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Discussion of AC mains isolation transformers


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I had schaffners filters but since i optmised my digital chain with battery decoupling and network isolation, i have much less harchness in SQ and i realize i probably liked before the schaffner for their low pass action on audio spectrum and digital harchness more that their ability to filter ac noise. They probably do it well, but they colored the sound too and affect the dynamics.

I just removed them.

 

The Schaffner filter needs to supplied with a balanced power supply, common the neutral to ground and it loses its effectiveness.

 

The most important point on the Schaffner filters and devices like them, is that it isn't a filter. It's a low pass selective mirror, it reflects frequencies in its domain back to the origin. On the line side, to the rectifiers, on the load side also back to the rectifiers on the load device, but it will not mix the two systems for RF. The attenuation of frequencies vary but they start throttling EMC above low MHz values. It will pass 50/60Hz and low order harmonics very well.

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You do realise that this is meant to normally be the rear panel of a 1 Unit rack case such as the attached from Altronics ?

H5031 1U Black Aluminium Front Panel 19" Rack Case - Altronics

 

It has it's power lead on the same surface as the outlets though. Behind the furniture it wouldn't be visible at all.

 

And it's the only type of board I can find with no circuit breaker, no switch, no filters.

 

Wouldn't work? Apart from the visual aesthetics, any other issues with using it to plug Hi-Fi into?

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Forget double adapters, their connections are too sloppy. There's nothing on the Australian market that does what we need to do.

 

You mentioned an electrician that is re-working the Elgar when it arrives? I thought to use standard 4 Way Outlets and a mounting block.

Put two of these back to back, and wire via shielded power cable to the RCD. A fire resistant timber perhaps would jazz it up. The joining wires can be short, there are only three, so impedance is not an issue.

 

[ATTACH=CONFIG]30450[/ATTACH] Available here

 

[ATTACH=CONFIG]30451[/ATTACH] Available here

 

This is what I made before standardising on Oyaide and Furutech Euro standard plugs and sockets, there's nothing much for AU style even from Furutech only one or two models, that's it. Euro gear is rated for 230V and it stops anyone else using a vacuum cleaner out of the system. Choices.

 

Never use NEMA 120V plugs and sockets on 230V systems. You don't pressurise a tyre rated maximum at 30psi and you put in 60psi?

 

[ATTACH=CONFIG]30452[/ATTACH]

 

Very nice! You're a lot handier with this stuff (and qualified) than me. But yes, my Elgar has arrived ! And I just dropped it off today with a gentleman (who also makes some pretty well known amps here in Oz) to 'do up' for me. But he won't be working on it till next week.

 

I'll scrap the idea of double adapters.

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It has it's power lead on the same surface as the outlets though. Behind the furniture it wouldn't be visible at all.

 

And it's the only type of board I can find with no circuit breaker, no switch, no filters.

 

Wouldn't work? Apart from the visual aesthetics, any other issues with using it to plug Hi-Fi into?

 

The 3m lead would not be shielded.

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The 3m lead would not be shielded.

Noted. I can ask them to put an IEC socket instead of a lead and use my existing shielded power cable.

 

They're pretty open to customisations. Any other issues with using this type of product for my/our application? Apart from the looks of course

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It has it's power lead on the same surface as the outlets though. Behind the furniture it wouldn't be visible at all.

 

And it's the only type of board I can find with no circuit breaker, no switch, no filters.

 

Wouldn't work? Apart from the visual aesthetics, any other issues with using it to plug Hi-Fi into?

 

Sure it would work. I do like Garry's suggestion though.

 

And I just dropped it off today with a gentleman (who also makes some pretty well known amps here in Oz) to 'do up' for me. But he won't be working on it till next week.

Are you from Melbourne ? If so, you may mean AKSA from DIY Audio who makes Aspen amplifiers ?

If this is the gentleman, please say hello to Hugh from me !

 

Alex

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

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Sure it would work. I do like Garry's suggestion though.

 

Are you from Melbourne ? If so, you may mean AKSA from DIY Audio who makes Aspen amplifiers ?

If this is the gentleman, please say hello to Hugh from me !

 

Alex

Yes, I'm in Melbourne. Earle from Weston Acoustics is helping me out. One of the nicest people you could ever meet ! First time meeting him today.

 

For anyone interested, here is a John DARKO review: Weston Acoustics Troubadour integrated | DAR__KO

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You do realise that this is meant to normally be the rear panel of a 1 Unit rack case such as the attached from Altronics ?

