Jump to content
IGNORED

Discussion of AC mains isolation transformers


Recommended Posts

So I checked connectivity today on my topaz. The shield seems to be in continuity with the chassis, as well as in continuity through its primary and secondary shield wires. Measuring across all these points gives a resistance too low to measure. 

 

Im guessing that’s why there is no chassis ground point, as the shield appears to be already bonded to chassis?

 

 

Link to comment
On 2/9/2018 at 4:19 AM, One and a half said:

When the reference is lost, there's additive common mode noise, since the supply rails float to what they want to do. There's no cancellation either as explained before, can explain why the grain is appearing. The ultra isolation transformers are common mode killers, they do a great job at that, they don't add!

 

I tried two Curios cables and found them to add crud in a balanced system, rather than take it away, perhaps if you have a generic cable to try, this might be an eye opener. Also keep the polarity the same on the output for AC powered devices.

 

Well, I connected everything the way you advised and.. ehh.. I am part of your balanced school! I am very grateful to you. The effect now is nothing short but spectacular. Like a serious component upgrade. The complete opposite of my former experiences with floating secondary. Less grain, more resolution and detail, and much quieter in comparison to direct AC from the wall socket. 

 

Now I have to expand my test setup and include the rest of my gear. First I have to get something like a Jensen CI-1RR IsoMax to isolate my powered subwoofer from my amp. This is due to placement restrictions (the sub is in another corner of the room) but also because of the modest 1KVA capacity of my Xentek. To isolate ethernet I will use an Emo Systems EN-70HD. I hope these measures will work to keep the effect of an isolated system.

 

Would a dedicated line from the breaker box to the Xentek bring even more of the goodness? And what is the best cable from transformer output to power distribution block (in terms of AWG, shielded or not etc.)? Any suggestions?

 

Side notes: the temperature of the transformer with only DAC and LPS connected is (guessed) less then 30 degrees celcius and I can hear a small humming noise but only within 1m distance or so.

Streamer dCS Network Bridge DAC Chord DAVE Amplifier / DRC Lyngdorf TDAI-3400 Speakers Lindemann BL-10 | JL audio E-sub e110 Head-fi and reference Bakoon HPA-21 | Audeze LCD-3 (f) Power and isolation Dedicated power line | Xentek extreme isolation transformer (1KVA, balanced) | Uptone Audio EtherREGEN + Ferrum Hypsos | Sonore OpticalModule + Uptone Audio UltraCap LPS-1.2 | Jensen CI-1RR Cables Jorma Digital XLR (digital), Grimm Audio SQM RCA (analog), Kimber 8TC + WBT (speakers), custom star-quad with Oyaide connectors (AC), Ferrum (DC) and Ghent (ethernet) Software dCS Mosaic | Tidal | Qobuz

Link to comment
1 hour ago, skatbelt said:

I am part of your balanced school! I am very grateful to you. The effect now is nothing short but spectacular. Like a serious component upgrade. The complete opposite of my former experiences with floating secondary. Less grain, more resolution and detail, and much quieter in comparison to direct AC from the wall socket. 

 

Before being an alumni you should know that the way you had it before was NOT a part of my school either. The optimal way in my school with a balanced IT the safety ground is connected to chassi with ONE wire (not two). The center tap and electromagnetic shield is connected to the chassi as well. It is also crucial that this balanced ITs output is connected to a star earth wired power distributor (via a 2-pole RCD/GFCI). A DC Blocker trap filter pre the  balanced IT. 

 

I actually have a switch on my balanced IT where I can change from floating sec and grounded sec in a split of a second. In my setup floating sec is MUCH better than grounded sec.

Here is the schematics for the curious minded. One of my best hifi related investments ever. 

 

IT_Cornan.thumb.png.892a14ac0c306b0bcb6f68bc125fb5c3.png

 

 

Link to comment
1 hour ago, skatbelt said:

 

Well, I connected everything the way you advised and.. ehh.. I am part of your balanced school! I am very grateful to you. The effect now is nothing short but spectacular. Like a serious component upgrade. The complete opposite of my former experiences with floating secondary. Less grain, more resolution and detail, and much quieter in comparison to direct AC from the wall socket. 

