Discussion of AC mains isolation transformers

[tapatrick]

1 hour ago, SoundSparks said:

 

Why is the new unit better? Is it because of the lower capacitance (2 times lower) or is it due to the higher power (2.5 times higher)? What is the major contributing factor here?

Should think its a combination of both lower capacitance and power...

 

1 hour ago, SoundSparks said:

 

Should the distance from the gear to the iso trans be taken into consideration? 2' vs. 10', e.g.?

I have mine a metre away from my equipment in an alcove..

 

1 hour ago, SoundSparks said:

 

Is 1000VA iso trans powerful enough for 600VA (total) of connected gear? I.e. is (Total VA)/0.6 = (iso trans power rating) an accurate enough approximation?

Should think that would be enough although some opinions I've read say it needs more to allow for the peaks..

 

1 hour ago, SoundSparks said:

 

[esmit]

26 minutes ago, tapatrick said:

Yes does hum a fair bit, more than the 1Kva, which is a expected but its only noticeable when the room is completely silent.

Mine is balanced, but not floating. I will try with a heater connected some time, great tip.

[One and a half]

1 hour ago, esmit said:

Mine is balanced, but not floating. I will try with a heater connected some time, great tip.

For the Northern Hemisphere, this time of year the heater method works well, but not desirable in the summer

[tapatrick]

1 hour ago, One and a half said:

For the Northern Hemisphere, this time of year the heater method works well, but not desirable in the summer

...Its well know in audiophile circles that air warmed above 20˚C leads to improved SQ...

[One and a half]

@tapatrick, finally had the inclination and a time window to install the 2500VA Topaz. There were a few other things to remove like three other transformers which are now redundant.

The Equitech Q 1000VA is not used for the main system only the Topaz now. Not listening all that critical, since the install took most of the day, but what i did listen to, noted Dark side of the Moon (MFSL) a little cleaner and about 20% lift in height for Gregory Porter's Take Me To The Alley (96/24), which was an unexpected surprise. Will take some voltage measurements and compare them to the Equitech. The loads are radically different which will affect the readings, but should be interesting.

 

The key to a balanced transformer is the symmetry of the output windings. Crud cancellation depends on this symmetry, lets see what happens.

[SoundSparks]

On 2017-12-21 at 10:57 AM, lmitche said:

While at the factory I was told about the new transformers referenced above. They are likely to sound the same.  Plug a tripplite power strip into the transformer outlet and you are good to go.

 

Thank you very kindly for the info @lmitche!

 

Hopefully, 1000VA, the largest Balanced Power Supply offered, will provide adequate power for my gear...

Could you please suggest me a suitable power strip from Tripp Lite? There are way too many choices and am not sure what product would be the best: Bench and Cabinet Power Strips, Hospital and Medical Power Strips, ...

 

[One and a half]

21 minutes ago, SoundSparks said:

 

Thank you very kindly for the info @lmitche!

 

Hopefully, 1000VA, the largest Balanced Power Supply offered, will provide adequate power for my gear...

Could you please suggest me a suitable power strip from Tripp Lite? There are way too many choices and am not sure what product would be the best: Bench and Cabinet Power Strips, Hospital and Medical Power Strips, ...

 

Only use plain Jane power strips, no surge suppressor, no conditioning. This is cheapest and works 100%.

Theres only a handful of elaborate audiophile distribution that are of any use.

[lmitche]

1 hour ago, SoundSparks said:

 

Thank you very kindly for the info @lmitche!

 

Hopefully, 1000VA, the largest Balanced Power Supply offered, will provide adequate power for my gear...

Could you please suggest me a suitable power strip from Tripp Lite? There are way too many choices and am not sure what product would be the best: Bench and Cabinet Power Strips, Hospital and Medical Power Strips, ...

 

Here is one, they have other models as well.  Avoid surge protectors.

