Discussion of AC mains isolation transformers

[Rsbrsvp]

Hi Friends.   I have a Topaz isolation transformer in balanced mode.  .00005 

 

Would something like the Puritan Audio PSM 156 improve on the Topaz or should they not be used together?  ANd if they could be used together, what should be the order?

[Rsbrsvp]

I have compared my Topaz .0005 with power strip to my PSM156 and to my ears the 156 definately reduces noise substantialy more.   The sound is so much more detailed, clean, tight- like day and night.    Now- does it sound better than the Topaz option?  Not sure...  The Topaz option to my ears is a whetter, fuller bodied, more tonally saturated sound.   It is kind of like solid state (PSM156) vs Tube (Topaz).

 

I dont understand technology and you guys can talk about impedence and leakage all day;- and I dont get it at all- but my ears hear two very valid forms of purifying mains noise.   Check out the revieews on the PSM156--- go to audio circle-   people are floored by it.

 

It seems that there are many ways to get good results...  Maybe something like the PSM156 increases impedence and leakage but makes up in other ways.....  Ways- I do not understand.......      Honestly- this contest is a matter of taste- and only the ear can decide..

[Rsbrsvp]

25 minutes ago, Savolax said:

What kind of power strip did you use? Generic store one or maybe something fancy?

SOmething I got on Amazon.  Around $35.   No filtering, no surge protection,- just a power strip...  Hard to find them these days...

[Rsbrsvp]

I have a topaz 91097-31.  Does anyone know what fuse size and amps it uses.  I want to get a better ceramic fuse if possible...

[Rsbrsvp]

5 minutes ago, oneguy said:

Are you wiring it for balanced power?

 

If so then 3.1 Amp would max out the transformer. 
 

If not, wiring for balanced power then 6.2 amps would max it out. 

I do have the Topaz in Balanced mode   230V.   But what size fuse do I buy?  ALso- I have no idea where it goes.  I guess I need to unscrew the sides to see...

[Rsbrsvp]

Just now, oneguy said:

Sorry about that I should have looked at the country flag. I gave you numbers for 120v. For 230v it should be not more than 3.2A (3 amp fuse) for conventional and 1.6A (1.5 amp fuse) for balanced power. 
 

The -31 series do not have a specific place built in to put the fuse. It’s up to you to wire it in to the secondary side. 

What does that mean?   There must be one there now- that I can pop out and replace....  

[Rsbrsvp]

By the way- what physical size fuse do I purchase- and is it a problem to have a slightly higher amp rating?  How about slow blow and fast blow?

[Rsbrsvp]

8 minutes ago, oneguy said:

Nope. I’ve had over 15 Topaz/MGE/Eaton isolation transformers. -31 models are more DIY. 

 

I have used 5x20mm and 6.3x32mm fuse for isolation transformers. The size only matters for fuse housing or holder. I would use slow blow. 
 

As for a higher amp rating, I wouldn’t recommend it. Why put your life, house and equipment in peril?

In other words- it has no fuse now....  I would be adding one.  What would I gain from that?

[Rsbrsvp]

I wanted to ask John Swenson's opinion about adding the following EMI blocker; which the company clains does not increase impedence to the chain before or after the Topaz model 31 or 32?  Do you think it would have any value?

 

https://www.onfilter.com/ac-emi-filters-af-series

[Rsbrsvp]

Thank you John so much for the response.

 

One more mains purifier that has got literally hundereds of praises on the internet is the Puritin PSM156.  

 

I would be thankful if you could share with us what you think of it.  The reports are so so numerous and perhaps the approval rate is around 90%....  I cant help but wonder what they are doinbg inside of that box????

[Rsbrsvp]

8 hours ago, One and a half said:

Every filter like for a DAC has a roll off slope either side of the frequency that is a little flexible. If you have several overlapping filters, as source impedance changes, and the level of noise the filter is trying to remove, it's possible to end up with a bit of mess... depends on how the filter is designed.

