think I Might have chosen the wrong transformer because although it has two secondary 58v windings, it doesn't have the shield tied to ground with ground wire to use :/


----------



## johnzz4

So, I purchased a 0.0005pF Topaz transformer and experimented with it as a standalone solution, and also in combination with the PS Audio P3 regen.  The sound with the Topaz in-line (with or without the P3) is smoother, but I wouldn't call it better.  It seems transients and dynamics take a hit.  An interesting data point is that when I plug the P3 into the wall directly, it reports 1.4% THD on the incoming power and 0.1% THD on the regenerated power.  With the Topaz in-line before the P3, incoming power has 6.5% THD and regenerated power is at 1.6% THD.  I'm not sure how important that is since I believe 1.6% THD is still quite good, but 6.5% I'm not so sure about.  Anyone more knowledgeable on the subject have any thoughts on this data?


----------



## zilch0md (Sep 5, 2017)

uncola said:


> the interwinding capacitance problem, I think I read newer balanced isolation transformers have a shield tied to ground in between the primary and secondary winding that prevents it.. so is it still necessary to get the topaz with low interwinding capacitance transformers?  I've ordered parts to put together my balanced isolation transformer but I think I Might have chosen the wrong transformer because although it has two secondary 58v windings, it doesn't have the shield tied to ground with ground wire to use :/



The last thing I want to do is discourage a DIY project - I have great respect for your skills, but I do have string doubts that you can achieve the 0.0005 pF inter-winding capacitance of the Topaz -31 and -32 models.  John Swenson of Uptone Audio has made several posts about the need for a low capictance in a couple of ComputeAudiophile threads.  All transformers suffer capacitive coupling of the coils. 

As you've commented, here, a grounded Faraday shield can reduce the capacitive coupling, but there are many different ways to construct the shield, apparently, and some transformer designs have been made with double or triple Faraday shields.  See articles and diagrams I've provided in earlier posts.  Another variable is the distance between the coils - this alone will reduce the capacitive coupling, but does so at the expend of efficiency.


Most modern, commercially made isolation transformers have much higher pF ratings, if they are published at all.  I've seen some with ratings of 10 pF to 40 pF - and that's with grounded Faraday shields.  John Swenson has stated that these fail to do a good job of Common-Mode noise reduction in the higher frequencies where you need it the most.  *THE LOWER A TRANSFORMER'S CAPACITIVE COUPLING, THE GREATER THE ATTENUATION OF COMMON-MODE NOISE IN THE HIGH FREQUENCIES. * See the curves charted in one of my first posts to this thread.  It shows that attenuation is much greater in the lower frequencies.  So, if you're only interested in noise reduction for a sub-woofer, then get a Tripp-Lite or Hammond isolation transformer.  

So, you are basically trying to reinvent the proverbial wheel, when attempting out to replicate the design of a Topaz/MGE/Daitron 0.0005pF isolation transformer.  It could still be a very fun project, of course.


----------



## zilch0md

johnzz4 said:


> So, I purchased a 0.0005pF Topaz transformer and experimented with it as a standalone solution, and also in combination with the PS Audio P3 regen.  The sound with the Topaz in-line (with or without the P3) is smoother, but I wouldn't call it better.  It seems transients and dynamics take a hit.  An interesting data point is that when I plug the P3 into the wall directly, it reports 1.4% THD on the incoming power and 0.1% THD on the regenerated power.  With the Topaz in-line before the P3, incoming power has 6.5% THD and regenerated power is at 1.6% THD.  I'm not sure how important that is since I believe 1.6% THD is still quite good, but 6.5% I'm not so sure about.  Anyone more knowledgeable on the subject have any thoughts on this data?



Hi John,

That's great that you could make that comparison.  Regarding the hit on dynamics, are you using a headphone amp or a much hungrier power amp?  Is the VA rating of the Topaz transformer at least half again the combined VA consumption of all the gear that's plugged into it?

The THD measurements provided by the PS3 are a real head-scratcher, but for sure, no matter any degree of error, I would think it would at least be consistent, so 6.5% THD vs. 1.4% is a huge difference.  It's enough to make me consider mailing you my Topaz for measurement, but I like what I hear, so I'll not burden you with that request.


----------



## johnzz4

zilch0md said:


> Hi John,
> 
> That's great that you could make that comparison.  Regarding the hit on dynamics, are you using a headphone amp or a much hungrier power amp?  Is the VA rating of the Topaz transformer at least half again the combined VA consumption of all the gear that's plugged into it?
> 
> The THD measurements provided by the PS3 are a real head-scratcher, but for sure, no matter any degree of error, I would think it would at least be consistent, so 6.5% THD vs. 1.4% is a huge difference.  It's enough to make me consider mailing you my Topaz for measurement, but I like what I hear, so I'll not burden you with that request.


I'd be happy to measure if you change your mind.  That way I can make sure there's nothing wrong with mine!  I have a 70VA load - just a streamer, DAC and headphone amp.  My Topaz is rated for over 200VA.


----------



## zilch0md

johnzz4 said:


> I'd be happy to measure if you change your mind.  That way I can make sure there's nothing wrong with mine!  I have a 70VA load - just a streamer, DAC and headphone amp.  My Topaz is rated for over 200VA.



That's very generous of you, truly, but my curiosity is overwhelmed by my laziness.  It would be a hassle to box it up and ship it.  Ignorance is bliss, in this instance.     Thanks, though!


----------



## pctazhp

zilch0md said:


> That's very generous of you, truly, but my curiosity is overwhelmed by my laziness.  It would be a hassle to box it up and ship it.  Ignorance is bliss, in this instance.     Thanks, though!



A man after my own heart. I hate shipping stuff and I revel in ignorance


----------



## pctazhp

So I'm thinking about ordering one of the new Emotive power conditioners. Price is right and little risk with their return privilege. Anyone think it's a waste of time?


----------



## uncola

Emotive or Emotiva?  got a link?  Furman Reference series power conditioners have a balanced ac isolation transformer built in but are pretty pricey


----------



## pctazhp

uncola said:


> Emotive or Emotiva?  got a link?  Furman Reference series power conditioners have a balanced ac isolation transformer built in but are pretty pricey



Sorry. It's Emotiva  https://emotiva.com/product-category/accessories/


----------



## uncola

that's just a power strip and a dc blocker, you won't notice any difference unless you have a vibrating toroid


----------



## foreverzer0 (Sep 6, 2017)

uncola said:


> that's just a power strip and a dc blocker, you won't notice any difference unless you have a vibrating toroid



But it's stated "*Precision Common Mode AC Line Filter & Power Distribution System"*:


High-quality common mode and differential mode L-C noise filtering
"free of high-frequency line noise"


----------



## foreverzer0

Even the SurgeX devices offer common mode and normal mode filtering: http://espei.com/catalog/pdfs/product-sheets/ESP-SurgeX-Product-Line-STANDALONE.pdf


----------



## uncola

That's the same thing $2 power strips offer, literally a 10 cent cap and resistor.  There are high quality noise filters such as the pi audio group products but they cost more


----------



## zilch0md

foreverzer0 said:


> But it's stated "*Precision Common Mode AC Line Filter & Power Distribution System"*:
> 
> 
> High-quality common mode and differential mode L-C noise filtering
> "free of high-frequency line noise"



My Tripp-Lite is500 is a big, heavy isolation transformer that does common-mode noise reduction, but nowhere near as well as the Topaz 0.0005 pF transformer.  In other words, the Emotiva blurb is most likely exaggerating when they say "_*free*_ of high-frequency line noise."

I would nevertheless *encourage* you to order the CMX-2 and see (hear) for yourself if it makes any improvements for your system, in your home.  Listen for any lowering of the noise floor, expansion of soundstage, improved separation and detail in the treble signals, etc.  

Reading reviews I've found, the happiest customers are those who had an acoustically humming transformer in one of their components (when putting an ear next to the chassis.). This is evidence of DC offset and, apparently, the CMX-2 does a good job of fixing that, but it does have a small isolation transformer inside (for *some amount* of common-mode noise reduction, no doubt greater in the lower frequencies than the higher frequencies) and it has an L-C filter (y-caps at the input and x-caps at the output) for *some amount* of normal-mode noise reduction.

Here's the thing: *When it comes to noise reduction, you often don't even know you had a problem until you fix it.  Then, your're blown away when you realize what you've been suffering, all along. * So, my advice is to just order the CMX-2 and give it a good listen.  You may be pleasantly surprised or you may find that your AC power didn't need any noise reduction - at least not that your gear and your ears can detect.  When it comes to power conditioning, no two people are likely to have the exact same results using a given solution, unless they have the same gear, plugged in the same way, in the same building.


----------



## pctazhp

I have the feeling I'm trying to fix a problem that doesn't exist for me, or at least that I'm not aware of. But I'll give the CMX-2 a shot.


----------



## uncola

a used surgex sx1115 on ebay might be good too.. they are $699 new but I see the used for $150 or less sometimes


----------



## foreverzer0

Thanks for the clarification guys! So you think surgeX might be done better? I recall Bob Katz uses it in his mastering studio.

On that note, are the monster power centers also just snake oil or actually help in this regard too?


----------



## zilch0md

I'm completely open-minded about "the monster power centers."  I haven't tested any of them, but I wouldn't be surprised to discover that some of them do what they claim to do.   If I don't have the time, money or inclination to test everything that's available, I experiment within my budget, but even then, I listen to people I trust - like John Swenson (of Uptone Audio). Nearly all of his recently released designs have been products that address some aspect of noise reduction, so if he's OK with a big Topaz isolation transformer in his home system, I feel I can safely assume there's not much to gain by replacing it with a "monster power center," but again, I wouldn't be surprised to find that one of those expensive solutions does a better job.  

(In short:  I don't know.)


----------



## Leo-

Thanks OP for all the very good information here. I'm thinking about an isolation transformer as a future upgrade. Just yesterday I found this transformer from Rowen. I *believe* it is an isolator transformer but I am not 100% sure of what is inside. 

http://www.rowen.ch/en/data/rowen_pt2000.php


----------



## foreverzer0

These days I try to take all these things with a grain of salt; I actually didn't find the new IsoRegen to make a difference for me besides the usb drop-out every time I suspend my computer.


----------



## Leo-

foreverzer0 said:


> These days I try to take all these things with a grain of salt; I actually didn't find the new IsoRegen to make a difference for me besides the usb drop-out every time I suspend my computer.



What's your setup? Depending on which clocks you have and how they sync, the IsoRegen won't do anything for you. Have you thought of it before buying one?


----------



## foreverzer0

Leo- said:


> What's your setup? Depending on which clocks you have and how they sync, the IsoRegen won't do anything for you. Have you thought of it before buying one?



I had the LH Labs Pulse Infinity previously, which has femto clocks and three layers of buffering from all inputs already. When I had the original Regen it seemed to have made things more "analog" but thinking back it was possibly placebo/autosuggestion or at least just "different" but not necessarily "better".


----------



## Leo-

I would imagine that in your case, especially if it runs on asynchronous usb, the isoregen won't make that much of a difference anyways. The effect of relocking the source would be small or negligible...


----------



## foreverzer0

Yeah it was, I imagine almost any respectable usb dac for the last 8-9 years were async usb... which was before the original regen came about.


----------



## Leo-

Imho it's the combination of a good clock and the fact that it acts as the master. It seems that the other clocks may still matter, but definitely a lot less and whether or not you can listen to it is debatable. Of course the other duty of the return is to feed clean power to the fact, however if the DSC is self powered this is not used.

Sorry we're getting a bit ot here...


----------



## zilch0md

Leo- said:


> Thanks OP for all the very good information here. I'm thinking about an isolation transformer as a future upgrade. Just yesterday I found this transformer from Rowen. I *believe* it is an isolator transformer but I am not 100% sure of what is inside.
> 
> http://www.rowen.ch/en/data/rowen_pt2000.php



Hi Leo!

That thing looks really well made.  The PDF has three sections - English language is in the middle.  The specifications don't tell us the inter-winding capacitance, but given that they manufacture HiFi gear, maybe they know what they're doing.  ???  It appears to be a 1:1 transformer for 240V, rated up to 800 VA.   I like that it offers 4 outlets.  And it sure is "pretty."   

Before ordering (and at this point, I don't even know what it costs - which could be a showstopper in itself),  I would write them and ask if the Secondary Coil's Neutral is grounded, if it has a Faraday Shield, and if they have measured the inter-winding capacitance.  (Is it anywhere near or better than the 0.0005 pF capacitance of the obsolete Topaz/MGE/Daitron -31 and -32 models?)

Mike


----------



## Leo-

Hey Mike, looks very neat to me as well. I'll contact them sometimes, I'm quite busy at the moment. It is not really that expensive, around 1100 Swiss francs, that's less than a 2.5kva Topaz from surplus sales. Probably 800VA is sufficient for most people, hopefully for me as well! For the moment I'm planning to get a power strip from them, they use 2.5mm2 wiring with no circuits or switches or lights - can't find a similar one elsewhere for the price.


----------



## uncola

You can get a balanced isolation transformer from toroid corp of Maryland pretty cheap I'll post a link when I get home.  Not an audio company but should still be good...  Sorry if I came across negative earlier but Ive never heard a difference from power strips clc ac noise filters no matter how many marketing terms they invent to describe them


----------



## zilch0md (Sep 8, 2017)

Leo,

The fact that they have gone to the trouble to design, produce and sell those simple power bars as an accessory to their HiFi components, tells us a lot about what may have gone into the design of their isolation transformer.  I'm just guessing, but it seems they went to the John Swenson school of noise reduction, figuratively speaking.   

John Swenson and Alex Crespi (now Uptone Audio) previously owned a company called Hovland, offering high-end HiFi components, including their own isolation transformers (called Volt Aire), much as this Swiss company, Rowen, is doing today.  I don't get around much, but I don't know of any other HiFi component manufacturers who are designing and building their own isolation transformers to bundle with their gear.

Hovland went out of business a long time ago, but I found this page with some photos of their gear:

http://www.estroarmonico.com/amplificatori.html












How's that for a "good looking" isolation transformer? 

Last I read, Alex Crespi still uses these Hovland transformers in his home system, today.  John, on the other hand, is using a 2.5 kVA Topaz.

I'll take 0.0005 pF capacitance over "good looking," any day.  I want clean highs!


----------



## uncola

https://toroid.com/Home/Product-Details/ProductID/32


----------



## Leo-

zilch0md said:


> Leo,
> 
> The fact that they have gone to the trouble to design, produce and sell those simple power bars as an accessory to their HiFi components, tells us a lot about what may have gone into the design of their isolation transformer.  I'm just guessing, but it seems they went to the John Swenson school of noise reduction, figuratively speaking.
> 
> ...



That's very cool, thanks for sharing. I read somewhere Alex commenting about this transformer, however I hadn't seen a picture of it yet. It was reading John's excellent writings about the ITs that I got curious about them. I still have questions to be clarified before jumping into this wagon, it is a serious commitment not only in financial terms but also in terms of safety and space. 

I don't know much of Rowen's products, haven't listened to them. However they do have a few interesting ideas. Of course needs some more information on the product, however I like the idea of a single box product - I would need two or three boxes to do the same job with a Topaz.


----------



## zilch0md (Sep 8, 2017)

Leo- said:


> That's very cool, thanks for sharing. I read somewhere Alex commenting about this transformer, however I hadn't seen a picture of it yet. It was reading John's excellent writings about the ITs that I got curious about them. I still have questions to be clarified before jumping into this wagon, it is a serious commitment not only in financial terms but also in terms of safety and space.
> 
> I don't know much of Rowen's products, haven't listened to them. However they do have a few interesting ideas. Of course needs some more information on the product, however *I like the idea of a single box product - I would need two or three boxes to do the same job with a Topaz*.



And it's not just an issue of aesthetics or making things look tidy. Multiple, identical transformers might be able to provide identical voltages to the components they power, but the best way to discourage leakage currents that can affect sound quality is to ensure that every component is not only powered at the same voltage (you don't want any potential between components), but to also minimize the impedance between the outlets into which they are plugged.  That's why Swenson strongly advocates plugging everything into one transformer and its also why he advocates (as do the folks at Rowen, apparently, to their credit) that, if more outlets are needed, to use only one outlet on the transformer, plugging everything into a simple power strip that offers a sufficient number of outlets (with no switches, LEDs or circuit breakers, not to mention no surge protection or other filter circuitry).  Ideally, there would be very little wire between each outlet on the strip - again, to reduce the impedance between outlets. This allows all the loads to see exactly the same voltage.

Oddly, as I mentioned in a recent post, above, this issue of dissimilar voltages encouraging leakage currents hasn't been an issue with any but one of my rigs - namely, using the Oppo Sonica DAC together with a Metrum Acoustics Aurix headphone amp. I discovered that by removing the B&K 1604A (floating-neutral secondary) from in between the Topaz and the Sonica DAC, I may have forfeited any benefit offered in terms of breaking a ground loop or preventing any backwash of digital hash back onto the power seen by the amp, BUT... the treble just sounds so much better, for that combo, when both loads are plugged directly into the Topaz - the big difference here, being that both loads now see the exact same voltage. I can only deduce that the mismatched voltages caused by serially stacking two transformers ahead of the DAC but not ahead of the amp, was encouraging leakage current - precisely as John Swenson has so vehemently preached.

Even if we were to learn that the inter-winding capacitance of the Rowen transformers is low enough to compete with the Topaz -31 and -32 models (for improved common-mode noise reduction in the higher frequencies), there is that need to provide sufficient VA for all of your components, as you've hinted could be a problem with only one Rowen, rated at 800 VA.  I don't have a HiFi system of any merit, so 500 VA is way more than enough for my Head-Fi systems.

Do you have a Kil-A-Watt, with which to measure the combined VA needs of your system when playing at the loudest typical SPL?   Multiply that measurement by at least 1.5 and you would have a good figure for determining which Topaz you need. (Stuff I've said before - sorry!)


----------



## zilch0md

uncola said:


> https://toroid.com/Home/Product-Details/ProductID/32



I can't tell what I'd end up with, in terms of inter-winding capacitance. I do know that nearly all of the currently manufactured, commercial 1:1 isolation transformers use toroidal cores and some of them offer capacitance specs, that run very high - from 10 to 40 pF, for example - not good for common-mode noise reduction in the high frequencies.


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## uncola

I know you've done the research so how does the common mode cancellation effect of 120:60+60 balanced ISO transformers rank compared to very low intertwining capacitance ei ISO transformers like the topaz?  I haven't seen any db reduction figures for balanced ac like the 140+ for topaz


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## Leo-

@zilch0md, by "two or three boxes" I meant one transformer, one APC or whatever voltage regulator and one power strip. You're absolutely right with regards to connecting grounds together. I currently have only two outlets to connect (DAC and amp), however I would like to keep a spare plug for a separate preamp power supply in the future. Therefore I say a single box solution would be neat - a power strip has its own capacitance, plus the space and mess needed and so on. 

I haven't tried to size the transformer yet, however I understand that oversizing the transformer is not a problem (size and price considerations aside). It is hard to measure the peak power anyways, so I may skip the measurements and see what the theoretical calculation tells me.


----------



## zilch0md

uncola said:


> I know you've done the research so how does the common mode cancellation effect of 120:60+60 balanced ISO transformers rank compared to very low intertwining capacitance ei ISO transformers like the topaz?  I haven't seen any db reduction figures for balanced ac like the 140+ for topaz



Hi uncola,

Well that's the problem - most designers of isolation transformers (balanced or unbalanced) seem to be unaware, or perhaps just secretive, as to how effective their Faraday shields are, at reducing the capacitive coupling between the two coils. 

Elsewhere in this thread, you can find a post by Winders, where he states that he had heard (where?) a center-tapped secondary (balanced power) offers an additional 20 dB of common-mode noise reduction vs. a neutral-tapped secondary (unbalanced power).  I've read that elsewhere, myself, but everybody who states that is saying "they heard it somewhere."  

Even if it's true, generally speaking, it's a gross oversimplification to conclude that balanced power is "better" than unbalanced, in terms of Common-Mode noise reduction, because it ignores all of the other variables that can impact the efficacy of a transformer's ability to reduce common-mode noise. 

Specifically...  The design's elimination of capacitive coupling.  You can't get rid of capacitive coupling between the primary and secondary coils, just by grounding the secondary from a center tap.   So, who's to say whether a given unbalanced transformer has a lower or higher capacitive coupling than any given balanced transformer?  It would be like saying, "My car is painted white, so it goes faster."  

The problem with 1:1 transformers (balanced or unbalanced) is that even though, at first glance, they can isolate a load from the mains power, in effect regenerating the mains power by way of magnetic inductance, capacitive coupling of the coils allows some common-mode noise (noise that exists as DC between the Line and Ground and at an equal amplitude, between Neutral and Ground) to flow across to the secondary coil and, thus, into your load. That's why grounded Faraday shields are inserted between the coils - to give the common-mode, reactive voltage transients a lower-impedance path back to their source than having to flow through the Secondary and whatever load you are powering.  So, again, I have to point out that no two Faraday shields are created equal - meaning your balanced transformer might have a better Faraday shield design than my unbalanced transformer - or the other way around!  

The best way to measure the efficacy of a transformer's Faraday shield is to measure the capacitive coupling between the coils.  The lower the capacitive coupling, the "better" the design of the Faraday shield, and for that matter, the transformer as a whole, again, whether balanced or unbalanced.  One way to reduce the capacitive coupling is to increase the distance between the coils - in addition to inserting a Faraday shield.  But this decreases the efficiency of the transformer - meaning you'll consume a lot more power from your AC outlet for any given load, than you would if the coils were closer together.  Then there's the question of how many Faraday shields you've put between the two coils.  I can't find any specific information about this for the Topaz, but i believe it to be a double-shield design, in addition to being an inefficient design - all to get the capacitive coupling way down to only 0.0005 pF, in the case of Topaz models ending in -31 or -32.

So, I'm not in the least bit interested in a comparison of balanced vs. unbalanced transformers unless somebody can tell me which has the lowest capacitive coupling.  I'll take the balanced transformer in a heartbeat if it can better the Topaz' 0.0005 pf rating.  I've compared modern off-the-shelf unbalanced 1:1 transformers to the Topaz 0005 pF and the difference in treble clarity is night and day - no lengthy listening sessions were required - I could instantly discern a whole new world of clarity and detail in the high frequencies, when I replaced my Tripp-Lite is500 (toroidal unbalanced with grounded-neutral secondary) with the Topaz 19095-32.  Not just any 1:1 transformer will do the job of common-mode noise reduction in the high frequencies as well as these Topaz/MGE/Daitron units. It's sad that they are no longer manufactured.

 

Mike


----------



## uncola

thanks zilchmod I think I finally get your point about the uniqueness of the topaz' design and now I realize balanced isn't a cure all for noise.. I was just curious about the difference between attenuation and "cancellation" that balanced does.. it's a shame we don't have any info other than "20db" about balanced... too bad we can't get a transformer winder guy to post here


----------



## zilch0md

uncola said:


> thanks zilchmod I think I finally get your point about the uniqueness of the topaz' design and now I realize balanced isn't a cure all for noise.. I was just curious about the difference between attenuation and "cancellation" that balanced does.. it's a shame we don't have any info other than "20db" about balanced... too bad we can't get a transformer winder guy to post here



No kidding!  I want someone who can explain it a lot better than I can.


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## johnzz4

So I tried putting my Topaz inline before the PSAudio P3 again and it was buzzing and vibrating away (never did that before).  It seemed to be running fine until I checked the info on the P3 and it was getting 136V.  I quickly took the Topaz out and voltage returned to 117.  Repeated to confirm.

I was at 12% incoming THD from the Topaz while the voltage was ridiculously high.

The moral of this story is to take my previous THD info with a grain of salt since it appears my Topaz is malfunctioning.  Sigh.


----------



## zilch0md (Sep 8, 2017)

johnzz4 said:


> So I tried putting my Topaz inline before the PSAudio P3 again and it was buzzing and vibrating away (never did that before).  It seemed to be running fine until I checked the info on the P3 and it was getting 136V.  I quickly took the Topaz out and voltage returned to 117.  Repeated to confirm.
> 
> I was at 12% incoming THD from the Topaz while the voltage was ridiculously high.
> 
> The moral of this story is to take my previous THD info with a grain of salt since it appears my Topaz is malfunctioning.  Sigh.



Thanks for sharing that disclaimer, but I'm thinking your Topaz might still be functioning perfectly.  

Transformer hum is almost always due to DC on the AC mains and the source of DC current can be very transient - here today, gone tomorrow, or from one minute to the next.  We know that your Topaz wasn't humming previously, but suddenly started humming today.  What are the chances that the transformer itself has changed internally?  So, again, I think you've got some DC on the mains that you didn't have previously.

There are DC blockers out there that some people have placed in between the wall outlet and their transformer - just to stop a transformer from humming - and not necessarily isolation transformers - but transformers that reside inside their audio components.

The Emotiva CMX-2 has received several reviews saying that even the small toroidal transformers in DACs or amps were humming before they put the CMX-2 inline.  It may not be the "best" solution for common-mode or normal-mode noise, but it has a great reputation as a DC blocker.  By the way, the CMX-2 has huge heat sinks, which I've read can get very warm to the touch if it's having to do a lot of DC blocking.

There's another device, called the AVA HumDinger DC Blocker.  Read their description of what it does:

http://www.avahifi.com/products/humdinger-dc-line-blocker

I think it's really cool that your PS3 has proven that humming transformers are NOT something you want to silence by just putting them into a baffled box (as some people do.)  A jump from 6.5% THD to 12% THD (on the power coming into your PS3 from the Topaz) is all the proof I need for arguing that any transformer that is humming is not delivering clean power.  There's been quite a lot of discussion on the ComputerAudiophile threads about whether or not to use DC blockers to silence humming isolation transformers.  Your THD measurements make it obvious that audible humming equates to higher THD on the output power.

I'd be curious to find out if your Topaz hums the next time you plug it in - or if it hums were you to take it to another building. I doubt that it will continue to hum with any persistence.  I just think you have some intermittent DC coming in on the mains.

And I wouldn't be surprised to find out that your PS3 has a DC blocking circuit right up front, on the inputs.


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## zilch0md (Sep 15, 2017)

Also: Read this post made by none other than Nelson Pass, on the subject of building a DC blocker to stop transformers from humming:

http://www.diyaudio.com/forums/solid-state/2080-dc-filter-post15973.html

And here's an informative review of another DC blocker product:

http://www.isol-8.co.uk/hres/hfc19_isol_8_72dpi.pdf

*But THIS is the best article I've found on the subject of DC on the mains and how to block it:*

*http://sound.whsites.net/articles/xfmr-dc.htm*

Here's another DC blocker (for the EU market), with a good sales pitch for why you might want one:

http://www.jenving.com/products/view/dc-blocker-md01-16-eu-3024000378


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## Leo-

Hey Mike

I don't have a kill a watt, but I'm not keen on underizing a transformer. These things like to get on fire or explode rather spectacularly when they do. Seen it more times than I should already. Therefore I thought of just adding up the nominal ratings of the transformers to be powered and that's about it. Im guessing I will end up with something around 800 VA - could not confirm the numbers yet, which would end up between a .75 and 1.25 kVA models. If I understand well, it would not be an issue to have a Topaz close to electronics or speakers, is that right? Total overkill I know, some other day I pressed play with the volume at about 12 o'clock. The sofa was displaced by a few centimetres before I could get hold of the volume knob, not kidding you!


----------



## zilch0md

Haha!  I _hate_ it when that happens!  

You'll be fine doing the arithmetic instead of using a Kil-A-Watt.  Regarding the magnetic influence of the transformer, I had similar concerns initially, but I've since learned that they're designed to get all the flux happening in close to the coils and then there's the usual, "radiation falls off with the square of the distance," so if you leave a gap as large as the transformer itself, you'll probably be fine.


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## johnzz4

zilch0md said:


> Thanks for sharing that disclaimer, but I'm thinking your Topaz might still be functioning perfectly.
> 
> Transformer hum is almost always due to DC on the AC mains and the source of DC current can be very transient - here today, gone tomorrow, or from one minute to the next.  We know that your Topaz wasn't humming previously, but suddenly started humming today.  What are the chances that the transformer itself has changed internally?  So, again, I think you've got some DC on the mains that you didn't have previously.
> 
> ...


Thanks for the thorough response.  The hum isn't my concern.. I've read a lot about DC creating hum.  My concern is that the voltage isn't 1:1 anymore.  117V in and 136V out.  Can the DC affect voltage as well?


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## oneguy (Sep 10, 2017)

foreverzer0 said:


> Even the SurgeX devices offer common mode and normal mode filtering: http://espei.com/catalog/pdfs/product-sheets/ESP-SurgeX-Product-Line-STANDALONE.pdf



I've been running an SA-1810 for about a year plus now. I really like the power surge protection and it was the only thing that could get the noise out of my Bottlehead Crack when I added Ethernet over Power in my apartment a few weeks ago. The Crack was the only gear that I could audibly tell was effected by this change.

I may be looking to try an isolation transfer next to see if it gives any benefits in my system.


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## zilch0md (Sep 10, 2017)

Congrats on the SA-1810 fix for your Bottlehead Crack's discernment of noise.

For some reason, I just remembered how, when I was little, my dad would always mow the lawn on Saturday mornings, starting in the front yard, then bringing the mower around to the backyard, still running - all while I was still asleep in a bedroom at the rear of the house.  The funny thing is that, I wouldn't wake-up, sometimes actually startled into waking up, until he was finished and turned the mower off.  The abrupt silence would wake me. The noise of the mower had come into my sleep-state consciousness very slowly, getting louder slowly, as he moved from the front yard to the back, but when he silenced it, THAT would wake me up.  It happened again and again - almost every Saturday morning - at least until I was old enough he started waking me up himself with, "It's time to wake up and mow the lawn!"

Sudden elimination of a noise for which we had no knowledge is a wonderful thing.  Unfortunately, the only way to find it is to spend money on gear that has helped others and find out for yourself if any improvement can be made for the power coming into your gear.  When it comes to power conditioning, YMMV greatly.


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## zilch0md (Sep 12, 2017)

Here's a great troubleshooting chart by Hammond Manufacturing, on the subject of transformers that are overheating:

https://www.hammondpowersolutions.com/innovation/overheating/

As a point of reference, with my 500 kVA Topaz 19095-32 having been energized for several weeks, seated on the floor of my den, while not loaded, my laser thermometer measures a maximum (peak hold) temperature (a couple of spots on top of the core) of 105.0 F (40.6 C), with an ambient temperature (of the flooring, 12 inches away from the transformer) of 73.0 F (22.8 C). 

*That's a difference of 32.0 F (17.8 C) between ambient temperature, at floor level, and the top of the transformer core.*


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## zilch0md (Sep 14, 2017)

But for having a circuit breaker, not necessarily a bad thing, in my opinion, here's a great six-outlet power strip for use on the output of a Topaz isolation transformer, that has all the outlets spaced close together (to minimize impedance between outlets and, thus, to deliver the same voltage to each component, discouraging audibly noisy leakage currents), no surge protection (which only creates common-mode noise; surge protectors, if used at all, should be placed between the wall outlet and the transformer), no LED or incandescent pilot light, and no rocker switch - ideal for maintaining clean sound on the output of the transformer:










The 1.5-ft. cord is great for use with Topaz/MGE/Daitron -32 models, that have a dual-outlet receptacle, instead of screw terminals, as seen on the -31 models (with which you would be hard-wiring an outlet strip and can make the cord as short as you want.)

http://www.tripplite.com/not-for-pa...6-hospital-grade-outlets-1.5-ft-cord~PS602HG/

https://www.amazon.com/dp/B0016HIMTC

https://camelcamelcamel.com/Tripp-Lite-Medical-Grade-Patient-Care-PS-602-HG/product/B0016HIMTC

Here's an even more robustly constructed power strip, also with closely mounted outlets, also having a circuit breaker, but no other bells or whistles, that's available with as many as 8 outlets. Read the impressive specs:

https://www.hammfg.com/electronics/outlet-strips/standard/1584h.pdf

https://www.amazon.com/HAMMOND-1584T8DH6-POWER-STRIP-OUTLETS/dp/B005T920A0 
(The picture shown is a six-outlet version, but model number is for the 8-outlet version.)

http://www.newark.com/hammond/1584t8dh6/power-strip-8-outlets-15a-120v/dp/50H6010 
(The picture shown is correct.)

http://www.nextwarehouse.com/item/?1744543_g10e 
(The picture shown is a six-outlet version, but model number is for the 8-outlet version.)

*IMPORTANT: * Do _*not *_use the second outlet of your transformer in combination with a power strip on the first outlet. This will completely defeat the goal of minimizing the distance between outlets into which your components are plugged (it will defeat the goal of discouraging leakage currents.)   Going by what John Swenson has preached on this subject, I wouldn't even use two identical power strips on the same transformer, because the distance between an outlet on one power strip to the outlet on another power strip could create too great an impedance between those two components.


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## zilch0md (Sep 15, 2017)

On the subject of surge protection, as I've stated earlier in this thread (which feels more like a blog than a discussion, thus far), MOVs (metal oxide varistors) can actually create common-mode noise while reducing normal-mode noise, so the _last _place you would want to insert surge protection is _after_ your Topaz transformer has done such a fine job of removing common-mode noise!

Transformers have an intrinsic ability to provide surge protection - up until the voltage spikes become so high that the transformer is beyond saturated and holes are burned through the insulation on the primary windings, creating a permanent short.  But... If you live in an area of frequent lightning strikes and you want to protect your gear _*and*_ your transformer with a surge protector, this is about the best surge protector I've seen -- rated at a whopping *5100 joules*, it also comes with two, detachable power cords - one that's 10-ft. long and the other, only 18-inches!

Note that its internal circuit breaker will pop when the load exceeds 12 Amps (which works out to only 1440 VA or 1.44 kVA, with a 120V line).  A 1.8 kVA isolation transformer could pull 15 Amps, exceeding this surge protector's 12 Amp limit. Given that 1440 VA is 80% of 1800 VA and that your rms load should be at 60% of peak transformer capacity, I seriously doubt a system that's properly sized for a 1.8 kVA transformer could pop this surge protector's 12A circuit breaker. It is, after all, made for "home theater" systems. Those peak voltage demands that your amplifier might place on a 1.8 kVA (15 Amp) transformer are very short in duration, and would not be likely to pop a 12 Amp circuit breaker. (Circuit breakers tend to behave more like slow-blow fuses than fast-blow.)  If your transformer is rated at anything less than 1.8 kVA, all the better, but you would't be able to use a transformer rated higher than 1.8 kVA.

YMMV, so it's best, of course, to use the following 12A surge protector ahead of a 12A or lower transformer (1.44 kVA or lower) - if you absolutely must have a surge protector, at all.






http://www.tripplite.com/isobar-2-o...ter-10-ft-cord-5100-joules-low-profile~AV2FP/

http://www.tripplite.com/shared/product-pages/EN/AV2FP.pdf

https://www.amazon.com/Tripp-Lite-Isober-Conditioner-AV2FP/dp/B007U86LZI

https://camelcamelcamel.com/Tripp-Lite-Isober-Conditioner-AV2FP/product/B007U86LZI

If you think you can get by with only 1440 joules of surge protection ahead of your transformer, I like this two-outlet Tripp-Lite unit that plugs directly into the wall outlet:
















https://www.amazon.com/Tripp-Lite-Protector-Suppressor-ISOBLOK2-0/dp/B0000510R4

It's currently priced at only $22.91, at Amazon, and given that it has a "Protection Present" LED that will warn you when its MOVs have literally become worn out through repeated use, you can easily replace this unit with another one at little expense.

It also offers the advantage of being rated at 15 Amps, which is high enough to support a 1.8 kVA transformer, even at peak load.

*All this is offered with the reminder that transformers naturally offer a good deal of surge protection, so I personally run my 500 kVA Topaz 19095-32 without any upstream surge protection*, but I might regret that decision some day.  We don't get thunder storms very often in the Dallas area, compared to somebody living in Denver, for example.


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## uncola (Sep 15, 2017)

I got a used surgex sx1120rt on eBay for a cheap price because of all this surge protection talk.  Cut off the 20 amp plug and screwed on a Chinese copper plated 15 amp plug and its working great.. doesn't buzz like my tripplite isobar8 even if I put my ear against it.  I can't hear any improvement but I already had a nice filtered power bar


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## zilch0md

Here's a short article that gives examples of common-mode vs. normal-mode noise sources.

http://www.controlledpwr.com/whitepapers/electrical_noise_attenuation.pdf

You can think of common-mode sources as generally being more constant or persistent, where normal-mode noise sources are intermittent and even rare (lightning, electric motors kicking on, etc.)


----------



## One and a half

zilch0md said:


> I'm completely open-minded about "the monster power centers."  I haven't tested any of them, but I wouldn't be surprised to discover that some of them do what they claim to do.   If I don't have the time, money or inclination to test everything that's available, I experiment within my budget, but even then, I listen to people I trust - like John Swenson (of Uptone Audio). Nearly all of his recently released designs have been products that address some aspect of noise reduction, so if he's OK with a big Topaz isolation transformer in his home system, I feel I can safely assume there's not much to gain by replacing it with a "monster power center," but again, I wouldn't be surprised to find that one of those expensive solutions does a better job.
> 
> (In short:  I don't know.)


I have a Monster Power Centre that was installed in front of an Equitech Balanced supply. The sound was thin and lifeless. The Monster is now used a conditioner for a printer.