 

Now I have to expand my test setup and include the rest of my gear. First I have to get something like a Jensen CI-1RR IsoMax to isolate my powered subwoofer from my amp. This is due to placement restrictions (the sub is in another corner of the room) but also because of the modest 1KVA capacity of my Xentek. To isolate ethernet I will use an Emo Systems EN-70HD. I hope these measures will work to keep the effect of an isolated system.

 

Would a dedicated line from the breaker box to the Xentek bring even more of the goodness? And what is the best cable from transformer output to power distribution block (in terms of AWG, shielded or not etc.)? Any suggestions?

 

Side notes: the temperature of the transformer with only DAC and LPS connected is (guessed) less then 30 degrees celcius and I can hear a small humming noise but only within 1m distance or so.

@skatbelt, you have defected from the @Cornan regime :)  It's all part of the process!

 

If the balanced transformer is wired correctly, then the attributes you mention become very apparent, so good to hear this is working OK.

 

The subwoofer is always a problem, analog ground loops are a big issue. The Jensen transformer is a good way out of this problem since the sub would need to be driven from the wall for now. @Em2016 has a substantial sub woofer system, and a problem last year or before now where he measured the load to size an ultra isolation transformer, the acoustic levels were close to deafening, but the power draw was also very modest. I hope @EM2016 can provide some input. The 1kVA model will be fine for now, but I have noted less background chatter with a larger transformer, it's a small difference but noticeable.

 

A dedicated line will always help from the breaker box almost de rigeur ;)

 

Cabling is always very subjective, I found Furutech (the cheaper silver bulk cable) or Oyaide Tunami (if still available) cables very good, the shielding is top notch which is important. I use a Furutech Schuko type distributor, very nice design, with good grip on plugs  and also helps with background chatter. Details are in my profile at CA. 

 

If you read further back in the thread, you can find a method to quieten the transformer. With the age of these devices, noise is a bit hit and miss;  the laminations become loose over time and need tightening. 30C is about normal, will reduce with load oddly enough, hence the reason to use high temperature cables, so you will need two boxes at either end to fit off the high temperature cables to the audiophile cables, since the latter cannot cope with high temperature environment of the transformer. Can guide you through this on a PM.

 

 

AS Profile Equipment List        Say NO to MQA

Link to comment
2 hours ago, seatrope said:

So I checked connectivity today on my topaz. The shield seems to be in continuity with the chassis, as well as in continuity through its primary and secondary shield wires. Measuring across all these points gives a resistance too low to measure. 

 

Im guessing that’s why there is no chassis ground point, as the shield appears to be already bonded to chassis?

 

 

Yes, that's right, but not according to new regulations, there needs to be a wire.

AS Profile Equipment List        Say NO to MQA

Link to comment
7 minutes ago, One and a half said:

@skatbelt, you have defected from the @Cornan regime :)  It's all part of the process!

 

Ah, it was just a half win One! ? The end result can never be good if you are not prepared to go all-in. You just win some and you loose some depending on the nature of the setup. IME floating is not really floating unless you put it in series. No isolation is not absolute on its own. Adding just one floating component is not doing much. It could just as well make it worse since the noises you want to get rid of just choose a less optimal path (DAC for example). Everything needs to be floating/isolated in series to perform the true magic. Series isolation school rather than floating school is a more appropriate name for my specific learning if you ask me! ? 

 

 

 

 

Link to comment
2 hours ago, Cornan said:

 

Before being an alumni you should know that the way you had it before was NOT a part of my school either. The optimal way in my school with a balanced IT the safety ground is connected to chassi with ONE wire (not two). The center tap and electromagnetic shield is connected to the chassi as well. It is also crucial that this balanced ITs output is connected to a star earth wired power distributor (via a 2-pole RCD/GFCI). A DC Blocker trap filter pre the  balanced IT. 

 

I actually have a switch on my balanced IT where I can change from floating sec and grounded sec in a split of a second. In my setup floating sec is MUCH better than grounded sec.