 

https://www.amazon.com/Tripp-Lite-Outlet-Cabinet-PS361206/dp/B00VESUMSM/ref=pd_sim_23_4?_encoding=UTF8&pd_rd_i=B00VESUMSM&pd_rd_r=3P7HRMGPWYNJ8W54HCAW&pd_rd_w=pULWA&pd_rd_wg=E2wZ9&psc=1&refRID=3P7HRMGPWYNJ8W54HCAW

[One and a half]

Spent most of the the day listening to music, read music, with the absence of noise down in the smallest crevices. Certainly noticeable when its gone, that's for sure.

 

Following on from yesterday's Topaz transformer install where it replaced the Equitech Model Q as the main AC power source for the audio system. 

The Topaz was wired
Input 240V H1 L1, H4 Neutral, Join H2&H3. Shield to ground
Output X1 Hot 1, X4 Hot 2, Join X2 & X3. Shield joined at X2
120 - 0 - 120V in classic balanced or symmetrical fashion.

 

The Equitech won't be missed, the Topaz does the same if not better job than the Equitech and it's there to stay.

Stage height has now real body and focus, even on pop material :), which implies, common and normal mode noise, interferes with imaging, all other parts of the system remaining the same, apart from receiving a cleaner AC signal for audio devices. 

It may not win the slickest awards for looks, but for function the Topaz cannot be beaten, especially for the price, but please try to find the 0.0005pf models, every bit helps, sorry @Speedskater. The new ifi Purifier is a toy, 40db reduction in common mode noise is a drop in the ocean and it adds more leakage currents by adding surge suppression... I can mouth of in this thread, cause it most likely be deleted in the product page (ahem).

 

The Topaz and its brethren, have 140db of common mode and 65db of normal mode noise reduction totally due to material that can kill that noise, iron, and lots of it without adding further leakage currents or other side effects.

 

To avoid circulation paths, the ground connections on the secondary on the primary were wired out and both were grounded at the same point. It's important to wire the Topaz with 90C or higher rated wire, when I pulled out the 1000VA Topaz, it was a little warm and the 75C wires were very sloppy and the insulation felt uncomfortably compressible. For this install I used 10AWG PTFE with silver plated copper, which is rated at 200C.

 

Stats:
Input 
H1-H4 : 236 Vac

 

Output:
X1-Gnd : 122.1 Vac
X4-Gnd : 122.0 Vac
X1 - X4 : 244.1 Vac
X1: 0.8A AC
X2: 0.8A AC
Both X1 and X2: 0.00A (no leaks to ground at 50Hz anyway)
Ambient : 29.6
Case Temp : 45.6
The Topaz is rated to 50C, so based on this load at 50C, 74C would be the case temperature, so it does get hot, but doesn't buzz or hum.

The voltage symmetry between X1 and X4 is very good, long term could be better, this was just a spot measurement.

 

[tapatrick]

4 hours ago, One and a half said:

Spent most of the the day listening to music, read music, with the absence of noise down in the smallest crevices. Certainly noticeable when its gone, that's for sure.

 

Thanks @One and a half for your nice report on your Topaz install (same as mine just installed 2 days ago too). I confirm with your findings on the effect of noise removal which brings out the best in the music - in my system this brings tauter bass, clearer sound all round, wonderfully natural sounding voices and oodles of delicate details and reverberations leading to greater ease and listening pleasure.

[jamesg11]

I’

19 hours ago, One and a half said:

Spent most of the the day listening to music, read music, with the absence of noise down in the smallest crevices. Certainly noticeable when its gone, that's for sure.

 

Following on from yesterday's Topaz transformer install where it replaced the Equitech Model Q as the main AC power source for the audio system. 

The Topaz was wired
Input 240V H1 L1, H4 Neutral, Join H2&H3. Shield to ground
Output X1 Hot 1, X4 Hot 2, Join X2 & X3. Shield joined at X2
120 - 0 - 120V in classic balanced or symmetrical fashion.

 

The Equitech won't be missed, the Topaz does the same if not better job than the Equitech and it's there to stay.

Stage height has now real body and focus, even on pop material :), which implies, common and normal mode noise, interferes with imaging, all other parts of the system remaining the same, apart from receiving a cleaner AC signal for audio devices. 

