[One and a half]

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]

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.

 

[zilch0md]

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.

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

 

[One and a half]

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.

Thanks again!

Mike

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.

 

[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.

 

[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]

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

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]

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.

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.

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]

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



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

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]

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]

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.

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]

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.



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

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...