I looked at the Purtian PSM156, seems like a regular T network of chokes and caps, plus some controls. I would be tempted to buy, but the cost is a little high just to experiment. It's a drawback that the PSM156 doesn't have under or over voltage protection, this is simple to implement. Surges are a different story some magnitudes higher, but are shorter in duration like ms/us. The longer term where there is sustained overvolts (>260V) for 1/2s or longer, they do happen. Supply monitoring, like a lost neutral is also important., should also be included, and won't impact SQ.

 

In a few months, will either add a Furman sequencer and power conditioner, the regular pro audio kind. Both of these, when healthy can operate a relay which switches an Equitech output to the rest of the audio system. This way, the audio equipment is protected, the power conditioning section of the Furman remains not used, and full isolation from the regular AC.

 

The thing I like about the PSM156 is it does it's job on each output seperately- not like a power strip.  this should eliminate leakage going back into other components....  A power strip will not do this...

[Rsbrsvp]

1 minute ago, Rsbrsvp said:

The thing I like about the PSM156 is it does it's job on each output seperately- not like a power strip.  this should eliminate leakage going back into other components....  A power strip will not do this...

In fact, I thought the reason we do not put another filter after the Topaz is to prevent leakage from seeping back in- but if I put a PSM156 after the Topaz, each output independantly prevents this from happening- I think....  

[Rsbrsvp]

Seems the Topaz is best at common noise removal and OK at normal noise removal...

 

The question- is - is this the most important factor to lead to better sound?

 

How about low impedence, leaks, voltage regulation, ground noise, isolation of components, and al the other stuff I don't understand?

 

I had a PSM156 which focusus on independant isolation and grounding with soem EMI supression and it sounded much different than the Topaz 31.  Much more clarity, energy, dynamics, extention, transparency, crisper-   but a leaner sound as well.

 

I want to try the cleensweep but I live in Israel and shipping and duties is not doable for me.

[Rsbrsvp]

I will say that focusing on EMI removal as the "cure all" for mains issues is wrong.   I hear conditioners which remove less EMI than my Topaz 31 but which perform other functions better and which many audiophiles would say sound better.......

 

 

[Rsbrsvp]

2 hours ago, flkin said:

 

 

I went for the Online CleanSweep industrial device and it's been in my system for few weeks now. In a nutshell it works for audio and has replaced my Topaz. 

 

I have it from wall to CleanSweep to the system except for power amps. System includes pre-amp/DAC, streamer and a DC power supply feeding the router and USB card inside the streamer. For power amps I still have them direct to wall through a Shunyata Hydra 8 as before. In this configuration I am getting more details with cleaner edges. More accurate tones.

 

I'll do a proper writeup when I get some time. A lot of details to share like using it alongside the Topaz, placing it on different devices separately, effect on my power amps, EMI measurements using a line meter etc.

 

This is just a quick nod for the CleanSweep and to thank @Rsbrsvp for bringing it to my attention.

Thanks for the update.   I'm hoping to order mine too.    I will be curious about EMI measurements- but truth is- not everything is EMI.  Isolation, grounding, leakage, impedence, and all this other technical stuff I dont understand seems to make a difference.  What matters is what sounds better at the end of the day.  I am not a scientist, but rather an audiophile.

[Rsbrsvp]

FLkin,

 

Does the Cleansweek onfilter make the sound thin or bright?  Is the sound as tonally dense as when using the Topaz?

[Rsbrsvp]

So- I wrote to Mike Lester of Puritan Audio.   Anyone who searches the internet will see the nearly unanimous praise on head-fi, audiocircle, audiogon, etc regarding his PSM156 mains filter.  I say nearly unanimous because around 10% of reports complain his mains conditioner makes the sound thin or bright.  Perhaps another roughly 10% say it is a subtle change for the good and around roughly 80% say the change is substantially for the good.  Please check yourselves.   He is a genius in the field whether one likes his way of doing things or not.  His filters are so popular, he cannot make them as fast as he sells them.  He is literally inundated...