----------



## One and a half

johnzz4 said:


> So I tried putting my Topaz inline before the PSAudio P3 again and it was buzzing and vibrating away (never did that before).  It seemed to be running fine until I checked the info on the P3 and it was getting 136V.  I quickly took the Topaz out and voltage returned to 117.  Repeated to confirm.
> 
> I was at 12% incoming THD from the Topaz while the voltage was ridiculously high.
> 
> The moral of this story is to take my previous THD info with a grain of salt since it appears my Topaz is malfunctioning.  Sigh.



The PS Audio P3 is a 'UPS' without the battery in essence. The P3 rectifies the incoming AC to DC, then creates AC again, by switching DC. Now, rectifiers, draw pulsed currents with sharpish rise times. The Topaz opposes such sharp rise times and depending on the timing of the current pulses can start to react with the incoming waveform from the main AC. This means the frequency of the current pulses start to resonate with the windings of the Topaz. 
What happens is the voltage starts to rise, as you've seen, and there is much wailing and gnashing of teeth. The P3 reports a ghastly THD, but it's the interaction of the Topaz which is doing its job to the P3's rectifier's rather nasty current draw. The Topaz is working fine 

Now. You can wire the Topaz after the P3. Why? The Topaz is an isolation transformer for one and crap reducer at the same time. Any common mode noise from the P3 is killed by the Topaz. Plug all the audio devices into a non suppression type distributor from the Topaz. Installing isolation transformers after UPS is very common practice.

Initially, the P3 might complain having a transformer on the output, it will allow it through, or the protection circuitry will stop the output, depends.


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## zilch0md (Sep 22, 2017)

One and a half said:


> The PS Audio P3 is a 'UPS' without the battery in essence. The P3 rectifies the incoming AC to DC, then creates AC again, by switching DC. Now, rectifiers, draw pulsed currents with sharpish rise times. The Topaz opposes such sharp rise times and depending on the timing of the current pulses can start to react with the incoming waveform from the main AC. This means the frequency of the current pulses start to resonate with the windings of the Topaz.
> What happens is the voltage starts to rise, as you've seen, and there is much wailing and gnashing of teeth. The P3 reports a ghastly THD, but it's the interaction of the Topaz which is doing its job to the P3's rectifier's rather nasty current draw. The Topaz is working fine
> 
> Now. You can wire the Topaz after the P3. Why? The Topaz is an isolation transformer for one and crap reducer at the same time. Any common mode noise from the P3 is killed by the Topaz. Plug all the audio devices into a non suppression type distributor from the Topaz. Installing isolation transformers after UPS is very common practice.
> ...



Thanks for jumping in @One and a half ! 

I didn't even know you were a Head-Fi member, so I'm really surprised _and _pleased to see you contributing to this thread.

At the risk of embarrassing you, I want to point out to other readers of this thread that, in my opinion, of all the people posting half-baked understandings (as I've sometimes done) on the ComputerAudiophile threads related to* power conditioning* (not to mention other topics, no doubt) _you are the single most knowledgeable and trustworthy source of information for this topic. _Your posts are priceless.

I apologize for burdening you by making that proclamation here, but I want people who read this thread to realize that you are a valuable resource, who's advice should be heeded, whenever you find the time to make a contribution.

I really wish I could have replied to johnzz4 with the depth of understanding you've exhibited.

Thanks again!

Mike


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## One and a half

zilch0md said:


> Thanks for jumping in @One and a half !
> 
> I didn't even know you were a Head-Fi member, so I'm really surprised _and _pleased to see you contributing to this thread.
> 
> ...



Hi Mike, Glad to offer some guidance here, you've resurrected the Topaz transformer from the grave to have a life again. The Topaz and others like it are the ideal for audio, since they provide protection against high voltages, kill common mode and squash differential noise, all in a passive package that lasts for years. Apart from undervoltage, the Topaz does it all. Maybe that was their downfall, too reliable! Power conditioners like Monster/Furman just don't work, there are many reasons why, they've had their day for audio. 
The newer Eaton equivalents are not sold for EU 50 Hz markets, a crying shame, so we have to hunt what's left in the surplus yards. In transit is a 2.4 kVA Topaz 0.0005 pf Model 91002-31/U to complement a 1 kVA 0.005pf Topaz which is in use for the audio system now. I will publish some on the bench figures for inrush and output symmetry, maybe a test against an Equitech to see which one does a better job of harmonics reduction. Still need to publish protection systems for the Topaz, which hopefully will be next two weeks.


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## zilch0md

^ That's great!  I'm looking forward to your measurements and whatever you have in mind for "protection systems for the Topaz."  

I think the fact that nothing like the Topaz/MGE/Daitron transformers are manufactured today, is just a symptom of the demise of engineering knowledge, in general. The movie, _Idiocracy_ comes to mind.


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## uncola

Reminds me of the loss of vacuum tube production knowledge


----------



## zilch0md

*Here are some currently available 0.0005 pf  transformers offered by various sellers.*

*Note that I am not vouching for any of these sellers, nor the items they are selling - I'm only presenting the links to their listings.*

Check the model numbers and specs against this reference:  http://www.pacificparts.com/vends/mge/images/t1.pdf

*250 VA Topaz with screw terminals*:
http://www.ebay.com/itm/TOPAZ-ULTRA-ISOLATOR-LINE-NOISE-SUPPRESSOR-91092-31-KJS-/291940046326

*250 VA Topaz with power cord and receptacle:*
http://www.ebay.com/itm/TOPAZ-ULTRA...PRESSOR-250VA-AUDIOPHILE-STUDIO-/332320547261

*750 VA MGE with screw terminals - converted to plug and receptacle:*
http://www.ebay.com/itm/MGE-UPS-Systems-1-8kVA-Ultra-Isolation-Transformer-91097-31T-/331702654341

*750 VA MGE with screw terminals:*
http://www.ebay.com/itm/MGE-91097-3...RANSFORMER-750VA-120-240VAC-2E2-/263238539609

*1.8 kVA MGE with screw terminals:*
http://www.ebay.com/itm/MGE-UPS-Systems-Ultra-Isolation-Transformer-91018-31T-120-240V-/361851179634

*2.5 kVA (or 500 VA?) Topaz with screw terminals: *
http://www.ebay.com/itm/Topaz-91002...-Isolation-Transformer-120-240V-/182788704015
(This is a STEAL if the labels seen in the photo are correct, but his item description is conflicted.  Model  91002-31 is 2.5 kVA (matching the labels), not 500 VA (matching his description.)

*2.5 kVA MGE with screw terminals - converted to plug and receptacle:*
http://www.ebay.com/itm/MGE-UPS-SYSTEMS-Ultr-Isolation-Transformer-91002-31T-120-240V-/331707625109

*5 kVA MGE with screw terminals:*
http://www.ebay.com/itm/MGE-UPS-SYS...ISOLATION-TRANSFORMER-91005-31T-/263205161267


----------



## oneguy (Oct 1, 2017)

zilch0md said:


> *Here are some currently available 0.0005 pf  transformers offered by various sellers.*
> 
> *Note that I am not vouching for any of these sellers, nor the items they are selling - I'm only presenting the links to their listings.*
> 
> ...


The person owning the 5 kVa unit above will accept $350 as an offer. I had a deal with him lined up but he canceled my order since I was having it shipped to the hotel I was going to stay at in Seattle vice my verified PayPal address. That was my only option as shipping that thing across the Pacific would cost me my first born and having it as a “carry on” for the flight back is free.


----------



## One and a half

Thanks Mike for listing the rarer Topaz.

The 91002-31 is a 2.5kVA 60Hz and was a model with plugs and leads. 

Ebay
The purchase cost comes at a real price. The Topaz transformers are electrical devices and should be suitable for use. There are simple tests that can be performed, like an IR and can be documented to verify the transformer is safe to connect to an electrical source without reasonable fear of it shorting out, or worse leak to ground when the customer receives. I haven't seen any of these results online.


----------



## zilch0md

oneguy said:


> The person owning the 5 kVa unit above will accept $350 as an offer. I had a deal with him lined up but he canceled my order since I was having it shipped to the hotel I was going to stay at in Seattle vice my verified PayPal address. That was my only option as shipping that thing across the Pacific would cost me my first born and having it as a “carry on” for the flight back is free.



That's a shame!  I was wondering how that deal had concluded.  Bummer.  



One and a half said:


> Thanks Mike for listing the rarer Topaz.
> 
> The 91002-31 is a 2.5kVA 60Hz and was a model with plugs and leads.
> 
> ...



Any info you could provide on checking out a used transformer would be most welcome.  I recall the low-voltage DC testing you recommended recently in one of the CA threads.  

Mike


----------



## One and a half

zilch0md said:


> That's a shame!  I was wondering how that deal had concluded.  Bummer.
> 
> 
> 
> ...



A Topaz is due at the end of this month, will post testing routines as part of the process. It had better pass!


----------



## oneguy

I finally received the adapter to allow me to power up the MGE transformer. I’m getting a hum out of it but I am working at a disadvantage powerwise with 128v and 50Hz. I don’t know if I should try the CMX-2 first or try to rewire it for balanced power. Are the -32 series re-wireable for balanced power like the -31 series?


----------



## One and a half

oneguy said:


> I finally received the adapter to allow me to power up the MGE transformer. I’m getting a hum out of it but I am working at a disadvantage powerwise with 128v and 50Hz. I don’t know if I should try the CMX-2 first or try to rewire it for balanced power. Are the -32 series re-wireable for balanced power like the -31 series?



Yes,  you can rewire the output to balanced mode.  It is highly recommended to install a 2 pole RCBO on the output.  

An Rcbo is a combined thermal magnetic circuit breaker and GFCI / RCD in the one package.


----------



## zilch0md (Oct 3, 2017)

oneguy said:


> I finally received the adapter to allow me to power up the MGE transformer. I’m getting a hum out of it but I am working at a disadvantage powerwise with 128v and 50Hz. I don’t know if I should try the CMX-2 first or try to rewire it for balanced power.* Are the -32 series re-wireable for balanced power like the -31 series?*



I know it seems like overkill to put a device like the CMX-2 in front of a Topaz, with its various chokes and/or L-C filters, MOVs and such for surge protection, but reading all the reviews on Amazon - not necessarily the most experienced consumers, of course - but reading all the of the CM-X reviews, there are a lot of people who had humming transformers inside their audio components that were silenced by plugging them into the CMX-2 - I suspect due to its claimed ability to act as a DC blocker.  I know that MOV-equipped surge protectors can actually generate common-mode noise, but the CMX-2 specs claim an overall reduction of common-mode noise at its outlets, so I would think that as long as the CMX-2 is positioned ahead of the Topaz and the VA rating of the Topaz is not greater than what the CMX-2 can handle, everything would be fine - and hum could be eliminated in the Topaz.

CMX-2 specs include the following:


AC power source:
120 VAC +/- 20% @ 60 Hz; 15 Amps

In your case, the 128V wouldn't be a problem, but 50 Hz might be --- as the specs don't say "50 or 60 Hz"

And the CMX-2 doesn't provide anything akin to voltage regulation - to get the output down to 120V.

*I would personally prefer to insert nothing more than a DC Blocker ahead of a humming Topaz. * For the record, John Swenson's comments regarding DC blockers are negative, but admittedly due to his having experienced some kind of accident working with big capacitors, in a DIY DC blocker he had designed, if I recall correctly. But there are a couple of people on the CA threads who are thrilled with this guy's very affordable products:

http://www.atlhifi.com/shop/fully-assembled-devices/dc-blocker-trap-filter-assembled-in-case/

This version with a soft-start circuit is pretty slick, too - all the better, were it mounted in a case:

http://www.atlhifi.com/shop/populat...blocker-trap-filter-assembled-and-tested-pcb/

Here's the same product at his eBay store:

http://www.ebay.com/itm/Combined-So...rap-filter-assembled-and-tested-/132036687414

Quoting from the page at that second link, above:

"*Note*: Since the capacitive divider value and value of resistor in series with transformer’s primary winding depend on the AC mains voltage applied to schematic, let me know your variant – 230V or 120V AC. *In case the AC mains voltage in your country is different than noted above, let me know* and the optimal value for capacitor will be find. PCB is populated with all possible paralleled resistors (7 pcs.) which form the series resistor. This corresponds to the max. handled transformer power (approx. 3000 VA). In case your transformer is smaller than the mentioned above, contact me prior to purchase and the optimal resistor’s value will be picked up. Otherwise you will get the full resistors set and could tune it’s value by un-soldering (cutting) unneeded ones."​
He's apparently very affordable and open to applying customizations to his DC Blocker, so you might send him an email and tell him that you have a 128V 50 Hz source - to see what he would recommend in the way of creating a 50 Hz version and maybe even adding a voltage regulator.  Let him know what size transformer you're trying to drive.  I would very much appreciate your sharing any wisdom you gain from communicating with him.  Reading between the lines, I think he would actually get excited about your peculiar situation, but wouldn't exploit your predicament, either.  I can't believe his low prices.  



One and a half said:


> *Yes,  you can rewire the output to balanced mode.*  It is highly recommended to install a 2 pole RCBO on the output.
> 
> An Rcbo is a combined thermal magnetic circuit breaker and GFCI / RCD in the one package.



In all sincerity, I feel like the apprentice questioning the master's words, here, but I've been well into both sides of my 19095*-32* (500 VA with power cord and receptacle), having replaced the fuse holder (and power plug) at one end and the two-outlet receptacle on the other, but I saw nothing in the way of screw terminals inside - just wires coming out of the core on both sides and get this - the manufacturer didn't concern themselves with using uniquely colored insulators on those wires!  If you just started cutting wires free without labeling them as you go, you could easily get things screwed up. I also didn't see anything approximating an unattached center-tap wire coming from the secondary - nothing dangling with a wire nut or electrical tape covering the end of it.  *So... I don't believe it would be an easy task to convert a -32 model to balanced operation* - even if you could find a center-tap on the Secondary. Perhaps I am speaking in ignorance, though.

*I love your recommendation of using a 2-pole RCBO on the output of a balanced transformer* - as you've smartly promoted on the CA forum.  I read somewhere that if you plug _any_ load into a balanced power source that does _not_ itself have a 2-pole (DPDT) on/off switch, the 120V appliance or lamp or fan or audio component or whatever it is,_ will remain energized with 60V_.  I don't know of a single 120V product in my home that has a 2-pole on/off switch.  There might be a few of which I am unaware, certainly, but I think the majority of them have SPDT power switches

Mike


----------



## oneguy

zilch0md said:


> I know it seems like overkill to put a device like the CMX-2 in front of a Topaz, with its various chokes and/or L-C filters, MOVs and such for surge protection, but reading all the reviews on Amazon - not necessarily the most experienced consumers, of course - but reading all the of the CM-X reviews, there are a lot of people who had humming transformers inside their audio components that were silenced by plugging them into the CMX-2 - I suspect due to its claimed ability to act as a DC blocker.  I know that MOV-equipped surge protectors can actually generate common-mode noise, but the CMX-2 specs claim an overall reduction of common-mode noise at its outlets, so I would think that as long as the CMX-2 is positioned ahead of the Topaz and the VA rating of the Topaz is not greater than what the CMX-2 can handle, everything would be fine - and hum could be eliminated in the Topaz.
> 
> CMX-2 specs include the following:
> 
> ...



I don't want to go too far down the custom route for my current issue since I wont have this issue when I move next year. Or at least if I do it will be with different input power properties. :/ decisions decisions...


----------



## One and a half

Hi Mike,

There are a few topics in the post which will be spread over several posts, if that's ok.

DC blocker 
The main problem in selecting the diodes for the DC blocker which cannot under any circumstances fail, is how to determine the peak current due to the inrush of the Transformer.

Gut feeling, the Topaz is 'not too bad' as far as inrush is concerned, with a a disclaimer,  have not measured.
However a 120/60 1000VA toroid measures 10 times load current around 80A. Diodes are rated with continuous as well as peak values, which needs usually a lit larger diode. Please check the peak rating of the DC blocker. 

Formula

Peak current (amps) = n x VA/V
n = 10 for power toroid, less for Topaz,  but will measure my 1000VA on the weekend. 

The caps in DC blockers also need some thought, usually voltage rating and how much shift above the zero is needed.

A little bit to consider!

Did you know.....
During a short circuit the voltage has a DC offset for AC waveform, the higher the voltage, the more current.


----------



## zilch0md

^ Thanks @One and a half !  Good stuff!


----------



## One and a half

zilch0md said:


> In all sincerity, I feel like the apprentice questioning the master's words, here, but I've been well into both sides of my 19095*-32* (500 VA with power cord and receptacle), having replaced the fuse holder (and power plug) at one end and the two-outlet receptacle on the other, but I saw nothing in the way of screw terminals inside - just wires coming out of the core on both sides and get this - the manufacturer didn't concern themselves with using uniquely colored insulators on those wires!  If you just started cutting wires free without labeling them as you go, you could easily get things screwed up. I also didn't see anything approximating an unattached center-tap wire coming from the secondary - nothing dangling with a wire nut or electrical tape covering the end of it.  *So... I don't believe it would be an easy task to convert a -32 model to balanced operation* - even if you could find a center-tap on the Secondary. Perhaps I am speaking in ignorance, though.
> 
> Mike



Topaz went through a few changes in ownership, themselves, Square D, then MGE. Square D are still about absorbed by Schneider. The models changed to, Mike, you have a penchant for finding Topaz transformers, I wonder if there are more catalogues out there that describe the model numbers accurately. 
During the Sqaure D time, the 910, 911 series were transported to the MGE model numbers. It is here where the models came with cords and without. It's very likely the corded variety did not have the terminals of the fixed series to save 50c and had looses wires joined by wire nuts. 
If you're lucky the wires are marked, but over time, if Topaz used a wrap around number with sticky goo, it would have fallen off in service by now and on opening the terminal cover, the wire markings would indeed be very ambiguous. In that case, to test requires the use of a very small transformer of 3V or less to check what wires went were. Matter of measuring and working out where the taps are, then with a scope measure the phase, to see where the peaks line up. Not a job of a Saturday afternoon!

Transformer tips
Topaz/MGE quote the impedance of the transformers of 3-5%. This value has certain properties, namely:
- If the impedance is known, the inductive reactance can be worked out. If there's a meter about with some accuracy, and ohms law, the inductance can be calculated. Google can help out there.
- The 3-5% value is the minimum voltage to flux the transformer, so it starts to work. For a 120V supply, 3% is 3.6V is all you need for the transformer action to work. 5% is 6V. The variance depends on the model and construction. Generally the higher power models like 5kVA are 3%.


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## zilch0md (Oct 5, 2017)

Reading your posts, I feel like a sixteen-year-old, who barely knows how to drive the car, much less what makes it go.  

*Xentek* is another brand that had the same look as the Topaz/Square D/MGE/Daitron transformers, but until just now, I'd never seen a Xentek with a capacitance rating as low as 0.0005 pF, as with the -31 and -32 Topaz and MGE models.

*But check this out!  

Here's a 5kVA Xentek with a label that rates its capacitance at* *0.0001 pF*


*




*

http://www.ebay.com/itm/Xentek-Extr...-5000VA-Laboratory-Power-0001pf-/232480809471

They want a pretty penny for it.


----------



## pctazhp

zilch0md said:


> Reading your posts, I feel like a sixteen-year-old, who barely knows how to drive the car, much less what makes it go.



I feel exactly the same way. This thread is certainly not for the faint at hear, particularly for someone like me whose eyes glaze over at most of the posts. I'm moving to Europe before the end of the year and want a transformer that will step down 240 V to 120. Any SQ improvement would be welcome but mainly I don't want a transformer that will degrade SQ. Even more important, I don't want a transformer that will damage my gear, and have no way to know how to make sure that doesn't happen.


----------



## oneguy

zilch0md said:


> Reading your posts, I feel like a sixteen-year-old, who barely knows how to drive the car, much less what makes it go.
> 
> *Xentek* is another brand that had the same look as the Topaz/Square D/MGE/Daitron transformers, but until just now, I'd never seen a Xentek with a capacitance rating as low as 0.0005 pF, as with the -31 and -32 Topaz and MGE models.
> 
> ...


I found one a couple of weeks ago but figure it was a misprint since I couldn’t find any other corroborating data. I guess it may not have been. 

http://www.surplussales.com/item/_tp/eit-5551.html


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## zilch0md (Oct 5, 2017)

pctazhp said:


> I feel exactly the same way. This thread is certainly not for the faint at hear, particularly for someone like me whose eyes glaze over at most of the posts. I'm moving to Europe before the end of the year and want a transformer that will step down 240 V to 120. Any SQ improvement would be welcome but mainly I don't want a transformer that will degrade SQ. Even more important, I don't want a transformer that will damage my gear, and have no way to know how to make sure that doesn't happen.



This will only burden @One and a half , but he's at least thinking about posting some steps for testing these critters when they are unboxed.



oneguy said:


> I found one a couple of weeks ago but figure it was a misprint since I couldn’t find any other corroborating data. I guess it may not have been.
> 
> http://www.surplussales.com/item/_tp/eit-5551.html



It is dubious when you consider that every *other *Xentek label I've seen that actually has a capacitance rating (many Xentek's don't) is rated at 0.001 pF, not 0.0001 pF.   Just a typo?

Here you go -- fixed it!


----------



## mwhitak (Oct 7, 2017)

Thanks Mike and @One and a half !  Great thread and info. Learned a lot from you guys and John S. I am looking forward to testing procedures and recommended protection ideas. Topaz 2.5 kva 91002-31 on the way. Listed on ebay as 500 VA but probably an error. I think you mentioned it in an earlier post Mike. Got great price. Figured it was worth the chance since the model number and pictures seem to match the 2.5 kva unit. Trying to decide which way to wire the secondary, grounded neutral, floating neutral, or balanced. Lots of opinions on this. I'm leaning to try balanced 60-0-60 with equipment grounds wired/referenced to center tap of secondary (only), then running power output through a 2 pole rcbo. A  fault (to chassis) by either power conductor on the secondary should trip the rcbo., but the secondary side equipment grounds will stay isolated from the primary/house side equipment ground and potential nastiness. My thinking is get rid of the equipment grounds, if possible, safely. They are only present on equipment to provide an alternate pathway for current in the event of a fault condition, that trips the overcurrent protection, thus making the circuit safe. However, in the US, current NEC code allows for the elimination of equipment grounding on appliance type (receptacle) loads that are protected by a GFI. This was done to allow the safe use of 3 prong plugs in older houses with no equipment ground conductor present in the original wiring.  A secondary wiring setup that allows tripping of the overcurrent device (on the entire secondary), in the event of a fault to chassis by either current carrying conductor, would seem to meet the spirit of the code, even if/though the equipment ground is only connected to the center tap of the secondary (and not the transformer chassis/primary side equipment ground).  I would also mention that it's technically a code violation to use balanced power set ups in a residential environment, just so everyone is clear. The reason is it's atypical from the norm, and would confuse people (read homeowners). Proceed with caution.  Also waiting for delivery of Eddy Current Aficionado SET to pair with current HD800S. I'm thinking my PC/file server on UPS (networked to my MicroRendu with FMC's right before the Rendu) would probably not need to be plugged into the Topaz power strip as it's sufficiently isolated already with the FMC's in line on the ethernet connection to the Rendu....and....the UPS and PC smpt's will spew a lot of crap out ? I'm thinking another dedicated circuit, maybe with a smaller, second topaz or B&K isolation transformer for the PC. Is there a minimum amount of loading the topaz would like to see ? I know total actual load should be no more than about 50 or 60 % of total rated VA, but what about a minimum amount ? The flea watt SET will not present a big load, so I'm hoping the 2.5 kva isn't too big...couldn't pass it up though for the price and future expansion possibilities. Cheers and many thanks guys !


----------



## zilch0md

Thanks for the many good points you've made in your first post, mwhitak!

Regarding balanced power, you'll not find me promoting it anywhere.  I'm certainly tolerant of other people trying it, but I'm not interested in doing so, myself.  In addition to introducing some inherent risks, it seems to be a "novelty" solution looking for a problem that doesn't exist. I can't say that I've done any comparison testing, but I'm content in the knowledge that my "unbalanced" Topaz is providing -146 dB of CMNR and -65 dB of DMNR.  I've come across a couple of references where it's said that balanced power can reduce CMNR by another -20 dB, but no one has ever been able to tell me where they got that figure or explain how that's possible.  In the end, even if that's true, I have to ask myself, could I possibly hear a difference between -146 dB and -166 dB of CMNR?

Here's hoping that your purchase does indeed turn out to be a very good deal. 

By the way, I lived in Novato, CA for a year, at age nine - went to Lu Sutton Elementary when my dad was stationed at Hamilton AFB - which was closed, long ago - then we moved to Homestead AFB, south of Miami, then to... then to...  

Revealing my age, one weekend, my mother wanted to drive into San Francisco to see "the hippies."  While stopped at a red light behind some other cars, at the notorious corner of Haight and Ashbury, the sidewalks were covered with people painting flowers on their faces, sitting on mattresses in the lotus position, etc .  It was everything we had seen on TV and more.  My mother's disgust and disdain must have been plainly visible on her face, as a white guy with a perm, bell bottom jeans and a tie-dyed sweatshirt walked right up to her side window, making crazy faces and even started licking the glass - giving her exactly what she came to see.  My mother started freaking out, telling my dad to go, but we were stuck behind traffic, so my dad was telling her to just sit still and stop making eye contact.  When we finally started to pull away, the "hippie" saw me smiling at him from the backseat, stood erect and winked at me, making a peace sign with his outstretched arm.  He knew that I knew it was all an act.  Somehow, my mother didn't get it.  That happens to be my most vivid memory of living in Novato.  LOL


----------



## mwhitak

[


zilch0md said:


> Thanks for the many good points you've made in your first post, mwhitak!
> 
> Regarding balanced power, you'll not find me promoting it anywhere.  I'm certainly tolerant of other people trying it, but I'm not interested in doing so, myself.  In addition to introducing some inherent risks, it seems to be a "novelty" solution looking for a problem that doesn't exist. I can't say that I've done any comparison testing, but I'm content in the knowledge that my "unbalanced" Topaz is providing -146 dB of CMNR and -65 dB of DMNR.  I've come across a couple of references where it's said that balanced power can reduce CMNR by another -20 dB, but no one has ever been able to tell me where they got that figure or explain how that's possible.  In the end, even if that's true, I have to ask myself, could I possibly hear a difference between -146 dB and -166 dB of CMNR?
> 
> ...



Great story, thanks for sharing ! Hamilton AFB in Novato is now a residential neighborhood, and the hippie thing could never happen now in SF, housing costs are astronomical and you can barely scrap by there on a 6 figure income. The whole Bay Area is just nuts for housing. You should see how many people are in Novato now....with everyone renting out rooms in their houses...the population has tripled in the last 10 years !

Your point is well taken on the CMNR. The Topaz has arrived, and it is indeed 2.5 kva !


----------



## uncola

wow congrats on your lucky find!  It's not a topaz with low inter winding capacitance but I did find an interesting kit.. it's a kit to build a balanced isolation transformer
http://www.transcendentsound.com/Transcendent_Sound_Power_Supply.html


----------



## mwhitak

uncola said:


> wow congrats on your lucky find!  It's not a topaz with low inter winding capacitance but I did find an interesting kit.. it's a kit to build a balanced isolation transformer
> http://www.transcendentsound.com/Transcendent_Sound_Power_Supply.html



 Thanks uncola...very interesting ! Does anyone know the way to actually measure the interwinding capacitance ? I think I read in the CA thread that someone measured a topaz and got a different reading than the spec. But no one challenged it or questioned it further. Also interesting is the differing language on the topaz units. Some say "effective capacitance" and some just say "capacitance". I wonder if this is just semantics, or if there is a real difference.


----------



## zilch0md

mwhitak said:


> [
> 
> 
> Great story, thanks for sharing ! Hamilton AFB in Novato is now a residential neighborhood, and the hippie thing could never happen now in SF, housing costs are astronomical and you can barely scrap by there on a 6 figure income. The whole Bay Area is just nuts for housing. You should see how many people are in Novato now....with everyone renting out rooms in their houses...the population has tripled in the last 10 years !
> ...



Yeah, congratulations on that really good price for the 2.5 kVA Topaz!

And I hear you regarding the housing costs.  Out of sight!  My daughter has a friend who's paying $2800/month for an 800 sq. ft. apartment in the Mission district.  Housing costs are so crazy out there, with people suffering as much as four hour commutes from "affordable" housing, that there are homeowners here in the Dallas area and Austin who rent out upstairs rooms to tenants who fly to San Jose daily.  A room and private bath in a house in Grapevine, Texas, near DFW airport goes for about $500 a month. It's really hard to believe that expense plus the cost of five round-trip flights a week actually allows them to save money, but they sometimes overnight at a friends' place in San Jose, to avoid flying.  And... they officially live in Texas - with no state income tax - only Federal.  That's surely a big plus, right there.  I wonder if their travel expenses are deductible.  Sheesh!  




mwhitak said:


> Thanks uncola...very interesting ! Does anyone know the way to actually measure the interwinding capacitance ? I think I read in the CA thread that someone measured a topaz and got a different reading than the spec. But no one challenged it or questioned it further. Also interesting is the differing language on the topaz units. Some say "effective capacitance" and some just say "capacitance". I wonder if this is just semantics, or if there is a real difference.



I suspect @One and a half  can answer your question, but I also suspect these old transformers can deviate from their factory fresh specifications.   :-|


----------



## mwhitak (Oct 8, 2017)

zilch0md said:


> Yeah, congratulations on that really good price for the 2.5 kVA Topaz!
> 
> And I hear you regarding the housing costs.  Out of sight!  My daughter has a friend who's paying $2800/month for an 800 sq. ft. apartment in the Mission district.  Housing costs are so crazy out there, with people suffering as much as four hour commutes from "affordable" housing, that there are homeowners here in the Dallas area and Austin who rent out upstairs rooms to tenants who fly to San Jose daily.  A room and private bath in a house in Grapevine, Texas, near DFW airport goes for about $500 a month. It's really hard to believe that expense plus the cost of five round-trip flights a week actually allows them to save money, but they sometimes overnight at a friends' place in San Jose, to avoid flying.  And... they officially live in Texas - with no state income tax - only Federal.  That's surely a big plus, right there.  I wonder if their travel expenses are deductible.  Sheesh!
> 
> ...



Thanks Mike ! Man-o-man that's crazy to fly in from TX for a commute. What won't people do for a job ? To me, if you can't live relatively near where you work, there's a fundamental breakdown in the 'social contract'. I do commercial electric, and I always get offers from companies in silicon valley which I turn down (Tesla recently). I refuse to help them since I could never afford to live in that community. They have driven up the cost of living here. And throwing money away to rent like that...when you could be throwing money away on audiophile pursuits lol !  So I work in hospitals mostly. Thought of leaving for TX, then I heard lots of californians where going there...so scratch that idea...lol. The occupational licensing makes it hard to move from state to state for me, and there's very little reciprocity between states.

My microrendu has returned with the 1.4 board upgrade ! It was hard to have it gone for a while. Thinking about a DAC upgrade. Musical Paradise MP D2 seems a great value. Can't afford a totaldac or lampizator.


----------



## One and a half

mwhitak said:


> Thanks uncola...very interesting ! Does anyone know the way to actually measure the interwinding capacitance ? I think I read in the CA thread that someone measured a topaz and got a different reading than the spec. But no one challenged it or questioned it further. Also interesting is the differing language on the topaz units. Some say "effective capacitance" and some just say "capacitance". I wonder if this is just semantics, or if there is a real difference.



Not a trivial task! 
Some digital handheld meters can measure a few thousand pf, are accurate to 1%. Any better and bench models take the prize, worth more than 6 Topaz transformers. The AC current method is a better for digital hand helds, quite a few can measure down to 1uA. There's a but. The transformers under discussion here draw a lot lower current about 20pA for the 0.0005 pf models, that's 20 x 10 ^-6 uA.. I think you'd have to trust the nameplate data. Effective capacitance takes into account a calculated measurement, could be based on the current method. 
Have a look here how to calculate these values.


----------



## mwhitak

One and a half said:


> Not a trivial task!
> Some digital handheld meters can measure a few thousand pf, are accurate to 1%. Any better and bench models take the prize, worth more than 6 Topaz transformers. The AC current method is a better for digital hand helds, quite a few can measure down to 1uA. There's a but. The transformers under discussion here draw a lot lower current about 20pA for the 0.0005 pf models, that's 20 x 10 ^-6 uA.. I think you'd have to trust the nameplate data. Effective capacitance takes into account a calculated measurement, could be based on the current method.
> Have a look here how to calculate these values.





One and a half said:


> Not a trivial task!
> Some digital handheld meters can measure a few thousand pf, are accurate to 1%. Any better and bench models take the prize, worth more than 6 Topaz transformers. The AC current method is a better for digital hand helds, quite a few can measure down to 1uA. There's a but. The transformers under discussion here draw a lot lower current about 20pA for the 0.0005 pf models, that's 20 x 10 ^-6 uA.. I think you'd have to trust the nameplate data. Effective capacitance takes into account a calculated measurement, could be based on the current method.
> Have a look here how to calculate these values.


 

Thanks One and a half ! Great stuff ! I have a Fluke 87 somewhere...but I see it's not up to the task.


----------



## One and a half

Finally receiving the 2.4kVA Topaz, here is a list of inspections and tests for 'older' transformers.

With the AC power totally unplugged from the Transformer, open both ends of the terminal boxes.
1. Look for debris, gunk dirt, especially on the terminals. A quick spray with Electra-Clean, or Iso-Propyl, with a clean rag and remove any contaminants. Don't go overboard with the spray, since the chemicals may dissolve any labels.

2. Check the connections, make sure the are tight, but not FT. The earth/ground connection is very important. This 2kVA had the shield wired to the incoming neutral which was rather odd, it should be on the earth chassis connection. Compare the voltage you are to use with the Topaz Bulletin 05160-001-TI REV A August 1984. I removed it to measure what was on it, close to 1/2 line volts on the primary.

3. Obtain an Insulation Resistance (IR) Meter. An IR meter applies a DC voltage on the transformer to measure its insualtion resistance. The voltage applied needs to be 2 x the working voltage on the transformer. For 120V systems, use 250V, for 230V systems use 500V. Since the IR meter is DC, it will not jump to the secondary from the primary or vice versa. The one I use is here. There are many others.

Connect the red lead to H1 and black lead to earth/ground.

Keep the meter in test mode on for at least 30s and observe the readings.
The minimum is 1000 M Ohm. The 2.4 kVA delivered Topaz had a reading of 2457 M Ohms - Brilliant! 

Disconnect the Red lead from H1 and connect to X1, leave the black connected. 

Keep the meter in test mode on for at least 30s and observe the readings. The minimum again is 1M Ohm, with the same voltages applied as before.

If all IR readings are good, then, there's good confidence to apply power, but not yet.

4. Prepare the connections to the line and the load, make sure that the connectors on plugs if you use them are all good and the connected right way round. Leave the connections off the transformer for now.
Use the IR meter to test the cable, same levels for voltages apply. 

This time connect the red lead of the IR meter to the hot conductor (Black for USA/Canada, Brown for IEC) and the earth/ground cable. Ensure that any ends don't touch metals. Start the test, it should show open, or OL. If less than 1M Ohm, check the connections again. If it's an old cable, it may have to be retired as a lot of moisture contributes to a low reading.
Repeat the test for the white cable (USA/Canada, Blue for IEC), and compare with the hot.

There's then no shorts in the connecting cables, so now they can be connected to the transformer terminals.

5. With any multi meter, connect the leads to the output of the transformer to X1 and X4. I used  a small Variac to gradually wind up the voltage, but this is luxury. Power on the primary of the transformer and you  should see 120V or 230V depending on which config you have.

6. Leave the transformer on no load for a 'while' at least 3-6 hours, to listen for buzzes and measure the case temperature. Use your hand to gauge the temperature, the 2kVA was barely warm, and you could just hear a very faint hum with an ear about 3" from the frame.

7. If that's all good, the transformer is ready for use.


A) IR testing is at elevated voltages. Touching any terminals or probes while the IR test is on, WILL give you a very nasty bite. After the test, allow a few seconds for the voltage to discharge through the IR meter. The IR meter will let you know if any residual voltage is left.

B) 120V or 230V live testing requires the correct PPE, glasses and gloves. These voltages will and can kill. If you are not comfortable working on systems like this don't. Seek a professional out, these tests don't take long and the meters are in every electrician's kit.


----------



## mwhitak

One and a half said:


> Finally receiving the 2.4kVA Topaz, here is a list of inspections and tests for 'older' transformers.
> 
> With the AC power totally unplugged from the Transformer, open both ends of the terminal boxes.
> 1. Look for debris, gunk dirt, especially on the terminals. A quick spray with Electra-Clean, or Iso-Propyl, with a clean rag and remove any contaminants. Don't go overboard with the spray, since the chemicals may dissolve any labels.
> ...




Thanks for this write up One and a Half ! Very helpful. Will you be using any overcurrent protection (such as a fuse) on the primary side (besides the breaker on the circuit that supplies power) ? I seem to recall seeing pics of topaz units with fuseholders mounted on the primary side access plate.


----------



## zilch0md

@One and a half - Thanks for those welcome instructions!

Surely that transformer didn't leave the factory with the shield grounded to the primary's neutral.  Somebody must have been experimenting and decided they liked the way it sounded (or some other reason for leaving it that way.)  