H5031 1U Black Aluminium Front Panel 19" Rack Case - Altronics

Also, there other rack mounted PDU's I had seen before that had the inlet power lead on the opposite side to the outlets, which would make for awkward cable routing on the ground. But this particular one (made in Oz) has the inlet lead and outlets on the same face. So on the ground it would look like a typical powerboard, with the addition of a couple mountain plates/flanges on the ends.

 

I think that's the only downside? Provided I can get an IEC socket to use with my shielded power cable.

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Thanks for this good idea. The GE adapter should fit right onto the two-gang outlet of the small Topaz I'm planning to pick up from an industrial recycler today.

 

I'm getting a 500VA one to run my front end. But I have a 100W Class D amp I'd also like to plug into it (I can never really crank it for long since my listening room is a bedroom).

 

What will be the signs that I'd be overtaxing the Topaz? Are there any fire hazards or other damage (say to my system) to worry about?

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The Schaffner filter needs to supplied with a balanced power supply, common the neutral to ground and it loses its effectiveness.

 

The most important point on the Schaffner filters and devices like them, is that it isn't a filter. It's a low pass selective mirror, it reflects frequencies in its domain back to the origin. On the line side, to the rectifiers, on the load side also back to the rectifiers on the load device, but it will not mix the two systems for RF. The attenuation of frequencies vary but they start throttling EMC above low MHz values. It will pass 50/60Hz and low order harmonics very well.

 

Hi,

 

Interesting thank you.

I have checked for my two schaffners (FN352 and FN690), both are -10b minimum at 10khz !

So even if the schaffner is not on audio output i am not suprise they have an impact on output sound on audible frequencies.

 

B.

 

 

Sent from my iPhone using Computer Audiophile

 

Tplink optical bridge/etalon streamer/audiogd nfb29/linn klout/athom sirrocco + athom rafale v38 hypex

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Now you have the schaffners do you think it was worth the effort? Cheap and easy to wire (I can do that)☺........

Thanks for listing the ones you use. I haven't been able to see the Furutech rating but not sure if it's just a bit of fancy plating on a Schaffer. I was looking at these before John mentioning the ISO Transformer. ...

 

I just have a mytek brooklyn so I am unsure if an isolation transformer would benefit myself but lack electronics knowledge and being UK based wouldn't know we're to start looking for an alternative for a low power version....?

 

Shame I know more about a Picachoo than a Picofarad. .

 

Sent from my SM-G900F using Computer Audiophile mobile app

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Thanks for this good idea. The GE adapter should fit right onto the two-gang outlet of the small Topaz I'm planning to pick up from an industrial recycler today.

 

I'm getting a 500VA one to run my front end. But I have a 100W Class D amp I'd also like to plug into it (I can never really crank it for long since my listening room is a bedroom).

 

What will be the signs that I'd be overtaxing the Topaz? Are there any fire hazards or other damage (say to my system) to worry about?

 

Picked it up and found a 2 dollar IKEA multi-plug adapter lying around the house. I have my entire system plugged into it, including the 100W amp. Interventions welcome if I'm playing with fire!

 

Is SQ improved? Yes, subtly, and I don't think it's expectation bias.

Is it warm? Barely warm to the touch at all.

 

Is the IKEA adaptor hospital grade? Of course not. Those who swear by audiophile outlets are cringing . . .IMG_0095.jpg. Thanks to John S. and this thread.

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Hi Joel. I have not purchased an iso transformer sized for my entire system (though I plan to for the house my wife and I will be building in the near future). I have purchased a couple of small iso transformers for (1) my MacBook's SMPS, and (2) my preamp. I also placed a network isolator (though not a transformer) on one Ethernet connection from the router supplying network service to my system, and am awaiting delivery of a second isolator for the second connection from that router. Like iso transformers, it is a function of network isolators to stop leakage currents. https://en.wikipedia.org/wiki/Network_isolator

 

While making these changes, I have had in my system a device that serves the function of a "noise sniffer" (see for example Welcome to AudioPrism Noise Sniffer). It takes whatever noise you have in your system and amplifies it to the point where it is plainly audible. I can tell you that iso transformers and network isolators do work to reduce noise, since they made noise in my system inaudible even with the "sniffer."

 

A very interesting thing that I remarked about to a friend is that when the noise was inaudible, these measures subjectively resulted in the sorts of classic changes we've all described in these pages - better soundstage and imaging, more detailed intonation in vocals and instrumental playing, a greater sense of ease in listening.

 

So I know for a fact these things work to reduce noise, and my subjective impression is that even when noise was not audible they were beneficial in my system.