I wrote to him to ask if his conditioner raises impedance and if that is a problem and he basically answered "yes" without saying so literally.  He said anything you put between your wall and your component damages the sound.  The goal is to come up with a device which improves sound more than it damages.  He also said EMI is easy to get rid of.  He could have designed his units to remove much much more EMI than they do easily- but the problem is the damage that results from this process becomes more than the value of removing the EMI.  So- I am attaching his letter as a lesson to us. 

 

___________________________________________________________________________________________________________________________________________________

 

The only truly relevant measurement is with the instruments each side of your head.

 

We do not publish detailed blueprints of measurements,  materials, methods or other design aspects. This is hard earned knowledge that we accumulate and apply towards a better sound.

 

The thing with conditioners is that they can do as much harm as good and balance is critical:

 

Anything in between the mains wall socket and the power input of the equipment is going to be bad, even a just few centimetres of cable will have a resistance to current flow and an eagerness  to act as an antennae gathering interference, both bad.

 

But, the state of pollution of mains electricity worldwide is awful and this is something which has crept up on us massively over the last few decades with now very often in excess of a volt, sometimes several,  of high frequency hash carried on top of the legitimate voltage waveform. And this is really, really bad for trying to resolve every subtle nuance, phasing and clue from a musical presentation.

 

We quickly discovered, because we listen intensively to every step we take,  that that achieving more decibels of  noise reduction for the spec sheet was very  easy but definitely not desirable:

 

We noted  that taking away HF hash liberated electronics. By not having signals blurred, smeared and buried and not having  processes  swamped by supersonic garbage, then being able to concentrate solely on  those signals you want;  not only source components but amps as well benefited,  greatly  increasing dynamics,  broadening and giving greater depth to the sound stage and definition…….. But go over a line and you go backwards  flattening the image and draining the life.

 

This circles back to my earlier comment that introducing anything in the power line introduces a restriction = bad. With power conditioning you are inserting elements to eliminate the HF noise  but which by their nature will also have a negative side.

 

We went to enormous lengths to correctly identify  the sweet spot of just enough cleansing but not too much,  but this was not quite so easy as the sweet spot had to hold for a host of very different loads;   sources and amps alike, amps of low power through to high power  and  Classes  A through  to D. After a very long time with hundreds of adjustments to a series of potential  prototypes in countless different audio set ups we arrived at our solution of which we are extremely proud.

 

The PSM156 (and PSM1512) work by having the  optimum degree of noise filtration,  also  taking care of star grounding, DC offset , surge protection and importantly isolating  each connected component from each other so that cross contamination cannot occur.  We think we nailed it.

 

Best wishes – Mike

[Rsbrsvp]

Flkin,  have you tried using the Topaz and the onfilter togethee?

 

If so- how does it sound?

[Rsbrsvp]

Flkin,

 

I appreciate this and it fits my experiences with mains conditioners.

 

My PSM156, like the cleensweep makes things brighter and leaner.  Is it a bad brightness?  Depends on the system and the ears.

 

The amount of clarity, seperation, detail, crispness it allows through is way above the Topaz .0005 isolation transformer I have, but it is thinner sounding and brighter.   In the wrong system- the PSM156 can be to much of a good thing; to much filtering- and end up with unpleasant results.  The Topaz is to my ears revealing much less of the good which the PSM156 does, but still some of it, and with none of the bad.  In other words, the music remains sonically dense and tonally darker, rounder- which to my ears is preferable in general.  

 

I am convinced, seperate of numbers, measurements,  or any technical understanding, that the PSM156 is filtering much more noise than the Topaz- and no measuring device will change my mind.  Less noise equals more detail, transparency, seperation, crispness, authority;- and the PSM156 results in substantially more positives in these descriptors.  More detail also usually results in leaner, drier, sharper sound- perhaps not so positive if overdone.

 

One nice option for me is to combine.  I put my digital equipment on the PSM156 where I feel the benifits are greatest and the negitives are least and the Topaz on my preamp and amplifier to keep things thicker and rounder as I feel the PSM overdoes the cleanning process on the analogue section IMHO while the Topaz has it right on this equipment.  Its all a game and everyone will come to their own conclusions.