Higher up in this thread, somewhere, you can see a PDF where multiple shields are used.  That's the only case where I've seen somebody connect a shield (the one closest to the mains) connected to the primary's neutral, while another is connected to the earth ground and perhaps a third shield to the secondary's neutral.


----------



## One and a half

zilch0md said:


> @One and a half - Thanks for those welcome instructions!
> 
> Surely that transformer didn't leave the factory with the shield grounded to the primary's neutral.  Somebody must have been experimenting and decided they liked the way it sounded (or some other reason for leaving it that way.)
> 
> Higher up in this thread, somewhere, you can see a PDF where multiple shields are used.  That's the only case where I've seen somebody connect a shield (the one closest to the mains) connected to the primary's neutral, while another is connected to the earth ground and perhaps a third shield to the secondary's neutral.



Yup, can swear on two stacks of bibles,  the primary shield was connected to the 120V neutral. Very weird!


----------



## One and a half (Oct 25, 2017)

mwhitak said:


> Thanks for this write up One and a Half ! Very helpful. Will you be using any overcurrent protection (such as a fuse) on the primary side (besides the breaker on the circuit that supplies power) ? I seem to recall seeing pics of topaz units with fuseholders mounted on the primary side access plate.



Right, fuses I don't like. For the primary, a D curve circuit breaker will take care of the inrush and quick protection.
I need to measure the inrush current and select a breaker to suit. 
To protect the secondary, a little different approach.

For short circuit a combo GFCI / RCD will work, for long term thermal protection,  a thermal overload, which adjustable setting can accurately sense an overload.
To cut the power off, the primary needs to be switched off.
This can be a relay on the primary after the D curve breaker. So if the thermal overload trips, it cuts of the primary power.

Will show how this works on a drawing.


----------



## mourip (Nov 27, 2017)

Not sure how I missed this thread. I found out about the Topaz IT over on The Computer Audiophile and have used one for a while but this thread gets the highest marks for clarity and a collaborative spirit.

Thanks!


----------



## shyamwanne

I have both a MGE and Topaz unit that are in very good condition.  The improvement to the sound of my system was immense, however, I now have developed tinnitus and my ears hurt when I have either of the transformers in my audio chain.   Is it possible they are producing a very high frequency or something that could hurt my ears?  Would any kind of filter be appropriate to use with one of them?


----------



## mourip

Have you tried removing them from your system to rule out that something else is the culprit?


----------



## shyamwanne

Hi, yes.   When I remove them from the system my ears do not hurt.  As soon as I put them in, my ears hurt.  That is why I am asking in this thread.  My ears are sensitive to very high frequencies, so I was wondering if Isolation Transformers like these could be producing ultra high frequencies, or something of that nature, that could be filtered, so I could continue using them.


----------



## zilch0md

I can't imagine how that's happening, but another possibility is that, rather than generating high frequencies that are hurting your ears, perhaps they are just passing high frequencies that you cannot hear in their absence - high frequencies from the source signal, itself.  What are you actually hearing in the treble region that causes pain?  Is it more like noise than music?


----------



## knowhatimean

I could be mistaken,but, I don't believe that an Isolation Transformer would be passing along ultra high frequencies as the signal still has to pass through output transformers of whatever devices are connected to the Isolation Transformer.

In other words the IT is only affecting the input Power Supply of whatever it is sitting in front of.  I highly doubt that it is an IT that is producing ultra high frequencies that your ears are sensitive to, if anything the IT only a filter, unless your ears are sensitive to existing high frequencies in the music you weren't able to hear, beforehand..

Disclaimer ; I'm not an EE.


----------



## shyamwanne

It is indeed possible the Topaz is passing high frequencies that I would not hear without it.  The music is that much clearer.  This would again make me wonder if there is some sort of filter I could use to filter out very high frequencies. 

I had on an ultrasonic vaporizer constantly going in the house.  I noticed that also hurt my ears, as when disconnected, I felt relief as well.  That is what gave me the idea that perhaps the Topaz was generating (or passing through) ultrasonic frequencies. 

In the music itself, I audibly hear nothing.  However, just turning on the transformer I can 'feel' it even from a distance.  And with the headphones on, it hurts my ears.    Perhaps I am sensitive to some form of EMI?   

I've ordered some EMI/RF blocking cloth to wrap the transformer in, to test this.  Though that would not help anything being passed through the headphone itself.   Could EMI be passed through headphone drivers?


----------



## alpovs

shyamwanne said:


> That is what gave me the idea that perhaps the Topaz was generating (or passing through) ultrasonic frequencies.


It is unlikely that your headphones would emit those ultrasonic frequencies. What headphones do you have? 

Transformers do vibrate, especially those with a number of metal plates. But they vibrate at the frequency that goes through them which would be 60 Hz. If you ever walk in a residential area and pass by a transformer (in my area a large green box) you can hear a hum.


----------



## shyamwanne

My headphones are Audio Technica ADX5000, which are fantastic by the way 

The 60hz hum from the Topaz doesn't bother me.  It's the electromagnetic field.  For example, I get a headache if around those large transformers or large power lines on the street for very long too.  Small ones don't seem to bother me though.


----------



## alpovs

shyamwanne said:


> My headphones are Audio Technica ADX5000, which are fantastic by the way


Frequency Response: 5 – 50,000Hz. 


shyamwanne said:


> The 60hz hum from the Topaz doesn't bother me.  It's the electromagnetic field.  For example, I get a headache if around those large transformers or large power lines on the street for very long too.  Small ones don't seem to bother me though.


You said your ears were sensitive to very high frequencies. Transformers and power lines are everywhere, including house wiring. For most people, their principal sources of exposure to ELF magnetic fields are electrical appliances and house wiring. You should feel as bad when no music is playing.


----------



## Leo-

Hi shyamwanne, very interesting observation. I sometimes have headaches when listening to music especially when there is any excess brightness or harshness. It generally turns out that these days  I forget to close the blinds which help to kill the 1st order reflection from the glass wall, then it usually goes away. My theory is that the brain gets confused with the timings and it simply hurts. When I had my system in a different position it was terrible, so maybe you'd like to try some fine tuning in your system too. Very interested in your findings.


----------



## shyamwanne (Mar 20, 2018)

Thank you everyone for your input.

I bought an EMF meter, and what I have found out is that I am very sensitive to the Magnetic and Electric fields produced by transformers.   I bought an aluminum case for my Topaz Isolation Transformer and put some Faraday Fabric around it, and I immediately feel better.  I have found I am sensitive to all the transformers in my audio equipment, it was simply the size of the Topaz that made it so obvious. 

Using my EMF meter I measured the magnetic field and electric field generated from my headphones with and without the Topaz.  The magnetic field did not change.  However, the electric field was LOWER with the Topaz, than without.   So having the Topaz in my system actually is safer, as long as I am either physically far enough away from the transformer or I have it shielded.

I do not claim to understand the science behind any of this, just my personal experience.   But it is very nice to know that the effect of the Topaz through my headphones is beneficial, not just sound wise, but also health wise.   It is simply the transformer itself that I need to physically shield.   Below is a picture of the aluminum box I now have the Topaz in. The faraday fabric is also inside the box, and wrapped around the wires, which I found helped lower audible noise and decreased my discomfort around the transformer.   I have gotten it to a level where it does not bother me much anymore.


----------



## mourip

shyamwanne said:


> Thank you everyone for your input.
> 
> I bought an EMF meter, and what I have found out is that I am very sensitive to the Magnetic and Electric fields produced by transformers.   I bought an aluminum case for my Topaz Isolation Transformer and put some Faraday Fabric around it, and I immediately feel better.  I have found I am sensitive to all the transformers in my audio equipment, it was simply the size of the Topaz that made it so obvious.
> 
> ...



Nice job with the box. Where did you get it.


----------



## Leo-

Hi Shyamwanne, interesting observations. I especulate if it could be the side effects that come combined with magnetic and electrical fields like ultrasonic noise or something else, but not them directly. Would you feel sick also when passing beneath high power transmission lines? The fields near them are very powerful.


----------



## alpovs

Leo- said:


> Would you feel sick also when passing beneath high power transmission lines?


He mentioned this a few posts back - yes.


----------



## alpovs

shyamwanne said:


> Thank you everyone for your input.
> 
> I bought an EMF meter, and what I have found out is that I am very sensitive to the Magnetic and Electric fields produced by transformers.   I bought an aluminum case for my Topaz Isolation Transformer and put some Faraday Fabric around it, and I immediately feel better.  I have found I am sensitive to all the transformers in my audio equipment, it was simply the size of the Topaz that made it so obvious.
> 
> ...


I am curious about your EMF meter. How can it measure magnetic and electric fields separately? If you recall very very basic physics, a change in electric field produces magnetic field and at the same time a change in magnetic field produces electric filed. That's why it's called electromagnetic field. Electric and magnetic components are inseparable. 

That's not true for static fields, they can exist on their own. But static magnetic field is produced by permanent magnets or electromagnets that use DC current. Static electric fields are even more rare. You get statically charged when you walk on carpet in plastic shoes on a dry day. Do you get sick in such situations? Or when you hold a fridge magnet? 

Headphones have permanent magnets in them (not sure about the electrostatic ones but "regular" and planar-magnetics do). So you should measure magnetic field around them even when they are off and get sick when you are wearing them unplugged. Electric field or rather electromagnetic field is generated by music which in turn is generated by AC current. So it will depend on volume and intensity. 

Your EMF meter seems suspect to me if it gives you separate different readings for electric and magnetic fields for electromagnetic fields. And what frequencies does it measure? There are no simple devices that measure all frequencies, there is always a range. If it detects low frequencies like those of transformers it won't sense Wi-Fi.


----------



## Leo-

alpovs said:


> He mentioned this a few posts back - yes.



Oh sorry I must have missed that. Quite intriguing to say the least!


----------



## shyamwanne

*Aluminum Box:  *The box I used to put my 500VA MGE 91095-32T Ultra Linear Isolation Power Supply in is called 'DYT-1 Heightening Full Aluminum Enclosure': https://www.ebay.com/itm/302660809662?ViewItem=&item=302660809662.  Please note if you get this box, the switch it comes with sounds horrible.  I recommend this one: _Canal R Series Rocker Switch Double Pole 16A_, which sounds much better.  Its not a drop in fit, so requires a little filing, but the result is well worth it.

*EMF Meter:  *The meter I used is the TriField EMF Meter Model TF2: https://www.amazon.com/TriField-EMF-Meter-Model-TF2/dp/B078T2R64C   You can see the seperate measurements listed for magnetic and electric fields.   In my experience, they are related as you state alpovs, but from my basic experiement it seems the magnetic and electric fields can be _managed_ seperately.  More on that below.  

I experience heightened tinnitus when having headphones on, plugged or unplugged.  The Topaz (MGE) seems to not impact my wearing headphones.  If anything, it makes them for tenable.   On the other hand, boxing the Topaz (MGE) and putting Faraday Fabric, has increased my ease around my audio system greatly, so that is my focus here now.....ie. focusing on that which I can control

*Faraday Fabric: * I used 'Mission Darkness TitanRF Faraday Fabric': https://www.amazon.com/TitanRF-Shielding-Bluetooth-MILITARY-SHIELDING/dp/B01M294MGK

Note that the faraday fabric did almost nothing to stop the magnetic fields coming from transformer. So sitting a distance away (about six feet) is the solution for me.   However, the faraday fabric and aluminum case did a great job blocking the electric field, and this seems to be what impacts me the most.  The benefit was not subtle, it was obvious.  My whole body relaxed and the tinnitus in my ears lessened.  My wife kept walking in and out while I was experimenting and she also commented how much better it felt when the Transformer was in the box with the faraday fabric.  I'm convinced these fields impact the human body now.    My wife and I both feel the big power lines, now I know the effects exist inside my house too.    I have found a couple other 'culprits' in the house too. I sold my ultrasonic humidifier and got a 'cool mist' humidifier, and I unplug my microwave when not in use.   I'm sure this must sound hokey to many, but I honestly feel better, so I'm not going to argue with that, ha ha

*Kudos to JS-2:  *I want to give Kudos to Superdad here too, I just got an uptone audio JS-2 DC linear power supply which is incredibly good. It just smoked another expensive linear power supply I was using.  So I know others here understand way more about this stuff than I do.  I am a musical instrument designer by profession, so I am very good critical listener, and do believe our bodies (ears are part of our bodies) are amazing at reading information our minds may not yet understand.   So I am just trusting my direct experience when I share.


----------



## alpovs

shyamwanne said:


> *EMF Meter: *The meter I used is the TriField EMF Meter Model TF2: https://www.amazon.com/TriField-EMF-Meter-Model-TF2/dp/B078T2R64C You can see the seperate measurements listed for magnetic and electric fields. In my experience, they are related as you state alpovs, but from my basic experiement it seems the magnetic and electric fields can be _managed_ seperately. More on that below.


The seller of this meter posted this: "The meter accurately measures RF signals that are in the frequency range 20 Megahertz (MHz) to 6 Gigahertz (GHz). It reads low for RF waves outside that frequency range." So, supposedly it doesn't detect the electromagnetic field of transformers working at 60 Hz. Nor static magnetic fields. 


shyamwanne said:


> Note that the faraday fabric did almost nothing to stop the magnetic fields coming from transformer. So sitting a distance away (about six feet) is the solution for me. However, the faraday fabric and aluminum case did a great job blocking the electric field, and this seems to be what impacts me the most.


It's not possible to separate electric and magnetic components of an electromagnetic field. I would refer you to any basic physics textbook. Or google.


----------



## shyamwanne

alpovs said:


> The seller of this meter posted this: "The meter accurately measures RF signals that are in the frequency range 20 Megahertz (MHz) to 6 Gigahertz (GHz). It reads low for RF waves outside that frequency range." So, supposedly it doesn't detect the electromagnetic field of transformers working at 60 Hz. Nor static magnetic fields.
> 
> It's not possible to separate electric and magnetic components of an electromagnetic field. I would refer you to any basic physics textbook. Or google.



As I stated, my primary tool for this experiment has been my ears, and body.  I want good sound, to lower my tinnitus, and increase comfort around my audio gear.   This experiment got those results for me.   I only shared the EMF data as 'supporting information'.  The meter I have definitely registered changes when placed close to the transformers, even if it is not rated to do so.  And I found a correlation between tinnitus and discomfort, with other sources that registered high on the meter.  That is the extent of the information I'm sharing.


----------



## Leo-

shyamwanne said:


> I experience heightened tinnitus when having headphones on, plugged or unplugged.  The Topaz (MGE) seems to not impact my wearing headphones.  If anything, it makes them for tenable.   On the other hand, boxing the Topaz (MGE) and putting Faraday Fabric, has increased my ease around my audio system greatly, so that is my focus here now.....ie. focusing on that which I can control



Tinnitus always gets worse in the silence, due to the adaptive nature of the brain's gain. No exotic explanations needed for this. It equally tends to get worse if you concentrate in trying to hear it (similar effect) so you might just be being fooled by your brain on this one.


----------



## mourip

shyamwanne said:


> *Aluminum Box:  *The box I used to put my 500VA MGE 91095-32T Ultra Linear Isolation Power Supply in is called 'DYT-1 Heightening Full Aluminum Enclosure': https://www.ebay.com/itm/302660809662?ViewItem=&item=302660809662.  Please note if you get this box, the switch it comes with sounds horrible.  I recommend this one: _Canal R Series Rocker Switch Double Pole 16A_, which sounds much better.  Its not a drop in fit, so requires a little filing, but the result is well worth it.



Very nice find on that box. It even has AC socket cutouts...


----------



## mourip

Leo- said:


> Tinnitus always gets worse in the silence, due to the adaptive nature of the brain's gain. No exotic explanations needed for this. It equally tends to get worse if you concentrate in trying to hear it (similar effect) so you might just be being fooled by your brain on this one.



Interesting. I have some tinnitus that comes and goes. Usually just in one ear and almost never in both at once. I can make it go away by blocking my ear canal with my finger to the point of silence and either just waiting or else concentrating very hard on something like a small dot. When I told my ENT about it he was impressed and thought that I was basically doing biofeedback.


----------



## Willco

I'm interested in trying the Topaz or similar.  Has anyone looked into comparison
between the 30 series Topaz and a similar Eaton or others?  Thanks


----------



## zilch0md

Hi Willco,

You don't have to read very far into this thread to discover that several companies manufactured essentially identical products.   The original design changed hands several times over the years.


----------



## shyamwanne (Jun 2, 2018)

My Topaz and cases are sold.  I still have Synergistic Research Blue fuse ($100), and Black Duplex Outlet ($175) for sale though.


----------



## zilch0md

Cool!  

For specs, see:    http://www.pacificparts.com/vends/mge/images/t1.pdf


----------



## mourip

I just finished putting a Topaz “Series 30” 500VA low inter-winding capacitance transformer into this nice box that I purchased from a fellow HFer. Worked out well and looks good.


----------



## zilch0md

^ Well done, Mourip!  It's beautiful.  And those are great photos, too!


----------



## doraymon

Guys, any idea where I can find a Topaz series 30 or equivalent.
Nothing on e-bay and many manufacturers don't indicate the capacitance value.


----------



## zilch0md

doraymon said:


> Guys, any idea where I can find a Topaz series 30 or equivalent.
> Nothing on e-bay and many manufacturers don't indicate the capacitance value.




https://www.ebay.com/itm/TRANSFORME...780338?hash=item3f9d868c72:g:~IsAAOSwirFbAZLG

https://www.ebay.com/itm/MGE-UPS-Sy...559391&hash=item35db9ee7b3:g:u58AAOSwewJTmJGr

https://www.ebay.com/itm/MGE-UPS-TR...671993?hash=item2c87c936f9:g:eEQAAOSwI~VTzVtB

Hint:  Topaz = Eaton = MGE = Daitron

Keep searching.  They are out there.

Mike


----------



## Willco (Jun 3, 2018)

zilch0md said:


> https://www.ebay.com/itm/TRANSFORME...780338?hash=item3f9d868c72:g:~IsAAOSwirFbAZLG
> 
> https://www.ebay.com/itm/MGE-UPS-Sy...559391&hash=item35db9ee7b3:g:u58AAOSwewJTmJGr
> 
> ...


The Eaton is not the same as the Topaz.  It’s inter winding capacitance is much higher!  The difference, as I recall, as told to me by the engineers at Eaton is .9 on the Eaton compared to .0005 on the Topaz.  So be careful to check the specs on these different transformer models.


----------



## oneguy

doraymon said:


> Guys, any idea where I can find a Topaz series 30 or equivalent.
> Nothing on e-bay and many manufacturers don't indicate the capacitance value.



I am seeing 8 available on eBay right now. 4 under the Topaz brand and 4 under the MGE brand.


----------



## zilch0md

Hi Willco,

Even Topaz isn't the same as Topaz, in terms of capacitance - there are several models that exceed 0.0005 pF.  You may be right about Eaton, but I'm pretty sure there was a time when *Eaton* was manufacturing the .0005pF -31 and -32 models that look just like those made by *Topaz, MGE, Daitron *and, let me add, *Elgar and Xentek.*

I recommend not ruling out any of these names when searching for isolation transformers and, as you have advised, always check the specifications.


----------



## Zenvota

Id like to add for those searching for units, searching for the specific model numbers is an option as well, as thats how companies like radwell/plccenter list their units.  I.e. 91097-32 for the 750va unit .0005 with cord and outlet.  

-11 has terminals, -12 has a cord and outlet
-11 is .005, -22 is .001, -32 is .0005

Heres a list of the models, https://cdn.head-fi.org/a/9986070.jpg

Also just searching ebay for ultra isolation or extreme isolation

The xenteks have different model numbers like eit55-03, i couldnt find a list but they seem to all be .001, except for that magical .000001 

Other manufacturers include: deltec,
Utc, eca, schneider, square d

Theres a much larger inventory out there then you might expect theres just no consistency with listing keywords


----------



## Zenvota

Hoping maybe someone here has some insight or an opinion on what im doing.

I'm splitting the signal out of my dac, currently with emotiva xbal splitters to a bass shaker system comprising of an equalizer, crossover, and amplifier.  See below for system specs.

Im trying to decide how best to split and power the system with an iso transformer.  I'm mulling over the following options:

1.) Iso Transformer to power strip with everything, split with emotiva xbal
1b.) Split with bluejeans xlr splitters

2a.) IT to 2 separate cables to dac and amp; split with xbals, jensen iso max on the shaker side isolating that system.
2b.) Split with bluejeans xlr splitters and a use a jensen iso max.
2c.) Split with whirlwind imp splitters

The emotiva xbal splitters are on pcb if that makes any difference.

Im not sure if using the whirlwind splitters or the jensen iso max allows you to power the system separately from the iso transformer, but i do believe zilch mentioned them in the op and someone mentioned using them to power their subwoofers separately from a topaz.



P.S. System Details:
Source: windows computer evga p1200 p2 psu
Uptone iso regen and lps 1.2
Dac: audio gd nfb7, input is amenero with usb isolator
Headamp: audio gd nfb1amp
Currently just using monoprice premier xlr cables and emotiva xbal splitters
And 14awg standard tripplite power cables and a ge surge strip.

The shaker system is a monoprice dual 31 band graphic equalizer, art310 crossover, little kinter stereo amp.

Also on the same outlet but not used at the same time is a denon x4200w, audiosource amp100vs, bic v1220.


----------



## Alcophone

Zenvota said:


> Id like to add for those searching for units, searching for the specific model numbers is an option as well, as thats how companies like radwell/plccenter list their units.  I.e. 91097-32 for the 750va unit .0005 with cord and outlet.
> 
> -11 has terminals, -12 has a cord and outlet
> -11 is .005, -22 is .001, -32 is .0005
> ...


Is there seriously nothing like it still in production? I find that bizarre if they are so great (which I'm not doubting).


----------



## doraymon

Alcophone said:


> Is there seriously nothing like it still in production? I find that bizarre if they are so great (which I'm not doubting).


+1 I always thought this was crazy!


----------



## Superdad

Alcophone said:


> Is there seriously nothing like it still in production? I find that bizarre if they are so great (which I'm not doubting).



Well the home audio system use was never the target market for the industrial Topaz isolation transformers. And while large (10kVA+) transformers are still used in some commercial installations, I think the market for smaller units has gone away as the gear they were used for has evolved in the modern age.


----------



## Energy (Jun 13, 2018)

Does anyone know where I can get one? I will shorten the cable, increase the wire gauge, put it into an aluminum enclosure with a faraday cage, and fill the inside with roxul to silence the hum. *Does anyone have a unit that doesn't hum?*

I was going to get a Tripp-Lite IS100HG but this seems like a no brainer per John's recommendation and thorough explanation.


----------



## Zenvota

Alcophone said:


> Is there seriously nothing like it still in production? I find that bizarre if they are so great (which I'm not doubting).



Eaton power supress 100
I believe these r they, new for $600+
https://www.powercom.com/eaton-powe...s-100-500va-75kva-power-conditioner-hardwired

I picked up a 250va topaz .0005 for $30 though...


----------



## Superdad

Zenvota said:


> I picked up a 250va topaz .0005 for $30 though...



Great score!


----------



## Alcophone

Zenvota said:


> Eaton power supress 100
> I believe these r they, new for $600+
> https://www.powercom.com/eaton-powe...s-100-500va-75kva-power-conditioner-hardwired
> 
> I picked up a 250va topaz .0005 for $30 though...


Heh. Can't argue with that.


----------



## zilch0md

Zenvota said:


> Eaton power supress 100
> I believe these r they, new for $600+
> https://www.powercom.com/eaton-powe...s-100-500va-75kva-power-conditioner-hardwired
> 
> I picked up a 250va topaz .0005 for $30 though...



So far as I can tell, any mention of interwinding capacitance is conspicuously absent in the specifications for those new Eaton isolation transformers.  

I'd just as soon buy a $100 500VA Tripp-Lite brand new, if I was willing to forgo the benefits of a 0.0005 pF capacitance.

Those new Eaton's might actually be worthy of the old Topaz -30 and -31 models, but if so, why aren't they publishing or even boasting about the spec?

As John Swenson once wrote (paraphrasing heavily from memory), today's off-the-shelf isolation transformers offer almost no noise suppression above 400 Hz, for audiophile purposes - due to their poor (high) inter-winding capacitance.  Not just any isolation transformer will give you significant common-mode noise suppression well past 20,000 Hz.  

The Topaz 0.0005 pF transformers are a perfect example of a technology that has been lost to time. The actual knowledge of how to design them may even be lost. We might no sooner be able to manufacture such transformers today than we can put a man on the moon anytime soon.  We have to re-invent that wheel barrow from scratch.  Mankind did it in the past, but we can't do it now.  (Oops! Here come the conspiracy theorists.)


----------



## Zenvota

From the CA thread:

"Finally a response from Eaton on their Power Suppress 100:

We do have testing on our 1kVA T100 and the interwinding capacitance is about 0.90pF.  This is greater than the 0.005pF that is referenced below, but with the output filter network in play, the apparent noise attenuation is -136dB."

So ya better then the tripp lite but not as good as the old topazes


----------



## zilch0md (Jul 1, 2018)

^ Thanks for this valuable info, Zenvota!  Let me add that using more modern approaches to common-mode noise suppression comes with some pitfalls, but I will leave it to some of the more savvy contributors to reinforce (or rebut) what I'm saying. 

I just can't remember the specifics, but in the end, I do recall that we are better off achieving the desired noise suppression across the full audio spectrum without inserting caps and such (L-C networks ?) on the secondary output of the transformer.


----------



## Zenvota

That's what it sounds like when they say theres an output filter network.


----------



## sahmen

So how do these look in terms of specs, and also  price?  They alll seem to meet the "series 30" specs, but I do not know what else to look for...  I also want to get a sense of what a "reasonable" price range is for these units... Thanks for any helpful thoughts.

1
https://www.ebay.com/itm/MGE-UPS-Sy...179634?hash=item544002d272:g:3pQAAOSwJ7RYTRO2

2.
https://www.ebay.com/itm/MGE-UPS-Sy...288193?hash=item4b46ea01c1:g:6G4AAOSw0IJbLBXJ

3
https://www.ebay.com/itm/MGE-UPS-Ul...838565?hash=item2141431ea5:g:AXQAAOSwU4hbGyUS

4
https://www.ebay.com/itm/MGE-UPS-Sy...621511&hash=item285d7da1df:g:jM8AAOSwetNbKWhV

5.
https://www.ebay.com/itm/MGE-91097-...539609?hash=item3d4a3d5959:g:w9IAAOSwFhFZ0Dd9


----------



## zilch0md

^  Good hunting!

Specs for the -31 and -32 models can be found in this PDF:    http://www.pacificparts.com/vends/mge/images/t1.pdf

Prices seem to be a bit high, overall, but when you search for anything on eBay, you can look for a checkbox along the left side of the screen that says "Completed Auctions" - so that you can see what similar items sold for in the past.


----------



## Energy

@zilch0md

Mike. Does your Topaz make any audible hum at all?

I'm currently looking to put a 2.5kV Topaz into an aluminum chassis..
First I would unbolt it from the metal frame that it comes in followed by routing 8-gauge wires to the IEC and Receptacles. 

I noticed some people say that their unit hum. Because of that, I was planning on equipping custom heatsinks to the sides of the transformer and filling the empty area between the transformer and the chassis with some ROXUL (fiberglass equivalent) to suppress the noise. Then I realized since there will be a decent amount of space, I could easily build a DC filter to remove any DC offset. What would your opinion be on the matter?

*Thanh*


----------



## zilch0md

Energy said:


> @zilch0md
> 
> Mike. Does your Topaz make any audible hum at all?
> 
> ...



My 500VA Topaz has a wee bit of audible hum, but I have to hold my head no farther than about 300cm to hear it, even when the room itself is silent.  If you search this thread, you can find posts by others, more knowledgeable than I, who have advised that tightening the bolts which hold the transformer together can make a difference, but my understanding is that, in general, the more hum you get from a transformer, the dirtier the incoming power is and certainly, DC offset can be a culprit.  My incoming power is apparently "cleaner" in this regard than those who suffer a lot of transformer hum.  

That said, the "guru" of using isolation transformers for noise suppression, Jon Swenson (of Uptone Audio), eschews the use of DC filters to silence his own humming Topaz. If I remember correctly, from posts he has made to a forum at _ComputerAudiophile.com, _he advises that we not use DC filters, that we instead just allow the transformer to do its job, even it hums.  I clearly recall his writing that he built a wooden box around his transformer that has some kind of sound-deadening material in it, but he has gone out of his way to ensure that the transformer doesn't overheat - the box is well ventilated.  

On reading your intent to use ROXUL to suppress the noise, my first concern was that you might interfere with the transformer's ability to stay cool.  That said, I pull so little power from my transformer, operating a DAC and headphone amp, not a powerful speaker amp, that it never gets even warm to the touch.  It pretty much remains at ambient temperature - but it's not enclosed in an insulated case.

So... my advice, which is mostly the advice of someone I respect, is to avoid DC filters and build a much larger box than you had perhaps planned, preferably out of sound-absorbing wood, using no (sound-radiating) heat sinks.  You might even try to research the purchase of an extremely silent-running fan (that's small and turns at a low rpm) - just a little bit of forced airflow could allow you to shrink the box that baffles the sound.   :-/

Mike


----------



## Superdad

zilch0md said:


> That said, the "guru" of using isolation transformers for noise suppression, Jon Swenson (of Uptone Audio), eschews the use of DC filters to silence his own humming Topaz. If I remember correctly, from posts he has made to a forum at _ComputerAudiophile.com, _he advises that we not use DC filters, that we instead just allow the transformer to do its job, even it hums.  I clearly recall his writing that he built a wooden box around his transformer that has some kind of sound-deadening material in it, but he has gone out of his way to ensure that the transformer doesn't overheat - the box is well ventilated.



Hi Mike:
I think the reason John adviced against use of DC-offset blocking networks was concern for safety—as failure of such can result in a fire.  Given that these are used on the primary side, I don’t think he was advising against them for performance reasons.

Of course on the secondary side it is important to use outlets/power strips that have zero filter elements at all.  The whole concept being to reduce the impedance between the grounds of all attached equipment (reducing the interaction of the inevitable leakage loops which form between all components with AC-connected power supplies).  And the point of the isolation transformer is simply that it is a VERY effective surge suppressor and line noise filter.

BTW, here in the USA DC offset in our AC lines is rather rare.  Occurs much more in Europe.  Even there, blocking of the offset is not a sure-fire cure for transformer lamination hum.  Such is a bit inevitable with big trannys—and it is often worse in 50Hz countries.


----------



## kazsud

I’ve had a hell of a time getting rid of static, pops and other noise in my house. First thing I discovered was there wasn’t a ground in my basement. So I installed a 8ft grounding rod which didn’t help much.

So I hired a electrician friend to come access the problem. He found the line that came from the duplex was going thru a light before going to the box. I had him install two hospital grade duplex and ran them to the box.

That got rid of 90% of all the noise but still audible. I have everything connected to a Furman M-8DX which conditions as well. His boss who is a audiophile said the last of the problem is probably coming from outside the house and suggested getting a Pure Sine battery converter.

After searching I found too many with all different t power handling. My only other idea is to get a PS Audio Noise Harvester.

Any input or thoughts?


----------



## Zenvota

Got a couple noob questions

Attaching a metal electric box to the transformers do you just use the wire clamps or some kind of threaded pipe?

Using an ac receptacle on the output with a metal box is there any necessary requirements like using an outlet with an isolated ground or does that not matter?


----------



## zilch0md

Superdad said:


> Hi Mike:
> I think the reason John adviced against use of DC-offset blocking networks was concern for safety—as failure of such can result in a fire.  Given that these are used on the primary side, I don’t think he was advising against them for performance reasons.
> 
> Of course on the secondary side it is important to use outlets/power strips that have zero filter elements at all.  The whole concept being to reduce the impedance between the grounds of all attached equipment (reducing the interaction of the inevitable leakage loops which form between all components with AC-connected power supplies).  And the point of the isolation transformer is simply that it is a VERY effective surge suppressor and line noise filter.
> ...



Hey Alex!  Thanks very much for the clarification!   

I couldn't remember the details of John's advice regarding DC filters (nor even how to spell his first name!)  LOL

Like watching a movie you haven't seen in years, everything you've written came back to me as I read it.  Sheesh!

And for those who don't know Superdad, he and John Swenson are the guys behind UpTone Audio, who produce all the products seen here, which I have no reluctance to plug, as I'm a huge fan of their products and their knowledge of all things related to noise reduction:   

https://uptoneaudio.com/

https://www.computeraudiophile.com/forums/forum/25-uptone-audio-sponsored/

In other words, whenever you see a post by Superdad or John Swenson, here or at ComputerAudiophile, pay attention!  

Mike


----------



## Zenvota (Jul 10, 2018)

Copying this over from the ca thread would just like to make sure I'm gettin this setup correctly.

"
So per one and a half and john swensons advice I added a 250v 2a ceramic time delay fuse to the transformer.  The prewired 250va model says to use a 6a fuse, the 125va a 3a fuse.  I have the transformer wired 120 in 120 out and can't be putting more then a 1a load on it(specs say 50w dac 30w headphone amp).



Id just like to confirm grounding of the electrics boxes though.



I have the input like this(attached pictures ignore the red wires on the terminals those r gone now
Metal box
Pvc terminal adapter and brushing
Metal cover plate with fused iec inlet

Is this ok? In this situation the metal box isn't grounded.  On the output I'd use a metal electrical box and the standard ac outlet grounds to the box just by attaching it.

Thanks so much for the help and to everyone whos contributed to this thread the transformer makes a massive difference


----------



## oneguy

Zenvota said:


> Copying this over from the ca thread would just like to make sure I'm gettin this setup correctly.
> 
> "
> So per one and a half and john swensons advice I added a 250v 2a ceramic time delay fuse to the transformer.  The prewired 250va model says to use a 6a fuse, the 125va a 3a fuse.  I have the transformer wired 120 in 120 out and can't be putting more then a 1a load on it(specs say 50w dac 30w headphone amp).
> ...


No picture attached.


----------



## Zenvota

oneguy said:


> No picture attached.



Thx fixed it


----------



## oneguy

Zenvota said:


> Thx fixed it


I would think it would be ok. I only have a -32 at the moment because my -31 is being shipped but in -32 the grounding goes through the transformer case and probable does in the -31. The metal box on the input side shouldn’t need to be grounded as the rest of the transformer is.


----------



## oneguy

Here’s a question for the group. On the 91002-32 there is a 7uF capacitor connecting the live to neutral side of the built in recpeptacle. I surmise this is for so sort of filtering. Does anyone else concur? It is the black wire in the photo.



 

 



This isn’t present in the -31 so my plan is to omit it when I build 91002-32 into an aluminum enclosure with 3 outlets just as with my -31 enclosure build.


----------



## Zenvota

oneguy said:


> Here’s a question for the group. On the 91002-32 there is a 7uF capacitor connecting the live to neutral side of the built in recpeptacle. I surmise this is for so sort of filtering. Does anyone else concur? It is the black wire in the photo.
> 
> 
> 
> This isn’t present in the -31 so my plan is to omit it when I build 91002-32 into an aluminum enclosure with 3 outlets just as with my -31 enclosure build.



The topaz pdf says its for additional traverse noise attenuation.


----------



## oneguy

Zenvota said:


> The topaz pdf says its for additional traverse noise attenuation.


Thanks!


----------



## Zenvota

I attached the pdf but i don't see it on the post lol.

https://www.google.com/url?sa=t&sou...FjAAegQIAhAB&usg=AOvVaw37_4Dw8n0-F7sQwev_DPes


----------



## oneguy (Aug 22, 2018)

So I’m disassembling my 91002-32 so it can be rewired to have 3 duplex outlets in and an aluminum case and I had a question about how it came wired. On the receptacle that came with the transformer neutral was tied into ground. Any idea why this mat have been done?

 

Here are a couple more pics people may find interesting:


----------



## zilch0md (Aug 22, 2018)

Hey oneguy!

That's literally what defines these Topaz isolation transformers as having "grounded-neutral secondaries" as opposed to transformers like the B&K Precision, that have "floating-neutral secondaries.  Both types provide common-mode noise rejection, with attenuation in the higher frequencies being inversely proportional to the inter-winding capacitance.  The lower the capacitance between the coils, the higher the frequencies at which we can enjoy CM noise reduction.

The secondary's neutral is grounded in the interest of safety.  In the States, the NEC requires Neutral to be bonded to Ground at the mains entrance so that a ground fault will trip the circuit breaker.

A transformer with an ungrounded secondary is actually beneficial for energizing equipment on a workbench, where the chassis is open and the user is inserting probes onto energized components.  You can find YT videos where guys who repair electronic equipment explain how to modify a grounded-neutral secondary to turn it into a floating-neutral secondary.  These videos also include diagrams showing how doing so reduces shock hazard when working with an energized open chassis.

For our purposes, it's safest to use a grounded-neutral secondary.  See the blue text in this graphic:


----------



## oneguy

zilch0md said:


> Hey oneguy!



Thanks for the refresher. I read that graphic sometime ago and forgot that it mentioned grounded-neutral secondaries.


----------



## Zenvota

My 91092-12 came new sealed in the original packaging and doesn't look like that.


----------



## oneguy

Zenvota said:


> My 91092-12 came new sealed in the original packaging and doesn't look like that.


Yours is a -12 not a -32 so thats probably why (different model series). The -31 and -32 series are the ones with the lowest capacitance.


----------



## Zenvota

Yours also has the capacitor, that could be why.  I have a -31 also and I've never seen any wiring scheme that said to jumper the common and ground.


