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

[zilch0md]

On May 30, 2017 at 3:16 AM, marce said:

Had a look around at balanced power, I would be wary of using it in the USA, in the UK its a definite no way... Unless the whole dwelling has be designed for balanced power then to me the risks are not worth it for domestic audio (again we have approx 2X the line voltage here in the UK). Isolation transformers are far better.

Just one of the safety critical views, there are more:

http://www.soundonsound.com/sound-advice/crosstalk-readers-writes

 

I've only just now read this article.  Good reading!

 

Quoting it:

 

Quote

 

Figure 4. Using PME (unbalanced) power with an isolating transformer: Bridging between either terminal and ground is safe because there is no circuit through which the current can flow.

 

A much safer, much more familiar, and more accessible alternative to a balanced mains supply — but one that provides exactly the same benefits of reduced ground noise — is to use a mains-isolating transformer on standard unbalanced (PME) mains for each audio device that is susceptible to earth line noise (see figure 4). The working principle is that the output side of the mains transformer 'floats' — there is no earth connection at all — and you cannot, therefore, get a lethal shock off the equipment powered from it under any circumstances. Equally, there can be no leakage currents to or from the earth if there is no connection to it. However, it is critically important that you connect only one piece of equipment to an isolation transformer. Connecting multiple devices completely negates the safety aspect, and a fault in one item will render all connected equipment live!

 

Notice that he's recommending a floating-neutral secondary IT, not an IT with a grounded-neutral secondary.  Adding a RCD to the output would prevent a shock when touching both the hot and the neutral at the same time (improbable, but not impossible.)

 

Notice also his warning that each device should have its own (floating) IT.  He's saying this because one device could expose you to hot while the other exposes you to neutral. Unlikely, but not impossible.  I want only one device per floating IT to prevent "backwash" noise of a DAC or a component's internal SMPS from polluting the power supplied to another component on a shared IT outlet.  Letting them all share the outlets of a single, upstream grounded-secondary IT is not only OK, but ideal (to reduce the potential for current loops).

 

(See my recently posted diagrams.)

[Speedskater]

7 hours ago, EuroChamp said:

For a simple DC filter, I see no huge disadvantage, when the cable is not the very shortest.

Different story with a HF filter.

Correct, it doesn't apply to DC blockers. Only noise/interference filters, whether stand-alone or in a power conditioner need a short cord from filter to component.

 

I often wonder why so many audiophiles think that they need a DC blocker. What is it that creates this problem 24 by 7 year round?

[Cornan]

3 hours ago, Speedskater said:

I often wonder why so many audiophiles think that they need a DC blocker. What is it that creates this problem 24 by 7 year round?

 

I cannot speak for others, but personally I see the DC blockers as a "stress reliever" for my floating isolation transformer. My IT was dead silent (no audioble transformer hum from >20 cm distance), but the DC blocker trap filter still improved sq. I'll guess the DC blockers helps the floating IT to perform optimal without DC (SMPS) distrurbences.

[Speedskater]

I doubt it.

[Cornan]

8 minutes ago, Speedskater said:

I doubt it.

 

"When in doubt, tell the truth. It will confound your enemies and astound your friends" Mark Twain ?

[EuroChamp]

5 hours ago, Speedskater said:

I often wonder why so many audiophiles think that they need a DC blocker. What is it that creates this problem 24 by 7 year round?

 

A DC blocker made my transformer quiet. It totally depends on your location, if you have DC coming out of your power outlets.

[Speedskater]

So did you investigate just why DC was coming out of AC receptacles? It's not a normal condition and it doesn't make it through the big power company transformers (I did read about one exception though). So something near-by is the cause. Not many electrical units run all the time in a residential neighborhood. Most likely it's in or near your house.

 

But my first guess is that it's not a DC problem, it's that the line voltage is higher than the transformer was designed for. The blocker knocks the line voltage down a couple of volts and the transformer is happier.

[EuroChamp]

1. yes

2. no

 

[Superdad]

My recollection is that DC on the mains is much more common in Europe than in the USA.  I don't know why that is though.

[austinpop]

1 hour ago, Superdad said:

My recollection is that DC on the mains is much more common in Europe than in the USA.  I don't know why that is though.

 

I have a B&K 1604a arriving today, so after plugging it in, I will report how loud my "hmm" is!