Here is the schematics for the curious minded. One of my best hifi related investments ever. 

 

IT_Cornan.thumb.png.892a14ac0c306b0bcb6f68bc125fb5c3.png

 

Just a point of order, what IT are you using and what is the interwinding capacitance of this unit?

Streamer dCS Network Bridge DAC Chord DAVE Amplifier / DRC Lyngdorf TDAI-3400 Speakers Lindemann BL-10 | JL audio E-sub e110 Head-fi and reference Bakoon HPA-21 | Audeze LCD-3 (f) Power and isolation Dedicated power line | Xentek extreme isolation transformer (1KVA, balanced) | Uptone Audio EtherREGEN + Ferrum Hypsos | Sonore OpticalModule + Uptone Audio UltraCap LPS-1.2 | Jensen CI-1RR Cables Jorma Digital XLR (digital), Grimm Audio SQM RCA (analog), Kimber 8TC + WBT (speakers), custom star-quad with Oyaide connectors (AC), Ferrum (DC) and Ghent (ethernet) Software dCS Mosaic | Tidal | Qobuz

Link to comment
7 hours ago, skatbelt said:

 

Just a point of order, what IT are you using and what is the interwinding capacitance of this unit?

 

I am using a special order balanced IT made by ATL Hi-Fi. I have no figures of the inter-winding capasitance. I just ensured that I wanted a torrodial transformer with the best possible shield isolation. 

 

 

Link to comment

I want to clarify my point of view with balanced isolation transformers. I do think that a balanced isolation transformer with grounded secondary is optimal, but ONLY if you have a dedicated earth receptacle for it. Not many people have that. If you do not have a dedicated earth receptacle a floating sec one is what you want.

 

 

Link to comment

My IT is humming very gently. Like a pleased cat. For me this is not a problem because I will position it in a place that is - sound wise - isolated from my listening environment. Is there another reason I would want something like a DC blocker?

Streamer dCS Network Bridge DAC Chord DAVE Amplifier / DRC Lyngdorf TDAI-3400 Speakers Lindemann BL-10 | JL audio E-sub e110 Head-fi and reference Bakoon HPA-21 | Audeze LCD-3 (f) Power and isolation Dedicated power line | Xentek extreme isolation transformer (1KVA, balanced) | Uptone Audio EtherREGEN + Ferrum Hypsos | Sonore OpticalModule + Uptone Audio UltraCap LPS-1.2 | Jensen CI-1RR Cables Jorma Digital XLR (digital), Grimm Audio SQM RCA (analog), Kimber 8TC + WBT (speakers), custom star-quad with Oyaide connectors (AC), Ferrum (DC) and Ghent (ethernet) Software dCS Mosaic | Tidal | Qobuz

Link to comment
12 minutes ago, skatbelt said:

My IT is humming very gently. Like a pleased cat. For me this is not a problem because I will position it in a place that is - sound wise - isolated from my listening environment. Is there another reason I would want something like a DC blocker?

DC Blockers cause more problems than they try to remove. Most DIY and commercial offerings do not address the peak inrush of the transformer on the diodes as they should be sized for the transformer that they are connected to. If the ISO hums, no big deal, but it can't vibrate severely, that's not on and is a mechanical construction issue.  To experiment, connect a small heater to the ISO and see if the noise comes down. 

AS Profile Equipment List        Say NO to MQA

Link to comment
32 minutes ago, One and a half said:

DC Blockers cause more problems than they try to remove. Most DIY and commercial offerings do not address the peak inrush of the transformer on the diodes as they should be sized for the transformer that they are connected to. If the ISO hums, no big deal, but it can't vibrate severely, that's not on and is a mechanical construction issue.  To experiment, connect a small heater to the ISO and see if the noise comes down. 

 

Thx!