----------



## oneguy (Aug 22, 2018)

My -31 doesn’t have one either but I plan on adding one. I believe it is combat transverse-mode noise.




http://www.surplussales.com/Transformers/Pdfs/tp-91092-31_N.pdf


----------



## Zenvota

oneguy said:


> I believe it is combat transverse-mode nois



Yup, _additional_ traverse noise attenuation, the units already do something like 60db.  Im very curious about the jumpered ground and neutral though, I thought the grounded neutral secondary was an internal thing, neither of my units do this.


----------



## zilch0md (Aug 23, 2018)

Zenvota said:


> Yup, _additional_ traverse noise attenuation, the units already do something like 60db.  Im very curious about the jumpered ground and neutral though, I thought the grounded neutral secondary was an internal thing, neither of my units do this.



I'm really surprised to hear this.  I thought all of the Topaz and alternate brands of these transformers were manufactured with grounded-neutral secondaries.  Maybe some of them have been modified over the years by previous owners, but it's possible some were actually manufactured that way.  ???

You must have already been inside and had a close look, but for anyone wanting to know, without opening the transformer, whether it has a grounded-neutral secondary or a floating-neutral secondary...

While a load is pulling current from the transformer, unplug the transformer from the mains.  The load will completely de-energize the transformer.

Then, unplug the load and use a multimeter to check the continuity between ground and first the hot, then the neutral socket of the transformer's power outlet.  I would expect neutral to be grounded, but if not, your transformer is well-suited to working on open-chassis equipment that has to be tested while energized - the number one reason people modify them to float the secondary.  

Less known, is that a floating secondary can prevent ground loops and will also prevent backwash noise from DACs and gear equipped with switch-mode power supplies from polluting other components. Never plug more than one load into an isolation transformer with floating-neutral secondary.


----------



## Zenvota

zilch0md said:


> thought all of the Topaz and alternate brands of these transformers were manufactured with grounded-neutral secondaries. Maybe some of them have been modified over the years by previous owners, but it's possible some were actually manufactured that way.



On your unit the secondary neutral is grounded at the output receptacle?


----------



## zilch0md (Aug 23, 2018)

^ No, it's not grounded at the receptacle, but under the coils somewhere.

At the receptacle, I've proven with my multimeter that Neutral and Ground are connected.


----------



## zilch0md




----------



## DaaDaa

I just got a 1KVA 0.001pf topaz that when plugged in has a loud hum by itself. a mechanical hum that can be heard from a 10 feet away and also travels into my amp and makes my amp noisier. is this normal? do they have a hum by themselves?


----------



## Zenvota

Dadbeh said:


> I just got a 1KVA 0.001pf topaz that when plugged in has a loud hum by itself. a mechanical hum that can be heard from a 10 feet away and also travels into my amp and makes my amp noisier. is this normal? do they have a hum by themselves?



That sounds a bit too loud.

I have a 91092-31 that's dead silent and doesn't vibrate and a 91092-12 that has a slight hum and vibration only audible from inches away.

What is your exact model number?  Some pictures could help to.


----------



## DaaDaa

it is 91001-22


----------



## DaaDaa

i just needed to know if it is normal or not. it is going back to the seller.


----------



## Zenvota

Dadbeh said:


> i just needed to know if it is normal or not. it is going back to the seller.



Keep this post for reference if you happen to take it to an electrician for testing.


----------



## DaaDaa

thanks man. that's great.


----------



## Zenvota

Dadbeh said:


> thanks man. that's great.



You're welcome, good luck.  When you're doing a listening test, use something taxing and elaborate, hifi recordings with lots of room ambiance, acoustic instruments, etc.  Should be an easily noticeable improvement, unless your equipment already has elaborate filtering that reduces all the common/traverse noise.


----------



## oneguy (Oct 7, 2018)

I finally finished my 2.4 kva beast. Highlights include silver plated 10 Awg Teflon wiring, EMI/RFI resistant fuse holder and and everything needed to accept up to 20A on the primary side. She is heavy! I included the gallon jug for size reference.


----------



## Zenvota

oneguy said:


> I finally finish my 2.4 kva beast. Highlights include silver plated 10 Awg Teflon wiring, EMI/RFI resistant fuse holder and and everything needed to accept up to 20A on the primary side. She is heavy! I included the gallon jug for size reference.



Wow cool xD innie photos?


----------



## oneguy

Zenvota said:


> Wow cool xD innie photos?



Only some old ones. I’ll open her up and get some tomorrow


----------



## oneguy




----------



## Zenvota

oneguy said:


>



Awesome, done any listening yet? You still have those Adams?


----------



## oneguy

Zenvota said:


> Awesome, done any listening yet? You still have those Adams?


Not yet. I need to switch out the wall outlet to a receptacle that can accept a 20A plug. Waiting until my wife is available to read the multimeter as I flip circuit breakers to determine which one owns that outlet. I’ll report back once she’s been conscripted. 

I still have the Adams and originally this was supposed to be for that system and I was going to make a second one with a 500va isolation transformer (IT) for my headphone system. Well as it turns out the topaz transformer I had was a 125va not a 500 va so it’s useless to use with any more than 1 or 2 items. I’m going to use some more of the 10 awg and put plug ends on the 125va one and see if I can figure out a use for it while I seek out a good deal on a 500 or 750va IT. 

Here’s the shell for the next one:


----------



## Zenvota

oneguy said:


> Not yet. I need to switch out the wall outlet to a receptacle that can accept a 20A plug. Waiting until my wife is available to read the multimeter as I flip circuit breakers to determine which one owns that outlet. I’ll report back once she’s been conscripted.
> 
> I still have the Adams and originally this was supposed to be for that system and I was going to make a second one with a 500va isolation transformer (IT) for my headphone system. Well as it turns out the topaz transformer I had was a 125va not a 500 va so it’s useless to use with any more than 1 or 2 items. I’m going to use some more of the 10 awg and put plug ends on the 125va one and see if I can figure out a use for it while I seek out a good deal on a 500 or 750va IT.
> 
> Here’s the shell for the next one:


How much power does your headphone setup draw? O.o


----------



## oneguy

Zenvota said:


> How much power does your headphone setup draw? O.o



DAC 35w
LPS-1.2 36w
LPS-1.2 36w
Amp 200w
LPS4 20w?

So about 327w total


----------



## Zenvota

oneguy said:


> DAC 35w
> LPS-1.2 36w
> LPS-1.2 36w
> Amp 200w
> ...



I think optimally you wouldn't want the ultracaps connected to the topaz, theyre already isolated from the mains so the meanwell smps' would be injecting some noise into the system.  The headphone amp is 200w?  Whats the lps4?


----------



## oneguy

Zenvota said:


> I think optimally you wouldn't want the ultracaps connected to the topaz, theyre already isolated from the mains so the meanwell smps' would be injecting some noise into the system.  The headphone amp is 200w?  Whats the lps4?



-The ultracaps will be connected to a DIY sigma11 eventually which will be plugged into the IT so I stilll need to account for their power requirements. 

-The LPS4 is currently only pulling charging duty for my LH Labs 20G so I am going to build a separate rail in the sigma11 case for that and one other TBD item. 

-The T2 is rated at 200w power consumption. I’m having a DIY T2 built and I believe the power consumption of those is 180-200w

Here’s a pic of the LPS4:
https://goo.gl/images/QcdxFR


----------



## oneguy

oneguy said:


> Not yet. I need to switch out the wall outlet to a receptacle that can accept a 20A plug. Waiting until my wife is available to read the multimeter as I flip circuit breakers to determine which one owns that outlet. I’ll report back once she’s been conscripted.
> 
> I still have the Adams and originally this was supposed to be for that system and I was going to make a second one with a 500va isolation transformer (IT) for my headphone system. Well as it turns out the topaz transformer I had was a 125va not a 500 va so it’s useless to use with any more than 1 or 2 items. I’m going to use some more of the 10 awg and put plug ends on the 125va one and see if I can figure out a use for it while I seek out a good deal on a 500 or 750va IT.
> 
> Here’s the shell for the next one:


I just did about 15 minutes of listening on it and I’d say it’s a subtle but noticeable difference across the board. About a 5% improvement 95% of the time and the other 5% I need to do more in-depth listening to evaluate. Not bad considering the money spent and I’m well in the realm of diminishing returns.


----------



## oneguy

The 125’s have begun asexually replicating:

 

You can run a 125va in the middle of an IEC and have power cables that really do reduce noise through established methods as opposed to aftermarket manufacturers that claim a noise reduction through proprietary or “unnamed” methods. I’m not saying that those claims are wrong but at least I can put my finger on what power cables made using these actually do to reduce noise.


----------



## Zenvota

oneguy said:


> The 125’s have begun asexually replicating:
> 
> 
> 
> You can run a 125va in the middle of an IEC and have power cables that really do reduce noise through established methods as opposed to aftermarket manufacturers that claim a noise reduction through proprietary or “unnamed” methods. I’m not saying that those claims are wrong but at least I can put my finger on what power cables made using these actually do to reduce noise.



I'm a fan of 14awg silver plated teflon dielectric quadropole with a 12awg counter spiraled ground around the star quad.  High conductivity, low inductance, Science!  And not expensive if you want to make it yourself.


----------



## oneguy

Zenvota said:


> I'm a fan of 14awg silver plated teflon dielectric quadropole with a 12awg counter spiraled ground around the star quad.  High conductivity, low inductance, Science!  And not expensive if you want to make it yourself.



I’ll give it a look online. I’ve had some success with my 8 and 10awg mil spec silver plated Teflon so I may continue that route though since I have about 64-68’ of it that need to be used


----------



## oneguy (Nov 25, 2018)

Anyone seen a -32 series with internals like this?

  

My 2.4kva unit is an MGE -32 series and it doesn’t have the large white sheet metal piece.


----------



## oneguy

oneguy said:


> Not yet. I need to switch out the wall outlet to a receptacle that can accept a 20A plug. Waiting until my wife is available to read the multimeter as I flip circuit breakers to determine which one owns that outlet. I’ll report back once she’s been conscripted.
> 
> I still have the Adams and originally this was supposed to be for that system and I was going to make a second one with a 500va isolation transformer (IT) for my headphone system. Well as it turns out the topaz transformer I had was a 125va not a 500 va so it’s useless to use with any more than 1 or 2 items. I’m going to use some more of the 10 awg and put plug ends on the 125va one and see if I can figure out a use for it while I seek out a good deal on a 500 or 750va IT.
> 
> Here’s the shell for the next one:



Well it’s finally done (except waiting on fuse to come in). I managed to squeeze a 1kva unit in there but cutting the feet a little narrower. As you can see thought the fit is still snug in the length direction as well.


----------



## Zenvota

oneguy said:


> Well it’s finally done (except waiting on fuse to come in). I managed to squeeze a 1kva unit in there but cutting the feet a little narrower. As you can see thought the fit is still snug in the length direction as well.



Very nice.  Did you ever happen to find any information on the white metal sheet from the other one?


----------



## oneguy (Nov 29, 2018)

Zenvota said:


> Very nice.  Did you ever happen to find any information on the white metal sheet from the other one?


Thanks!

The transformer with the white metal sheet is actually in the unit I just built. Still haven’t found and info on it unfortunately. As I’m sure you know, finding info on these transformers is surprisingly difficult.


----------



## Zenvota

oneguy said:


> Thanks!
> 
> The transformer with the white metal sheet is actually in the unit I just built. Still haven’t found and info on it unfortunately. As I’m sure you know, finding info on these transformers is surprisingly difficult.



Yup, well worth it in the end though.  In my system it made music through the virtual speaker program my favorite thing, where before i found myself prefering to listen normally over headphones for music.


----------



## oneguy

Zenvota said:


> Yup, well worth it in the end though.  In my system it made music through the virtual speaker program my favorite thing, where before i found myself prefering to listen normally over headphones for music.


Agreed. Clean, very Lowe noise power. What’s not to like? This one is going in my headphone setup and the other one will go in my speaker setup. I am looking forward to hearing how my speakers will react to this. 

I am also going to replace the hospital grade outlets in my large box with the Leviton 8300 extra-heavy duty hospital grade outlets once I get the Roxul in. The unit I just built has the gray version of the 8300 and it grips plugs like no other.


----------



## oneguy

Selling two of the new 91091-31 transformers that I picked up: 

https://www.head-fi.org/threads/fs-...lation-transformers-new.895398/#post-14656050


----------



## Willco

zilch0md said:


> Hi John,
> 
> That's great that you could make that comparison.  Regarding the hit on dynamics, are you using a headphone amp or a much hungrier power amp?  Is the VA rating of the Topaz transformer at least half again the combined VA consumption of all the gear that's plugged into it?
> 
> The THD measurements provided by the PS3 are a real head-scratcher, but for sure, no matter any degree of error, I would think it would at least be consistent, so 6.5% THD vs. 1.4% is a huge difference.  It's enough to make me consider mailing you my Topaz for measurement, but I like what I hear, so I'll not burden you with that request.


----------



## Willco

*Advice needed!   Topaz inline with PS audio Regenerator.
*
 My current set up with the Topaz is as follows:  Dedicated line >  PS Audio P12 Regenerator >  Topaz w/floating ground  >  Oyaide Power Strip.

I connect my sources into the Oyade (coming off the Topaz as recommended by Swenson).  

My amp and the Topaz are coming out of the P12.  (I'd like to try the amp out of the Topaz-Oyade strip, but it creates too much
hum from the Topaz.)

I had originally thought I might star ground all components out of the P12, but the P12 creates noise (as measured by an Alpha lap EMI meter) about 
double what measures from the wall.  Typically 200 to 400 mV from the wall and 400 to 900 mV from the P12.

So, I thought to still gain the ac improvement from the P12, while cleaning up the noise after the p12, that I would run the Topaz inline after the P12.
The Topaz reduces the emi level to half of what comes from the wall outlet.

I'm curious to know what other's here, who know a lot more about this stuff than me,  think about this plan in theory or practice?  I had 
one engineer advise to run the Topaz before the P12 instead, but I haven't tried yet and I don't believe it would work with Swenson's power strip
idea (to prevent leakage currents between components).  But it might allow to star ground to the P12...

Any help/advice appreciated.


----------



## Zenvota

If your amp and source are electrically connected putting the topaz in between them should be infinitely worse than plugging them into the p12 after the topaz.

It's not preventing leakage currents between components, it's reducing impedance which reduces noise generated by the leakage currents.  For instance you can't galvanically isolate your dac and your amp(without detriment to sq), so they have an electrical connection and they have leakage currents, but having a filterless connection between the power outlets reduces that noise to negligible.

The p12 is supposed to have lower output impedance so it could be fine..  

Whats your source, dac, and preamp? How big is the topaz?  How big is the amp? did you measure the hum, can you put the topaz in a different room?


----------



## Willco

Zenvota said:


> If your amp and source are electrically connected putting the topaz in between them should be infinitely worse than plugging them into the p12 after the topaz.
> 
> It's not preventing leakage currents between components, it's reducing impedance which reduces noise generated by the leakage currents.  For instance you can't galvanically isolate your dac and your amp(without detriment to sq), so they have an electrical connection and they have leakage currents, but having a filterless connection between the power outlets reduces that noise to negligible.
> 
> ...




Thanks for the reply, Zenvota.

So if my set up is:   Wall-- Dedicated Line  >  P12 (with amp and Topaz connected to P12)  >  Topaz  >  Power Strip (with Switch, Server and Dac connected to Power Strip,
I suppose you're right that the Topaz is *in between the Amp and Source?*

Can you give me an idea why this is going to be worse than both Sources and Amp coming out of the P12?

So, if that's the case, I can see three alternatives to my current set up:

    1.   Wall-- Dedicated Line >  Topaz >  P12 (with all Sources and Amp connected to P12) .   I could also run the Speaker's Class D amps from the P12, but I currently have them    
          connected to dedicated lines.   

    2.   Wall-- Dedicated Line  >  (*Remove Topaz*) >  P12 (w/ Sources and Amp  and perhaps Speaker's Class D amps.)

    3.   Wall--Dedicated Line  >  (_*Remove P12)  >  *_Topaz with power strip connected to Switch, Server and Dac.   Amp connects to another Dedicated Line.

 Any thoughts on which combination might make the most sense?

Plugging my amp into the Topaz/power strip would only be an option if built an outdoor closet for the Topaz... 

My Source is Roon Nucleus >  Ethernet > Lampizator Pacific (with vol control and ethernet streamer)
My Amp is 8 watts/channel 300b Set 

Thanks again


----------



## Zenvota

Willco said:


> Can you give me an idea why this is going to be worse than both Sources and Amp coming out of the P12?


The transformer doesnt block leakage currents so if you have it in between electrically connected devices its going to raise impedance, and probably substantially due to the isolation barrier.  When you say amp by itself you mean preamp? separate from the class d speaker amps, correct?  I believe the ethernet connection should provide isolation, so ideally what you want on a filterless strip after the the topaz is the dac, preamp, and power amps.  Than put the server on the p12 on the separate dedicated line.

Dedicated Line 1: Topaz> Oyaide strip> Dac, preamp, speaker amps
Dedicated Line 2: P12> server


----------



## Zenvota

Or instead of the filterless strip try to the p12 after the topaz


----------



## Willco

Zenvota said:


> The transformer doesnt block leakage currents so if you have it in between electrically connected devices its going to raise impedance, and probably substantially due to the isolation barrier.  When you say amp by itself you mean preamp? separate from the class d speaker amps, correct?  I believe the ethernet connection should provide isolation, so ideally what you want on a filterless strip after the the topaz is the dac, preamp, and power amps.  Than put the server on the p12 on the separate dedicated line.
> 
> Dedicated Line 1: Topaz> Oyaide strip> Dac, preamp, speaker amps
> Dedicated Line 2: P12> server


----------



## Willco

Zenvota said:


> The transformer doesnt block leakage currents so if you have it in between electrically connected devices its going to raise impedance, and probably substantially due to the isolation barrier.  When you say amp by itself you mean preamp? separate from the class d speaker amps, correct?  I believe the ethernet connection should provide isolation, so ideally what you want on a filterless strip after the the topaz is the dac, preamp, and power amps.  Than put the server on the p12 on the separate dedicated line.
> 
> Dedicated Line 1: Topaz> Oyaide strip> Dac, preamp, speaker amps
> Dedicated Line 2: P12> server



"Amp"  refers to my SET Power Amp.  I don't have a preamp, as I use the Vol control on the Lampizator Dac.

The only problem for me in your scenario above is that the Power Amp (Set tube, 8 watts/channel) increases the Topaz hum too much when connected direct to the Topaz/Oyaide strip.
I would have to build a weatherproof  outdoor closet  to house the Topaz.

So, you are recommending to separate the Topaz and P12 in their own dedicated lines?  
Can you explain a little about the reasoning behind not using the Topaz and P12 in line? 

With the idea of using the Topaz to attenuate my line noise I just hooked up the Topaz and P12 in line and see that the Topaz *before* the P12 does indeed greatly lower the 
EMI noise from the P12.   But, I don't know how important this EMI noise out of the P12 is to Audio quality...

 To follow your suggestion of using 2 dedicated lines, what  do you think of:

Dedicated Line 1:  Topaz > Oyaide strip > Dac, Ethernet Switch, Class D speaker amps

Dedicated Line 2:  P12 > Server >  Power Amp  > Class D Sub Amps

Why do you separate the Server from the other Sources (Dac and Switch)?

Thanks!


----------



## Zenvota (Mar 11, 2019)

Willco said:


> So, you are recommending to separate the Topaz and P12 in their own dedicated lines?
> Can you explain a little about the reasoning behind not using the Topaz and P12 in line?


I think in the case of the P12, using it after the Topaz and plugging everything electrically connected into the p12 is fine.  The topaz replaces lesser conditioners the p12 looks like it does a bit extra ;] 

The reasoning is just due to the filtering of each outlet of the p12 increases impedance between electrically connected devices(which have leakage currents) and the higher impedance raises noise generated by the leakage currents.



Willco said:


> The only problem for me in your scenario above is that the Power Amp (Set tube, 8 watts/channel) increases the Topaz hum too much when connected direct to the Topaz/Oyaide strip.
> I would have to build a weatherproof outdoor closet to house the Topaz.



That's tricky because everything after and including the dac should be plugged into either the p12 or the oyaide power strip.  Youll see a few people on the CA/AL thread keep the transformers in a separate room or basement.



Willco said:


> Why do you separate the Server from the other Sources (Dac and Switch)?



Whats the switch?  The dac is connected via ethernet which doesnt have an electeical connection so no leakage is generated and they dont need to be plugged into the same power strip.

You have two dedicated lines correct?  and you also have sub amps... Mind giving me a complete chain?  breaker to transducer


----------



## Willco

Zenvota said:


> I think in the case of the P12, using it after the Topaz and plugging everything electrically connected into the p12 is fine.  The topaz replaces lesser conditioners the p12 looks like it does a bit extra ;]
> 
> The reasoning is just due to the filtering of each outlet of the p12 increases impedance between electrically connected devices(which have leakage currents) and the higher impedance raises noise generated by the leakage currents.
> 
> ...


----------



## Willco

_*Responses in Bold Below*_
_
"You have two dedicated lines correct? and you also have sub amps... Mind giving me a complete chain? breaker to transducer"_

*I have a total 3 Dedicated lines, but only using  2 at present

Current set up:

Line 1:  Topaz > P12 > (Cisco ethernet Switch, Nucleus Server w/ linear ps, Lampizator Dac w/ ethernet streamer) > Oyaide Strip > (Speaker Class D amps).  I  may also try 
Subwoofers into the Oyaide, but for now they are to wall outlets

(Interestingly, with this particular set up the Topaz is not attenuating the EMI noise as much as normal.  Now, about 20% from 250 to 200.  Before it would reduce by 50%)

Line 2:  Power Amp*


"_The reasoning is just due to the filtering of each outlet of the p12 increases impedance between electrically connected devices(which have leakage currents) and the higher impedance raises noise generated by the leakage currents."_

*Just to be clear, are you saying the filtering from the Topaz, in line withe the P12, is increasing the impedance?

"*_I think in the case of the P12, using it after the Topaz and plugging everything electrically connected into the p12 is fine_*."
"*_everything after and including the dac should be plugged into either the p12 or the oyaide power strip"
"The dac is connected via ethernet which doesnt have an electeical connection so no leakage is generated and they dont need to be plugged into the same power strip."
_
*Forgive my Neanderthal understanding of electricity, but I'm trying to understand the above lines.*
*Are you saying that the ideal might be using one of my dedicated lines for "electrically connected" components and one for everything else?*
*And which components are electrically connected (through capacitors)? * *You say not the Dac because it is connected by ethernet, but it is
 connected to Power Amp through interconnects, so...   I obviously am lost here.*

*Given that my Power amp and Topaz create hum, and it's not practical to build an outdoor, climate controlled Topaz Doghouse, what do you think of the  following scenarios?:
*
 1. *Topaz and P12 on Separate Lines*

*      Dedicated Line 1:  Topaz/Oyaide Strip >  Digital Components (Dac, Ethernet Switch, Nucleus Server).* *I think I read somewhere that the Topaz is      suited to attenuating*
*     common mode, high frequency noise from digital devices.  Do I have that right?
*
*Dedicated Line 2:  P12 for Power Amp , Class D sub amps and speaker amps*

*     Is the above ass-backward because it's not the right grouping of components vis a vis electrically connected components?

2.    Topaz and P12 Inline

       Ded Line 1 > Topaz > P12 > (Digital components).   
       Ded Line 2  > Oyaide strip > (all Amps)    

       This would utilize noise attenuation of the Topaz for Digital
       and also reduce the EMI noise from the P12

3.   P12 (Topaz eliminated)

       Ded Line 1 > P12 >  (all digital and all amps).  I would need to use the Oyaide strip as well coming from the P12 as there is not room for all the thick
       cables into the P12.  Might there be any issues from using the Oyaide strip and P12 together like this?   I guess the advantage of this options would 
       be a star ground?    But at the cost of losing the utility of the Topaz.

Thanks for you time and advice.  Hopefully this might be helpful to others 
*


----------



## Zenvota

Willco said:


> Subwoofers into the Oyaide, but for now they are to wall outlets


The subwoofers are electrically connected, so you would want them on the same strip as the adac an amps as well, or use these to isolate them and dont plug them into the dac/amp strip, they come in 1 channel rca 2 channel, xlr, etc. https://www.parts-express.com/jense...MI7cHssLP94AIVjIbACh0xfQApEAQYBCABEgIQz_D_BwE



Willco said:


> Speaker Class D amps
> Line 2: Power Amp


What's the power amp driving?



Willco said:


> Just to be clear, are you saying the filtering from the Topaz, in line withe the P12, is increasing the impedance?


The P12 has individual filtering per outlet, that's what increases impedance, however, the p12s information says low output impedance.



Willco said:


> Are you saying that the ideal might be using one of my dedicated lines for "electrically connected" components and one for everything else?
> And which components are electrically connected (through capacitors)? You say not the Dac because it is connected by ethernet, but it is
> connected to Power Amp through interconnects, so... I obviously am lost here.


Yes one line with the topaz for everything electrically connected.  And electrically connected would be via the interconnects, the dac and all the amplifiers.  There's no electrical connection between the server and the dac.



Willco said:


> Dedicated Line 1: Topaz/Oyaide Strip > Digital Components (Dac, Ethernet Switch, Nucleus Server). I think I read somewhere that the Topaz is suited to attenuating
> common mode, high frequency noise from digital devices. Do I have that right?
> 
> Dedicated Line 2: P12 for Power Amp , Class D sub amps and speaker amps
> ...


Close, you want the Topaz, dac, and amps together.  You could even use a second smaller topaz for the server and/or switch.  

The topaz reduces common mode noise by 140db and traverse mode noise by 70db, it affects all components, and is typically reduced well by balanced drive, but not as much as the good isolation transformers.

Digital components generate inductance across their power cables due to the variance in power draw, this is alleviated by quadrapole(star quad) power cabling which has a very low inductance.  

So...

Line 1: second topaz with switch and server

Line 2: topaz>p12> dac and speaker
amps

jensen isomax in front of each subwoofer input


----------



## One and a half

Willco said:


> _*Responses in Bold Below*_
> _
> "You have two dedicated lines correct? and you also have sub amps... Mind giving me a complete chain? breaker to transducer"_
> 
> ...





Willco said:


> "Amp"  refers to my SET Power Amp.  I don't have a preamp, as I use the Vol control on the Lampizator Dac.
> 
> The only problem for me in your scenario above is that the Power Amp (Set tube, 8 watts/channel) increases the Topaz hum too much when connected direct to the Topaz/Oyaide strip.
> I would have to build a weatherproof  outdoor closet  to house the Topaz.
> ...


Interested- why have you decided to float the output of the Topaz. Unless you build in earth fault or differential protection, the best is either ground the centre tap or the X4 on the output. There’s then a reference setup and in the case of the tube amp the reactive noise should reduce, provided the Topaz is large enough, safe bet 2x the watts of the set plus all the other watts / 0.6 in VA.

The Topaz is best installed on the output of the p12 and the Oyaide use to plug in everything else after the Topaz.


----------



## Willco

I'm glad you asked about the grounding, because I see now it is grounded.   It's the p12 which is ungrounded.  When I checked the Topaz it was down current from the P12, and I mistakenly assumed it was the Topaz, not the P12 with the floating ground.  

I don't recall seeing anywhere that the PsAudio Power Plants were designed to have floating grounds.   I'll ask them about that.  Does this make sense that the Power Plants would have floating grounds?

So, unfortunately, grounding the Topaz (which is in fact grounded) won't be a strategy for reducing the hum brought on by the amp.   The Topaz is 2.4 KVA so it should have plenty of power, so it must be a specific interaction with the tube amp (and a previous tube amp brought on the same hum).   So I don't know if there's any solution to the hum other that banishing it  to an exterior climate controlled Topaz Doghouse.  I'm also concerned it will overheat the Topaz as it runs pretty hot with just just sources connected...

_      "The Topaz is best installed on the output of the p12 and the Oyaide use to plug in everything else after the Topaz."_

That's what I've been doing before my recent experimentations, but with the Power Amp either connected to the P12 or direct from a dedicated line.
I don't have any idea which of those options is theoretically better...

I thought I might remove the Topaz and  try the P12 with everything, sources and amps connected through a combinations of the P12 outlets and Oyaide strip.

Trail and error...


----------



## Willco

Zenvota said:


> The subwoofers are electrically connected, so you would want them on the same strip as the adac an amps as well, or use these to isolate them and dont plug them into the dac/amp strip, they come in 1 channel rca 2 channel, xlr, etc. https://www.parts-express.com/jense...MI7cHssLP94AIVjIbACh0xfQApEAQYBCABEgIQz_D_BwE
> 
> 
> What's the power amp driving?
> ...





* In the above plan, would you run the Power Amp from the 3rd dedicated line?    Thanks*


----------



## Willco

One and a half said:


> Interested- why have you decided to float the output of the Topaz. Unless you build in earth fault or differential protection, the best is either ground the centre tap or the X4 on the output. There’s then a reference setup and in the case of the tube amp the reactive noise should reduce, provided the Topaz is large enough, safe bet 2x the watts of the set plus all the other watts / 0.6 in VA.
> 
> The Topaz is best installed on the output of the p12 and the Oyaide use to plug in everything else after the Topaz.



*I did confirm that the P12 has a floating ground.  So if the Topaz is down current, it is ungrounded as well.   How would the plan change in this case?   Thanks*


----------



## Zenvota

One and a half said:


> nterested- why have you decided to float the output of the Topaz. Unless you build in earth fault or differential protection, the best is either ground the centre tap or the X4 on the output


This was just being discussed in the  CA thread wasnt it?  I thought I remembered John and Alex saying not to ground the neutral output. I also have a prewired 91092-12 that was new, and that doesnt have the neutral output connected to ground either which is why I wired my 91092-31 like this

 
But that other discussion and here youre saying x4 and ground should be jumpered as well?


----------



## Willco

I my case, does running the Topaz in line after the  ps Audio P12 Regenerator (which is not grounded) if effect make the Topaz ungrounded?


----------



## Zenvota

Willco said:


> * In the above plan, would you run the Power Amp from the 3rd dedicated line?    Thanks*


Nope everything connected to the dac via interconnects should be on the topaz.



Willco said:


> I my case, does running the Topaz in line after the  ps Audio P12 Regenerator (which is not grounded) if effect make the Topaz ungrounded?


yes


----------



## One and a half

Zenvota said:


> This was just being discussed in the  CA thread wasnt it?  I thought I remembered John and Alex saying not to ground the neutral output. I also have a prewired 91092-12 that was new, and that doesnt have the neutral output connected to ground either which is why I wired my 91092-31 like this
> 
> But that other discussion and here youre saying x4 and ground should be jumpered as well?


Well, here’s the gist of things.
There are rules and regulations for the NEC, AS which need to be followed. The point of an isolation transformer is mainly for use on grounded scopes measuring floating voltages under test purposes so the scope doesn’t blow up.
For general appliances and this includes everything else like audio equipment, there are no exemptions when connected through an isolation transformer, the output secondary must be grounded at either the centre point or one end, classically the X4 terminal.

The reason also is that EMC filters need to find a way back to the source, plus grounding the output severely knocks common mode noise. More, if the impedance between the neutral on X4 and ground is close to zero, which a short bridge will do avoids the neutral to ground voltages from rising and that has an impact on computing gear, digital equipment and so on.

I rather  pay attention  to regulations and engineering practice which work and are safe.


----------



## Zenvota

One and a half said:


> the output secondary must be grounded at either the centre point or one end, classically the X4 terminal


Thank you for the explanation, so based off these posts https://audiophilestyle.com/forums/...sformers/page/12/?tab=comments#comment-599055 and your suggestions, if grounding the secondary neutral, its best to use a gfci on the outlet as well, correct?


----------



## Willco

"......everything connected to the dac via interconnects should be on the topaz."


*Interestingly, I tried the Power Amp  into the Topaz/Oyaide strip, again.   This time, only a slight increase in the transformer hum.

Dedicated Line  >  P12 regenerator (ethernet Switch and Server) > Topaz/Strip  (Dac, Power Amp, class d Speaker amps).

Right now, the P12 is at 36% capacity.
Only the subs are still into the wall, and I may try them into the strip as well.  

And, also very curious, the Topaz is running much cooler now-- it used to be fairly hot to the touch.  And this is the same set up I've
used before, just not with Power Amp connected to the Topaz.
*


----------



## Zenvota

Willco said:


> "......everything connected to the dac via interconnects should be on the topaz."
> 
> 
> *Interestingly, I tried the Power Amp  into the Topaz/Oyaide strip, again.   This time, only a slight increase in the transformer hum.
> ...



That sounds great!  I'm fairly certain you can use those Jensen IsoMax transformers to isolate the subwoofer amps from the rest of the chain and leave them plugged in where they are, that type of isolation does block leakage currents.  Hopefully someone will correct me if I'm wrong, I use them to isolate my bass shaker system from my dac and headamp via an XLR split.  That's only for gaming though for the low latency, for music and movies I use voicemeter to split the signal to a different dac for the shakers and use the ACSS connection between my dac and headamp.


----------



## One and a half

Zenvota said:


> Thank you for the explanation, so based off these posts https://audiophilestyle.com/forums/...sformers/page/12/?tab=comments#comment-599055 and your suggestions, if grounding the secondary neutral, its best to use a gfci on the outlet as well, correct?



In the case X4 is bonded to ground, a GFCI on the feeder side can pick up the fault.


----------



## Willco

Zenvota said:


> That sounds great!  I'm fairly certain you can use those Jensen IsoMax transformers to isolate the subwoofer amps from the rest of the chain and leave them plugged in where they are, that type of isolation does block leakage currents.  Hopefully someone will correct me if I'm wrong, I use them to isolate my bass shaker system from my dac and headamp via an XLR split.  That's only for gaming though for the low latency, for music and movies I use voicemeter to split the signal to a different dac for the shakers and use the ACSS connection between my dac and headamp.



The weird thing is, now that the Topaz tolerates the power amp without a big increase in hum, there is *now much more measured noise coming out of the Topaz.*  For instance:  (as measured with Alpha Labs EMI meter:    Wall: 250 mV > P12:   500 mV  >  Topaz :  700 mV.   Until I measured just now, the Topaz has always been around 90 - 120 mV.  The only variable could be the power amp being connected, instead of running out of the wall or P12.


----------



## bequietjk

I recently bought the 91095-32 'MGE' branded iso transformer off of eBay and am very excited to see how this does added into my system.  Looking for better noise floor of course.

Is there anything I should look out for, re-wire or diagnose before connecting it to my APC voltage regulator and then connecting my dac and amp?  I'm not very knowledgeable in the electronics field save a few soldering jobs making power cables.  

My main concern is from this video 
Where the gentleman goes to say that the unit may be wired improperly for normal use.  I just don't want to blow anything up any equipment including myself trying to reach the pinnacle of audio. 

Any tips?

Thanks!


----------



## Zenvota

bequietjk said:


> I recently bought the 91095-32 'MGE' branded iso transformer off of eBay and am very excited to see how this does added into my system.  Looking for better noise floor of course.
> 
> Is there anything I should look out for, re-wire or diagnose before connecting it to my APC voltage regulator and then connecting my dac and amp?  I'm not very knowledgeable in the electronics field save a few soldering jobs making power cables.
> 
> ...




If you cant take it to an electrician to be tested, take some pictures of the wiring and post em here or on the other forum.  Very simple to open em up just 4 screws on each panel.


----------



## bequietjk

Absolutely I'll do that.  Expecting it sometime this week


----------



## Zenvota

bequietjk said:


> Absolutely I'll do that.  Expecting it sometime this week



Probably go ahead and get a new fuse.  You can use whatever the panel says, I think it might be 10a on the 500va model, but maybe go with 5a instead.  I use the 250va models and it was recommended to use 2a fuses.  

The bussman type mda slow blow(time delay) 6mmx30mm ceramic fuses like this:

Pack of 5 MDA 5A (BK/MDA 5A) 125V/250v Slow Blow Ceramic Fuses, T5A 5 amp, 6x30mm (1/4 inch x 1-1/4 inch) https://www.amazon.com/dp/B009WKGIBY/ref=cm_sw_r_cp_apa_i_KHJ4CbE07BWSS


----------



## Zenvota

Mind adding the rest of your equipment as well?  Nice to see the full chain, i.e. having a straight usb connection(no isolation) to a pc but only have the dac/amp on the ultra isolator isnt great.


----------



## bequietjk

So my chain will go like this...  

APC volt regulator > 91095-32 isolation transformer > Blue Circle PLC Puck (2x recepticles) > Project Horizon amplifier on receptacle 1 and PB4X4pro power distributor on receptacle 2

Connected to the PB4x4:
Receptacle 1 = ifi ipurifier 
Receptacle 2 = LPS to power Khadas Tone Board DAC
Receptacle 3 = LPS to power Paul Pang V2 usb card

Project Horizon amp is being powered by an LPS and I'm not sure where the best place to connect it is.  I keep reading that it's best to connect it on a separate outlet or at least on it's own, from the dac and other equipment.

I'm also trying to figure out if I might benefit more connecting my PC to one of the receptacles of the Topaz...  But these PCs generate so much noise of their own I don't want it to affect my audio equipment.

All of this is subject to change of course in my grand adventure of audio


----------



## Zenvota

bequietjk said:


> So my chain will go like this...
> 
> APC volt regulator > 91095-32 isolation transformer > Blue Circle PLC Puck (2x recepticles) > Project Horizon amplifier on receptacle 1 and PB4X4pro power distributor on receptacle 2
> 
> ...