 

I received the second network isolator today and connected that. In addition, I have recently purchased two power strips without filtering, surge suppression, etc. These strips take IEC inputs. I'd had old MIT Z-Cords feeding them, but thinking of avoiding filtering, yesterday I substituted two ordinary Tripp-Lite IEC cords. So I've got the strips plugged into the wall with these cords, a couple of the network isolators (inexpensive b/c bought used), a couple of small (about 5" cube) inexpensive iso transformers, and the LPS-1. I had this combo together for the first time tonight and just had time to listen to a few songs, not too loud because my wife had gone up to bed.

 

The sound is effing amazing. Effortless clarity and beauty. All the nuances, all the little differences in the way things are recorded, even from track to track on the same album...I'm loving it.

One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature.

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I received the second network isolator today and connected that. In addition, I have recently purchased two power strips without filtering, surge suppression, etc. These strips take IEC inputs. I'd had old MIT Z-Cords feeding them, but thinking of avoiding filtering, yesterday I substituted two ordinary Tripp-Lite IEC cords. So I've got the strips plugged into the wall with these cords, a couple of the network isolators (inexpensive b/c bought used), a couple of small (about 5" cube) inexpensive iso transformers, and the LPS-1. I had this combo together for the first time tonight and just had time to listen to a few songs, not too loud because my wife had gone up to bed.

 

The sound is effing amazing. Effortless clarity and beauty. All the nuances, all the little differences in the way things are recorded, even from track to track on the same album...I'm loving it.

Very nice. Which power strips if you don't mind me asking?

 

 

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Very nice. Which power strips if you don't mind me asking?

 

Not Jud, but IIRC, he may have ordered one of these based on John's recommendation.

 

Audio Catalog

 

They are very nicely made and the price is hard to beat. But I think they took a long time to arrive.

 

Another decent no-filter-element, heavy-duty USA power strip series is this one from TrippLite.

 

12 Outlet Vertical Power Strip 120V 15A 6 ft Cord 5 15P 36 in (PS361206) | Tripp Lite

 

Attractive extruded aluminum housing, outlets that grip like crazy, and a 14awg cord. The linked 12-outlet version is $41.

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Not Jud, but IIRC, he may have ordered one of these based on John's recommendation.

 

Audio Catalog

 

They are very nicely made and the price is hard to beat. But I think they took a long time to arrive.

 

Another decent no-filter-element, heavy-duty USA power strip series is this one from TrippLite.

 

12 Outlet Vertical Power Strip 120V 15A 6 ft Cord 5 15P 36 in (PS361206) | Tripp Lite

 

Attractive extruded aluminum housing, outlets that grip like crazy, and a 14awg cord. The linked 12-outlet version is $41.

Very nice indeed. Thanks for that. Looking forward to getting my Elgar back next week and hooked to my system.

 

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The Wiremold power strips are nice with lots of configurations available (e.g. number of outlets, 6 & 15 foot cords, switched & no switch) and sturdy metal housing.

 

I use the compact "Plug-in Outlet Center Units".

 

Allied Electronics - Catalog

 

 

 

Sent from my iPad using Computer Audiophile

 

 

The discussion on this thread is in line with Naim recommendation which is always to avoid using any power conditioners, circuit breakers and surge protection for best performance. In North America, Naim recommends the Wiremold L10320 which I currently have two of these and they are excellent sonically and the build quality is first class. This is a nice read to get some background info on why Naim recommends a plain power strip by Stereophile Listening #153 Page 2 | Stereophile.com

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Another decent no-filter-element, heavy-duty USA power strip series is this one from TrippLite.

12 Outlet Vertical Power Strip 120V 15A 6 ft Cord 5 15P 36 in (PS361206) | Tripp Lite

Attractive extruded aluminum housing, outlets that grip like crazy, and a 14awg cord. The linked 12-outlet version is $41.

The only problem with that Tripplite is that it has a 15A breaker. I would think this Tripplite hard wired version would be better and made for 20A, no breaker. https://www.amazon.com/dp/B00006B820/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=13RTTM92VAYI&coliid=ICJ1VG4X0JQSS&psc=1

 

But you will need to wire in your own plug, which is probably better so you can match your transformer receptacle and get the exact length you need.

(JRiver) Jetway barebones NUC (mod 3 sCLK-EX, Cybershaft OP 14)  (PH SR7) => mini pcie adapter to PCIe 1X => tXUSBexp PCIe card (mod sCLK-EX) (PH SR7) => (USPCB) Chord DAVE => Omega Super 8XRS/REL t5i  (All powered thru Topaz Isolation Transformer)

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Here are informative pdfs on leakage currents, especially those caused by SMPS. Wondering what frequency leakage currents can be, and they form part of the EMC spectrum up to 30MHz, but can bottom by regulation to 100kHz. That doesn't mean the lower than 100kHz frequencies aren't there, it's only a limit of compliance.

