AC Filtering, Grounding Boxes, Linear PSU and Balanced Power.

[Speed Racer]

1 hour ago, allhifi said:

archtype: ALSO, dispense with the idea and use of the Tripp-lite strip --it's a BAD idea. 

Consider a simple, but well -built (removable IEC) power strip instead.

 

pj

 

Why? The TrippLite PS series of power strips are great.

[allhifi]

1 hour ago, Speed Racer said:

 

Why? The TrippLite PS series of power strips are great.

 

TrippLite = Great ! Seriously ?

 

Please forward me the EXACT model number --and price.

Then, I will forward you what I consider "really good" (compared to TrippLite would be considered superb) power extender --at a comparable price.

 

peter jasz 

[Johnseye]

A great strip would be the Shunyata Venom PS8.  High quality outlets and cable with no conditioning.  Overpriced for a PDU?  Sure, but it's great.  TrippLite is "good enough".  You probably don't need anything better, but if you believe in power cords and outlets get something great.

[Speed Racer]

50 minutes ago, allhifi said:

 

TrippLite = Great ! Seriously ?

 

Please forward me the EXACT model number --and price.

Then, I will forward you what I consider "really good" (compared to TrippLite would be considered superb) power extender --at a comparable price.

 

peter jasz 

 

How about the TrippLite PS2408RA for $48.25.

 

There is nothing wrong with these power strips. They are well made and, as John Swenson tells us, putting everything on a single power strip "dramatically cuts down on the impedance between boxes, significantly lowering noise generated by leakage loops."

[Speed Racer]

15 minutes ago, Johnseye said:

A great strip would be the Shunyata Venom PS8.  High quality outlets and cable with no conditioning.  Overpriced for a PDU?  Sure, but it's great.  TrippLite is "good enough".  You probably don't need anything better, but if you believe in power cords and outlets get something great.

 

There is no way I am going to spend that kind of money ($1,000 plus) when I can do better using a used $135 Topaz isolation transformer and an inexpensive quality power strip.

[Speedskater]

I would go with a Tripp Lite long before any of the boutique products.

I'm only interested in brands that also serve the commercial, industrial and IT markets.

[archtype]

Here goes a long response to a short question….

To answer your questions Allhifi about the use of the B&K Precision 1604A IT and the Tripp Lite strip, and to clarify my own thinking, I would refer to several posts by John Swenson and zilch0md (who in my mind are both amazing).  I won’t quote them, but will refer to them by date and location and then attempt to briefly summarize what they were saying in terms of my ability to understand this topic.  (I hope I don’t get myself in hot water from them and others by doing this!)

Zilch0md: See posts in this thread on pages 12, 13, 14, and 61 dated 7/8/15, 7/19, 28, 29/15 and 6/4/17. 

John Swenson: See posts in Discussion of AC Mains thread on pages 1, 2 and 16, dated 10/19,20, 24, 29/16, 11/30/16 and 12/1/16.   (https://www.computeraudiophile.com/forums/topic/29662-discussion-of-ac-mains-isolation-transformers-started-wposts-moved-from-quotlps-1-troubleshootingquot-thread/) (I appreciate Speed Racer for directing me to this thread.)

As I understand the issue, there are two types of noise in a system.  The first, Common-mode Noise arises outside the audio circuit due to the crap that is in the AC mains (i.e. refrigerator motor starting, LED lamps, etc.).  It may be of high or low frequency.  Depending on the quality of your AC mains power, this can be a larger or smaller issue for each system. 

Cleaning up this common-mode noise may be accomplished by using an Isolation Transformer with a grounded-secondary such as the units made by Topaz and the Tripp Lite Isomax transformers.  These all provide complete isolation from the AC mains, and provide a degree of surge protection.  As JS so clearly spells out however, these IT transformers vary widely in their ability to filter out high frequency noise from the secondary signal.  The ability to truly clean this signal correlates inversely with the capacitance of the winding of the transformer.  Only with capacitance of >0.005 pF or so does the IT truly clean the high frequency signal effectively.  Thus arises the great interest in the Topaz and other such ultra-low capacitance transformers as a foundation of clean power.  The Tripp-Lite medical IT units don’t seem to have this low capacitance documented. 