You want _everything_ electrically connected to be on the topaz.  If the pc has a large smps then you might want to consider some kind of data transport with isolation.  The paul pang usb card is externally powered but does it have galvanic isolation? if not then youd want the pc on the topaz as well.  The horizon should also be on the topaz.


----------



## bequietjk

The item arrived today (in TERRIBLE shipping condition).  The bottom bolt was not even in, it was sitting in the shipping box.  The only packing in the box was a half full amount of that popcorn packing which is very poor material for how much the item weighs.  All 4 bolts holding the middle transformer connecting it to the outer off white cases ends are broken.  Gosh, such luck.  This is the first time ive had a bad egg for shipping condition.  Guess it had to happen sometime aye?

Here's a picture of the power cord and.  Need pics of the receptacle end?


----------



## bequietjk (May 22, 2019)

Receptacle side


----------



## bequietjk

Should the fuse port look like this?


----------



## Zenvota

That looks like a take it to an electrician situation.  

Also, the PC you're using, what kind of specs does it have? cpu, gpu, psu


----------



## bequietjk

I7 5820k
Gtx 1080ti
750w seasonic gold rated

I plugged the iso to the wall and theres no audible hum.


----------



## bequietjk

Sorry for all this late info.  I should compile this all into one post haha. 

Better picture of the receptacle


----------



## Zenvota

bequietjk said:


> I7 5820k
> Gtx 1080ti
> 750w seasonic gold rated
> 
> I plugged the iso to the wall and theres no audible hum.



Thats too much pc for that transformer, you would want high speed usb galvanic isolation or optical before the dac.



bequietjk said:


> Sorry for all this late info.  I should compile this all into one post haha.
> 
> Better picture of the receptacle



Heh for the pictures just very clear photos of the wiring connections


----------



## bequietjk

I was planning to pickup an iso regen for GI!  From my paul pang v2 usb card, to the iso regen to the dac.

In this current wiring state would it be feasable to at least connect my headphone amp, before seeking an electrician?  Certainly unadvisable, but what's the worst that could happen side blowng my amp up o_o


----------



## Zenvota

bequietjk said:


> I was planning to pickup an iso regen for GI!  From my paul pang v2 usb card, to the iso regen to the dac.
> 
> In this current wiring state would it be feasable to at least connect my headphone amp, before seeking an electrician?  Certainly unadvisable, but what's the worst that could happen side blowng my amp up o_o



The negative effect of only having the headphone amplifier on the isolation transformer would be very high noise generated by leakage currents.  

if the transformer is improperly wired, anythings possible...  The ground wiring on that unit is diffrent then other units, with the ground wire attached to the outside chassis instead if the inside.


----------



## bequietjk

Good morniing all 

Upon reading back on the first page it was recommended to use a single receptacle for all components and to keep cord length and outlet spacing to very minimal for low impedence and leakage currents. 

Does leakage currents basically represent the current flow across the electrical circuitry that goes beyond what is usable and what is actually needed for your components?  Basically, leakage currents = wasted current/extra unncessary noise?  I'm now thinking of a better way to setup my rig.  NOT using my Art4x4pro power distributor and plugging my LPS that powers my dac straight into the PLC Puck, along with my headphone amp plugged into the second receptable of the Puck.

Wall outlet > APC volt regulator > ISO > (Using only 1 receptacle on ISO) Blue Circle PLC Puck (x2 receptacles) > Puck Receptacle#1: DAC / Receptacle#2: Headphone amp

Since it was stated that it's best not to have power conditioners (although the PLC Puck being one) the art4x4pro has an LED on/off switch, 6ft' power cable and surge protection.  Basically it checks all of the marks on that list.  I'm going to try this setup when I get home and test for SQ.

My other concern is the LPS that powers the Paul Pang v2 usb card...  Now because this LPS connects to the usb card connected to the computer which will all know harbors tons of noise due to the SMPS, would it be best to keep this LPS on an entirely different circuit?  If I were to keep this LPS connected to the ISO would the noise generated from the PC not transfer back to the ISO and into the headphone/dac?

Just for reference my PC is connected to another wall outlet in my room like so:

Wall outlet > APC UPS > x6 receptacle power conditioner > Both of my monitors (powered by smps wall warts), PC, and audio interface (Behringer UMC404HD) are connected to this power conditioner, along with the LPS that powers the PPA V2

Btw as a note I wanted to mention that the detail extraction and noise floor was lowered to a level I'm still trying to comprehend.  The decay as mentioned and extension of micro details is much more present and noticeable.  Now it's just a matter of keeping things connected where they can yield optimal performance.  

Anthony


----------



## Zenvota

bequietjk said:


> Does leakage currents basically represent the current flow across the electrical circuitry that goes beyond what is usable and what is actually needed for your components? Basically, leakage currents = wasted current/extra unncessary noise?


Not quite, they're current loops that form between electrically connected devices. 

See post 25 here
https://audiophilestyle.com/forums/...-of-ac-mains-isolation-transformers/#comments



bequietjk said:


> I'm now thinking of a better way to setup my rig. NOT using my Art4x4pro power distributor and plugging my LPS that powers my dac straight into the PLC Puck, along with my headphone amp plugged into the second receptable of the Puck.
> 
> Wall outlet > APC volt regulator > ISO > (Using only 1 receptacle on ISO) Blue Circle PLC Puck (x2 receptacles) > Puck Receptacle#1: DAC / Receptacle#2: Headphone amp
> 
> Since it was stated that it's best not to have power conditioners (although the PLC Puck being one) the art4x4pro has an LED on/off switch, 6ft' power cable and surge protection. Basically it checks all of the marks on that list. I'm going to try this setup when I get home and test for SQ.


Im not sure what the puck does or if it would be beneficial after the topaz, you want filterless power distribution after the topaz, the simplest being a tripp lite power strip with no movs or anything just wire connecting the receptacles.



bequietjk said:


> My other concern is the LPS that powers the Paul Pang v2 usb card... Now because this LPS connects to the usb card connected to the computer which will all know harbors tons of noise due to the SMPS, would it be best to keep this LPS on an entirely different circuit? If I were to keep this LPS connected to the ISO would the noise generated from the PC not transfer back to the ISO and into the headphone/dac?


The power supply for the usb card should not be on the topaz.  a normal power supply for the iso regen should be on the topaz, however, if using an uptone ultracap, the charging supply should not be on the topaz.


----------



## bequietjk

@Zenvota The blue circle plc puck is a power line filter.  The double outlet plugs into a single receptacle. 










I think ill remove the puck and place it to connect my PC, see how it sounds.


----------



## MasterSplinter

Hello everyone. I just bought and received an Ultra Isolator myself. Am I wrong or is it already wired for balanced power? It looks odd in both the configuration and using both brown and red wiring jackets which from what I know usually are both used for hot wires? I'm not really educated enough in this matter to know what's going on here and there's not really a detailed wiring configuration like one sees on other models, only a single picture on the side that I've included.

I purchased this one as it was essentially brand new (unused), and it had an actual inlet that one could use with a power cable of one's choosing (which I thought would be easier than the usual user wired models) but instead of it being a 20 amp iec or even a 5-20p inlet plug it's a 6-20r inlet plug, so that has to be replaced with either an iec inlet or hard wiring a nice power cable into it (the outlet will be replaced with a better one as well). There is an included power cable with hospital grade plugs, and I could just swap the female plug end onto a nice power cable (if the hot and neutral wires are reversed on 6-20r plugs compared to standard 20 amp plugs since the horizontal and vertical pins are reversed though that would be something I need to know ahead of time, again I'm not educated enough on that matter), but I think I may want nicer wiring inside the unit anyway and I want to replace the outlets on the unit as well, so why not just go the whole way. I'm just intrigued by the wiring configuration.

I apologize for the last picture being blurry. Any help is greatly appreciated, thank you.


----------



## bequietjk

Bump for MasterSplinter's concern.

Out of curiosity, does anyone have experience 'upgrading' the receptacles of these topaz transformers with something like an Oyaide, Synergistic Research or Furutech?  Any audible benefits?  I'm not able to change receptacles in my current room so it has me thinking that perhaps swapping the topaz receptacle would yield some audio bliss!  Plus it will add some extra flare and color to it.  Mine is in plain sight so it would be nice to look at as well.


----------



## oneguy

@MasterSplinter 
I’m not sure of the wiring for your units since it’s typical for the -31 and and -32 that I’ve seen.

@bequietjk 
Let us know what you find. I was going to swap the receptacles on my aluminum enclosure unit with some rhodium ones but the deal fell through so now I only have 2 of the 8 I was planning on having. Those two are now in the walls instead.


----------



## bequietjk

@oneguy I'll have to crack open the panel to see how difficult it will be replacing the receptacle.  I've never done something like this and A) do not want to fry myself and B) fry the unit.  But I'm looking towards either the Maestro or the Oyaide R1 receptacle!


----------



## oneguy

Replacing the receptacles is straight forward so you shouldn’t have any problems. You can and should check for grounding to the case on the hot and neutral of the primary and secondary before plugging it in just to make sure you won’t get electrocuted.


----------



## Zenvota

oneguy said:


> You can and should check for grounding to the case on the hot and neutral of the primary and secondary before plugging it in just to make sure you won’t get electrocuted.


Could you elaborate on this?

When I tested my transformers with a floating neutral secondary(the way the prewired, -12 -22 -32,  units are stock), I measured ~120 from hot to neutral, but hot or neutral to ground read nothing.  I measured 120 from either hot/neutral to ground at the wall outlet, and confirmed continuity of the ground from the wall to the transformers output.


----------



## oneguy (Jun 1, 2019)

Zenvota said:


> Could you elaborate on this?
> 
> When I tested my transformers with a floating neutral secondary(the way the prewired, -12 -22 -32,  units are stock), I measured ~120 from hot to neutral, but hot or neutral to ground read nothing.  I measured 120 from either hot/neutral to ground at the wall outlet, and confirmed continuity of the ground from the wall to the transformers output.



I test mine by measuring resistance from the case to primary-hot, primary-neutral, secondary-hot and secondary-neutral. All of these should read as on open circuit. If their open circuits no voltage is flowing between the two and no risk of shock.

ADD: Case to ground should read as a closed circuit to shunt any current flow in the event you do get a short from one of the wires.


----------



## Zenvota

oneguy said:


> I test mine by measuring resistance from the case to primary-hot, primary-neutral, secondary-hot and secondary-neutral. All of these should read as on open circuit. If their open circuits no voltage is flowing between the two and no risk of shock.
> 
> ADD: Case to ground should read as a closed circuit to shunt any current flow in the event you do get a short from one of the wires.



Do you have secondary neutral grounded?


----------



## oneguy (Jun 1, 2019)

Zenvota said:


> Do you have secondary neutral grounded?



I don’t. My three larger transformers are -32’s so they aren’t wired that way and my 2 smaller ones are -31 but only 125va so I haven’t had a use for the them yet.


----------



## Zenvota (Jun 1, 2019)

oneguy said:


> I don’t. My three larger transformers are -32’s so they aren’t wired that way and my 2 smaller ones are -31 but only 125va so I haven’t had a use for the them yet.



Hmm, so if I measure resistance(the ohm symbol at 2m) and put the probes together I get .000, ground to case(the center unpainted iron part?) I get .000, but the secondary hot or neutral to case or ground I get no reading.


----------



## MasterSplinter (Jun 1, 2019)

It seems my unit doesn't even turn on with a 250 volt 6-20r to 120 volt 5-20p adapter cable (cost nearly $50 to find that out  ). I thought these were nearly all step up step down 120/240 in and out units (all the ones I've seen have been specified as such and this unit is brand new unused), so I expected this to work, but maybe it has to be one voltage all the way from input receptacle to compatible cable? I could try just wiring in a standard iec, but I'm wary of spending more, so I'd have to test it with a cheaper one and the wiring to match (lugs only on one end). I may try just stripping a disposable power cable and hard wiring it in to see if that works.

I actually accidentally purchased this unit as I thought the input inlet plug was a 5-20 one, but got the pins mixed up (it's not something I'm used to looking at, so I didn't expect the reverse to exist). So I'm trying to see if this now nearly $350 mistake can actually work out for me.

I did find out the wiring uses a floating neutral, which I had no experience with (just putting standard 15 or 20 amp plugs on power cables and putting in some wall outlets). There's just no information out there at all on this unit and it'd figure if I grabbed the only one that isn't both 120 and 240 volt compatible.


----------



## Zenvota

MasterSplinter said:


> I thought these were nearly all step up step down 120/240 in and out units (all the ones I've seen have been specified as such and this unit is brand new unused


The hardwired ones will specifically say 120/240 on both the input and output and have a plate with thr wiring diagram:


Spoiler: hardwired



 



The prewired ones are often one voltage in and one out


Spoiler: prewired


----------



## bequietjk

That would mean my 91095-32 MGE is prewired.


----------



## MasterSplinter (Jun 1, 2019)

There's unfortunately not a single label on this unit (inside or out) that gives the voltage information, or any useful technical info at all save for the labels I already posted (that very basic version of the wiring diagram, and the unit's model number). I'm going to have to use a multimeter to test this, so I just ordered a new one (old one is lost).

I only know the weight coincides with 1.8 kva models (which mainly seem to be 120v for the prewired versions and 120/240v for hardwired, but that's for the 31 and 32 lines and a few others I've seen on eBay with the 11 line but this is a 50 line unit and I've never seen another in the 50 line), and that trying to find information on the unit is quite difficult as Topaz is no longer and MGE sends you to another company in Eaton who is of no help.


----------



## oneguy

Zenvota said:


> Hmm, so if I measure resistance(the ohm symbol at 2m) and put the probes together I get .000, ground to case(the center unpainted iron part?) I get .000, but the secondary hot or neutral to case or ground I get no reading.



I get all the same results when I measure mine.


----------



## Zenvota

oneguy said:


> I get all the same results when I measure mine.



oh ok good XD

I've been thinking about putting my AV receiver(with a second smaller 2channel amp for 2 height channels and 1 subwoofer) and projector on ultra isolators as well.  I just picked up a 91001-42(for the avr) and 91095-32(for the projector).  Finally getting better cables(hdmi fiber hybrids) and the ultra isolator should make a big difference in the projectors image, I'm not sure what to expect from the AVR though as it's already got a giant smps and alot of processing going on, hopefully it'll do what you expect it to and clean up the sound a bit.  

I'm not sure if I should put the computer on the isolator as well, that probably pulls a good 200-300w when loaded.  The AVR probably 150-250 on the more intense action scenes, I'd be surprised if the amp for the 2 height channels pulled more than 50, and the subwoofer could probably spike to 100-200, but it's a small room and I usually listen at about 15-20db below reference.

These things are pretty heavily shielded, but has anyone measured em fields from around the transformer? I sit fairly close to them.


----------



## MasterSplinter

Well, I have some good news. I decided just to try to hard wire a disposable 12 gauge cable into the unit and it works. Tested it with a few simple things like old Radioshack power strips first and then tried my Transparent Reference Isolator in it and then something else plugged into the Transparent and it all works. I still don't know anything else about the unit, but thankfully it's not incompatible with 120 volt systems. Still going to wait on the multimeter before trying anything else. Hopefully I can sell the adapter on eBay (it has really nice Pass and Seymour hospital grade connectors too).


----------



## Zenvota

MasterSplinter said:


> Well, I have some good news. I decided just to try to hard wire a disposable 12 gauge cable into the unit and it works. Tested it with a few simple things like old Radioshack power strips first and then tried my Transparent Reference Isolator in it and then something else plugged into the Transparent and it all works. I still don't know anything else about the unit, but thankfully it's not incompatible with 120 volt systems. Still going to wait on the multimeter before trying anything else. Hopefully I can sell the adapter on eBay (it has really nice Pass and Seymour hospital grade connectors too).



So you need 120v? it could be a 120in 120out unit.  Looking at it I don't think it was wired as balanced, from left to right is hot, neutral, shield, with neutral and shield jumpered, and then the ground on the chassis.


----------



## oneguy

Zenvota said:


> oh ok good XD
> 
> I've been thinking about putting my AV receiver(with a second smaller 2channel amp for 2 height channels and 1 subwoofer) and projector on ultra isolators as well.  I just picked up a 91001-42(for the avr) and 91095-32(for the projector).  Finally getting better cables(hdmi fiber hybrids) and the ultra isolator should make a big difference in the projectors image, I'm not sure what to expect from the AVR though as it's already got a giant smps and alot of processing going on, hopefully it'll do what you expect it to and clean up the sound a bit.
> 
> ...



I don’t recall the exact quote but I believe John Swenson said electronics no closer than a few feet away would be fine. Assuming electronics are more sensitive than people, then as long as you aren’t sitting on it then you should be fine. That’s my theory at least. Mine are hidden behind my record shelf to help mask the transformer buzz. That puts them about 8 ft away from my listening position.


----------



## Zenvota

ok lemme try n phrase this a lil better, asked on ca/as too but just in case some people don't go there I'll post here too.

Im planning on adding Topaz ultra isolators to my AVR and projector, and as well breaking leakage loops between the htpc, avr, and projector

Current setup:
Outlet 1:
HTPC
AVR
Subwoofer 1
2 channel amplifier for 2 height channels

Outlet 2:
Projector
Subwoofer 2

The AVR, subwoofer 1, and 2ch amplifier on a 91001-42 topaz ultra isolator.

The projector on a 91095-32. Perhaps use a Jensen isomax isolator for subwoofer 2.


-Trying to figure out what exactly to try for hdmi.  I can't find a full fiber cable, they're all hybrids, fiber for the data and copper for 5v ground edid etc. 

So I was considering the hdmi to ethernet convertors.  They mention power over cable(POC) to power the receiver, although I believe it can be powered by its own supply as well.  Not sure if that will still have a leakage loop?
https://www.monoprice.com/product?p...MI2ayg-Pa54gIVFo_ICh1dcgd2EAQYASABEgK97fD_BwE

For ethernet the shield needs to be unconnected to break the leakage loop.  Not aure if I'd have to make your own cable or if theres one i can buy.

I would also power the receiver and transmitter with an hdmi connection to the AVR with a linear power supply and connected to the same topaz as the avr.

-Anyone have any suggestions for breaking leakage loops over hdmi?


----------



## zilch0md (Jun 7, 2019)

Here are some EMF measurements, but the opinions as to what levels create a health hazard are as varied as our tastes in music, so I will leave that to each reader to research on his own.

I will offer my opinion that this 500vA Topaz and the APC voltage regulator are "safe" even at 18 inches, at least when supplying power to my Oppo Sonica DAC and Metrum Acoustics Aurix (headphone amp).

Really, my headphones are a much greater cause for concern, thanks to their EMF emissions and close proximity to the brain.  For those who are or want to be EMF "aware," I recommend the $50 *Meterk MK54* for measuring MF and EF.  With the exception of streaming sources, you don't have to worry about measuring RF from audio gear, but the *EMFields Acousticom 2* is $180.

Please don't ask me to report my headphone measurements. 



   

Mike



Zenvota said:


> These things are pretty heavily shielded, but has anyone measured em fields from around the transformer? I sit fairly close to them.


----------



## Zenvota

zilch0md said:


> Here are some EMF measurements, but the opinions as to what levels create a health hazard are as varied as our tastes in music, so I will leave that to each reader to research on his own.
> 
> I will offer my opinion that this 500vA Topaz and the APC voltage regular are "safe" even at 18 inches, at least when supplying power to my Oppo Sonica DAC and Metrum Acoustics Aurix (headphone amp).
> 
> ...



O awesome dude thank you.

Do you have measurements of anything else for comparison? like an av receiver or something with a large transformer in it but just plugged straight into the wall, or some power cables not plugged into the topaz.


----------



## Zenvota

heres your standard 60w switching supply


----------



## zilch0md (Jun 2, 2019)

I really don't want to start reporting  measurements for anything else, especially since field strength varies greatly with brand, not to mention proximity, but several appliances/devices in our home are far "hotter" at 18 inches than the Topaz transformer and APC regulator (I.e. Cordless phones, microwave ovens, induction stovetop, etc.). The Topaz is way down at the bottom of the list, given that RF emissions are of the greatest concern, then electrical, then magnetic.  The Topaz and APC are putting out effectively nothing but magnetic field energy and according to some of the many published standards is perfectly safe (at sufficient distance and limited duration.)

This topic is very deep and worthy of a thread unto itself, but headphone enthusiasts and manufacturers alike might not want us to dig too deeply.  . There are plenty of dedicated forums out there, already.

See:  https://www.powerwatch.org.uk


----------



## bequietjk

Has anyone had any experience using one of these Topaz' with just their desktop PC connected to it?  I would imagine there are some benefits but I have no idea.  Being that the PSU in these desktops are SMPS.


----------



## Zenvota

bequietjk said:


> Has anyone had any experience using one of these Topaz' with just their desktop PC connected to it?  I would imagine there are some benefits but I have no idea.  Being that the PSU in these desktops are SMPS.



Ive wondered about that as well, at least for the movless surge protection thats a good enough reason.  How noise would effect those circuits I have no idean could result in lower error correction, lower heat, better efficiency, etc.

Pretty sure I've read that reducing common mode noise is of great benefit to switching supplies.

For audio though I've noticed very audible differences with galvanic isolation between the pc and dac, either optical or high speed usb.  Which is why I'm keen on trying it with my AVR, the same negative qualities(sibilance and boomyness/boxyness in vocals) I notice when using my surround system are alleviated when adding an iso regen and topaz to a dac/headamp unit.


----------



## bequietjk

I love the isoregen.  Made a nice clear difference in audio and it seems to have crystalized the audio output in a way that makes everything more transparent.

Very soon I'll be buying an audience ar2p and adding into my system.  Where it will go is the real case.  I'm not sure how it will affect the SQ with the Topaz in the line, but I'm first thinking of adding it to the wall first and then testing it plugged directly into the Topaz.  Should be fun


----------



## MasterSplinter

Looks like I spoke a bit too soon as only certain things seem to work with the isolator. 
Plugs into the wall fine, draws power from it. Power strips and the Transparent Isolator work fine with it. Even plugged a Nintendo Switch dock into it (though that works with a wide range of voltages), a home phone, all fine (only one with the voltage requirements listed on it though. Other things not so much, plugged in my XBR 960 crt and it was rapidly shutting on and off, tested it with the cable box and that doesn't even turn on, tried it with my main system, no power, so the multimeter will tell me what is up.


----------



## bequietjk

Omg is that a XBR CRT TV!?  I bet N64 would be AMAZING on that thing!


----------



## bequietjk (Jun 3, 2019)

So I had to come back to report that I've had much success having just my project horizon tube amplifier connected to the ISO > connected to one socket of the wall outlet.  And the other outlet I have my blue circle puck filter attached to it via 6" uninex grounded ext. cable with my ART PB 4x4 PRO power distributor connected to one socket of the Puck and a iPurifier connected to the top receptacle of the Puck.  My Khadas DAC is connected to the first port on the ART PB.

If I connected both lines to the 2 receptacles of the ISO there seems to be better instrument seperation, but great loss in dynamics.  I prefer the other way.

Now I'm wondering if I should get another Topaz just for my DAC line or get the ar2p for the DAC line.


----------



## MasterSplinter

Tested my isolator with the multimeter, going in it's getting 117 volts. The output though is only 65/66 volts, which is the problem. I'm assuming this is due to the isolator needing a full 240 volts to run properly.


----------



## Zenvota

MasterSplinter said:


> Tested my isolator with the multimeter, going in it's getting 117 volts. The output though is only 65/66 volts, which is the problem. I'm assuming this is due to the isolator needing a full 240 volts to run properly.



Can you get a clearer picture of the outputs wiring?


----------



## MasterSplinter

I'll snap better pictures later today. 

I also have a Liebert pure sine wave output regenerator coming today, I think it has voltage regulation, but I'm not positive. If it does, maybe I can get this to work.
If the isolator is 240 volts strict it's going to be a pain to re-sell.


----------



## oneguy

MasterSplinter said:


> Tested my isolator with the multimeter, going in it's getting 117 volts. The output though is only 65/66 volts, which is the problem. I'm assuming this is due to the isolator needing a full 240 volts to run properly.


Makes sense. 2:1 step down from 117v is 58.5 so 65-66 volts sounds like it supports that theory. My 1:1 transformer outputs a voltage slightly higher than 1:1.


----------



## bequietjk

Today I happened to listen to a video by Paul from PS Audio concerning isolation transformers and one bit of information stuck out.  That high impedence is created from the use of transformers especially when added to the line.  There is a specific video, I don't want to post the link here but can somebody with more technical knowledge follow up on this?  If this is the case what exactly does high impedence do to the sound?  How does it affect our audio and is this the case with our Topaz units?

I'm wondering if this is a negative impact on both DAC and amplifier?  In what case is high impedence either good or bad?


----------



## bequietjk

Can anyone tell me if this is the fuse or is it a part of it?  When my topaz was sjipped to me the circular black plastic piece was broken off, this being there.


----------



## Zenvota

bequietjk said:


> Can anyone tell me if this is the fuse or is it a part of it?  When my topaz was sjipped to me the circular black plastic piece was broken off, this being there.



That's part of the locking cap, you push in and twist and it pops off, then you slide the fuse in.  The actual fuse looks like this, ceramic slow blow 6x30mm


----------



## bequietjk

@Zenvota Lifesaver!  I was trying to figure out by pullit it a bit...  Bad idea.  There is definitely a fuse in there.  

I wonder if there are audiophile fuses? xD


----------



## Zenvota

bequietjk said:


> I wonder if there are audiophile fuses? xD


zero knowledge of audiophile fuses here I just used whatever, but its in the input side, and I couldn't tell a difference with cabling on the input side, regular 14/3, 10/3 cryo, 12/2 twisted cryo with counter spiraled ground(vh flavor 2), and 12/4 quadrapole(vh audio flavor 4).

I did drop the amperage down to 2a for a 250va model, 5a for a 500va model, per John Swensons and One and a Halfs instructions


----------



## Zenvota

bequietjk said:


> There is definitely a fuse in there.



you can probably find a fuse cap on ebay, i wouldnt leave that exposed.


----------



## bequietjk

Slap some JB weld over it?  Hah! jk.  

This looks pretty good
https://www.ebay.com/itm/NOS-Vintag...=11333625815094fa62f5c508408fbad9097087378697


----------



## bequietjk

So of course this will differ from user to user, but I bought a kill-a-watt to find out the wattage that my PC was using.  Since I run a 1080Ti I was worried that wattage usage would be over what my 91095-32 can give out.  Luckily it only peaked just under 400W so I decided to take my DAC off the ISO and put my PC and Iso Regen on it and while the difference is hard to describe being that my DAC kind of took a hit on sharing the outlet with my tube amp, there was another clarity and dynamic boost with my PC and IR on the topaz.  Now I'm VERY curious to see how Topaz'ing my PC along with a Topaz'd DAC line would sound...  Just need to keep my eyes out for a good deal!


----------



## zilch0md

This is what I used when I "restored" the Topaz seen in the first post of this thread:

Fuse Holder:              https://www.amazon.com/gp/product/B00EUF6JDS

20A 250V Fuses:       https://www.amazon.com/Divine-Lighting-Slow-Blow-Ceramic-MDA20A/dp/B004I36FJA

Or if you prefer:
15A 250V Fuses:       https://www.amazon.com/Qty-Slow-Blow-Ceramic-MDA15A-MDA15/dp/B004I32K2Q


----------



## Zenvota

bequietjk said:


> So of course this will differ from user to user, but I bought a kill-a-watt to find out the wattage that my PC was using.  Since I run a 1080Ti I was worried that wattage usage would be over what my 91095-32 can give out.  Luckily it only peaked just under 400W so I decided to take my DAC off the ISO and put my PC and Iso Regen on it and while the difference is hard to describe being that my DAC kind of took a hit on sharing the outlet with my tube amp, there was another clarity and dynamic boost with my PC and IR on the topaz.  Now I'm VERY curious to see how Topaz'ing my PC along with a Topaz'd DAC line would sound...  Just need to keep my eyes out for a good deal!



For sizing transformers theres a general rule that you take your max load and divide by .6.  So if your max load is 1000w you would want to use the 1800va transformers.  

Interesting though with the pc on the transformer.  2 questions(sry if youve said previously):
1 whats powering the iso regen?
2 is the iso regens isolation set to 1(isolation on) or on(isolation off)?


----------



## Zenvota

zilch0md said:


> This is what I used when I "restored" the Topaz seen in the first post of this thread:
> 
> Fuse Holder:              https://www.amazon.com/gp/product/B00EUF6JDS
> 
> ...



I believe the smaller transformers(500va and under) need smaller fuses, they can catch fire if they're hit with 15 amps.


----------



## zilch0md

Zenvota said:


> I believe the smaller transformers(500va and under) need smaller fuses, they can catch fire if they're hit with 15 amps.



That's good advice.  Really, you could bring the fuse rating down to nominatlly exceed your peak current demands - even if that's well below the transformer's rating.


----------



## bequietjk

Indeed @Zenvota  , the plate has the rating described for Bussman 250V MDA 5a.  

@zilch0md Im definitely SHOULD replace the fuse holder.


----------



## bequietjk

@Zenvota At the moment the IR is being powered form a teradak dc-30w LPS.  But my PPA V2 usb card is also being powered by that same LPS via split y adapter cable.  On the way I have another teradak so I can seperate the IR from the PPA.

VERY excited to hear the SQ benefit.


----------



## Zenvota

bequietjk said:


> @Zenvota At the moment the IR is being powered form a teradak dc-30w LPS.  But my PPA V2 usb card is also being powered by that same LPS via split y adapter cable.  On the way I have another teradak so I can seperate the IR from the PPA.
> 
> VERY excited to hear the SQ benefit.


oo hmm and the iso regens isolation is on?


----------



## bequietjk

It's in the 1 position.  Is that on?


----------



## Zenvota

bequietjk said:


> It's in the 1 position.  Is that on?


yes.  maybe experiment with turning it off too since that and the usb card are on the same psu, granted since the pc is on the topaz and the dac isn't idk what will happen. Complicated, Sir.


----------



## bequietjk

No audible difference with it on or off, and this could be because of the PPA V2 doing work?  Not sure.  

Concerning the Topaz I'm reeeeally considering replacing the default brown receptacle (hubbell?) with an Oyaide R1!


----------



## Zenvota

bequietjk said:


> No audible difference with it on or off, and this could be because of the PPA V2 doing work? Not sure.


I have a dac/headamp unit on a topaz and a pc isnt, the iso regen is on an ultracap lps with the ground shunted smps, and turning off the isolation turns crystal clear imaging into a hazy mess xD



bequietjk said:


> Concerning the Topaz I'm reeeeally considering replacing the default brown receptacle (hubbell?) with an Oyaide R1!



Its probably a good idea to replace plugs and outlets on these old things.  I have a few old units I plan on doing that with.  Look at this 91001-42, thats probably the original oil capacitor from 1990... I should probably take that out lol


----------



## bequietjk

Oil capacitor!?  I see mine has one too, ill take a picture tomorrow.  

As long as replacement is as easy as replacing that capacitor and the new receptacle has the same posts then I'm ordering one for sure.

Btw, I was wondering if there is any level of surge suppression in these topaz rigs.  If there is then that would give me more reason to seek out the 91001-32 for my PC xD


----------



## Zenvota (Jun 16, 2019)

bequietjk said:


> Btw, I was wondering if there is any level of surge suppression in these topaz rigs. If there is then that would give me more reason to seek out the 91001-32 for my PC xD



Yup good movless surge suppression, can reduce a 5kv spike to .05v or something like that. However, they dont supress traverse spikes(hot to neutral). But that is half of the reason for using these isolation transformers, the surge suppression, with filterless power distribution after the transformer.


----------



## bequietjk

Sweet.  I was considering a surgex but maybe not so much now.


----------



## akb48jue

Hey Guys
Now i'm looking for a cable for my audio 64 tia trio, i prefer warm sounds. Do you guys have any recommendations?

Thanks,


----------



## Zenvota

akb48jue said:


> Hey Guys
> Now i'm looking for a cable for my audio 64 tia trio, i prefer warm sounds. Do you guys have any recommendations?
> 
> Thanks,


https://m.gearbest.com/headphone-accessories/pp_712517.html


----------



## oneguy (Jun 19, 2019)

My 5kVa Topaz will arrive tomorrow. It’s untested so hopefully it’s not a dud but the price was to good to pass up. It list as weighing north of 100 lbs so it’s probably going to stay on a furniture dolly so it’s easy to move for wiring and testing. I’ll edit this post with pics tomorrow night.

Edit: Here it is next to one of my 2.4kVa units. Sorry for the bad pics. I just got home and it’s midnight here.


----------



## bequietjk

Best of luck to you guy, yeah these Topaz' are beefy.  Im curious to see how your experience unravels!


----------



## oneguy

It works! I hooked up a cord to it it and I get 115v in and 119.6v out. Well worth every penny!


----------



## bequietjk (Jun 21, 2019)

@oneguy Can we get a pic of the beast!?  I have a 91001-31 on it's way ^_^.  I'm afraid of the hum though...  Maybe put it inside of some type of box?  I may have to make a DIY box of some sort if the hum is too bad.  New Topaz will be dedicated to my PC for surge protection and hopefully some SQ benefit.  We'll see.


----------



## Zenvota (Jun 21, 2019)

bequietjk said:


> @oneguy Can we get a pic of the beast!?  I have a 91001-31 on it's way ^_^.  I'm afraid of the hum though...  Maybe put it inside of some type of box?  I may have to make a DIY box of some sort if the hum is too bad.  New Topaz will be dedicated to my PC for surge protection and hopefully some SQ benefit.  We'll see.



Of the units I have, the -12 or -11 units have a hum/buzz and the -32 -31 units are silent.  

Did you get it off ebay just recently? I saw a 91001-31 all wired up with a plug and 4 outlet box, nice unit.



oneguy said:


> It works! I hooked up a cord to it it and I get 115v in and 119.6v out. Well worth every penny!


gz!


----------



## oneguy (Jun 22, 2019)

bequietjk said:


> @oneguy Can we get a pic of the beast!?  I have a 91001-31 on it's way ^_^.  I'm afraid of the hum though...  Maybe put it inside of some type of box?  I may have to make a DIY box of some sort if the hum is too bad.  New Topaz will be dedicated to my PC for surge protection and hopefully some SQ benefit.  We'll see.



Both of my -32 2.4 kva units have a slight hum that you can’t hear any further than 3ft away in a completely silent room. If there is anything blocking that “line of sight” the it drops significantly. I have never run my -32 500 unit by itself so I can’t comment.

EDIT: If there is nothing between the -31 125 va transformers and my ears I can begin to faintly hear them at 2 ft. If obstruct that direct “line of sight” with something as simple as cardboard it drops down to about 10 in.

Here’s the photo of it next to a 2.4 kva and 125 va unit for reference.


----------



## bequietjk

That is a behemoth.  WOW that is a massive transformer!  I wonder how hot all of those things get.  My setup with all of the equipment firing it gets hot in my room, especially when im pushing my video card for gaming haha.

@Zenvota 
When it comes to replacing the oil capacitor would you deem it necessary or...  I really would like to replace my receptacle but I'm not sure if I should replace the cap too and what specifications to look out for in a replacement.  I'm all in for do it right the first time.


----------



## Zenvota

bequietjk said:


> @Zenvota
> When it comes to replacing the oil capacitor would you deem it necessary or...  I really would like to replace my receptacle but I'm not sure if I should replace the cap too and what specifications to look out for in a replacement.  I'm all in for do it right the first time.



I dont know Dx I need to look into it as well.  I would imagine if its not leaking its ok to leave it, if its old and ineffective it just won't do anything, its meant to filter some extra traverse mode noise.  Should be very simple to remove though.


----------



## bequietjk

I noticed on the stock receptacle that there are 4 input posts per side, and the Oyaide R1 only has 2 inputs per side.  Because of the way this Topaz is wired you can see the neutral has a ground going into it as well.

If i am to wire this to work the R1 would I need to terminate the neutral and ground together into one crimp or is this not advisable?


----------



## Zenvota

bequietjk said:


> If i am to wire this to work the R1 would I need to terminate the neutral and ground together into one crimp or is this not advisable?


If you connect ground and neutral on the output make sure you add a gfci between the receptacle and anything you're plugging into the topaz.  If you don't connect the ground and neutral on the output then it's floating and you don't need to do anything else.


----------



## bequietjk

Ah!  So it's the output not input.  Doh!  Learned something new hehe.

I may consider the Furutech GTX or the Maestro in this case.  I'm afraid implementing a GFCI for the R1 is beyond my technical ability and understanding.


----------



## Zenvota

bequietjk said:


> Ah!  So it's the output not input.  Doh!  Learned something new hehe.
> 
> I may consider the Furutech GTX or the Maestro in this case.  I'm afraid implementing a GFCI for the R1 is beyond my technical ability and understanding.



Using a gfci is for grounding the neutral not for using the r1


----------



## bequietjk

You're saying the chain would go

Topaz(R1 receptacle) > GFCI > Component?

Something like this cable?


----------



## Zenvota

bequietjk said:


> You're saying the chain would go
> 
> Topaz(R1 receptacle) > GFCI > Component?
> 
> Something like this cable?


yesm


----------



## Zenvota

bequietjk said:


> My setup with all of the equipment firing it gets hot in my room, especially when im pushing my video card for gaming haha.