Streamer dCS Network Bridge DAC Chord DAVE Amplifier / DRC Lyngdorf TDAI-3400 Speakers Lindemann BL-10 | JL audio E-sub e110 Head-fi and reference Bakoon HPA-21 | Audeze LCD-3 (f) Power and isolation Dedicated power line | Xentek extreme isolation transformer (1KVA, balanced) | Uptone Audio EtherREGEN + Ferrum Hypsos | Sonore OpticalModule + Uptone Audio UltraCap LPS-1.2 | Jensen CI-1RR Cables Jorma Digital XLR (digital), Grimm Audio SQM RCA (analog), Kimber 8TC + WBT (speakers), custom star-quad with Oyaide connectors (AC), Ferrum (DC) and Ghent (ethernet) Software dCS Mosaic | Tidal | Qobuz

Link to comment
On 19/02/2018 at 11:51 AM, One and a half said:

DC Blockers cause more problems than they try to remove. Most DIY and commercial offerings do not address the peak inrush of the transformer on the diodes as they should be sized for the transformer that they are connected to. If the ISO hums, no big deal, but it can't vibrate severely, that's not on and is a mechanical construction issue.  To experiment, connect a small heater to the ISO and see if the noise comes down. 

Yes, I tried a local DIY item here in Melb, after reading some of the encouragement here & elsewhere - didn’t eliminate the not-all-that-intrusive hum, but changed it’s pitch, to somewhat higher ... no sense at all that it impacted on music sonics. So I took it out.

macmini M1>ethernet / elgar iso tran(2.5kVa, .0005pfd)>consonance pw-3 boards>ghent ethernet(et linkway cat8 jssg360)>etherRegen(js-2)>ghent ethernet(et linkway cat8 jssg360) >ultraRendu (clones lpsu>lps1.2)>curious regen link>rme adi-2 dac(js-2)>cawsey cables>naquadria sp2 passive pre> 1.naquadria lucien mkII.5 power>elac fs249be + elac 4pi plus.2> 2.perreaux9000b(mods)>2x naquadria 12” passive subs.

Link to comment

Another question regarding building an fully isolated system with all critical components on a single power distributor block on a single iso transformer: if I power one component in the chain with an Uptone LPS-1/1.2 that in it's turn is powered by a Meanwell SMPS, is it than better to power that SMPS outside the IT chain? The LPS-1/1.2's are galvanically isolated from mains power so this scenario wouldn't 'break' the isolation. As a plus, keeping the SMPS out of the chain prevents it from spitting dirt back into the system. Is this correct?

Streamer dCS Network Bridge DAC Chord DAVE Amplifier / DRC Lyngdorf TDAI-3400 Speakers Lindemann BL-10 | JL audio E-sub e110 Head-fi and reference Bakoon HPA-21 | Audeze LCD-3 (f) Power and isolation Dedicated power line | Xentek extreme isolation transformer (1KVA, balanced) | Uptone Audio EtherREGEN + Ferrum Hypsos | Sonore OpticalModule + Uptone Audio UltraCap LPS-1.2 | Jensen CI-1RR Cables Jorma Digital XLR (digital), Grimm Audio SQM RCA (analog), Kimber 8TC + WBT (speakers), custom star-quad with Oyaide connectors (AC), Ferrum (DC) and Ghent (ethernet) Software dCS Mosaic | Tidal | Qobuz

Link to comment
On 2/22/2018 at 9:46 PM, skatbelt said:

Another question regarding building an fully isolated system with all critical components on a single power distributor block on a single iso transformer: if I power one component in the chain with an Uptone LPS-1/1.2 that in it's turn is powered by a Meanwell SMPS, is it than better to power that SMPS outside the IT chain? The LPS-1/1.2's are galvanically isolated from mains power so this scenario wouldn't 'break' the isolation. As a plus, keeping the SMPS out of the chain prevents it from spitting dirt back into the system. Is this correct?

 

Anyone?