The second type of noise, Normal-mode Noise, is the low amperage, high frequency noise that arises from “leakage loops” in the audio circuitry itself.  In terms of affecting Sound Quality, in most systems this is of much greater significance than the Common-mode Noise described above.  These are especially likely to arise whenever unbalanced (i.e. RCA) connectors are used, and from wall-warts and other power supplies, etc.  They often manifest themselves as a high frequency DC potential underlying the signal (I think I have this right).  JS explains that by keeping the impedance that separates the components in the system extremely low, the generation of these leakage loops is minimized.  Thus, his recommendation to use a very simple output strip with all the components attached to minimize the impedance between each circuit.  JS however is clear that in order to eliminate these leakage currents, another modality must be used.  He references the Ultra-Cap LPS-1 in this regard. 

It is in this context I believe that zilch0md raises the question of using an Isolation Transformer with a floating-secondary to eliminate the Normal-mode Noise.  This basically provides a dead end for all these leakage currents.  This would be used particularly on the low current digital circuits where these currents are a problem.  The B&K Precision 1604A is an example of such a device. In effect, this would be plugged into the low impedance power strip, and the digital component plugged into this, thus dead-ending all leakage currents in that circuit.   One of these would be used for each component.  Zilch0md describes this well in his posts. 

I realize it is more than a little brash to attempt to summarize the thinking of others on the forums.  I hope that I have correctly interpreted the intent and understanding of both JS and zilch0md, and hope that no offence will be taken at my attempts to do so.  And I welcome the opportunity to be corrected. In any event, I highly encourage taking a few minutes and reviewing their actual posts which explain this a lot more clearly that I am able. 

(Please pardon the long post).

 

 

 

 

[One and a half]

8 hours ago, archtype said:

Thank you both for your thoughtful responses.  I have read through the other thread you mentioned and found some great ideas.  I looks like I will be moving ahead with a Topaz 1kW IT and a Tripp Lite outlet strip like John Swenson recommended.  At one point the question was raised of using a B&K Precision 1604A IT for each line level circuit, but no one picked up on it.  Wouldn't that have the same effect as the Ultra-Cap that was so often discussed in that thread?

The moment another transformer is included for other devices creates differences in voltages supplied to the equipment. 

We have enough drama with signal ground loops already, having different mains potentials and worse ground differences by including a separate transformer is therefore not recommended.

 

One Topaz,  one power strip = simple and effective 

[Speedskater]

Different power line voltages won't matter at all. Each component has it's own power transformer and the inputs and outputs are isolated from each other. What matters is that all the chassis's are connected to each other through short Safety Ground/Protective Earth wires.

True the component's power transformers are not as good as isolation transformers but that's a different subject.

[allhifi]

3 hours ago, Johnseye said:

A great strip would be the Shunyata Venom PS8.  High quality outlets and cable with no conditioning.  Overpriced for a PDU?  Sure, but it's great.  TrippLite is "good enough".  You probably don't need anything better, but if you believe in power cords and outlets get something great.

 

 

A solid recommendation --but pricey. 

 

Archetype, I'm not on this forum often, last chance at providing me your TrippLite model number/price so I can forward you a link for something MUCH better ...

 

pj

[allhifi]

3 hours ago, Speed Racer said:

 

How about the TrippLite PS2408RA for $48.25.

 

There is nothing wrong with these power strips. They are well made and, as John Swenson tells us, putting everything on a single power strip "dramatically cuts down on the impedance between boxes, significantly lowering noise generated by leakage loops."

 

In that case, you are good to go !