I feel you... I have a htpc with a 4770k and gtx1070, a 250w projector lamp, a 9channel avr, 4 separate power amps in an 12' x 15' room, and soon 2 ultra isolators, in south florida... suprisingly the electric bill isnt to high xD


----------



## bequietjk

Surprising you haven't melted and are able to reply in forums unexhausted!  MAN that's a real test of character hahaha.


----------



## oneguy

bequietjk said:


> That is a behemoth.  WOW that is a massive transformer!  I wonder how hot all of those things get.  My setup with all of the equipment firing it gets hot in my room, especially when im pushing my video card for gaming haha.
> 
> @Zenvota
> When it comes to replacing the oil capacitor would you deem it necessary or...  I really would like to replace my receptacle but I'm not sure if I should replace the cap too and what specifications to look out for in a replacement.  I'm all in for do it right the first time.



http://www.surplussales.com/Transformers/Pdfs/tp-91092-31_N.pdf
Look under the “Extreme Transverse-Mode Noise” section for capacitor sizing considerations.


----------



## bequietjk

Ok let me do the math.
be back next year xD


----------



## Zenvota

Well it worked and it worked really well.

Added the following:
-Topaz 91001-41 for the AVR, 2 channel amplifier(for 2 height channels), 3 mono amplifiers(2 subwoofers, 1 tactile transducer system), and the fiber transmitters psu(jameco 12v1a lps)

-Topaz 91095-32 for the projector

-VH Audio Flavor 4 cabling to the projector and AVR

-Atlona AT-HDR-EX-70-2PS ethernet hdmi extender between the HTPC and AVR, transmitter powered by a jamevo 5v1a regulated lps, receiver powered by an Uptone Ultracap LPS at 7v with the ground shunted smps and Canare 4s8 dc cable. The ultracap and uptone smps are necessary to break all leakage.

-AV Access 4KEX300-F om3 fiber hdmi extender between the AVR and projector. transmitter powered by a jamevo 12v1a regulated lps, receiver powered by an Uptone Ultracap LPS at 12v with the ground shunted smps and Canare 4s8 dc cable. The ultracap isnt required for leakage loops here because of the optical connection.

-Replaced front left/right and center speaker wire from bargain 16awg to canare 4s8.

Audio(Denon X4200W and Polk LSIMs):
Sibilance gone, prodigous bass, immediately had to turn the subs down, extension is better? how thats possible is beyond me, i would use a loudness eq curve(denon dynamic eq) to get better bass extension and had to turn it off. imaging is just incredible, overhead localization is much more pronounced. Atmos content is just unreal now. Voices are so much more natural, as I said there was heavy sibilance with the polks, and female voices had a very boomy quality, all alleviated. Music sounded meh before now it sounds more or less perfect for the hardware used.

Video(Benq W1070, 1080p60hz rgb full signal)
Lower black level(i think more just a noise free image makes the blacks more solid and appear lower), better shadow detail, better bit depth, colors, and sharpness, image is significantly more stable, easier to focus on, incredible really. I was very curious what the effects on video would be, being limited to an idea of a washed out image with less than perfect signal integrity. Really looking forward to a 4k projector with a better lense now.

So ya... any surround sound enthusiasts and tinkerers out there, putting your AVR and display on a line noise suppressor, isolating from a htpc with a fiber hdmi extender(or ethernet with ultracap lps and uptone smps), providing excellent signal integrity and ultra clean power makes a huge difference, despite not using audiophile class a nonfeedback current signal amplifiers ;]


----------



## bequietjk

Dang Zen, I've always wondered how putting video into ISO would be.  I imagine a crisp and refined image with great detail just as you described!  I'd really need to do a test run with my 2 Topaz for my 2 computer monitors.

My 91001-31 came in!  The seller wrapped the hell out of it and it took me a good 10 minutes just to get it free!  Styrofoam, MILES of cardboard and saran wrap.  Super glad and excited but the only problem is there is no grounding!  My little iFi AC purifiers let me know by showing no grounding on the units.

This is the tricky part especially for a beginner in electronics...  How can I set this up for grounding to provide my computer and other components with full benefit?


----------



## bequietjk

The ground looks like its connected to the whole chain but my ifi ac purifier is saying noooo


----------



## Zenvota

Thats wired with a floating neutral secondary that could be what the ifi is reading.  You can double check continuity of the ground through the unit by touching the probes of a meter to the ground pin of the plug and the electrical box, case, and ground pin socket of the receptacles.  vn unit btw that should be plug n play just double check ground continuity first and then plug it it and measure voltage on the secondary


----------



## bequietjk

Aha!~  So it would be best to connect the ground to the neutral on the secondary side!


----------



## Zenvota

bequietjk said:


> Aha!~  So it would be best to connect the ground to the neutral on the secondary side!


I couldnt say if it would be best, but on all 4 of my units in use I didn't.  But if you did thats when you would need a gfci.


----------



## zilch0md (Jun 28, 2019)

bequietjk said:


> I recently bought the 91095-32 'MGE' branded iso transformer off of eBay and am very excited to see how this does added into my system.  Looking for better noise floor of course.
> 
> Is there anything I should look out for, re-wire or diagnose before connecting it to my APC voltage regulator and then connecting my dac and amp?  I'm not very knowledgeable in the electronics field save a few soldering jobs making power cables.
> 
> ...




It's importamt that you understand the context for which the narrator of that video is concerned.  He works at a test bench, often with energized circuits in an exposed chasis where there is a high probability of unintentenionaly electrocuting himself by simultaneouesly touching both hot and neutral.  Guys who work with energized, open equipment NEED isolation transformers with a floating-neutral secondary.

Hospital staff and their patients, audiophiles, and the public at large almost never have both hands stuck into an open chasis that's energized, right?  The probability of somehow touching hot and neutral simultaneously while handling closed components that are UL or CE certified, is extremely low.  But there is a slight chance that hot could short to the closed case of a device while you're touching it and in THAT context you WANT the protection of a grounded-neutral secondary - the same as in hospitals, adhering to electrical codes.

All IT transformers made for applications OTHER THAN test benches, where solder monkeys do things like sticking oscilloscope probes into energized, open equipment, have grounded-neutral secondaries, just the way the guy in the video found his factory fresh Topaz. That's why it's easy to find a lot if videos where electronics techs explain how to CONVERT an IT made for general purpose applications (grounded-neutral secondaries) into ITs that are much safer for THEIR purposes (floating the secondary.)

We should be doing the same as the hospitals do for our audio gear - using ITs with grounded-neutral secondaries.  There are two exceptions, however:  1) When you want to prevent a source that has a DAC from backwashing noise onto the mains, polluting other gear in your chain or 2) You want to prevent a component that uses a SMPS from backwashing noise onto the mains - you can give each such component its very own IT, with a floating-neutral ground, but to be safe from the possibility of an internal short to the cabinet, you should install a GFCI between the output of the floating-neutral secondary and the noisy load AND you should NEVER plug more than one device into an IT that has a floating-neutral secondary - for safety and to prevent the backwash noise of one component from entering another that's sharing tha same transformer's output.

Do your homework, but always strive to understand the context from which someone is teaching anything about grounded vs. floating neutral secondaries.

Kill the noise, not yourself!


----------



## zilch0md

See:  https://www.head-fi.org/threads/top...ably-clean-power.857448/page-17#post-14834948


----------



## Zenvota

Just wanna add this here too, as Johns recommendation is to use a floating neutral secondary with all electrically connected components on filterless distribution to reduce impedance of the connected devices and keep noise from leakage loops to a minimum.  The transformer is meant to provide conditioning and surge suppression in that situation.

https://audiophilestyle.com/forums/...sformers/page/12/?tab=comments#comment-599055


----------



## zilch0md

Yes, there are at least three schools of thoughts, here:

1) Use nothing but grounded-neutral secondary ITs (ideally, just one big one with all component power cords plugged into outlets that are as close together as possible, sourced from that one ITs secondary).

2) Use nothing but floating-neutral secondary ITs (with each component getting its own IT, 1:1, and nothing upstream but a power strip from the mains).

3) Use a mix (as I do), with the floating-neutral secondary ITs deployed 1:1 only for stopping backwwash noise from DACs and SMSPs components, but with everything (whether it has its own floating IT or not) plugged into a single, higher-capacity grounded-neutral secondary IT.  (See my big diagram in the first post of this thread.)

In the end, none of these configurations pose as great arisk as standing barefooted on a mountain top during a thunder storm or perhaps even driving a car to work each day.  . 

So, you have to ask, "What's my goal?"  The absence of that ground shunt on the secondary's neutral certainly does stop anything and everything from backwashing onto other gear, as long as every "backwashing" component has its very own IT.  Common-mode noise is greatly reduced by both types of ITs, affecting a frequency range that increases as the pF rating decreases; thus, our quest for 0.0005 pF, model -31 and -32 Topaz ITs and their siblings.

Without hesitation, I defer to the expertise of John Swenson in these matters, but I can't find fault wiith someone choosing to stick with national safety codes.  If you go back to my big diagram in the first post to this thread, you can see that I use a blend of the two types, beginning with a grounded-neutral secondary IT at the mains and branching from there.  I have to confess, however, that I'm not using GFCIs anywhere.  So, call me "conflicted," when it comes to SQ vs. safety.     But again, what are the odds of a UL-certified component with an unopened metal chassis suddenly being "hot" while you're touching it?  Thus, if the goal is hardcore audiophilia, walk in John Swenson's footsteps and trust that he doesn'tt want to get electrocuted, either.  

That said, I can still respect people who choose to adhere to national safety codes.  They will enjoy a lot of common-mode noise reduction and surge protection, too, albeit without completely "isolating" each component from backwash noise (DACs and SMPS) or loop currents.

Is one school of thought better than another?  That's for each of us to decide.


----------



## bequietjk

Does it matter to ground the neutral on the secondary side VS down the AC cable line at the receptacle?


----------



## Zenvota

bequietjk said:


> Does it matter to ground the neutral on the secondary side VS down the AC cable line at the receptacle?


either should be fine

@One and a half  or @Speedskater Is this adequate for a GFCI?  Transformers wired 120v in 120v out unbalanced

https://www.amazon.com/dp/B01N6AEEIK/ref=cm_sw_r_cp_apa_i_nIRfDb5ESHCX6


----------



## One and a half

Zenvota said:


> either should be fine
> 
> @One and a half  or @Speedskater Is this adequate for a GFCI?  Transformers wired 120v in 120v out unbalanced
> 
> https://www.amazon.com/dp/B01N6AEEIK/ref=cm_sw_r_cp_apa_i_nIRfDb5ESHCX6



For a grounded 120V neutral at the transformer, the GFCI from Amazon is OK, presume it's 6mA tripping.
BTW, the neutral must be grounded at the transformer, not anywhere downstream, against code.


----------



## bequietjk

Contacted Albert Porter for an Isolated Ground Ivory Porter Port and it's on the way now   SUPER excited.  Have not officially decided if I should put it on the Topaz connecting my PC or the Topaz connecting my DAC/Iso Regen.  

Probably the DAC ^.-


----------



## bequietjk

500VA MGE Topaz sounding VERY good to my DAC with the Porter Port.  I will say this though, the hospital grade receptacle that comes with the Topaz is built like a tank!  But the Porter Port is destroying it with dynamics and presentation.


----------



## bequietjk

Picture of the oil cap


----------



## Energy

any plans of wiring it in balanced mode and removing the polypropylene cap?


----------



## bequietjk

Energy said:


> any plans of wiring it in balanced mode and removing the polypropylene cap?



I'm VERY curious about balanced configuration but I am just beginning in this realm of audio and DIY.  So taking on that will be a challenge as there is much research to do before I fully understand what it means to have a balanced device and whether it meets my needs.  Of course, better audio is always part of the pursuit but for now the way it is setup is good for me.

I remember reading a few testimonials here and there about wiring the Topaz up for balanced and came across some negative experiences.  Postitive ones too, but the negatives kept me from looking further into it.


----------



## FiGuY1017

Not to many inpressions so ill add that since i added a 32 series topaz into my headphone system the changes have been dramatic. I already had good power and this thing runs with no noise but the increase in depth and blackness and the contrast between instruments is incredible.


----------



## bequietjk

Has anyone had any lasting, positive results wiring the Topaz for balanced?


----------



## ray-dude

Absolutely!  In made my humming basically go away, runs MUCH cooler, and at least it feels like less stress (that may just be the lack of humming).  Big positive difference for me


----------



## oneguy

Out of pure curiosity and inability to pass up a good deal, I bought a series 60 Topaz unit. 

This particular unit can accept 5 different input voltages and has 2 output voltage options. Those amount of options are mind boggling given what I know about the jumper configuration for the -31 models. I’m not quite sure how they managed that. We’ll see next week though when it arrives. I’ll post internal pics since I couldn't find much on the internet about the -69 model. AFAIK, it is the only model outside of the well known -31 and -32 models with 0.0005pF capacitance.


----------



## oneguy

FedEx must have been working overtime for thanksgiving. They got me the transformer today. 

-69 core:
8.25” long
7.5” wide
6.25” tall

-31 core
7” long
7.25” wide
6.25” tall

The -31 is in the background. It looks taller because it’s on a wooden platform so I can slide to around easier.


----------



## bequietjk

Hey Topaz-heads.  I had a couple concerns about my own Topaz, especially the 1KV Topaz.  It does give off a hum that i would love to take care of, and im wondering if wiring it for balanced would help this.  Additionally, i have a single receptacle on the output of the 1KV.  Should I be careful of what connect to a balanced version of the Topaz?  I read that some components are not designed to play with balanced power.

Is there a section in this thread that shows how to wire up for balanced?

Also, since i have my DAC connected to my 250V Topaz i wanted to ground the shielding at the Topaz end.  Has anyone seen benefit from this?  

Best regards!


----------



## bequietjk

Here is how it is setup


----------



## ray-dude

I can only speak to my Topaz units here in the US (110VAC), but changing them to balanced made 95%++ of my hum go away, and the units run MUCH cooler. A++.


----------



## oneguy

I’ve never run balanced power. Both my 2.4’s are -32 models and thus incapable of balanced power. The 5’s are capable but not in service yet. @Energy has a 1.8 running in balanced and loves it though.


----------



## bequietjk

I have a 500VA -32 and a 1KVA -31

Here's the input side of the -31.  Does balanced wiring happen on both input and output?


----------



## oneguy (Dec 4, 2019)

bequietjk said:


> I have a 500VA -32 and a 1KVA -31
> 
> Here's the input side of the -31.  Does balanced wiring happen on both input and output?


Balanced wiring happens on just the output side but the input side will need to be changed from the 120v wiring setting. You wire the input side for 240v (jumper H2 and H3) and  wire the output side for 240v (jumper X2 and X3). The balance wiring comes in when you wire X2 or X3 (it doesn’t matter which one) to ground.

Balanced wiring diagram:



(https://www.equitech.com/the-origin-of-balanced-power/)

Explanation:
-The 240v setting on the output side allows you to have a center tap (X2 or X3) to ground which you need for balanced power.

-The 240v setting on the input side side allows the input side to be 1:1 with the output side (both sets of input coils and output coils are now in series in the respective sides). If you left the input set up for 120v this would cause a step up in voltage.

-Grounding the center tap allows the wave forms to be halved thus creating two 60v sine waves 180 out of phase with each other.

I hope this helps.

EDIT:
PS. Since the coils are now in series instead of parallel I would expect the current carrying (amps) capability of the unit to be cut in half.


----------



## bequietjk

@oneguy thank you for this!  This gives me something to research and think upon before wiring up when i get home.  Im excited.  Not sure of SQ benefits, as my PC and 2 monitors are connected to it but at least this hum should go away.  I appreciate you helping me to understand.


----------



## Zenvota

bequietjk said:


> Not sure of SQ benefits, as my PC and 2 monitors are connected to it.


I always notice a big improvement in sound quality when isolating from the pc.  Switching supplies(and especially the large ones for computers, the monitors use them too) generate alot of leakage and leakage loops form between the pc, the monitors, the dac, and other audio components.  Fiber optic is the simplest way to block it.  USB requires the galvanic isolation device to be powered by something like the uptone ultracap supply which blocks low impedance leakage, and a ground shunted charging supply for the high impedance leakage.

https://audiophilestyle.com/forums/topic/37034-smps-and-grounding/

Real huge boost to imaging/transparency and treble performance though.

I have two setups that use usb from a windows desktop.
1) Uptone USB Regen powered by a jameco reliapro lpsu > Breeze Audio DU-U8 optical out > only dac/amp on the topaz.  Buying stuff used kept this transport under $150

2) Uptone ISO Regen power by uptone ultracap lps with ground shunted smps charger > The dacs usb to i2s board has an isolator on the i2s side and is powered by the ultracap > only dac/amp on the topaz

Since we're on the subject of noise, there are a couple other simple ways to remove noise from your system.  For DACs and digital devices with a varied current draw, low inductance quadrapole/star quad ac and dc cables reduce noise caused by a voltage that develops across the inductance of the cable due to the varied current draw, low inductance, reduced noise.  

Removing/reducing phy noise generated by error correction in things like usb chips by ensuring optimal signal integrity with devices like the usb regen.  Phy noise will even pass through fiber optic, in my first setup the breeze duu8 is greatly improved by the use of the usb regen.

If using fiber optic having decent crystal oscillators(tcxos) on either side with even just decent linear power supplies does a good job of reducing jitter.

And keeping only the audio components on the topaz with unfiltered power distribution reduces the amount of leakage loops and the noise generated by the ones you cant break.


----------



## bequietjk

I have a fortified response for your post ill habe to post when i get home, regarding each of those subjects you covered.


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## bequietjk

Hows this?

Primary


Secondary


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## FiGuY1017 (Dec 4, 2019)

My 250 va has been eye opening. The biggest single influence ive added sq wise


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## bequietjk

Ok here we go.  Few things i wanted to state.

I've tried fiber optic straight from my PC and the sound is good.  Smoother than via USB. But is it as dynamic as USB?  and how much does the USB or fiber optic cable construction matter here?  Topic for another thread?

The ISO REGEN I had seemed to be the cherry on top.  The finalizing point that sharpened the image and get the last details.  I ended up selling it so that i could buy the Matrix XSPDIF2 in hopes that the Matrix would provide the benefits of the ISO REGEN, as well as have the,multiple outputs.  Its hard to say what i prefer here because i dont have the ISO to pair WITH the Matrix.  I do miss the IR in a way.  Curious how it would sound in my setup now.

In regards to the Ultracaps, they were way out of my budget and at the moment im using Teradak DC30W LPS units where I upgraded all caps from Nippon Chemi Cons to Nichicon HWs.

@Zenvota What is your take on having your analog unit(amp) and digital unit(dac) on the same transformer?  Do they not affect each other negatively, being on the same power circuit?  Or do you have them each isolated like zilch further down the line with BK iso transformers?

Ive read that digital equipment isnt affected so much on transformers or conditioners as much as analog equipment.  That ISO transformers raise the impedance which for analog equipment, amps specifically, is definitely not the way for sound quality.  Paul of PS Audio has a video on youtube about them.  Whether its to promote his REGEN units, im not sure.  Theres much for me to learn and understand about electronics and engineering.


----------



## bequietjk

@FiGuY1017  Is that a 250VA?  Nice thag you have one of those suggested outlet extenders.  I was thinking of making a custom extender using Porter Port receptacles!


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## FiGuY1017 (Dec 4, 2019)

bequietjk said:


> @FiGuY1017  Is that a 250VA?  Nice thag you have one of those suggested outlet extenders.  I was thinking of making a custom extender using Porter Port receptacles!




Yes sir it is, and these exteders are so cheap i figured why not.  It wasnt until i added my audiolab cdt6000 that i bought it, otherwise it was great as well with using both outlets on the unit for my dac/amp.

 I honestly bought the topaz thinking i wouldn't hear a difference, as i have pretty good quality power imo. Things just took on a ease, or how to describe it.... more depth up down side to side just pretty wild stuff lol. Music just got pushed out closer to the horizen. Especially with my hd800 and Hekv2


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## bequietjk (Dec 4, 2019)

Just connected my Topaz after the wiring and tripped the breaker.  

I should also mention that i live in the US with 120V.


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## oneguy

bequietjk said:


> Just connected my Topaz after the wiring and tripped the breaker.
> 
> I should also mention that i live in the US with 120V.





bequietjk said:


> Hows this?
> 
> Primary
> 
> ...



You didn’t wire it properly.

Primary: the black and white wires you have going to H2 and H3 should be going to H1 and H4 instead. Black to H1, white to H4. 

Secondary: the black and white wires you have going to X2 and X3 should be going to X1 and X4 instead. Black to X1, white to X4

The way you wired it created a short on the input side between the hot and neutral wires with the jumper completing the circuit.


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## bequietjk

@oneguy I see.  And keep the jumpers on H2/H3 + X2/X3?


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## Zenvota

My usb transport definitely sounds better than the toslink, but I wonder how a similarly optimized toslink would sound. Toslink is bandwidth limited, and while that shouldnt be an issue for 16/44 2.0 pcm, Im sending 32/48 binaural stereo from OOYH with stereo music up to 7.1 surround input, so the extra bandwidth of usb could be beneficial.

Im not aware of any dac or usb transport that has a hub chip before the usb receiver so in all cases Id keep at least a usb regen powered by a jameco reliapro.

I could tell the difference between the power supplies used on a usb regen. The stock smps was fatiguing(noisey/sibilant), the ifi ipower smps was smooth but lacked detail, and the jameco lps is more detailed without being fatiguing, i currently feed it into a lt3042 regulator and then the star quad cable to the regen(best budget transport ive heard). The ultracaps are a big big step up and provide the extra isolation and necessary with the iso regen for full isolation(the iso blocks some leakage, the ultracap blocks low impedance leakage, and the uptone smps shunts high impedance leakage). But just as important is that star quad dc cable between the power supply and the regen, knocking that noise always suprises me.

Ive talked to him about that and had seen alot of different setups here and on ca. For me all I have is the dac and head/pre on the topaz, and I use vh audio flavor 4 cables, which should aid in reducing any harmonics kicked back into the line by the dac and amps power supplies(big double stage linear supplies). But since these components always have an electrical connection via the signal cables and I dont believe the isolation transformers block any 60hz mains leakage(otherwise how would they provide power?), I tend to be drawn to the filterless distribution and let the ac cables do the work. It sounds very good so I havent been trying any different setups.

I couldnt really say as far as the isolation transformers affecting analog components. I just use them to knock noise and any household surges and leave it at that. Im pretty sure the filtered outlets of those conditioners raise impedance as well, and the slight increase(3%) in impedance from the topaz shouldnt affect good power supplies with high input impedance anyway.

I have my entire surround system on a single topaz with filterless distribution, avr, 2 subwoofers, a 2 channel amp for 2 height channels, a mono amp for the tactile transducers, and an hdmi extender. The avr is a very mixed digital/analog device and the subwoofers(all analog) performed much better on the topaz, I had to turn them down about 10-20db after adding the topaz it was crazy. Imaging with the surround speakers was greatly improved, as well as the frontstage, and with the front speakers that use ring radiators sibilance was alleviated. I have polk lsims and I had greatly prefered my headphone system with loudspeaker virtualization to the actual loudspeakers, but after all the signal and power conditioning the lsims sound excellent.

I also have the projector on a topaz and the systems(pc, multi channel audio, and projector) are all isolated from each other as well. The projector is 100% digital(dlp using the ti 0.95 dmd) and uses pwm for the sequential rgb 3led light source as well as frame by frame dynamic dimming. Ensuring no external noise hits the led psu and voltage regulators drastically improves the performance of the light source, the dimming systems become completely unnoticeable and any color tearing(while already minimal compared to color wheels) is gone. I couldnt say the affect on the imager but its a much more solid and pure image then without the tweaks, which of course includes powering the mm om3 hdmi extender with an ultracap xD


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## bequietjk

Would 1KVA wired for balanced be enough for a PC + 2 monitors?


----------



## Energy

Depends how much your PC and monitor draws. Usually a PC is around 200-400W and monitors are anywhere from 25-50W.

It would be better to run all the audio gear on the Topaz connected to one outlet of the wall receptacle, followed by getting a thick cable splitter for the rest such as PC, monitor, or noisy SMPS that powers devices like LPS-1.2. 

After running a separate power line to the circuit breaker, I now have two lines/receptacles for the audio room. The line with the thicker gauge Romex has the Topaz on it while the other line is used for the PC and other devices. By doing this there is less modulation happening on the line that powers the audio equipment. Using a higher rated VA isolation transformer will have thicker gauge wires that are used internally which should help further with modulation and offer higher current handling.


I am still trying to see if using a Topaz on the PC will improve the sound quality in any way if one was using a standard ATX power supply. When using a linear one which spits less noise out I do notice an improvement when connected to the Topaz, but using a noisy ATX might benefit the PC but then raise the noise floor for all other components connected to the Topaz.


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## Zenvota

bequietjk said:


> Would 1KVA wired for balanced be enough for a PC + 2 monitors?


Lets see, my pc has an i7 4770k, gtx1070, 80+plat psu, 6 mechanical drives, 2 pumps, 14 fans and pulls about 150-350w, monitors generally dont pull alot of power, i have an xr3501 that pulls about 50w, so ya 1kv would be perfect


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## oneguy (Dec 5, 2019)

bequietjk said:


> @oneguy I see.  And keep the jumpers on H2/H3 + X2/X3?


Correct, I always check the finished wiring with a multimeter to make sure it’s wired properly.

1. H1 and H4 to the case HAS TO read as an open circuit.

2. X1 to X4 should read something really low. Probably less than an ohm

3. H1 to H4 should read something really low. Probably less than an ohm

4. X3 to the ground should be low, close to 0 ohms or reading 0 ohms depending on your multimeter.

5. Re-check all the screws to make sure they are all tight then...

AFTER you have done the steps above (the first one is the most important) then plug it in and check the output voltage. On my non-balanced transformer setup I typically see 2-3v higher on the output side than the input side. I haven’t personally done a balanced setup and tested the voltage output but I imagine it should be about the same 2-3v above input voltage.


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## bequietjk (Dec 5, 2019)

IIRC it wouod not matter if X2 and X3 were jumped at the secondary.  Since it is jumped at H2/H3 at the primary, when the center (Lets say X3) is tapped with ground, it is shared to X2, because they are jumped at the primary?  I read a thread in auduogon where the gentleman only jumped H2/H3, then just ground tapped X2 or X3.

My link of reference:
https://forum.audiogon.com/discussions/wiring-an-isolation-transformer


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## oneguy (Dec 5, 2019)

bequietjk said:


> My link of reference:
> https://forum.audiogon.com/discussions/wiring-an-isolation-transformer



TLDR, got to get ready for work

That sounds fishy. That would leave you with an open circuit since the black coil and white coil would not be connected to form a circuit.

Give it a shot though test it with a multimeter first. If there is a 120v potential across X1 and X4 then you know it worked. If there isn’t (this is where my mom let us at) then you know it didn’t.

I could be wrong but I don’t think I am.


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## Zenvota

Energy said:


> noisy SMPS that powers devices like LPS-1.2.


Yup, I keep all the ultracap chargers off the topaz' as well.


Energy said:


> I am still trying to see if using a Topaz on the PC will improve the sound quality in any way if one was using a standard ATX power supply. When using a linear one which spits less noise out I do notice an improvement when connected to the Topaz, but using a noisy ATX might benefit the PC but then raise the noise floor for all other components connected to the Topaz.


I've wondered about this as well.  I've read some studies about how line noise negatively impacts the performance of switching supplies, so using these with pcs should be beneficial in some sense.  And the studies on phy noise starting at the modem would suggest that you can improve audio quality well before the transport to the dac.


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## bequietjk (Dec 5, 2019)

At the VERY LEAST, i have a peace of mind that my PC is isolated from the mains.  I believe a layer of hash was removed from the quality of sound after putting my PC on the Topaz.

Im running a 750W Seasonic PSU with a 1080ti GPU.  IIRC i plugged a killawatt in front of my PC and it was measuring around 250-300watts, but when that GPU runs hard it gets cooking.  Ill have to hook the killawatt up again and run the GPU hard and spec it.


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## bequietjk (Dec 5, 2019)

Ive got most everything separated, but maybe there are still some noise that gets shared through the lines.

-PC and monitors on a 1KVA.
-DAC and USB transport on THE 500VA.
-Paul Pang V2 USB card taking external power from an LPS that is plugged into an Tripp Lite Isobar 8.
-THX AAA 789 & Bottlehead Crack plugged straight into the Porter Port receptacle in the wall. 

Really loving this setup.


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## bequietjk (Dec 5, 2019)

DMM leads on H1 and H4 reading 0.7 ohms

DMM leads on X1 and X4 doesnt read.  But X3 and X1 read 0.7 and X4 and X2 read 0.7ohms.


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## oneguy (Dec 5, 2019)

bequietjk said:


> DMM leads on H1 and H4 reading 0.7 ohms
> 
> DMM leads on X1 and X4 doesnt read.  But X3 and X1 read 0.7 and X4 and X2 read 0.7ohms.



PM me, it looks like from the photo you removed the jumpers From X2 to X3 which you had jumpered in a previous photo.

EDIT: If that was intentional, then disregard


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## oneguy

Downsizing one of my boxes. If interested PM me. 

https://www.head-fi.org/threads/fs-topaz-91002-32-in-aluminum-enclosure.921004/


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## bequietjk

I've got to say.  With my PC and 2 monitors connected to my 1KVA Topaz the humming can get pretty gnarly.


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## oneguy

bequietjk said:


> I've got to say.  With my PC and 2 monitors connected to my 1KVA Topaz the humming can get pretty gnarly.


Is that in the balanced setup?


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## bequietjk

oneguy said:


> Is that in the balanced setup?



Yeah.  The change in hum is most noticeable when my monitor is functioning.  For example, whenever I change tabs in internet explorer, basically any type of action the monitor is making the Topaz will definitely take note and you can hear it.


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## bequietjk

But taking my PC and monitors off the mains has definitely helped the rest of my equipment.  That I am sure.


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## oneguy

bequietjk said:


> Yeah.  The change in hum is most noticeable when my monitor is functioning.  For example, whenever I change tabs in internet explorer, basically any type of action the monitor is making the Topaz will definitely take note and you can hear it.


My theory: the power factor (true power divided by apparent power) is being reduced causing an increased amp draw which is causing an increase in magnetostriction (what causes the hum). 

-transformer hum is due to magnetostriction which is caused by a magnetic field
-the magnetic field in a fixed transformer (resistivity and coil length not changing) is directly related to current flow (actual amps)

I say power factor because in your example of the changing tabs in internet explorer I doubt the true power (measured watts) is increasing with such a simple task. If the true power isn’t changing then it has to be the reactive power increasing which in turn causes the apparent power (volts multiplied by actual amps) to go up. 

https://www.mgmtransformer.com/faqs/why-do-transformers-hum/

https://www.allaboutcircuits.com/textbook/alternating-current/chpt-11/practical-power-factor-correction

On a semi-unrelated topic here’s a good read on noise that I think was posted in thi thread earlier:

http://www.surplussales.com/Transformers/Pdfs/tp-91092-31_N.pdf

Under “Special Noise Problems” it talks about “Extreme Transverse Noise” and adding a capacitor to reduce this. In my topaz transformer tear downs I’ve noticed that the -31 transformers don’t come with the capacitors to reduce this form of noise. 

Transverse noise isn’t directly related to your specific issue but adding a capacitor that reduces transverse noise may also reduce the overall reactive power in your system. You’d have to run the numbers to see if you can match the two capacitor values for those  separate problems (or at least get them close).

I incorporated such a capacitor in my transformer transformer boxes that I build for the transverse noise reduction aspects.


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## bequietjk (Dec 15, 2019)

@oneguy

You know what man I used to be skeptical when people talked about how moving your mouse and using your keyboard can have an impact on sound because of the fluctuations and electrical aspects of when they are in use, and I can tell you now that I have finally experienced it.  

As of right now, I've dialed my PC fans down to silent so that my room is pretty damn quiet, and the only thing making noise, really, is the 1KVA Topaz (what my PC is conncted to).  With that, i can hear the hum actuate everytime I use my mouse.  Every little movement that is made, every scroll.  It isn't loud of course, but I can hear the Topaz go "eh...    eh.   eh."  Everytime I make a mouse movement.  And my mouse is connected to my monitor, which is now connected to my 500VA Topaz.  

The benefit I see here is I finally see and hear how electricity at it's very roots, no matter where it comes from is all connected and every little detail matters.


----------



## chrisdrop

I just wanted to say a big "thank you" to this info-packed thread, especially to @zilch0md for putting starting / continuing the whole story. I have spent 2 days reading the whole history. I can't say that I have grokked everything but I have learnt a lot and have a ton more reading via links from this thread.

I am working through a painful noise issue that I will perhaps post about elsewhere as it is not Topaz related and as said in an earlier post on this thread:

*That's the insidious thing about noise: You don't know it's there, until you get rid of it!*​
Any and all info has been greatly appreciated!

Best,
Chris


----------



## zilch0md

Thanks Chris,

As evidenced by many great posts, there are several contributors here who have a much better understanding than I do on how to make the most of these low-capacitance ITs.  The good news for the common audiophile is that you can accomplish a lot, just by inserting an appropriately sized Topaz between your mains and your loads.  But do's and don'ts can make a difference, so my hat's off to you for studying the entire thread - and for your obvious enthusiasm.  

Mike


----------



## chrisdrop

I realise I am stoking an old thread, but I will ask anyhow  I have continued my reading on this topic, on the other forum that has a lot to say on this topic... The hole is deep!

In seeking a UK-based isolation transformer (so much advice on US systems, less on UK), I came across the below unit. I can't find a capacitance rating in the same form as the Topaz units. Is there any way to derive the value from the spec? 

https://www.aldetronics.co.uk/product/it-15-isolation-transformer/

Given that this has a switch for floating/ grounded - if it was sufficiently low capacitance, and I got 2 units with sufficient VA, it could serve both functions in a serial setup I believe. Does that seem rational? 

In _very_ short, I'd like to use this in front of a valve headphone amp. Either of 2 excellent valve headphone amps I have used in my home have buzz that I'd like to eliminate. 

Further, I have used a single https://airlinktransformers.com/product/conditioning-balanced-power-supply-cbs1500  that did not sort my issue. After grazing on this thread, I wonder if it actually didn't isolate. It is also possible that I plugged two things into it, nullifying my experiments. 

Tx for any thoughts!


----------



## oneguy

chrisdrop said:


> I realise I am stoking an old thread, but I will ask anyhow  I have continued my reading on this topic, on the other forum that has a lot to say on this topic... The hole is deep!
> 
> In seeking a UK-based isolation transformer (so much advice on US systems, less on UK), I came across the below unit. I can't find a capacitance rating in the same form as the Topaz units. Is there any way to derive the value from the spec?
> 
> ...



AFAIK, from the the information given on the website, there isn’t a way to determine the capacitance.


----------



## oneguy

Keeping the thread going this some pics:

   

I wired one of my 5kVa’s to output balanced power and attached it to a 10 receptacle power strip with 10 AWG wiring and rhodium receptacles. Input into the transformer is 8 AWG with a rhodium plug.

In balanced configuration the transformer runs about 60-70F cooler and has no noise at all. Also, my LH Labs LPS4 used to make a faint high pitch noise when powering my 20G through the USB port. The noise is now gone. 

Overall I’d say it was worth the $225 in upgrades and two nights of work.


----------



## L0rdGwyn (Jan 16, 2020)

I pulled the trigger just now on a used MGE UPS 91002-31T 2.5kVA.  $210+shipping, I thought that was a pretty good price from the reading I've done.

https://www.ebay.com/itm/MGE-UPS-91...83.l44720.c10&nordt=true&rt=nc&orig_cvip=true

Spec sheet: http://www.pacificparts.com/vends/mge/images/t1.pdf

Seller lists a "30 DAY WARRANTY!!!!."  That's four exclamation points...I trust him.  Curious to see how it improves my listening.


----------



## Zenvota

oneguy said:


> Keeping the thread going this some pics:
> 
> 
> I wired one of my 5kVa’s to output balanced power and attached it to a 10 receptacle power strip with 10 AWG wiring and rhodium receptacles. Input into the transformer is 8 AWG with a rhodium plug.
> ...



Stunning.  I have a 1kv .005 unit thats very noisey.  Im going to try replacing it with a .0005 unit if that doesn't work ill have to research balanced power xD



L0rdGwyn said:


> I pulled the trigger just now on a used MGE UPS 91002-31T 2.5kVA.  $210+shipping, I thought that was a pretty good price from the reading I've done.
> 
> https://www.ebay.com/itm/MGE-UPS-91...83.l44720.c10&nordt=true&rt=nc&orig_cvip=true
> 
> ...



very nice unit.  What components are going on it? whats your chain like?


----------



## L0rdGwyn (Jan 16, 2020)

Zenvota said:


> very nice unit.  What components are going on it? whats your chain like?



Thanks!  That's a tricky question as my chain is in a state of flux at the moment, lots of things being bought, sold, or built, so I will say what it will be in 1-2 months.

SW1X DAC II Special
Glenn OTL
Single-ended triode amplifier of my own design (build is in progress)
ZMF Auteur

I plan to add the ZMF Vérité Closed later this year.  Yes, I am a tube junkie


----------



## oneguy (Jan 16, 2020)

L0rdGwyn said:


> I pulled the trigger just now on a used MGE UPS 91002-31T 2.5kVA.  $210+shipping, I thought that was a pretty good price from the reading I've done.
> 
> https://www.ebay.com/itm/MGE-UPS-91...83.l44720.c10&nordt=true&rt=nc&orig_cvip=true
> 
> ...