It may not win the slickest awards for looks, but for function the Topaz cannot be beaten, especially for the price, but please try to find the 0.0005pf models, every bit helps, sorry @Speedskater. The new ifi Purifier is a toy, 40db reduction in common mode noise is a drop in the ocean and it adds more leakage currents by adding surge suppression... I can mouth of in this thread, cause it most likely be deleted in the product page (ahem).

 

The Topaz and its brethren, have 140db of common mode and 65db of normal mode noise reduction totally due to material that can kill that noise, iron, and lots of it without adding further leakage currents or other side effects.

 

To avoid circulation paths, the ground connections on the secondary on the primary were wired out and both were grounded at the same point. It's important to wire the Topaz with 90C or higher rated wire, when I pulled out the 1000VA Topaz, it was a little warm and the 75C wires were very sloppy and the insulation felt uncomfortably compressible. For this install I used 10AWG PTFE with silver plated copper, which is rated at 200C.

 

Stats:
Input 
H1-H4 : 236 Vac

 

Output:
X1-Gnd : 122.1 Vac
X4-Gnd : 122.0 Vac
X1 - X4 : 244.1 Vac
X1: 0.8A AC
X2: 0.8A AC
Both X1 and X2: 0.00A (no leaks to ground at 50Hz anyway)
Ambient : 29.6
Case Temp : 45.6
The Topaz is rated to 50C, so based on this load at 50C, 74C would be the case temperature, so it does get hot, but doesn't buzz or hum.

The voltage symmetry between X1 and X4 is very good, long term could be better, this was just a spot measurement.

 

I’ll save these details, thanks.

What would be the expected sonic uptick by going balanced?

[One and a half]

17 minutes ago, jamesg11 said:

I’

I’ll save these details, thanks.

What would be the expected sonic uptick by going balanced?

Here are advantages.

[jamesg11]

Separating out the balanced info cf to the non-balanced on the Tortech site was a bit opaque ... I’ll re-read back thru the thread. Would get someone else to do the mod, so need a summary for them. Thanks.

[SoundSparks]

Merry Christmas and a Happy New Year dear friends!

 

Thank you very kindly @One and a half and @lmitche for your most appreciated help!

 

On 2017-12-23 at 1:00 AM, One and a half said:

The Topaz and its brethren, have 140db of common mode and 65db of normal mode noise reduction totally due to material that can kill that noise, iron, and lots of it without adding further leakage currents or other side effects.

 

 

It is a very, very impressive performance from Topaz: 140dB/65dB noise reduction! I wonder how would Balanced Power Supply from Goertz Audio compare... 

 

Please chime in!

[Speedskater]

On 12/23/2017 at 9:30 PM, One and a half said:

Here are advantages.

While there are advantages for a permanent hard wired unit, but not so much for a portable unit.

Permanent hard wired balanced transformers are expensive and have electrical code restrictions. Most of their advantages are matched by a isolation transformer at lower cost and less code restrictions.

[Johnseye]

For those that own a Topaz or MGE, I'm looking at a 750 or 1k transformer.  How loud is the hum?  Does the transformer need to be close to the equipment, or can I place it near the breaker box?  I've got a 50 ft run from box to outlets.

[Speedskater]

Near (but maybe not in) the audio room is best. At lest for large transformers wired as Separately Derived Systems. Shorter Safety Ground wires from component to component & Neutral are good and a S.D.S. is a big part of that.

[Jud]

47 minutes ago, Johnseye said:

For those that own a Topaz or MGE, I'm looking at a 750 or 1k transformer.  How loud is the hum?  Does the transformer need to be close to the equipment, or can I place it near the breaker box?  I've got a 50 ft run from box to outlets.

 

I have a 2.4k, and it hums sufficiently loudly that I would not want it within earshot of the listening room.  The spec says less than 50dB, which is dishwasher territory.  It certainly isn't that loud, but if you think "Fluorescent light with a bad ballast," you won't be too far off.