 

I would have thought the higher RF would be mitigated by audio components in one way or another, so these frequencies should be covered by reflecting the noise back to the source. It's the lower frequencies that cause the problem, supposing they have greater energy.

In essence and reality hits home here, to remove the leakage currents on the AC is not so easy based on filtering. That's most likely why power conditioners with L and C get the frequency wrong and cause a worsening of SQ. I found this out the hard way by installing a Monster power Center on the upstream of a balanced transformer. There must have been a resonance of the harmonics from the audio equipment reactive adversely with the L & C of the power conditioner. The bass vanished and the performance just sucked the life out of recordings, so bad idea there.

 

The way around this is to corral the AC leakage currents so they follow some path of our choosing and not into audio devices. Ony way is the practice of star-ring the components never goes out of fashion, heh the Naim Hydra is a good idea but needs some DIY at voltages that bite to make sure the AC leads are the same length, if possible especially for sources, but can't be avoided in all circumstances. Not easy for the hobbyist though.

 

Hopefully these discussions may shed some light on techniques that work for everyone.

 

Don't forget the built in transformers of audio equipment of reputable quality have shields between windings and in some cases, enveloped shields over the winding. Inherently this provides for voltage suppression and avoids an easy path for leakage currents to enter.

 

 

2004NOV16_POW_TA.pdf

 

Electromagnetic-Interference-EMI-in-Power-Supplies.pdf

 

APEC-2002.pdf <-- From Henry OTT

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The discussion on this thread is in line with Naim recommendation which is always to avoid using any power conditioners, circuit breakers and surge protection for best performance. In North America, Naim recommends the Wiremold L10320 which I currently have two of these and they are excellent sonically and the build quality is first class. This is a nice read to get some background info on why Naim recommends a plain power strip by Stereophile Listening #153 Page 2 | Stereophile.com

 

You would have to ask why the Hydra didn't work in the North America, where the power strip does. That extra bit of copper makes a difference?

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Now you have the schaffners do you think it was worth the effort? Cheap and easy to wire (I can do that)☺........

Thanks for listing the ones you use. I haven't been able to see the Furutech rating but not sure if it's just a bit of fancy plating on a Schaffer. I was looking at these before John mentioning the ISO Transformer. ...

 

I just have a mytek brooklyn so I am unsure if an isolation transformer would benefit myself but lack electronics knowledge and being UK based wouldn't know we're to start looking for an alternative for a low power version....

 

Shame I know more about a Picachoo than a Picofarad. .

 

Sent from my SM-G900F using Computer Audiophile mobile app

Before i clean my digital chain, YES, schaffners were efficient. Price is very different with model, you can have cheap ones on eBay, with the risk to get fake or broken ones... You connect neutral, ground and phase on input and output (and it must be in a case). the right amperage has to be checked for the schaffer to be efficient, and each model act not the same.

But : Schaffner decrease the dynamics on power devices (amps), and they colored the sound. IME The low pass effect has effects on the trebles.

I did use them only on my player and DAC.

As i write before, since i clean the digital chain, i found my schaffners less useful and i think they did act more like a low pass filter on trebles, than on HF filtering to remove high frequencies that affect digital signal in my DAC.

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Not Jud, but IIRC, he may have ordered one of these based on John's recommendation.

 

Audio Catalog

 

They are very nicely made and the price is hard to beat. But I think they took a long time to arrive.

 

Thanks, Alex. I ordered two of them, and they are indeed nicely built. They did take a while to arrive, because I selected the cheapest shipping method, surface from Hong Kong to the eastern US. You can have them shipped as fast as you like, but they are substantial so the speediest methods may be relatively expensive.

One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> optical Ethernet to Fitlet3 -> Fibbr Alpha Optical USB -> iFi NEO iDSD DAC -> Apollon Audio 1ET400A Mini (Purifi based) -> Vandersteen 3A Signature.

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Thanks, Alex. I ordered two of them, and they are indeed nicely built. They did take a while to arrive, because I selected the cheapest shipping method, surface from Hong Kong to the eastern US. You can have them shipped as fast as you like, but they are substantial so the speediest methods may be relatively expensive.

Thanks, i sent them an email enquiry.

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I just had a quick look...I wonder if they do UK flavours. Fantastic for junior experimenters like me.

or I can Mod UK plates by drilling out and using self tapping screws......

Fantastic site.....Thank you for listing it.

 

Anyone in the UK using an isolation transformer? Links advice along the lines of John's suggestion..?

I can get second hand kit tested at work for safety.... But no idea on models to search for..

Interesting reading thanks all posters..

 

Sent from my SM-G900F using Computer Audiophile mobile app

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