 

pj

[allhifi]

3 hours ago, Speed Racer said:

 

There is no way I am going to spend that kind of money ($1,000 plus) when I can do better using a used $135 Topaz isolation transformer and an inexpensive quality power strip.

 

Very smart ! I agree with you. But, do get a no-nonsense (inexpensive/reasonably priced) power extender. NO filters, "Spike protection", nothing just good AC receptacles, internal wiring and solid chassis --the same recipe for any good quality device.

 

 pj 

[allhifi]

3 hours ago, Speedskater said:

I would go with a Tripp Lite long before any of the boutique products.

I'm only interested in brands that also serve the commercial, industrial and IT markets.

 

" I would go with a Tripp Lite long before any of the boutique products".

 

" Long before (any of the boutique products) " ? Interesting. In which case you should proceed as originally directed.

 

 pj

[allhifi]

3 hours ago, archtype said:

Here goes a long response to a short question….

To answer your questions Allhifi about the use of the B&K Precision 1604A IT and the Tripp Lite strip, and to clarify my own thinking, I would refer to several posts by John Swenson and zilch0md (who in my mind are both amazing).  I won’t quote them, but will refer to them by date and location and then attempt to briefly summarize what they were saying in terms of my ability to understand this topic.  (I hope I don’t get myself in hot water from them and others by doing this!)

Zilch0md: See posts in this thread on pages 12, 13, 14, and 61 dated 7/8/15, 7/19, 28, 29/15 and 6/4/17. 

John Swenson: See posts in Discussion of AC Mains thread on pages 1, 2 and 16, dated 10/19,20, 24, 29/16, 11/30/16 and 12/1/16.   (https://www.computeraudiophile.com/forums/topic/29662-discussion-of-ac-mains-isolation-transformers-started-wposts-moved-from-quotlps-1-troubleshootingquot-thread/) (I appreciate Speed Racer for directing me to this thread.)

As I understand the issue, there are two types of noise in a system.  The first, Common-mode Noise arises outside the audio circuit due to the crap that is in the AC mains (i.e. refrigerator motor starting, LED lamps, etc.).  It may be of high or low frequency.  Depending on the quality of your AC mains power, this can be a larger or smaller issue for each system. 

Cleaning up this common-mode noise may be accomplished by using an Isolation Transformer with a grounded-secondary such as the units made by Topaz and the Tripp Lite Isomax transformers.  These all provide complete isolation from the AC mains, and provide a degree of surge protection.  As JS so clearly spells out however, these IT transformers vary widely in their ability to filter out high frequency noise from the secondary signal.  The ability to truly clean this signal correlates inversely with the capacitance of the winding of the transformer.  Only with capacitance of >0.005 pF or so does the IT truly clean the high frequency signal effectively.  Thus arises the great interest in the Topaz and other such ultra-low capacitance transformers as a foundation of clean power.  The Tripp-Lite medical IT units don’t seem to have this low capacitance documented. 

The second type of noise, Normal-mode Noise, is the low amperage, high frequency noise that arises from “leakage loops” in the audio circuitry itself.  In terms of affecting Sound Quality, in most systems this is of much greater significance than the Common-mode Noise described above.  These are especially likely to arise whenever unbalanced (i.e. RCA) connectors are used, and from wall-warts and other power supplies, etc.  They often manifest themselves as a high frequency DC potential underlying the signal (I think I have this right).  JS explains that by keeping the impedance that separates the components in the system extremely low, the generation of these leakage loops is minimized.  Thus, his recommendation to use a very simple output strip with all the components attached to minimize the impedance between each circuit.  JS however is clear that in order to eliminate these leakage currents, another modality must be used.  He references the Ultra-Cap LPS-1 in this regard. 

