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

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I recognize my question may be a little off topic, but I am not sure where else to ask it. 

I am a total newbie to CA and to forum communication.  I have however read nearly this entire blog (62 pages!) and am really impressed with the breadth of understanding of this complex topic that I find here.  I can only claim a rudimentary understanding of power, and would not be comfortable putting together a DIY solution from scratch.  I am however interested in using commercially available transformers and other equipment to assemble a reasonable power system for under $1K or so.  The sound of my current system is pretty good, but I am hoping to take it to the next level. 

After reading all your enlightened comments, I have decided to put together the system described by zilch0md with a voltage regulator feeding a Tripp Lite IS1800hg, in turn feeding a B&K Precision 1604A and RCD for each source component including my preamp and phono amp.   

My current system: Modwright modified OPPO BDP-83SE CD player with external tubed power supply (PS 9.0), Pioneer PLX1000 turntable feeding Schiit Mani with Swagman PSU, Schiit Freya, EVS 500M monoblocks, Gallo Subwoofer Amp, Gallo Reference 2.0 speakers.  My only power conditioning at this time is an MIT Z Duplex Super outlet, and a dedicated line.    

I assume that the Freya, CDP, Mani should each have separate 1604As.

My question:  Should I consider the OPPO CD player and its standalone power supply as one circuit or two? It would seem to me that both components should be fed by the same 1604A to avoid any possible differences in potential between the two intermingled circuits in the same chassis. Would you not agree with this? 

Also, what do I do with the turntable?  Does it need a separate 1604A as well, or could it come off of the Tripp Lite directly (along with the power amps)?

Thank you for your thoughts, and sorry if I am a little off topic.  It seems to me that what I am reading here represents an opportunity to put together a really good power system for only pennies on the dollar.  I would think that other “budget” audiophiles like myself might find this to be of great interest as well.   

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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?

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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).

 

 

 

 

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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?

 

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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). 

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Thanks again for your suggestions.  I shall be upgrading my Topaz for a 2.4kVA 0.0005 pF unit (ordered but not here).  

My question again:  Is there a place for modalities designed to block "leakage current" (other than filtering AC main with ultra-low capacitance IT)?  I would guess that most commercially available power conditioners have them built in already--part of the "Black Box".  For those not relying on third party all-in-one "black box" power conditioning solutions, do you find benefit from modalities designed to directly address "leakage current", or is a good IT enough?

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Topaz 91002-32 2.4 kVA, 0.0005 pF 120V.  

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I have two EVS 500M monoblocks (class D, 500 watts into 8 ohms), a Gallo Subwoofer Amp (850VA), feeding Gallo Reference 3.1 speakers (88 dB, 8 ohms).  Even though I don't prefer high amplitude listening, I felt like I needed some headroom in terms of power.  

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I realize this thread may be on its last leg, but I wanted to thank you all for your assistance in helping this newbie make some remarkable improvements in my SQ.  

 

I ended up ordering three Isolation Transformers (and returning two of them), and A/B testing them all.  (I did so using the Tripp Lite Outlet strip SS3612, the one without surge protection, with everything plugged into it).  

 

These are the transformers I compared:  Tripp Lite IS1800HG, Topaz 91001-22 1kVA 0.001pF, and Topaz 91018-32 1.8kVA 0.0005pF.  

 

I found that the Tripp Lite yielded only marginally better SQ than plugging directly into the wall.  The 0.001pF Topaz sound was a major improvement over the Tripp Lite.  The 0.0005pF Topaz sound was a noticeable step up in clarity from the 0.001pF Topaz.  I realize that the smaller Topaz has less potential for high current draws, but even with quiet listening, the larger Topaz with 0.0005pF offered a much broader soundstage and greater depth. To me the difference was startling.  If I were to give them each a SQ Score (scale 1-10, poor to incredible), I would rank them…
AC Mains—4
Tripp Lite—4.5
Topaz 0.001pF—7
Topaz 0.0005pF—8

 

In the end I returned both the Tripp Lite and the Topaz 91002-22, and am delighted with the sound I am getting out of the Topaz 91018-32.  

 

My take home?  The Topaz 0.0005pF IT gave me significantly better sound than either the Tripp Lite Hospital Grade IT or the Topaz 0.001pF unit.  The difference is enough for me to recommend upgrading to the 0.0005pF unit from either of the other units.  

BTW, this is a listing of the specs and details on the 0.0005pF Topaz transformers… http://www.pacificparts.com/vends/mge/images/t1.pdf

 

Lastly, I tried inserting a B&K Precision 1604A IT with a floating secondary into my system.  First I tried it upstream from my CD player (modified with a dedicated linear power supply) and could notice no difference.  I then tried it upstream from my Freya preamplifier.  Here I noticed a small but significant improvement in SQ.  (On my scale of 1-10, I would rate it 8.5).  In doing so however, I discovered that the 1604A significantly stepped up the secondary voltage (from 124V to 130V).  This was too high for my comfort, so I added an APC LE1200 voltage regulator upstream from the Topaz unit and set the regulator at 107V.  With this setup, my sound is magic.  

 

Thanks again to you all.  
Ben
 

 

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 I have not tried it, so I could only give you my thoughts on what it might be like.

 

 I can think of no reason why it couldn't be done.  Theoretically, it  should help reduce the high frequency harmonics that degrade sound quality.  However the 0.0005 pF transformer is so effective, I would be surprised if the addition of the 0.005 pF transformer would add enough to make a difference in sound quality. However I can't prove that.

 

 If you decide to give it a try,   it is possible that you may end up with higher voltage coming out of the two of these in series than is desirable for your system.  The voltage is stepped up by small degree with each isolation transformer. Putting them in series would increase this obviously. If you were going to give this a try, before you hook your equipment up to it, I would probably check your voltage going in and out of each transformer using a Kill A Watt.  

 

 If you decide to give it a try, please report your results. I think it would be very interesting to  hear your observations. 

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Miki

In a previous post, I described my experience using a 1KVA topaz 0.001 pF transformer and comparing it to a 1.8 KVA 0.0005 pF topaz transformer. My experience was that the transformer with lower capacitance made a discernible improvement in my sound quality. This was even when listening to sounds at a very low amplitude. 

 Regarding the question as to how much power I was drawing, using my Kill A Watt, at peak  listening levels with my two 500 W monobloc's, I was drawing about 1100 W at peak. Most of the time at softer or more usual levels of listening, I am drawing around 400 W. 

Based on my experience, I believe the lower capacitance does make a difference, and if you have a chance to choose between the two transformers, I would choose the one with the lowest capacitance.