[Johnseye]

4 minutes ago, Jud said:

 

I have a 2.4k, and it hums sufficiently loudly that I would not want it within earshot of the listening room.  The spec says less than 50dB, which is dishwasher territory.  It certainly isn't that loud, but if you think "Fluorescent light with a bad ballast," you won't be too far off.

 

I have 2 options.  Under the breaker box which is in our "game room" with pool table, bar, etc.  It would be in an enclosed box and I could further build some isolation around that to better contain the noise if needed.  The other location is in a closet within the "theater room".  This is a 22 ft. long room and the closet is in the far back corner, while the listening area is within the first 15 feet of the room.  I could build some sound insulation around this if necessary as well.

 

I'm not familiar with these transformers.  Can I connect 2 different breaker circuits to one transformer?  I noticed there's a primary and secondary, but wasn't sure if that would allow for connectivity to two runs.

[Speedskater]

23 minutes ago, Johnseye said:

'm not familiar with these transformers.  Can I connect 2 different breaker circuits to one transformer?  I noticed there's a primary and secondary, but wasn't sure if that would allow for connectivity to two runs.

I thank that you need a good electrician.

[Johnseye]

5 minutes ago, Speedskater said:

I thank that you need a good electrician.

 

I've got one.  I want to have some knowledge and my ducks in a row before buying it.  I don't need a 1k VA transformer for just my 2 channel equipment.  If I can use the same transformer for my home theater gear, which will be on a different circuit, then I'll get one that big.  Buying these things off ebay doesn't provide good if any instructions.

[Johnseye]

17 hours ago, Speedskater said:

I thank that you need a good electrician.

 

I got a very helpful answer from @zilch0md regarding the transformer.

 

1) Keep the cable coming out of the Topaz' secondary as short as possible - because you don't want it to act like an antenna that picks up EFI and RFI between the transformer and your devices.  

 

2) That cord should go to a simple power strip that has just enough outlets to service your devices, and the outlets on that power strip should be as close together as possible.  The goal here is to discourage leakage currents by minimizing the impedance between any two outlets.  You will lose that advantage if have multiple power strips coming from the transformer's secondary.

 

3) Ideally, the devices themselves should have short power cords, too, but that's not easy to do.

 

Answering your question, you won't be able to wire two breaker through the Topaz to different outlets and you wouldn't want to do that, anyway, because you want all the devices to be on the same power strip (same transformer and same circuit breaker upstream from the transformer).

 

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.

 

At most, I would have the electrician wire run a dedicated circuit to the transformer, with it situated as close as possible to your gear.  Then, perhaps, directly wire a power strip to the transformer's output (that power strip can have a circuit breaker, but no chokes or MOVs for surge protection - and, again, the outlets should be as few in number and as close together as possible, for your gear.  If you're not going to cut the cords on your gear, to shorten them, then make the cord that connects the power strip to the transformer as short as possible.

[Speedskater]

But a 1kVA transformer is not anywhere big enough to power two circuits.

 

[sdolezalek]

When we built our current home, one of the changes we made was to replace the wiring strung from the electrical post on the street to the roof of the old house with a meaningfully thicker cable, run by itself in a 1 inch PVC conduit and buried 4 feet deep under the driveway running 300 feet from the street.  The difference in noise level from old to new was stunning, but as I also moved the audio system on its own circuit and made other changes I never thought about whether the combination of long undergrounding and thicker guage might have a noise effect on its own.

 

Thoughts? 

[look&listen]

4 hours ago, Johnseye said:

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.

Uh, I don't think "preached" is the best word. How about "suggested" or "explained" ?

 

I get what you are saying about the distance between different outlets causing different impedances. But if you wired the power strips with the same wire type, cord lengths, number of connections, and a fan-out to the receptacles, that problem goes away. Every power strip I have seen was wired in series: outlet1 to outlet2 to outlet 3 and so on. So the length of wire and number of connections increases from outlet to outlet, causing a small, but real, change in impedance. Instead, a fan out of equal length wires from a central point to each and every outlet will equalize the impedances.

I've collected the parts to do this, but it's behind a couple of other projects.