It is in this context I believe that zilch0md raises the question of using an Isolation Transformer with a floating-secondary to eliminate the Normal-mode Noise.  This basically provides a dead end for all these leakage currents.  This would be used particularly on the low current digital circuits where these currents are a problem.  The B&K Precision 1604A is an example of such a device. In effect, this would be plugged into the low impedance power strip, and the digital component plugged into this, thus dead-ending all leakage currents in that circuit.   One of these would be used for each component.  Zilch0md describes this well in his posts. 

I realize it is more than a little brash to attempt to summarize the thinking of others on the forums.  I hope that I have correctly interpreted the intent and understanding of both JS and zilch0md, and hope that no offence will be taken at my attempts to do so.  And I welcome the opportunity to be corrected. In any event, I highly encourage taking a few minutes and reviewing their actual posts which explain this a lot more clearly that I am able. 

(Please pardon the long post).

 

 

 

 

 

 

archtype: You are a passionate guy ! Nice to see.

 

There's no need to reference any previous posts.

 

I will suggest (again) to read up on Isolation transformers including symmetrical (tapped secondary)for so-called "Balanced" operation .

 

Look up Equi=tech, Torus and (although long discontinued) Blue Circle MR-800/1200.

 

Also, look into the PSAudio P-3 AC power re-generator.

 

From there, simply plug all of your digital audio gear into the multiple-receptacles of these units. Indeed, use a quality power strip if more connections are required or if you should you decide to construct a single receptacle IT yourself.

 

There is much to learn far from these pages and the wise words offered by well-meaning posters. 

 

pj

 

[allhifi]

2 hours ago, One and a half said:

The moment another transformer is included for other devices creates differences in voltages supplied to the equipment. 

We have enough drama with signal ground loops already, having different mains potentials and worse ground differences by including a separate transformer is therefore not recommended.

 

One Topaz,  one power strip = simple and effective 

 

Beautifully said :

 

" The moment another transformer is included for other devices creates differences in voltages supplied to the equipment. 

We have enough drama with signal ground loops already, having different mains potentials and worse ground differences by including a separate transformer is therefore not recommended.

 

One Topaz,  one power strip = simple and effective"

 

ATTN: archtype. One and a half (quoted above) said it PERFECTLY.

 

pj 

[Speed Racer]

1 hour ago, allhifi said:

 

In that case, you are good to go !

 

Why not post for everyone what you think is a better power strip for similar money?

[EuroChamp]

2 hours ago, allhifi said:

 

Beautifully said :

 

" The moment another transformer is included for other devices creates differences in voltages supplied to the equipment. 

We have enough drama with signal ground loops already, having different mains potentials and worse ground differences by including a separate transformer is therefore not recommended.

 

One Topaz,  one power strip = simple and effective"

 

ATTN: archtype. One and a half (quoted above) said it PERFECTLY.

 

pj 

 

The power supply inside each device makes many different voltages, which are needed by the device itself. I would definitely say, it does not matter if the input voltage of all you Hi-Fi gear is identical or not.

There is no common voltage for all together.

 

But take care of the grounding of course, as you mentioned.

[allhifi]

4 hours ago, Speed Racer said:

 

Why not post for everyone what you think is a better power strip for similar money?

 

 

Simply look to any of the Hammond (metal body) models found everywhere.

 

 pj

[Speed Racer]

I don't really see anything that would cause one to conclude that the Hammond is better made than the Tripp Lite or vice versa. Why do you think the Hammond power strip is better made? The price is certainly higher (50% or more) on the Hammond units for the same feature set.

 

It would seem to come down to features. The Hammond has the plugs much closer together which is bad if you are using any wall warts. But, that same design feature could make the Hammond better if you are not using wall warts since the plugs are closer which should reduce the impedance between devices.

[archtype]

Thank you all so much for your words of wisdom.  I have decided to go with a Topaz IT (with 0.005 pf capacitance) and a Tripp Lite PS2408 which I was able to pick up for $35.  I am confident that this will give me excellent filtering of my AC main.  