Streamer dCS Network Bridge DAC Chord DAVE Amplifier / DRC Lyngdorf TDAI-3400 Speakers Lindemann BL-10 | JL audio E-sub e110 Head-fi and reference Bakoon HPA-21 | Audeze LCD-3 (f) Power and isolation Dedicated power line | Xentek extreme isolation transformer (1KVA, balanced) | Uptone Audio EtherREGEN + Ferrum Hypsos | Sonore OpticalModule + Uptone Audio UltraCap LPS-1.2 | Jensen CI-1RR Cables Jorma Digital XLR (digital), Grimm Audio SQM RCA (analog), Kimber 8TC + WBT (speakers), custom star-quad with Oyaide connectors (AC), Ferrum (DC) and Ghent (ethernet) Software dCS Mosaic | Tidal | Qobuz

Link to comment
5 hours ago, One and a half said:

Keeping the SMPS out of the protected zone is a good idea. This applies especially to computers with built in SMPS. The LPS-1 provides the isolation between the good and bad.

 

Thanks again. Will this principle hold even when I connect the SMPS negative DC output (DC input to LPS-1/1.2) to ground? Note that this ground than comes from a receptacle out of the 'protected zone'.

Streamer dCS Network Bridge DAC Chord DAVE Amplifier / DRC Lyngdorf TDAI-3400 Speakers Lindemann BL-10 | JL audio E-sub e110 Head-fi and reference Bakoon HPA-21 | Audeze LCD-3 (f) Power and isolation Dedicated power line | Xentek extreme isolation transformer (1KVA, balanced) | Uptone Audio EtherREGEN + Ferrum Hypsos | Sonore OpticalModule + Uptone Audio UltraCap LPS-1.2 | Jensen CI-1RR Cables Jorma Digital XLR (digital), Grimm Audio SQM RCA (analog), Kimber 8TC + WBT (speakers), custom star-quad with Oyaide connectors (AC), Ferrum (DC) and Ghent (ethernet) Software dCS Mosaic | Tidal | Qobuz

Link to comment
10 minutes ago, skatbelt said:

 

Thanks again. Will this principle hold even when I connect the SMPS negative DC output (DC input to LPS-1/1.2) to ground? Note that this ground than comes from a receptacle out of the 'protected zone'.

If you ground the 0V on the SMPS, the high impedance leakage currents will be gone on the DC side, but the AC side, not so sure.

AS Profile Equipment List        Say NO to MQA

Link to comment

Okay thanks @One and a half and @lmitche. I will experiment and report back. In the meantime I have a Jensen Isomax on the way to isolate my subwoofer from the 'protected zone'. With this installed I can broaden my test setup to loudspeaker listening.

Streamer dCS Network Bridge DAC Chord DAVE Amplifier / DRC Lyngdorf TDAI-3400 Speakers Lindemann BL-10 | JL audio E-sub e110 Head-fi and reference Bakoon HPA-21 | Audeze LCD-3 (f) Power and isolation Dedicated power line | Xentek extreme isolation transformer (1KVA, balanced) | Uptone Audio EtherREGEN + Ferrum Hypsos | Sonore OpticalModule + Uptone Audio UltraCap LPS-1.2 | Jensen CI-1RR Cables Jorma Digital XLR (digital), Grimm Audio SQM RCA (analog), Kimber 8TC + WBT (speakers), custom star-quad with Oyaide connectors (AC), Ferrum (DC) and Ghent (ethernet) Software dCS Mosaic | Tidal | Qobuz

Link to comment
On 2/11/2018 at 11:23 AM, Speedskater said:

Please define 'dedicated earth'

On 2/11/2018 at 11:31 AM, Cornan said:

Isolated Ground Circuit (IG).

 

An Isolated Ground System is when the Safety Ground/Protective Earth wire is run directly back to the main breaker panel Neutral.

This is only effective in situations with metal conduit (tubing) either ridge or flexible.  Or in building with metal framing. It does not apply to Romex®  non-metallic insulated cables. An IG ground prevents leakage, noise, interference, lost neutral and ground currents from other circuits, using your interconnects as a path back to the Neutral.

 

If on the other hand an Isolated Ground System is connected to a ground rod rather than the Neutral, it is vary, vary wrong and dangerous.

 

In wiring an Isolated Ground System. it should use about the same amount of Hot, Neutral & Ground wire, all run in close proximity to each other.

 

 

 

 

 

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



×
×
  • Create New...