Lol, I just pointed that listing out to my friend. It was quite a good deal. There are deals to be had out there but you have to be patient and search the far corners of eBay. My 5kVa units were $320 shipped and $175 shipped.

I’d consider anything anything south of $350 total for 2kVa and above to be a good deal.


----------



## Zenvota

I think one caution with the larger units is under loading them.  I tested a 20w headphone dac/amp combo on a 1kv unit and it did not sound good, but on a 250va unit sounded excellent.


----------



## L0rdGwyn

oneguy said:


> Lol, I just pointed that listing out to my friend. It was quite a good deal. There are deals to be had out there but you have to be patient and search the far corners of eBay. My 5kVa units were $320 shipped and $175 shipped.
> 
> I’d consider anything anything south of $350 total for 2kVa and above to be a good deal.



Oof, well tell your friend I say sorry!  But I am glad my instincts were correct.  Looks like my renewed interest in getting one of these transformers happened on the right day.



Zenvota said:


> I think one caution with the larger units is under loading them.  I tested a 20w headphone dac/amp combo on a 1kv unit and it did not sound good, but on a 250va unit sounded excellent.



Thanks, I'll keep that in mind.  Worst case scenario this unit will be moved to my two-channel setup and I will get a smaller transformer for my headphone rig.


----------



## Zachik

oneguy said:


> I’d consider anything anything south of $350 total for 2kVa and above to be a good deal.





Zenvota said:


> I think one caution with the larger units is under loading them.  I tested a 20w headphone dac/amp combo on a 1kv unit and it did not sound good, but on a 250va unit sounded excellent.



Any guidelines on what size unit does one need? My setup consists of:
- Music server PC which is NUC based (so very low power)
- Lampizator Amber DAC
- GOTL headphone amp
- Another headphone amp being built by Glenn
- Couple other headphone amps, but they're not all powered at the same time...

Also, can anyone confirm (or dispute) the claim that being under-loaded is bad (and therefore bigger is not always better)?
I mean is it possible that the 1kva that @Zenvota used initially was just faulty?


----------



## L0rdGwyn

@oneguy did you build the chassis for the 2.4kVA Topaz in your classifieds listing?

https://www.head-fi.org/threads/fs-topaz-91002-32-in-aluminum-enclosure.921004/

It's very sleek, I have thought of doing something similar for the unit I ordered.  Having a bare naked 60lbs anvil on the floor isn't going to sit well with the Mrs.


----------



## Zenvota (Jan 16, 2020)

Zachik said:


> Any guidelines on what size unit does one need? My setup consists of:
> - Music server PC which is NUC based (so very low power)
> - Lampizator Amber DAC
> - GOTL headphone amp
> ...


I think a general guideline is keep your load between 10% to 60% of the rated value of the unit.  I still use that 1kv unit on my multichannel system and it works wonders.  It doesnt appear to be faulty, Ive checked unloaded and loaded voltage, power draw, etc.  Currently have on it:
Denon x4200w
Audiosource amp100vs
2x bic v1220s
and a dayton sa70

Typically load during dialog is 140w, and max spl is 700w for the whole system.

If the transformer is underloaded power transfers between the windings differently I forget the word ><


----------



## oneguy

@L0rdGwyn the cases can be found on eBay. It’s hard to find them now because all of the sellers on “away” which pulls their listings from the search engine. Here is the listing for a case the same size as the one I sold. 

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/302660809662

While that case worked for my -32 2.4kVa I had to shoe horn it in by cutting transformer narrower and shorter. You have the 2.5kVa -31 which is 0.9 longer and won’t work with the above listing without extreme cutting. Maybe not event then.





When the sellers come back from what I suspect Chinese New Year holiday try searching for “300 311 aluminum.” It should yield some results of cases like the one below. That may just barely work for your increased length without cutting. These cases measure 300mmx300mmx311mm. Expect to pay about $160-170 shipped. I turned my transformer sideways to make it fit. You may or may not be able to do that. The listing will have the internal dimensions posted.

 
 

Here is the first case next to a the same jug for comparison



The next larger cases can be found by searching for “356 aluminum enclosure” these are 356mm long and will definitely fit your transformer. These cases measure 300mmx300mmx356mm. I believe they are about $25 or $30 more than the 300x311 case. Your transformer will fit with no cutting running lengthwise.


----------



## L0rdGwyn

@oneguy thank you sir, that is extremely helpful.  I'll most likely seek out the 356mm chassis when those eBay sellers return, think that would be the easiest route and I'd like to avoid trimming the transformer.  That big chassis could make for a nice footrest  since the cost will be pushing $200, I suppose another option would be to have a custom chassis cut, but the cost would be a bit higher, probably around $250-300 through Landfall Systems, they are doing a chassis for me now for another project.  Something to think about, thanks again.


----------



## Zachik

Zenvota said:


> Typically load during dialog is 140w, and max spl is 700w for the whole system.


How do you measure? Using one of those "Kill A Watt"?


----------



## Zenvota

Zachik said:


> How do you measure? Using one of those "Kill A Watt"?


Yup, I use those cyberpower ups units (surge + autoformer + sinewave ups) that have a readout.  

I think it makes for a nice power system, wall > ups > isolation transformer, im in florida so anytime theres a surge or brown out or black out(which is daily) the transformers would lose power and then in rush current and i dont think thats great for components.  

Reducing all the surges, maintaining stable voltage, and reducing line noise is probably good for the lifespan of electrical components as well, especially alot of the budget ht audio gear and projectors(not so budget projectors) with switching supplies.


----------



## oneguy

Zachik said:


> How do you measure? Using one of those "Kill A Watt"?


I’m almost positive the Kill A Watt has a VA setting. That’s the one that should be used for these measurements since it accounts for reactive power and real power which is what these units are rated in (VA). 

 

I couldn’t find my Kill A watt so I need to do more searching to verify what my system is using but with a 5kVA in balanced or a 2.4kVA in conventional and powering the following components (speakers/pre-amp and headphone amp not at the same time) I haven’t heard any negative effects from low loading.

KG Grounded Grid
Spire KTE
LH Labs Pulse Blue
LH Labs 20G
Emotive XPS-1

Schiit Freya
Emotiva last Stealth 8


----------



## L0rdGwyn

Can anyone share what design considerations must be made before wiring for balanced power?  For example, does equipment connected to a balanced transformer require DPDT switches since both poles are hot relative to ground?

I specifically went for the -31 model for the option of wiring in balanced, but want to be sure the implementation is safe before I move forward.  Diving into this topic this weekend.


----------



## oneguy (Aug 2, 2020)

@L0rdGwyn
1. Consult the manufacturer to make sure you’re  equipment accepts balanced power. That being said, the CTO of Emotiva told me my Stealth 8’s wouldn’t cut on with balanced power. That was incorrect. So the company may not have correct info for you either.

2. Wire your transformer for 240 in and out. (Jumper x2/X3 and h2/h3)

3. Ground x2 or x3 on the output side (doesn’t matter which one)

then:




oneguy said:


> Correct, I always check the finished wiring with a multimeter to make sure it’s wired properly.
> 
> 1. H1 and H4 to the case HAS TO read as an open circuit.
> 
> ...



Now your transformer is wired for balanced power. All my switches are stock.


----------



## L0rdGwyn

Well thank you again @oneguy , I'll do my due diligence and be sure everything that could potentially be connected will function properly.  I'll post here once I have taken the plunge, will give the transformer a go non-balanced first.  Should hopefully have it early next week.


----------



## oneguy (Jan 17, 2020)

oneguy said:


> I’m almost positive the Kill A Watt has a VA setting. That’s the one that should be used for these measurements since it accounts for reactive power and real power which is what these units are rated in (VA).
> 
> 
> 
> ...



At idle in headphone listing configuration my system sits at 192W and 234VA

At idle in speakers configuration I sit at 133W and 157VA

At idle with both headphone and speaker related components at idle I sit at 262W and 313VA

Due to the Kill A Watt covering the top plug I can’t test it during a listening session because I need the top plug in the wall to power my other transformer (has LPS-1.2 powering SU-1 and iBOX-V1000 on it)


----------



## Zenvota

oneguy said:


> I haven’t heard any negative effects from low loading.


Oh, good!  I have some low power(5-10w) hdmi extenders/switchers on the transformers as well and was worried that they may be affected.


----------



## L0rdGwyn (Jan 21, 2020)

My 91002-31T arrived today.  Holy cow this thing is a BEAST.  Not sure I am comfortable carrying this more than a foot off the ground, pretty sure if I dropped it it would go straight through the original floor of my 1920s home 

Here is a pic:



Interestingly, it is wired for 120V on the primary, 240V on the secondary and has a Schuko connector on the secondary side.  Must have been used with some European equipment in its life.



Primary wiring:



Secondary wiring:



Going to have to do some rewiring before I can even test it, either go full balanced right away since I'm partway there or revert to 120V in and out.  Might have a connector lying around somewhere to replace the Schuko, or I could order an adapter to test just in case there is a problem, seller was very flexible about returning if there is an issue.  I did test for primary to secondary shorts at least, no issues there.

My girlfriend's first words upon seeing it: "Wow, that IS ugly."


----------



## Zenvota

Nice lookin' unit!



L0rdGwyn said:


> My girlfriend's first words upon seeing it: "Wow, that IS ugly."


Kind of anecotal but interesting I think.  Before adding these to my multi-channel system, my gf always kept the volume very low when watching things on youtube, even with range compression, as the audio just didnt sound good.  Say videos of people walking around urban areas, all the background sounds smeared into a convoluted mess.  After adding the topaz though and doing some additional isolating she keeps the volume much higher, and commented several times about how much more natural everything sounds.


----------



## L0rdGwyn

Zenvota said:


> Nice lookin' unit!
> 
> 
> Kind of anecotal but interesting I think.  Before adding these to my multi-channel system, my gf always kept the volume very low when watching things on youtube, even with range compression, as the audio just didnt sound good.  Say videos of people walking around urban areas, all the background sounds smeared into a convoluted mess.  After adding the topaz though and doing some additional isolating she keeps the volume much higher, and commented several times about how much more natural everything sounds.



That is interesting, hopefully the power of hifi audio will warm my girflriend's cold heart.  I actually don't find it very ugly, just bulky.  I'll get it into an attractive enclosure at some point.


----------



## L0rdGwyn

Well I made a late-night hardware run.  I replaced the Schuko plug and rewired the secondary side for 120V using the included jumpers, how convenient is that.  I also spotted the noise suppression capacitor, it is mounted behind the panel in the photo, wired in parallel across X1 and X4, the two white wires.  Haven't taken the panel apart yet to see its value, will have to investigate if it needs replacing.

Plugged the sucker in and measured voltages on the output.  I am getting 124V across hot and neutral and all of the continuity readings check out.  I know the secondary is floating, but I measured the hot and neutral voltages to ground as well, 44V between hot and ground, and 74V between neutral and ground.


----------



## L0rdGwyn

Well all appears to be working as intended.  I plugged in my amp (Glenn OTL), PC, and computer monitor.  As expected, the transformer does have a mild "in the room" hum.  It can also be heard on my amplifier at close to max volume without music playing (ear-bleeding volumes).  Tomorrow I think I will do a little A-B listening to see if the noise suppression is clearly audible.

The next step is to see if a balanced wiring setup is going to suit my needs and work with my gear.  Pretty keen on giving it a try, not so keen on damaging something that is incompatible.


----------



## L0rdGwyn (Jan 22, 2020)

Did some A-Bing this morning.  So as to remove other variables, I listened with my laptop and USB powered DAC so the only thing connected to the mains was my amplifier.  Listening was done with the ZMF Auteur and Glenn OTL.  I swapped back and forth powering the Glenn OTL from my old Furman PST-8 and the 91002-31T.

I like the track "Not Okay" by SOPHIE for testing.  This electronic song is not for the faint of heart, it is intense and dissonant, but it will put any amp through its paces with some very, very complex passages.  Took a few back-and-forth's to confirm what I was hearing.  Yeah, there is an improvement in sound.  There is a sort of veil that is lifted allowing more microdetail to be gleaned from the recording, better definition of space and a blacker background, better air on good recordings.

Funny as this noise is not something you can truly hear.  It isn't like, "oh there it is, now its gone," but the sound is noticeably more chiseled and well-defined with the 91002-31T.

While it is easy to pick out on headphones, I wonder if the same benefit is easily heard on a two-channel system, I'll have to experiment and find out.

Well I am sold.  Now to try balanced.


----------



## Zachik

L0rdGwyn said:


> Did some A-Bing this morning.  So as to remove other variables, I listened with my laptop and USB powered DAC so the only thing connected to the mains was my amplifier.  Listening was done with the ZMF Auteur and Glenn OTL.  I swapped back and forth powering the Glenn OTL from my old Furman PST-8 and the 91002-31T.
> 
> I like the track "Not Okay" by SOPHIE for testing.  This electronic song is not for the faint of heart, it is intense and dissonant, but it will put any amp through its paces with some very, very complex passages.  Took a few back-and-forth's to confirm what I was hearing.  Yeah, there is an improvement in sound.  There is a sort of veil that is lifted allowing more microdetail to be gleaned from the recording, better definition of space and a blacker background, better air on good recordings.
> 
> ...


Following this thread, my main concern is the hum from the Topaz itself...
You did comment yesterday that there IS a hum. I am curious how far from the Topaz do you sit, and whether you can still hear it or not?
I am also curious after you place it in a chassis how would that affect said hum.


----------



## L0rdGwyn

Right now it is on the left side of my desk, about 3-4 feet away from me.  In a silent room with open back headphones, it could probably be heard with quiet music (e.g, classical, chamber music, acoustic).  I suspect that if it were placed in a chassis, it would be significantly muted, others here can comment on that I am sure.

Once the transformer is wired in a balanced configuration, I suspect that the hum will be muted further still or go away completely, that seems to be the experience of many owners in the thread.  I'm probably going to wire it up in balanced later today, this will be going in my stereo eventually, so I would prefer the hum to be minimized, it will be less of an issue with headphone listening.


----------



## Zachik

L0rdGwyn said:


> Right now it is on the left side of my desk, about 3-4 feet away from me. In a silent room with open back headphones, it could probably be heard with quiet music (e.g, classical, chamber music, acoustic). I suspect that if it were placed in a chassis, it would be significantly muted, others here can comment on that I am sure.


IF added to my setup, it would probably live on the floor, 5-6 feet from when I sit. Can you still hear it if you move 2-3 feet away from the Topaz?



L0rdGwyn said:


> Once the transformer is wired in a balanced configuration, I suspect that the hum will be muted further still or go away completely, that seems to be the experience of many owners in the thread.


Interesting. What is the downside of balanced?
For the record, I have never heard that power can be balanced or non-balanced. I thought that AC power is just AC power...


----------



## oneguy

Zachik said:


> IF added to my setup, it would probably live on the floor, 5-6 feet from when I sit. Can you still hear it if you move 2-3 feet away from the Topaz?
> 
> 
> Interesting. What is the downside of balanced?
> For the record, I have never heard that power can be balanced or non-balanced. I thought that AC power is just AC power...



Same concept as balanced audio signal in that the same signal is being passed in each conductor just 180 deg out of phase. 

http://www.equitech.com/FAQ/whatis.html
http://www.aviom.com/blog/balanced-vs-unbalanced/

As far as negatives, I don’t know of specifically what can go wrong with equipment if they are plugged into balanced power other than my previous example of being told my speakers would not turn on with balanced power. 

As for noise, that can vary between based on how they have been cared for but in general the larger units are louder from what I have experienced.


----------



## ray-dude

When I flipped my Topaz ITs to balanced, it made a huge difference: hum went from audible 8' away to audible 8" away, and the temperature went from too hot to touch to barely warm.  Very very satisfying change.  I was careful to confirm that all devices I plug into the ITs are good with balanced power, and I have big "DO NOT USE" labels on those outlets, so someone doesn't mistakenly plug in something thinking it is a regular outlet.


----------



## Zachik

ray-dude said:


> When I flipped my Topaz ITs to balanced, it made a huge difference: hum went from audible 8' away to audible 8" away, and the temperature went from too hot to touch to barely warm.  Very very satisfying change.  I was careful to confirm that all devices I plug into the ITs are good with balanced power, and I have big "DO NOT USE" labels on those outlets, so someone doesn't mistakenly plug in something thinking it is a regular outlet.


Ray - how do you know which devices are compatible with balanced power and which are not?
What would be the risk of plugging in a device that is not compatible?


----------



## ray-dude

Zachik said:


> Ray - how do you know which devices are compatible with balanced power and which are not?
> What would be the risk of plugging in a device that is not compatible?



different countries are different, so I can speak only from my perspective of US power. As always, when working with power, know what you’re doing, or bring in an electrician that knows what they’re doing.  I am not an expert in this area, so please educate yourself and get professionals involved to be safe. 

Standard US power has 120V on the hot lead, relative to the neutral lead. These are where the device pulls power from. Ground should only be connected to neutral back at the panel, not in your device or outlet. Basically, the idea is that current should never flow to ground (the ground fault interrupt circuit in your bathroom actually trips when power flows to ground...this is to keep current from flowing through you to that puddle of water on your bathroom floor)

In a blanaced configuration, you basically have +60V on hot and -60V on neutral (I use the + and - loosely here...this is AC voltage). There is still 120V between hot and neutral and all current goes through hot and neutral, but it is off set to be balanced around ground reference. With the IT, this balance basically keeps certain types of noise from bucking the transformer (the hum and the heat) since it cancels out in the coils. 

the problem comes when you have a device where ground gets connected to neutral (usually with a switch). You turn off the lamp,  the switch connects neutral to outside of the lamp, and the outside of the lamp is energized to -60V vs ground. Not good for anyone or anything touching the lamp. 

If the device keeps ground to chassis ground, and uses hot and neutral for all current, and they are never connected no matter the position of the power switch, you should be fine.  Best to check with the device maker though, or have your electrician check. 

A trick to help though. If your device is able to switch between 120V and 240V operation, it is probably designed to work in Europe and other places where they have balanced power. Still worth checking with the manufacturer or your electrician. 

note that there are electrical codes around having balanced power outlets in the US (so someone doesn’t accidentally plug in something that doesn’t work with balanced power). Your electrician will have details


----------



## L0rdGwyn

Just rewired for balanced.  For the sake of ease and consistency of wiring used, I snipped off the excess length of the hot lead on the output side, soldered the ends and made a little jumper for the center tap.

All continuity and voltage readings check out, ~125V across + and - on the output, +/- to ground is ~62.5V.

Have my amp hooked up to it now in the same configuration as before, sounds excellent, background black as can be.  Transformer hum is completely gone.

Sorry, I am not going to do a back-and-forth A-B of balanced and unbalanced  suffice to say I am happy with this setup, just have to verify the rest of my gear is good to go.


----------



## oneguy

@L0rdGwyn  Welcome to the club!


----------



## Zachik

L0rdGwyn said:


> Just rewired for balanced.  For the sake of ease and consistency of wiring used, I snipped off the excess length of the hot lead on the output side, soldered the ends and made a little jumper for the center tap.
> 
> All continuity and voltage readings check out, ~125V across + and - on the output, +/- to ground is ~62.5V.
> 
> ...


So basically just plugging your GOTL to the Topaz?


----------



## L0rdGwyn (Jan 22, 2020)

Yes, I will be using a simple power strip to connect multiple components, at least until I get a chassis to mount a number outlets in parallel.  I plugged the GOTL in by itself initially for the sake of having a single variable for listening comparisons.  I also know the GOTL will work with balanced power.

Edit: all of my gear is working with balanced power, no issues whatsoever.


----------



## chrisdrop

Very jealous!!

I wish I could find a 230v low capacitance IT here in the UK. I haven't been able to find one. 

Is it really the case that only these Topaz (and other names mentioned here) have the low pF?
There are various companies that make toroidal tranfos (airlink etc) and balanced power supplies but they don't have the very low capacitance and thus have less noise rejection. 

I was thinking about just getting a toroid and making a small box with IEC socket on one side and plugs on the other but couldn't find a transformer. 

Jealous ! And well done.


----------



## felix3650

chrisdrop said:


> Very jealous!!
> 
> I wish I could find a 230v low capacitance IT here in the UK. I haven't been able to find one.
> 
> ...


Hey Chris,

I too need a 230v (with terminal) variant. Let me know when you find a supplier. I'll do the same if I come across one


----------



## L0rdGwyn (Jan 23, 2020)

chrisdrop said:


> Very jealous!!
> 
> I wish I could find a 230v low capacitance IT here in the UK. I haven't been able to find one.
> 
> ...



These are 1:1 transformers, if you get a terminal style that can be wired for 120V/240V and 50Hz/60Hz, there is no reason you couldn't use it for 230V.  Only issue as you know is they are USA-made, so you would probably have to pay big bucks for international shipping depending on the size.  Mine weighs 58lbs, but the weight drops rapidly for the smaller models.  The 750kVA for example is 27lbs.  As far as I have come across, this family of transformers are the only ones that feature the shielding for low inter-winding capacitance.  The descendents of these transformers are still being made by Eaton Corporation, they are now called "Power-Suppress 100", although someone in the thread reached out to them and the capacitance isn't quite as low as the Topaz, MGE, Xentec, etc., but still good for 136dB noise attentuation, which is still overkill.  Eaton has a presence in the UK, so that might be an option.  Oddly enough, their operational headquarters is 10 minutes away from my house, but like every good and honest US corporation that doesn't want to pay their taxes, their corporate headquarters is in Dublin.


----------



## chrisdrop

L0rdGwyn said:


> These are 1:1 transformers, if you get a terminal style that can be wired for 120V/240V and 50Hz/60Hz, there is no reason you couldn't use it for 230V.  Only issue as you know is they are USA-made, so you would probably have to pay big bucks for international shipping depending on the size.  Mine weighs 58lbs, but the weight drops rapidly for the smaller models.  The 750kVA for example is 27lbs.  As far as I have come across, this family of transformers are the only ones that feature the shielding for low inter-winding capacitance.  The descendents of these transformers are still being made by Eaton Corporation, they are now called "Power-Suppress 100", although someone in the thread reached out to them and the capacitance isn't quite as low as the Topaz, MGE, Xentec, etc., but still good for 136dB noise attentuation, which is still overkill.  Eaton has a presence in the UK, so that might be an option.  Oddly enough, their operational headquarters is 10 minutes away from my house, but like every good and honest US corporation that doesn't want to pay their taxes, their corporate headquarters is in Dublin.



Thanks for that. Very helpful. I have messaged them already. I wasn't sure how much changing the voltage from their intended would impact the max VA of the unit (or any other thing I don't know).

Go down the road, get one, put it in your luggage, I'll get you a ticket to London and it will probably be cheaper than shipping one of those big things from the US  Holiday as a transformer mule! They are massive.


----------



## oneguy (Jan 23, 2020)

chrisdrop said:


> Thanks for that. Very helpful. I have messaged them already. I wasn't sure how much changing the voltage from their intended would impact the max VA of the unit (or any other thing I don't know).
> 
> Go down the road, get one, put it in your luggage, I'll get you a ticket to London and it will probably be cheaper than shipping one of those big things from the US  Holiday as a transformer mule! They are massive.



EDIT: The max amperage for the 240V configuration should remain the same.


----------



## L0rdGwyn

chrisdrop said:


> Thanks for that. Very helpful. I have messaged them already. I wasn't sure how much changing the voltage from their intended would impact the max VA of the unit (or any other thing I don't know).
> 
> Go down the road, get one, put it in your luggage, I'll get you a ticket to London and it will probably be cheaper than shipping one of those big things from the US  Holiday as a transformer mule! They are massive.



Oddly enough, I just might be going to London later this year  I'm sure TSA will be totally cool when I try to put a 50lbs giant metal box through the X-ray machine.  "Guys, it's okay, it's just a low-capacitance isolation transformer with 136dB common-mode noise attenuation for improved audio performance."  They will understand.


----------



## Zachik

L0rdGwyn said:


> Oddly enough, I just might be going to London later this year  I'm sure TSA will be totally cool when I try to put a 50lbs giant metal box through the X-ray machine.  "Guys, it's okay, it's just a low-capacitance isolation transformer with 136dB common-mode noise attenuation for improved audio performance."  They will understand.


I bet the TSA guy would ask you:
Is that the 0.001pF or 0.0005pF version?


----------



## Zachik

Has anyone here tried to use both a Topaz isolation transformer AND Audioquest Niagara 1200? especially Topaz that is wired for balanced power?

I am curious whether it is possible, and whether it makes more sense to go:
a. Wall -> Topaz -> Niagara -> DAC & Amp
or
b. Wall -> Niagara -> Topaz -> DAC & Amp

Since the Topaz is wired for balanced power - would option "a" above even work?
Would I benefit from having both in my power chain, or would the Niagara negate the benefits of the Topaz balanced (or vice versa)?


----------



## Energy

Zachik said:


> Has anyone here tried to use both a Topaz isolation transformer AND Audioquest Niagara 1200? especially Topaz that is wired for balanced power?
> 
> I am curious whether it is possible, and whether it makes more sense to go:
> a. Wall -> Topaz -> Niagara -> DAC & Amp
> ...



In this setup I would go with option A.
However despite the Niagara offering some benefits, the Topaz might end up sounding better standalone. Adding too many power line filters/conditioners to the electrical line adds impedance and when using them in sync can add some issues.


----------



## Zachik

Zachik said:


> Has anyone here tried to use both a Topaz isolation transformer AND Audioquest Niagara 1200? especially Topaz that is wired for balanced power?
> 
> I am curious whether it is possible, and whether it makes more sense to go:
> a. Wall -> Topaz -> Niagara -> DAC & Amp
> ...





Energy said:


> In this setup I would go with option A.
> However despite the Niagara offering some benefits, the Topaz might end up sounding better standalone. Adding too many power line filters/conditioners to the electrical line adds impedance and when using them in sync can add some issues.


I have contacted Audioquest, and their support replied with:
The Niagara 1200 is designed for regular single phase ‘asymmetrical’ power.
We do not recommend to feed the Niagara from a balanced power outlet or daisy-chain it with any other AC power device.

No idea whether they're covering their butts, or maybe option A above would just not work properly...


----------



## vinylvalet

My Topaz transformer, even though rated at 120VAC in, 120VAC out measures 120VAC in, 123VAC out. As is often the case, my AC is above 120VAC and I would like it lower. It appears that I can reverse output and input on the Topaz, ie connect the power cord to the output of the Topaz and connect the AC outlets to the input side of the Topaz. Does anyone see a problem with that?


----------



## oneguy

vinylvalet said:


> My Topaz transformer, even though rated at 120VAC in, 120VAC out measures 120VAC in, 123VAC out. As is often the case, my AC is above 120VAC and I would like it lower. It appears that I can reverse output and input on the Topaz, ie connect the power cord to the output of the Topaz and connect the AC outlets to the input side of the Topaz. Does anyone see a problem with that?


Do you have -31 model? I can’t see any special reason from the diagram of the -31 that you can’t wire it backwards. As always though, before trying something new, check for shorts, continuity and voltages before touching it and putting it in service.


----------



## vinylvalet

Thanks very much, I agree. I have the 91002-13, 0.005pf instead of 0.0005pf; still an improvement. I'll reverse it and report back. That 3VAC drop should be a plus in my application.


----------



## Speedskater

How heavily loaded was the transformer when you made that voltage reading?


----------



## vinylvalet

Unloaded about 3VAC more on the secondary. Heavily loaded about 2.5VAC.


----------



## One and a half

vinylvalet said:


> Unloaded about 3VAC more on the secondary. Heavily loaded about 2.5VAC.
> 
> Not a problem, the regulation on the transformer is actually very good, that's how the regulation is measured, no load to full load voltage measurements.
> 
> Don't forget with heaps of linear and smps on the load side, the voltage can be distorted, some (cheaper) DMM have trouble measuring anything other than a pure sine wave.


----------



## Speedskater

a little "Kill-a-Watt" meter (or similar) will do a good job of measuring power line Voltage, Current & Power.
with any DMM if you measure before and after the isolation transformer, most of the meter's errors will cancel out.


----------



## rsbrsvp

I am not technically minded at all and I want to ask all you the following.

I just ordered from Schneider Electric a 750Kva  -31 115/230 model Topaz transformer.  

All my equipment together uses around 220 watts of power.  I have a mac mini, a Mutec Ref10 SE-120 clock, Audio-gd DI-20HE DDC, Audio-gd R-7HE DAC, and Audio-gd HE-9 Headphone amplifier.

1. Is my Topaz powerful enough to power my system?  If I balance it will that reduce its capacity and if so by how much?  Would it still be powerful enough for my system?

2. I have seen much talk about the hum issue and was wondering- how about just putting the Topaz on a thick rubber or silicon mat?  Shouldn't that help?

3. What is the conclusion on the DC filter issue?  Is it recommended or not to use it before the Topaz and if it is- which is the one to get?

Thanks......


----------



## Zenvota

rsbrsvp said:


> All my equipment together uses around 220 watts of power.  I have a mac mini, a Mutec Ref10 SE-120 clock, Audio-gd DI-20HE DDC, Audio-gd R-7HE DAC, and Audio-gd HE-9 Headphone amplifier.


Nice system, what headphones? Are you using filterless power distribution after the topaz?  Consider quadrapole power cables like vh-audios flavor 4 for the digital components. 



rsbrsvp said:


> 1. Is my Topaz powerful enough to power my system?  If I balance it will that reduce its capacity and if so by how much?  Would it still be powerful enough for my system?


Yes.  Yes by half.  Yes.  But I would confirm with audiogd that the components run on balanced.  I run an nfb7 but the topaz isnt balanced.  I find the -31 32 units dont hum anywhere near as loud as the -11 12 units so I never attempted balanced.  I have my projectors on a 750kv -32 unit, and the projectors have large current swing due to dynamic led dimming theyll go from pulling 100w to 300w in an instant.  no hum from the transformer.  The hum is due to the magnetic transference, using sorbothane wont even help.  If it buzzes its most likely due to the casing needs to be tightened, let it heat up and then tighten the bolts.



rsbrsvp said:


> 3. What is the conclusion on the DC filter issue?  Is it recommended or not to use it before the Topaz and if it is- which is the one to get?


Maybe someone else can help with this.  I settled on leaving my unit with a floating secondary and I just use a cyberpower sine wave ups with an autoformer(automatic voltage regulation) before the topaz due to im in south florida and we get daily brown/black outs.


----------



## rsbrsvp (Aug 5, 2020)

Audio-gd told me I'm good to go in balanced. 

I have great power cables.  I do use a -70dcb  filter on my mac mini only. It helps.  Everywhere else it hurts...  I may get rid of it after I get the Topaz- have to test...

One more thing...    I have read that the Topaz makes the sound more at ease- more mellow.  Does it round off the detail and suppress dynamics at all?


----------



## Zenvota

rsbrsvp said:


> Audio-gd told me I'm god to go in balanced.


Great, had you physically measured the power draw of the system? or just going off rated specs?



rsbrsvp said:


> I have great power cables.  I do use a -70dcb  filter on my mac mini only. It helps.  Everywhere else it hurts...  I may get rid of it after I get the Topaz- ave to test...


Cool.  I suggest the quadrapole ac and dc cables for digital components due to a specific noise generated by varied current draw of digital signal devices, a voltage develops across the inductance of the cable the only way to reduce it is with low inductance cables.  Quite possibly less of an issue with regenerative supplies though.



rsbrsvp said:


> One more thing...    I have read that the Topaz makes the sound more at ease- more mellow.  Does it round off the detail and suppress dynamics at all?



No quite the opposite, just like with the power cables, reducing all the external noise has a profound effect on dynamics and transparency, imaging/holography, treble performance/clarity/fatigue.  I think the more at ease mellow description is along those terms.

All the noise reduction plus audiogd components are what enabled me to push music like 1349 through Out of Your Head and have it not only be listenable, but sound natural and realistic.  So instead of a loss of dynamics and or "pleasant distortions", it went from unlistenable noise, to clean and clear and perfectly detailed.  And listening to straight stereo with high quality recordings is phantomlike in its imaging ability, any sign of a recording and audio system disappears and you hear what was recorded as if it were real.

Nope, no less of dynamics what-so-ever, quite the opposite for sure.

Using the topaz is two-fold.  It reduces common/traverse mode noise by a great amount.  But equally important is enabling the use of filterless power distribution after the transformer.  Electrically connected components form noise generating current leakage loops.  In some cases you can break these loops but in many cases you cannot, like between a dac and a preamp.  Higher impedance power connections like when using mov surge suppression or outlet specific filtering increase that noise, whereas filterless distribution and lower impedance connections decreases it.


----------



## rsbrsvp

Zenvota said:


> Great, had you physically measured the power draw of the system? or just going off rated specs?




Rated specs...  I would not know how to measure..


----------



## Zenvota

rsbrsvp said:


> Rated specs...  I would not know how to measure..


heh, first post on this page

any $20 power consumption meter will do.


----------



## rsbrsvp

I wouldn't know how to use it.

I'm an audiophile, not an engineer or a DIY guy....


----------



## Zenvota

rsbrsvp said:


> I wouldn't know how to use it.
> 
> I'm an audiophile, not an engineer or a DIY guy....


Oh theyre very simple, just plug the equipment into it hit the buttons and itll tell you how much power is being consumed.

If you can test and wire the isolation transformer you can operate a kilowat meter


----------



## oneguy

The newer lineage of the -31 and -32 series: 

https://www.alliedelectronics.com/PDF/Power Protection/MGE T100 Ultra Isolator Brochure.pdf

I should have a 1.8kVA unit available for a peek inside next week.


----------



## rsbrsvp

I checked with Audio-gd and they told me balanced power is fine.   

However the specs on all three of my audio-gd components state:  220V-240V.  The electricity from my wall is around 230V-235V.

However, my Topaz reads 240V and from what I understand it will go up around 6 or so volts when balanced.  Is this not dangerous for my equipment?

Is the Topaz 240V rating just the maximum or will it really take the 235V from my wall and output 240V?


----------



## oneguy

rsbrsvp said:


> I checked with Audio-gd and they told me balanced power is fine.
> 
> However the specs on all three of my audio-gd components state:  220V-240V.  The electricity from my wall is around 230V-235V.
> 
> ...



http://www.pacificparts.com/vends/mge/images/t1.pdf

From the specs, input voltage range is +/- 10% which 235V falls in


----------



## darkfireblade25

oneguy said:


> The newer lineage of the -31 and -32 series:
> 
> https://www.alliedelectronics.com/PDF/Power Protection/MGE T100 Ultra Isolator Brochure.pdf
> 
> I should have a 1.8kVA unit available for a peek inside next week.


Are these easier to get?


----------



## oneguy

darkfireblade25 said:


> Are these easier to get?


Not that I’ve noticed but I never really geared my searches towards them. But having more choices though increases the overall supply so finding a top notch solution should should be easier with more choices.

So far the top options are:
-MGE -31 and -32 (not sure if MGE made a -69)
-Topaz -31, -32 and -69
-Daitron -31 and -32 (can’t remember if I’ve actually seen one of these or not; not sure if Daitron made a -69)
-MGE T100R and T100H (also sold with “Topaz” on the label; some list these as being a collaboration with Eaton)


----------



## rsbrsvp

Just got my Topaz and with the kind guidance of Fred (oneguy) I wired it for  220V.

There must be something wrong with my ears but my stereo system sounds noticeably worse.  Less dynamic, less transparent, notably muddier and more veiled; honestly- sounds just terrible.

If a day or so of burn-in does not change this- I'm selling my Topaz .0005 cap transformer.


----------



## rsbrsvp

OK.  I just found the problem.  I was plugging my power distributor into the Topaz.  This is what damaged the sound.

I put in a regular power-strip instead and now it sounds fantastic.  Dynamic, transparent, crisp as ever....


----------



## oneguy

@rsbrsvp I’m glad everything worked out. Happy listening!


----------



## rsbrsvp

Now- the Topaz does get warm and it does hum- even in balanced mode.

It certainly is not boiling hot and neither is the hum severe-- but both issues are there.....


----------



## Zenvota

Whats plugged into the topaz? Are there any components in the audio chain not plugged into the topaz? and for the things on the topaz are they directly into the topaz or are you using extra power distribution?


----------



## Zenvota (Aug 21, 2020)

rsbrsvp said:


> OK.  I just found the problem.  I was plugging my power distributor into the Topaz.  This is what damaged the sound.
> 
> I put in a regular power-strip instead and now it sounds fantastic.  Dynamic, transparent, crisp as ever....


O woops didnt see the next posts.  I wonder if this is an example of being able to hear the impact of the noise from raising the impedance of the leakage current loops due to the per outlet filtered power distributor.  Using filterless distribution reduces the impedance and the level of noise.  And that being masked before by the effect of the high common/normal mode line noise.


----------



## oneguy

rsbrsvp said:


> Now- the Topaz does get warm and it does hum- even in balanced mode.
> 
> It certainly is not boiling hot and neither is the hum severe-- but both issues are there.....


How bad is the hum?


----------



## rsbrsvp (Aug 22, 2020)

Hum is mild.  I can only hear it if I get within about a meter of the transformer and it is mild.  Any further and I hear nothing.

It is warm by touch- not "cool" at all- but not boiling either.....

I do have my entire system- plugged into a non filtered power strip which is connected to the topaz output.

When I used my power distributor with additional filtering in it instead of the power strip- it HARMED the sonics noticeably...