[lmitche]

2 hours ago, austinpop said:

 

I have a B&K 1604a arriving today, so after plugging it in, I will report how loud my "hmm" is!

I have 3, ones a Hummer, but not very loud. Good luck.

[lmitche]

18 hours ago, austinpop said:

 

I have a B&K 1604a arriving today, so after plugging it in, I will report how loud my "hmm" is!

Here is a relatively cheap DC blocker for 110 volts from Canada.

 

http://www.bluecircle.com/page152a.html

[austinpop]

21 hours ago, lmitche said:

I have 3, ones a Hummer, but not very loud. Good luck.

 

Whew - mine's quiet as a mouse!

 

6 hours ago, lmitche said:

Here is a relatively cheap DC blocker for 110 volts from Canada.

 

http://www.bluecircle.com/page152a.html

 

Good to know, but hopefully I won't need one.

[zilch0md]

I have two B&K Precision 1604a.  When I put my hand on them, I can feel a slight vibration, but I can't hear them.

[zilch0md]

On 6/8/2017 at 4:52 AM, lmitche said:

Here is a relatively cheap DC blocker for 110 volts from Canada.

 

http://www.bluecircle.com/page152a.html

 

I might give this a try.  Thanks!  

 

Several of Blue Circle's early products look like a pipe full of snot, but they have a good reputation. You'd think they could trim off the excess silicon, though.  LOL

[Johnseye]

On 6/7/2017 at 10:39 AM, austinpop said:

 

I have a B&K 1604a arriving today, so after plugging it in, I will report how loud my "hmm" is!

 

Did you get any benefit from this device?  Or was your quiet as a mouse comment referring to that you had no hum and this device could add no benefit?

[austinpop]

6 minutes ago, Johnseye said:

 

Did you get any benefit from this device?  Or was your quiet as a mouse comment referring to that you had no hum and this device could add no benefit?

 

Yeah, just posted on a different thread.

 

 

[archtype]

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.   

[Speed Racer]

archetype,

 

I would use this thread as a guide instead of the one we are currently in:

 

https://www.computeraudiophile.com/forums/topic/29662-discussion-of-ac-mains-isolation-transformers-started-wposts-moved-from-quotlps-1-troubleshootingquot-thread/

 

You can easily stay within budget buying a used Topaz isolation transformer or two off of eBay. Read the thread....my sound quality improved noticeably by following John Swenson's advice. 

[allhifi]

1 hour ago, archtype said:

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.   

Hi: Sorry about dragging your "quote" in my reply, but can't seem to find a way to reply without inserting the quote ! lol

 

Just a quick suggestion to consider (look for) a second-hand Exact Power SP-15 AX4 (a balanced/symmetrical power unit with four independent tranny's isolated  from the other) and/OR to consider a PS Audio P-3 type AC Power re-generator (for source/preamp? components only).  I note the P-3 is currently sale priced  at $1,495. NEW --and although out-of budget, something to strongly consider.

 

To my mind. you are certainly taking the right steps, although my experience suggests voltage regulation is best suited to video/TV, negatively impacting audio performance.

If that can save some $$ (voltage regulation deletion), all the better.

 

peter jasz   

[archtype]

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?

[Speed Racer]

I would look for a 1.8 to 2.5 kVa Topaz unit if you can as the price difference is small and the extra power handling ability can be important. 

 

The B&K Precision 1604A is listed to 1.25 amp continuous. That's not much. I don't see these as a reasonable solution.

[allhifi]

1 hour 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?

Hey archtype: I"picked up" on it. But, had no idea of what you were referring to ? (Not everyone has the 62-pages of thread following insight as you !)

 

In any case, elaborate (clarify) on using the "B&K 1604A IT for each line-level circuit "

 

I will again, refer you to my earlier comments  concerning commercially available (some used) AC Re-gen's and Bal/Symm. power supplies as another option-consideration. 

 

pj 

[allhifi]

1 hour ago, Speed Racer said:

I would look for a 1.8 to 2.5 kVa Topaz unit if you can as the price difference is small and the extra power handling ability can be important. 

 

The B&K Precision 1604A is listed to 1.25 amp continuous. That's not much. I don't see these as a reasonable solution.

Also consider Output Impedance when moving forward.

 

 pj

[allhifi]

1 hour 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?

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