My question remains however as to the best way to attenuate or eliminate the "leakage currents".  John Swenson references this somewhat:

 

"So the system as a whole is the isolation transformer feeding a very simple, very low impedance power strip with everything plugged into that power strip. This gets rid of external AC mains noise, deals with surges and provides a very low impedance AC mains path that significantly cuts down on the noise from the leakage loops.

 

Note it does not decrease the actual leakage loops, they are still there, it just decreases the NOISE generated by these loops, and THAT is what really matters.

 

So devices like the LPS-1 will BREAK loops from the digital side of things, which are usually the worst ones in a system, the above AC mains topology will decrease the noise generated by the leakage loops in the rest of the system, DACs, preamps, poweramps etc."

 

My question going forward is how best to deal with the remaining leakage loops.  JS references using the LPS-1 to break the loops altogether. Zilch0md suggests using an IT with a floating secondary.  Or does breaking the loops really add much to SQ once you are using a ultra low capacitance IT upstream?

 

[Speed Racer]

What devices are you going to plug into this power strip plugged into the Topaz?

[allhifi]

8 hours ago, Speed Racer said:

I don't really see anything that would cause one to conclude that the Hammond is better made than the Tripp Lite or vice versa. Why do you think the Hammond power strip is better made? The price is certainly higher (50% or more) on the Hammond units for the same feature set.

 

It would seem to come down to features. The Hammond has the plugs much closer together which is bad if you are using any wall warts. But, that same design feature could make the Hammond better if you are not using wall warts since the plugs are closer which should reduce the impedance between devices.

 

Hey SR: Unless you actually compare a TrippLite type power bar against a (removable IEC inlet) PB of superior construction, little can be gained. Yet, to my frame of mind, a quality component (i.e. quality parts) is something I'd prefer to seek --and use. Assuming of course, one can be found at a reasonable (sensible for its parts compliment) price.

 

However, it strikes me unusual; that you users who go to the (very worthy) trouble of quality AC power quality yet squabble over a $100-$200 quality built power bar/extender ?

What a (detachable IEC inlet) WILL PROVE, is that a simple power cord swap (say, a throw-in #12 AWG (with a rubbery insulation) vs. another throw-in of a smaller gauge with harder covering --and any and every mix in between) results in 'shake-your-head-in-disbelief' realizations of the sound experienced --tonal distinctions, LF clarity/control/resolution, the sense of "musical lucidity" and definition are easy to pick out, think upon, enjoy and/or simply muse over.

 

Give it a try.    

 

NOTE: archtype Don't go deeper into this (for now) than what is required. I leave you with One-and-Half's wise words:

 

" The moment another transformer is included for other devices creates differences in voltages supplied to the equipment. 

We have enough drama with signal ground loops already, having different mains potentials and worse ground differences by including a separate transformer is therefore not recommended.

 

One Topaz,  one power strip = simple and effective" (One-and-Half)

 

pj

 

 

 

[archtype]

Everything.... Freya, Swagman PSU for Mani, Pioneer turntable, OPPO CDP, Modwright Powersupply for OPPO, 2 Class D monoblocks, Gallo Subwoofer Amp.    I have ordered a Kill-a-watt and will be checking my peak current draws (I don't listen to high volumes much at all). 

[Speed Racer]

Ah, I see. You are one of those folks that believes that $1000 power cords make a real discernible difference. Now I understand.....

[Speed Racer]

Just now, archtype said:

Everything.... Freya, Swagman PSU for Mani, Pioneer turntable, OPPO CDP, Modwright Powersupply for OPPO, 2 Class D monoblocks, Gallo Subwoofer Amp.    I have ordered a Kill-a-watt and will be checking my peak current draws (I don't listen to high volumes much at all). 

 

Regardless of your measured power draw, I would get a larger capacity Topaz isolation transformer than you think you need. I would get a 2.5 kVa unit if you can find one. Another benefit is that you can get a 2.5 kVa unit with .0005pf instead of the .005pf on many of the lower capacity models.