----------



## Zenvota

rsbrsvp said:


> Hum is mild.  I can ionly ear it if I get within about a meter of the transformer and it is mild.  Any further and I hear nothing.
> 
> It is warm by touch- not "cool" at all- but not boiling either.....


Probably better to be over a meter away from their electromagnetic field as well =/


----------



## rsbrsvp

I believe my power filter distributor is going to garbage soon now that I got the Topaz.

It did wonders for transparency- but it lost the meat on the bones and I was not thrilled about the compromise.

With the Topaz- I get stunning transparency with extra full bodied sound.....


----------



## Zenvota

rsbrsvp said:


> I do have my entire system- plugged into a non filtered power strip which is connected to the topaz output.  When I used my power distributor with additional filtering in it instead of the power strip- it HARMED the sonics noticeably...





rsbrsvp said:


> I believe my power filter distributor is going to garbage soon now that I got the Topaz.
> 
> It did wonders for transparency- but it lost the meat on the bones and I was not thrilled about the compromise.
> 
> With the Topaz- I get stunning transparency with extra full bodied sound.....


Gotcha, 5 components right? thats alot of leakage a per outlet filtering component would definitely increase noise from those loops.  I really like the improvements from just the topaz, filterless distribution, and quadrapole power.  Simple cheap and incredibly effective.  I used to really roll off the treble due to the source audio, but after adding the signal/power improvements I can use wasapi/asio or a less rolled off OOYH, really fantastic how much all this improved treble performance.

How are you setup, usb out from the mac to the mutec, 10mhz from the mutec to the di20?  Id be curious if an ultracap powered iso regen to break the loop from the mac would improve your audio quality, maybe even compared to mac directly to the di20, something to consider maybe, as well as the etherregens.  I go pc to iso regen + amanero with an i2s isolator so both are powered by a single ultracap, i havent been able to drastically improve on it, but im also using an old nfb7 with an es9018 with a tcxo, if the dac had dual es9038(or r2r) +the as318 xos i think id notice a difference then.  

@oneguy you did some power cable comparisons?  What was your conclusion?  I found the kimber cables or anything with braiding or a center ground to mask alot of detail on the dac, the low inductance of the standard quadrapole geometry with a counterspiral ground worked really well, vh audios flavor 4 is a good example of the wire geomtry and its very simple to make yourself.


----------



## rsbrsvp

I have mac mini by USB (data line only- no V-Bus connected) to DI20HE.  DI-20HE by way of HDMI to R-7HE DAC.  R-7HE by way of ACSS to HE-9.  HE-9 to Abyss, Susvara, and LCD-4.  All connecting cables in this sequence are 100% OCC silver.

The Mute Ref 10 SE-120 is connected by 50 ohm cable to both DI-20HE and R-7HE.

My Power cables I got from eBay from a company in Croatia named "NIMAK".  Their effect on the sound was STUNNING..

I have tried th REGEN ISO before the DI-20 and so not like the results.......


----------



## Zenvota

rsbrsvp said:


> My Power cables I got from eBay from a company in Croatia named "NIMAK". Their effect on the sound was STUNNING..


wow that looks intense, have you ever seen a cross section of the cable? that geometry sounds very interesting, twisted pairs in a quadrapole around a center ground?



rsbrsvp said:


> The Mute Ref 10 SE-120 is connected by 50 ohm cable to both DI-20HE and R-7HE.


oh! right, im dumb



rsbrsvp said:


> I have tried th REGEN ISO before the DI-20 and so not like the results.......


With the stock meanwell smps or an ultracap+star quad dc cable? even with the usb regen a cheap lps + low inductance starquad dc cable made a big big difference.  Is the usb reciever in the di20 powered by usb bus power or the di20s power supply?  Theres an isolation mote between the usb to i2s chip and the fpga and the clocks, right?

Youve gotta try room impulse response binaural rendering with that system, a Smyth Realiser, Impulcifer, or Out of Your Head with headphone compensation(a must or it sounds too bright).


----------



## oneguy

Zenvota said:


> Gotcha, 5 components right? thats alot of leakage a per outlet filtering component would definitely increase noise from those loops.  I really like the improvements from just the topaz, filterless distribution, and quadrapole power.  Simple cheap and incredibly effective.  I used to really roll off the treble due to the source audio, but after adding the signal/power improvements I can use wasapi/asio or a less rolled off OOYH, really fantastic how much all this improved treble performance.
> 
> How are you setup, usb out from the mac to the mutec, 10mhz from the mutec to the di20?  Id be curious if an ultracap powered iso regen to break the loop from the mac would improve your audio quality, maybe even compared to mac directly to the di20, something to consider maybe, as well as the etherregens.  I go pc to iso regen + amanero with an i2s isolator so both are powered by a single ultracap, i havent been able to drastically improve on it, but im also using an old nfb7 with an es9018 with a tcxo, if the dac had dual es9038(or r2r) +the as318 xos i think id notice a difference then.
> 
> @oneguy you did some power cable comparisons?  What was your conclusion?  I found the kimber cables or anything with braiding or a center ground to mask alot of detail on the dac, the low inductance of the standard quadrapole geometry with a counterspiral ground worked really well, vh audios flavor 4 is a good example of the wire geomtry and its very simple to make yourself.


My power cable quest stopped at my naked 8 awg magnet wire. I haven’t had much time due to work recently to construction a starquad version of the 8 awg magnet wire with. Plus I need to find a new source for the wire. The place that I bought my current stock from ran out.

That being said, I am completely happy with the 8 awg magnet wire. It has surpassed everything I have heard so far and at A very  reasonable cost.


----------



## rsbrsvp

Zenvota said:


> With the stock meanwell smps or an ultracap+star quad dc cable? even with the usb regen a cheap lps + low inductance starquad dc cable made a big big difference. Is the usb reciever in the di20 powered by usb bus power or the di20s power supply? Theres an isolation mote between the usb to i2s chip and the fpga and the clocks, right?



The DI-20HE power the USB as I only need data line from my mac mini USB to the DI-20HE.  With the Regen I need to use the v-bus from my mac or it will not work- and I do not like the results.  Detail is being rounded off with the regen


----------



## Zenvota

rsbrsvp said:


> The DI-20HE power the USB as I only need data line from my mac mini USB to the DI-20HE.  With the Regen I need to use the v-bus from my mac or it will not work- and I do not like the results.  Detail is being rounded off with the regen


But what power supply were you using with the Regen?  Just the stock supply that came with it?


----------



## rsbrsvp

I had the 1.2 from Uptone and compared it directly to my Mojo Audio Illuminati LPS.  The Mojo BLEW it away.

I know Uptone claims all this "isolation science stuff" which I imagine is true - but my ears liked the Mojo much more- as it was just more dynamic and clear, and it should be better at three times the cost.  The Uptone LPS sounds coloured.

But even with my Mojo LPS- the Regen ISO is rounding things out.   I owned a SOTM USBtx-ultra which was clearly better than the Regen ISO but even it was not great in my system. 
My DI-20HE is already galvanically isolated and has a regenerative power supply of the highest calibre and a Mutec Ref.10 120SE clock attached to it.  Adding multiple reclocking and regeneration at this point deteriorates the sound IMHO.

If anyone wants to purchase my Regen ISO and Mojo power supply- they are available.


----------



## Zenvota (Aug 23, 2020)

rsbrsvp said:


> I had the 1.2 from Uptone and compared it directly to my Mojo Audio Illuminati LPS.  The Mojo BLEW it away.
> 
> I know Uptone claims all this "isolation science stuff" which I imagine is true - but my ears liked the Mojo much more- as it was just more dynamic and clear, and it should be better at three times the cost.  The Uptone LPS sounds coloured.
> 
> ...


Gotcha, thank you very much for clarifying, that's very interesting.  Speaks volumes to the DI-20HE and is why I'm curious as that component is on my shortlist for upgrades, actually your system is my shortlist for upgrades ;]  I would imagine the mutec offsets benefits of the regen as well.  I'm still apprehensive about a direct electrical connection to a larger pc, which probably influences my experience with the regen, compared to using a mac mini.

The only thing I'm still curious about is the dc power cable between the regen and the ultracap, those standard high inductance cables increase another layer of noise and when you remove that(use a simple quadrapole dc cable) you get the transparency and dynamics similar to what you described when you pulled the power distributor out from after the topaz.  I would be curious, if you still have the components, of the sound when swapping out that dc cable between the psu and the regen.


----------



## Zenvota

Just to add, the main benefit of the Regen being to reduce error correction performed by the usb receiver, and the phy noise generated by that error correction.  

With that mac mini to the di20, what usb cable? and what's the cable length?


----------



## Zenvota

@rsbrsvp sorry for the excess of questions, also curious what power supply you're using for the mac mini and if you have a monitor connected to the mac mini and plugged into the isolation transformer as well.


----------



## rsbrsvp

I do NOT have my LPS 1.2 anymore.  Sold it.

I do have the Regen ISO and my Mojo Audio illuminati LPS.

I use Nimak Purple USB cables same company that made my power cables.  I have their reference USB and power cables.  My USB is one meter long.

My Mac Mini is an 2018 new design model with an i7 8th generation 6 core chip.  No LPS;- just straight to the wall.  But again- I have NO V-Bus attached to the DI-20HE from my mac mini- only data line- so there should be zero noise transferring between the mac and the DI-20HE. The Amanero USB receiver used by audio-gd only needs v-bus for the initial handshake when I restart the computer- so Nimak made me a dual headed USB cable with separate data and v-bus lines so I can disconnect the v-bus after I restart the mac and the mac and DI-20HE make that initial handshake.  I do not believe that the best galvanic isolation in the world will ever beat removing that v-bus from the usb connection.


----------



## oneguy (Aug 26, 2020)

The T100R arrived today. I haven’t plugged it in yet because I need need to re-terminate the plug.

There is so much empty space in there, lol.


----------



## Zenvota

bigger chassis more surface area for heat dissipation?


----------



## oneguy (Aug 27, 2020)

I suspect the width and height are to accommodate larger cores. {See edit below} Also, they may be larger so they don’t have to tightly bend wires?

EDIT: there are two sizes for the 1.8 kVA and larger with the same length, width and 0.206” difference in height. The smaller cases are all the same size save for the 0.065” height difference between the two variants.

For reference, this 1.8kVA core is 7.5”wide and 6.25” tall.

There isn’t much surface area for conduction of heat so I’m not sure the case dissipates a lot of heat that way. Just a conjecture though. The “L” bracket in the photo keeps the core off the metal chassis at the bottom.


----------



## oneguy

I just re-terminated the plug. I’d rate the magnetostriction transformer noise as on par with the large unbalanced -31 and -32 transformers. Makes sense considering the multitude of vents means the core isn’t well sealed from the air outside the enclosure.


----------



## oneguy (Aug 27, 2020)

Based on the photos (since I closed the case up) it appears the T100R core can be wired for balanced power if so desired. My guess is this allowed the manufacturer to use the same core for both the T100R and T100H models that corresponded to each other.

I plan on testing this out and wiring one a T100R for balanced power. If it works out this opens up a new avenue of isolation transformers for Topaz/MGE seekers that prefer balanced power to unbalanced power.


----------



## oneguy

Confirmed: The T100 R can be wired for balanced power just like the -31 and T100H. The magnetostriction transformer noise has now subdued to the point where it can only be heard from 6” or less from the core with the case off.


----------



## oneguy (Aug 30, 2020)

Wiring instructions (the wires were labeled with numbers)

Original wiring:
1/3 were tied together with the hot wire coming off the fuse
2/4 were tied together with the neutral wire coming off the cord
5 and 7 attached to hot side of receptacle
6 and 8 attached to neutral  side of receptacle

Balanced power wiring:
1 goes to hot wire coming off the fuse
2/3 tie together
4 goes to neutral wire coming off the cord
5 attaches to hot side of receptacle
6/7 attach to ground
8 attaches to neutral  side of receptacle
REMOVE WIRE GOING FROM NEUTRAL RECEPTACLE SIDE TO GROUND

Ground to 5 should measure 60VAC
Ground to 8 should measure 60VAC
5 to 8 should measure 120VAC
None of the input wires should measure as a short with ground


----------



## mkaza

Very useful info on this thread - many thanks to all the contributors. Am trying to revive this thread - hopefully will get some guidance!

I am evaluating deploying an Isolation Transformer in my setup to primarily tackle any EMI/RFI noise on the lines. I currently have an Emerson 3KVA double-conversion online UPS on a dedicated circuit/phase feeding the entire components - both digital/ analog and amplifier. 

I see the recommended setup is: wall plug --> IT --> Online UPS --> components; have any of you used an IT in conjunction with a double conversion UPS in a dedicated circuit and still obtained SQ benefits? Or are these  predominantly useful in a shared circuit where other household appliances emit noise on the line? 

Secondly any views/ experiences on the noise filtering capabilities of an IT versus a more compact surge suppressor/ EMI filter from SurgeX etc.

I will NOT be able to import/source a Topaz but the best available locally is rated 0.001 pf with >100 db of common-mode noise rejection ratio. Would it be useful at all or turns out a more futile exercise - from SQ perspective?

Appreciate any inputs/ guidance,

regards


----------



## zilch0md

Hi mkaza,

I wish I had an equation for calculating the maximum frequency at which NR is "effective" vs. the pF capacitance rating, but all I can say is that 0.001 is pretty good, compared to most new isolation transformers available today.  Still, the smaller the pF, the higher the audio frequencies at which effective noise reduction is audible.  I just don't have any data points to share.


----------



## oneguy

@mkaza

I’d think the best sound quality would come from the wall/IT/component combination but since you already have the UPS it won’t hurt to give it a shot.

I had a Surgex SA1810 prior to my Topaz/MGE units. They are good but don’t offer the same level of performance as my ITs. In the purely surge protector category, I’d highly recommend trying one though.

A dedicated circuit will provide less noise for an IT to attenuate but there still will be noise  on a dedicated circuit due to upstream power components outside of your home. If you are in the US it’s possible to use other 120v wire that comes into your house as a quieter and cheaper source for a “dedicated circuit.” It’s not truly dedicated since it has 240v components on it but the number of devices on it is smaller.


----------



## mkaza

zilch0md said:


> Hi mkaza,
> 
> I wish I had an equation for calculating the maximum frequency at which NR is "effective" vs. the pF capacitance rating, but all I can say is that 0.001 is pretty good, compared to most new isolation transformers available today.  Still, the smaller the pF, the higher the audio frequencies at which effective noise reduction is audible.  I just don't have any data points to share.



Many thanks @zilch0md for your reply. I agree, quantification is not easy - but your view that an IT with 0.001pf is pretty good - will make it worth a shot! Thanks.



oneguy said:


> @mkaza
> 
> I’d think the best sound quality would come from the wall/IT/component combination but since you already have the UPS it won’t hurt to give it a shot.
> 
> ...



Many thanks @oneguy for your reply. Yes, even my Audio Note dealer insists to remove the UPS but I am comfortable keeping it to address any power outages. My requirement is more towards noise filtration than surge protection currently. SurgeX components incidentally provide inherent EMI/RFI filtration (apart from surge protection) but your experience of IT proving more beneficial than SurgeX is an important data point for me.

One other q - my UPS is rated 3KVA - so, should the IT be also rated 3KVA or can I go with something smaller, say 2KVA considering my components' peak demand would be around 700W only?


----------



## oneguy

mkaza said:


> Many thanks @zilch0md for your reply. I agree, quantification is not easy - but your view that an IT with 0.001pf is pretty good - will make it worth a shot! Thanks.
> 
> 
> 
> ...


If the power draw tops out at 700W then an 2KVA IT should be fine if the UPS is t replenish itself. If it needs to replenish itself then you would have take that into consideration as well.


----------



## mkaza

oneguy said:


> If the power draw tops out at 700W then an 2KVA IT should be fine if the UPS is t replenish itself. If it needs to replenish itself then you would have take that into consideration as well.


Thanks much, appreciate it!


----------



## oneguy

I bought an EMI noise tester to see how the Topaz -69 does. The pics below are with the house air conditioner off. With it on it was roughly 350mV no IT and 8mV with the IT.

EMI tester specs:
Input voltage: AC 85Vac - 250Vac 50/60Hz (accuracy +/- 1 VAC)
Frequency range: 10KHz - 10MHz
Noise range: 1mV - 1999mV
Measurement accuracy: +/- 5% @ 1MHZ; +5% to -50% @ 10 KHz TO 10MHz
Noise indication: 4 digits yellow and blue two-color OLED digital dot matrix display
Dimensions: 132 X 91 X 41mm
Machine weight: 150g


----------



## mkaza

oneguy said:


> I bought an EMI noise tester to see how the Topaz -69 does. The pics below are with the house air conditioner off. With it on it was roughly 350mV no IT and 8mV with the IT.


Excellent - many thanks; a good confirmation that Topaz is doing its job pretty effectively. If you don't mind, what is the pF & CMNRR ratings for the '69'?


----------



## oneguy (Oct 24, 2020)

mkaza said:


> Excellent - many thanks; a good confirmation that Topaz is doing its job pretty effectively. If you don't mind, what is the pF & CMNRR ratings for the '69'?


The 91905-69 has the same 0.0005pf capacitance as the -31 and -32 transformers and the exterior construction is the same as well. The difference is it can accept 100, 120, 200, 220, or 240v input and outputs 120 or 240v. The only one I’ve seen is the one I have and unfortunately I don’t have any other specs sheets for it.

I tested this one because it’s outlets are not being used and thus nothing on the output side to pollute the readings.


At @Energy ‘s request, I plugged the 91905-69 in series with the 91005-31 (another 5KVA IT) to see what would happen. Here are the results:
From the wall

After the 91005-31

After the 91905-69


Things to consider: the 91005-31 had all of my audio stack plugged into it likely contributing to the high reading of 25mV. The things plugged in that are powered on are the Holo Spring KTE in standby mode, LPS-1.2 (SPMS powered), iBox-V100 (SPME powered), SU-1 (powered by LPS-1.2), EtherRegen (power by LH Labs LPS-4), LH Labs Pulse Blue (power by LH Labs LPS-4), Emotiva XPS-1 (power by LH Labs LPS-4). The SMPS powering my turntable was removed so I had a free outlet.


My takeaways:

-Components on a common strip on the output side can pollute the output side which I think we all knew that, the only question is to what degree and is it audible. I’ll eventually unplug everything from the 91005-31 and get baseline readings for it.

-The measurement of 2 IT’s of 0.0005pf each is series resulted in the same 8mV reading which leads me to believe the actual noise is at the floor of what this EMI reader can detect. So, the 8mV reading earlier for just the single IT is likely below that but the meter isn’t precise enough to measure it. (Makes sense given the high amount of noise attenuation of these units).

*NOTE: All of my transformers are wired for balanced power output.


----------



## rsbrsvp

I have a question for all you experts...

Should my entire system be hooked into the topaz or should my PC or my LPS for my regen iso NOT be plugged into the topaz?


----------



## Zenvota

rsbrsvp said:


> I have a question for all you experts...
> 
> Should my entire system be hooked into the topaz or should my PC or my LPS for my regen iso NOT be plugged into the topaz?


if youre using the iso regen with galvanic isolation and the uptone ultracap lps has the ground shunted smps i would not put the pc and the smps on the topaz.


----------



## rsbrsvp

I'm using the regen ISO with galvanic isolation but NT the LPS from uptone...


----------



## Zenvota

hmm, so the uptones lps + the shunted smps provide complete isolation breaking high and low impedance leakage loops.  You could try with the pc off the topaz but the regens lps on the topaz, but I think leaving the pc and lps on the topaz would be better, having leakage loops when one component is on the topaz and one off increases impedance and noise.  Your power cables and regenative supplies should offset any line noise or harmonics from the pcs smps


----------



## oneguy (Nov 6, 2020)

A couple updates:
I finally got around to unplugging everything from my mainstay the 5KVA-31 to see how it would compare to the 5KVA-69. The results are below. All measurements were done at the power strip. The 5KVA-69 and 2.5KVA-31 have powerstrips constructed nearly identically. The 5KVA-31’s power strip is constructed similarly to the other two just with one extra plug and the rhodium plated plugs from a different manufacturer. The T-100R is using stock wire and plugs just rewired by me for balanced power.


Baseline from the wall: 315mV
5KVA-31: 36mV
2.5KVA-31: 20mV
1.8K-T100R: 20mV
5KVA-69: 8mV

Takeaways:
The 5KVA keeps measuring 8mV which is the lowest. Interestingly, the 5KVA-31 last measured 25mV with a baseline of 290mV from the wall so it was actually worse this time. Although not likely, I thought the equipment being plugged into the 5KVA-31’s original test may have skewed the measurements for the better so I plugged everything that was into the 5KVA-31 into the 5KVA-69 and measured. The -69 remained at 8mV. So given this, I have been promoted from collecting dust status to main system use.

The the 1.8KVA-T100R and 2.5KVA came in at the same value but one without the silverplated copper wire wire and rhodium plated receptacles or plugs. Probably not a factor for this test but something worth noting. I have 2 more rhodium plated receptacles that I can wire into the 1.8KVA-T100R if I have time before I move.

Next update:

On the audiophile style a while ago the question was brought up about safe distances from transformers. I bought a GQ EMF-390 to take some measurements and here are the results:


(From the 5KVA-69 with my system not being used to make music)

Distance from core (inches)    EMF(mG)

27——————————————2.5
10.25—————————————30
5.75—————————————100

For EF and RF no significant increase at any distance.

Other:

-EF was 3V/m at about 3” from my unshielded power cords with my system at idle and increased with the amount of power being used.

-cords with their components switched off still affected the EF tester. Unplugging the cord caused it to not affect the tester.


-putting my hand in front of the tester was enough to significantly shield the tester from EF. For EMF my hand in front of the tester did not have a noticeable effect.

At my listening position with the system not making music I measured 0.4mG, 1.0V/m and 125-151pW/cm2. My listening position is approximately 8.5 ft from the transformer and behind by stack of vinyl.

CAVEAT: These are all approximate measurements and only data on small sample size of units. This is not meant to be definitive in anyway. Just food for thought.


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## Zenvota

oneguy said:


> A couple updates:
> I finally got around to unplugging everything from my mainstay the 5KVA-31 to see how it would compare to the 5KVA-69. The results are below. All measurements were done at the power strip. The 5KVA-69 and 2.5KVA-31 have powerstrips constructed nearly identically. The 5KVA-31’s power strip is constructed similarly to the other two just with one extra plug and the rhodium plated plugs from a different manufacturer. The T-100R is using stock wire and plugs just rewired by me for balanced power.
> 
> 
> ...


Is there anyway to reduce emf?  faraday cages?  iron cases?

i measure 0.0mg at my seating positions, but its a cheap $10 tester and i sit about 4' from a unit.

I realised an area with a bunch of switching supplies radiates a 10mg field on the other side of the wall.  interestingly uptones ultracaps have almost no radiation, whereas the linear supplies in my headamp have a fairly strong field but not that large.  cheap switching supplies have very high emf but very small fields

today i tried removing the topaz from the headphone system and it was immediately clear the difference in sound quality, couldnt listen as loud, less defined treble quality, impacted imaging and staging,  tried to ignore it and acclimate but after a while i plugged the topaz back in and again the difference was immediately noticeable, able to crank the volume back up, purely defined cymbals etc.  

Its especially noticeable with the music i listen to which is heavily distorted and just becomes a wall of unintelligible sound, its been really surprising how beneficial all this equipment has been to audio quality with lofi recordings, i never though hifi was something that would benefit me ^^

i like these things but i do worry about the emf.  Though i had read studies years ago that documented negative effects of emf were only from very large power generators and not from magnetic transformers, power cables, etc.

Im going to try removing them from my multi channel system and projectors next.  I dont think ill see a difference with the projectors due to the nature of the units(dmd + current driven leds) but i do like the effects of noise reduction on the units in terms of a power supply heat and processing as well as the surge supression.  But i have a feeling its going to be very noticeable with the multi channel system(it was adding it, imaging and treble quality drastically improved) so i may just try and find a better location for that unit where ill have less contact with it, since i need to rearrange all those switching supplies for the hdmi extenders anyway.


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## oneguy

Zenvota said:


> Is there anyway to reduce emf?  faraday cages?  iron cases?
> 
> i measure 0.0mg at my seating positions, but its a cheap $10 tester and i sit about 4' from a unit.
> 
> ...



Based in the follow owing graph you could make a faraday cage or box out of 0.067” thickness or greater 410 steel to shield the primary 60hz frequency. Also, adding distance between you and the source will help mitigate.




https://en.m.wikipedia.org/wiki/Skin_effect
(The red line represents 50hz)


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## Thenewguy007 (Nov 11, 2020)

Anyone know how this would compete with Topaz isolation transformers?
https://www.aliexpress.com/item/4001285233703.html
or
https://www.aliexpress.com/item/4000176601682.html

Price is much cheaper & is much more recent than used Topaz.
What should the input & output selection be for North America? Both 110v?


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## darkfireblade25 (Jan 7, 2021)

Is the chart in the OP still accurate in that you need to get 2 sets of transformers? I'm currently confused as to how you're supposed to connect your system with computer/dac/amp. There's a lot of stuff said in the thread but none are summarized into one recommendation after being discussed so far. 

I just have a computer/Schiit Bifrost 2/and THX 887 amp. The Bifrost 2's Unison USB claims to have electrostatic+electromagnetic isolation so I'm not sure if I need to move the PC off the Topaz or not. I see a lot of Topazs coming with two receptacles. Do you need to put every component on a strip off of 1 receptacle or can you mix and match?

(Edited for question clarifying)


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## zilch0md

darkfireblade25 said:


> Is the chart in the OP still accurate in that you need to get 2 sets of transformers? I'm currently confused as to how you're supposed to connect your system with computer/dac/amp. There's a lot of stuff said in the thread but none are summarized into one recommendation after being discussed so far.
> 
> I just have a computer/Schiit Bifrost 2/and THX 887 amp. The Bifrost 2's Unison USB claims to have electrostatic+electromagnetic isolation so I'm not sure if I need to move the PC off the Topaz or not. I see a lot of Topazs coming with two receptacles. Do you need to put every component on a strip off of 1 receptacle or can you mix and match?
> 
> (Edited for question clarifying)



DACs and PCs are known to generate "backwash" noise, polluting the power going into anything else that's plugged into the same outlet or power strip.

You've got three devices, so you will need a small, simple power strip, with a short power cord, no surge protection or pilot lights or fuses, into which you would plug your THX 887 amp, directly (i.e. Uninex PS28E).
*
Optionally*, go ahead and plug the Bifrost DAC and your computer - both of which _*might*_ be generating backwash noise - into that same power strip shared with the THX amp.   Now plug the power strip into the Topaz *grounded-neutral secondary* isolation transformer (rated to handle at least twice as many vA (Watts) as that consumed by all three devices when running).

*Ideally*, to ensure that neither your DAC or your computer can pollute the power coming into your THX 887 amp, you should purchase two more isolation transformers that will sit between the power strip and those two devices.  These two isolation transformers should have a grounded faraday shield and a _*floating-neutral secondary*_ (i.e. two B&K Precision 1604A).  

Mike


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## zilch0md

Thenewguy007 said:


> Anyone know how this would compete with Topaz isolation transformers?
> https://www.aliexpress.com/item/4001285233703.html
> or
> https://www.aliexpress.com/item/4000176601682.html
> ...


It's highly unlikely that those isolation transformers have the extremely low interwinding capacitance (0.0006 pF) of the Topaz  -31 or -32 model series.   

In other words, they can't compete.  They would only be able to attenuate common-mode and normal-mode noise below 400 Hz, typically.   

The Topaz  -31 and -32 series transformers can attenuate commond-mode noise by 146dB, all the way up through 20,000 Hz.  

Nothing like this is still manufactured, today.   If you find it, please let us know.


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## Thenewguy007

zilch0md said:


> It's highly unlikely that those isolation transformers have the extremely low interwinding capacitance (0.0006 pF) of the Topaz  -31 or -32 model series.
> 
> In other words, they can't compete.  They would only be able to attenuate common-mode and normal-mode noise below 400 Hz, typically.
> 
> ...



I think those Chinese ones are made for audiophiles. But who knows, since they don't publish their specs.


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## darkfireblade25 (Jan 8, 2021)

zilch0md said:


> DACs and PCs are known to generate "backwash" noise, polluting the power going into anything else that's plugged into the same outlet or power strip.
> 
> You've got three devices, so you will need a small, simple power strip, with a short power cord, no surge protection or pilot lights or fuses, into which you would plug your THX 887 amp, directly (i.e. Uninex PS28E).
> 
> ...



Great, so if I buy the *floating-neutral* *secondary *ones, they'd be plugged into the power strip as well? And as a follow up question, if you go the power strip route, the other receptacle on the Topaz shouldn't be used for anything then?

As an addendum, I think I bought a unit with a Va that is a bit under the double load requirement. Can't tell if the B&K Precision 1604A is gonna handle 250-300W that my computer outputs from its specs sheet either.


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## darkfireblade25

So I bought a Topaz 91095-32 and the internals look different than what was posted so far.

This is the output side.





This is the input side


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## rsbrsvp

Question for the experienced:

Should my en tire system be hooked up to the topaz or should my streamer and sotm tx-usb ultra which are on good linear power supplies but come before galvanic isolation not be attached to the topaz?


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## Energy

rsbrsvp said:


> Question for the experienced:
> 
> Should my entire system be hooked up to the topaz or should my streamer and sotm tx-usb ultra which are on good linear power supplies but come before galvanic isolation not be attached to the topaz?



I'd say to have them all connected to one unless you can find yourself multiple TOPAZ's to ground their GND (green wire) at the output altogether via Star Grounding. By doing so reduces the AC leakage currents while keeping their 0.0005pF galvanic isolation towards specific gear. For example by doing so you could have your digital setup on one while after the USB cable to the rest of your audio system can be on another. This should reduce the high frequency hash that's dumped back into AC mains that could potentially work it's way back to your DAC/AMP if they were all tied to a single isolation transformer.


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## bequietjk

I've decided to put my 91001-31 up for sale due to space.  Minimizing my workspace and having limited area makes this difficult so, gotta downsize now.

If anyone is interested, PM me.  
I'll also be wiring it for unbalanced (how it came to me initially).

Unbalanced is the standard 120V in/ 120V out, right?


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## bequietjk

Good morning and good afternoon gents,

Before I fire this topaz off to sell, can someone confirm this to be properly wired?

Input:




Output:




I appreciate all the help over the past year from everyone here.  Some day ill be able to afford having one of these in my chain again.


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## darkfireblade25 (Feb 5, 2021)

I'm trying to find a floating-secondary transformer that can go with my computer and this is what I got back from the Hammond Mfg rep when I asked about the 171 line that was mentioned in the OP:





Does this mean that the secondary is actually grounded?

Edit: Got a follow up finally after a few weeks. I'm just too paranoid and it is a floating secondary.


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## bequietjk

My 1kva is up for sale in Classified > Sources.


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## bequietjk

Hi, Topaz community

In the process of selling my Topaz and just wanted to be sure that this is correct.

I've been asked about wiring for 120/120 balanced.  Should I follow the diagram for 120/120 as displayed on the metal plate?





Appreciate the help guys.


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## oneguy (Jul 11, 2021)

bequietjk said:


> Hi, Topaz community
> 
> In the process of selling my Topaz and just wanted to be sure that this is correct.
> 
> ...


Apparently I stopped getting notifications for this thread at the end of last year and missed a bunch of stuff. This is probably too late to be helpful but for those that have the same question:

To get 120 balanced power wire both sides per the 240 diagram and ground the jumper on the output side.

You’ll know it’s balance because jumper to X1 will measure ~60v, jumper to X4 will measure ~60v, and X1 to X4 will measure ~120v.


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## oneguy

darkfireblade25 said:


> So I bought a Topaz 91095-32 and the internals look different than what was posted so far.
> 
> This is the output side.
> 
> ...


No real point in rewiring a -32 unless you want to change the power cable or outlets. They can’t do balanced power and can’t be configured to step up or down.


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## bequietjk

Thanks for getting back to us @oneguy 
:]
I'm thankful for all the help you've given to me and and appreciate what you've done for a community.


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## oneguy

bequietjk said:


> Thanks for getting back to us @oneguy
> :]
> I'm thankful for all the help you've given to me and and appreciate what you've done for a community.


No problem. I try to help where I can


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## FiGuY1017

I've got a Topaz I've always used with my amps, with great results. When I bought my most recent amp for my Susvara, the Kinki Studio Thr-1 I heard it was not advisable to use anything with it as it already has a huge toroidal transformer and it would squash the dynamics, do you think that's the case with a Topaz as I thought there was no power loss, isn't that what the 1 to 1 means?
 Thanks in advance;


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## L0rdGwyn

I would say it's worth trying for yourself!  Interestingly I had another audio designer, a DAC designer named Slawa Roschkow of SW1X Audio Design, tell me the same about "killing the dynamics" of his DAC using a Topaz isolation transformer, but I did not experience that whatsoever (I later realized this guy wasn't really very knowledgeable and his design was poorly engineered, I sold it and designed my own DAC, but I digress).

Assuming the toroidal is the mains transformer and not an isolation transformer itself, it being "huge" will result in higher primary-to-secondary capacitance and thus increased coupling of high-frequency mains noise, so that is actually all the more reason to try the isolation transformer.  Typically toroidals utilize a primary-to-secondary electrostatic shield to reduce the interwinding capacitance, so hopefully that has been implemented in the design of the Kinki Studio THR-1.

I would say it can't hurt to try it and see if you think it improves or degrades the sound.  If the THR-1 is well-engineered, maybe there will be little-to-no improvement or a degradation.


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## MasterSplinter

Well it's nice to see this thread still going strong now that I know a bit more about electricity and all its' wonders given my previous ignorance.

I recently opened up my ECA Extreme Isolation transformer (2.5 kVA model) and replaced the power cable with a nicer one that I already owned with larger gauge wire and a better plug and wired it in there, and replaced the outlet with a nicer one as well with a tighter grip and coupled the transformer's wiring with heavier gauge wire going to the duplex outlet. It works even better than before. What I found out though when I opened it up was that the outlet was wired for balanced power already, not only that, it had a capacitor wired into it (going from an unused hot/live screw/contact to a neutral screw/contact that it shares with another wire).

My main question here concerns potentially replacing the capacitor with an even better one. The capacitor that came with the transformer is an Aerovox 7uF 250v (assuming VAC, though it only shows the v) 50-60 Hz polypropylene film capacitor 1 and 7/8" long by 1" wide (so about 47.6 mm x 25.4 mm). I know the voltage can be 250v or higher, but I'm wondering what capacitance I should choose? 7uF capacitors are pretty rare (only a handful of 250v or higher 7uF capacitors show up on Mouser, forget it with finding audiophile capacitors with that rating), and it seems like with film capacitors of these dimensions the higher the voltage the lower the capacitance available. They are even rarer if you want something better than aluminum+polypropylene like polystyrene or Teflon or a really good ceramic one and maybe nicer foil.

Just looking for some capacitor suggestions to potentially replace the one that came with my transformer. Thank you.


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## oneguy

Look around this post and the posts around it. It should be about what you’re looking. 

https://audiophilestyle.com/forums/...-transformers/?do=findComment&comment=1178908


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## L0rdGwyn

MasterSplinter said:


> Well it's nice to see this thread still going strong now that I know a bit more about electricity and all its' wonders given my previous ignorance.
> 
> I recently opened up my ECA Extreme Isolation transformer (2.5 kVA model) and replaced the power cable with a nicer one that I already owned with larger gauge wire and a better plug and wired it in there, and replaced the outlet with a nicer one as well with a tighter grip and coupled the transformer's wiring with heavier gauge wire going to the duplex outlet. It works even better than before. What I found out though when I opened it up was that the outlet was wired for balanced power already, not only that, it had a capacitor wired into it (going from an unused hot/live screw/contact to a neutral screw/contact that it shares with another wire).
> 
> ...



6.8uF is a more standard value and should be easier to find, with a 5-10% tolerance, practically it shouldn't make a difference vs 7uF.  I would be very surprised if replacing this cap made an audible difference however.  If the original is within spec, I personally would just leave it.


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## MasterSplinter (Mar 15, 2022)

Thank you very much for the help guys. I might just try a couple other different caps to see what works best and stick within the tolerance rating limit from the 7uF Aerovox (I've seen capacitance ratings as low as 0.047 and 0.033 on outlets elsewhere, just not in one of the ultra/extreme isolation transformers, so I won't chance it), then use the other caps elsewhere. Nichicon and Cornell-Dubilier have some low ESR caps on Mouser and I'll see what Parts Connexion has as well.


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## Zachik

Have not seen any posts here for a while...  Also, nothing in the classifieds for a long time.
I wonder if these Topaz transformers are getting as rare and hard to find as some NOS tubes...


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## MasterSplinter (Sep 4, 2022)

I forgot to pop back in but I replaced the (still solid) Aerovox capacitor with a Mundorf Supreme Evo silver gold oil of the same rating and it was quite the success. I had to use a different, larger cover for the ECA since the capacitor was so much larger than the old one (and I needed to support the capacitor properly as well), but the difference with both audio and video is quite noticeable. I wouldn't suggest doeing this unless you have a cover that adds depth available, but I'm sure there are film capacitor upgrades that would fit better.

Does anyone have the capacitance specs for the ECA models? They use the "Extreme Isolation" moniker that Xentek does so I wonder is the capacitance can get as low (Xentek having a .00001 model)?


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