Puritan Audio PSM156 Review (AC Filter)

[Kingrex]

I am kingrex electric. I have developed all copper panels for use in residences to power high quality audio equipment.
I have clients who can't change panels and worse, can't get circuits to their listening rooms.

I have become interested in something along the lines of 1 to 2 x 100AH lithium 48 volt batteries attached to a quality inverter.
A good Victron inverter outputting 5000 watts in 120 volt has about 3% thd. The inverter in these units operate at a frequency of 20,000 hertz or 20khz. The output voltage is 8 volts, then boosted through a large step up.toroid to 120 volts.

Anyhow, they have switching noise at 20khz. I have heard people say anecdotally that the performance of any audio equipment attached to these inverters is improved by a Puritan 156. And seeing that it filters about 57db at 20khz, it makes sense to me people would find they help playback.
Yet, I read the analizer only review by the OP showing no change he can measure.with the parameters he selected. So why do people hear a pronounced difference using the Puritan 156. Has the OP actually measured the affect of a 20khz switching power supply on a piece of audio equipmemt? Is that noise impacting audio equipment if its not filtered out.

Thanks for any input.
Rex

 

[Mart68]

I am kingrex electric. I have developed all copper panels for use in residences to power high quality audio equipment.
I have clients who can't change panels and worse, can't get circuits to their listening rooms.

I have become interested in something along the lines of 1 to 2 x 100AH lithium 48 volt batteries attached to a quality inverter.
A good Victron inverter outputting 5000 watts in 120 volt has about 3% thd. The inverter in these units operate at a frequency of 20,000 hertz or 20khz. The output voltage is 8 volts, then boosted through a large step up.toroid to 120 volts.

Anyhow, they have switching noise at 20khz. I have heard people say anecdotally that the performance of any audio equipment attached to these inverters is improved by a Puritan 156. And seeing that it filters about 57db at 20khz, it makes sense to me people would find they help playback.
Yet, I read the analizer only review by the OP showing no change he can measure.with the parameters he selected. So why do people hear a pronounced difference using the Puritan 156. Has the OP actually measured the affect of a 20khz switching power supply on a piece of audio equipmemt? Is that noise impacting audio equipment if its not filtered out.

Thanks for any input.
Rex

People hear a pronounced difference with all sorts of bizarre stuff like crystals on their power cables and grounding boxes. It's just cognitive bias.

When they can reliably tell a difference when they don't know if the Puritan is in the system or not, then we'll pay attention to what might be going on that's currently outside the known laws of physics.

My bet is that will never happen.

 

[Killingbeans]

Thanks for any input.

I have a feeling you're not actually going to appreciate the vast majority of the inputs this site has to offer.

Most ASR users, myself included, don't hesitate to put the products you sell in the categories of either "snake-oil", or "severely delusional". Nothing personal.

So why do people hear a pronounced difference using the Puritan 156.

Placebo, in all likelihood.

 

[Kingrex]

I have a feeling you're not actually going to appreciate the vast majority of the inputs this site has to offer.

Most ASR users, myself included, don't hesitate to put the products you sell in the categories of either "snake-oil", or "severely delusional". Nothing personal.



Placebo, in all likelihood.

Some of these inverters put out 10%thd at 20khz to 25khz. You don't believe that might impact your audio equipments ability to operete properly.

And for what its worth. I have created blind tests for subjects and 100% they immediately call out what topology they are listening too. So, the world is not devoid of people doing as such.

 

[Kingrex]

And I'm asking for the scientific approach. Has anyone inserted a actual device that creates noise outside a simple frequency generator that dumps noise onto a line.
It seems to me there is a difference between making noise and overlaying it on a sine wave as opposed to creating a sine wave with noise embedded in the totality of the wave.
I'm not a scientist. I only obseve we see what we measure. But do we measure what we are actually trying to see

 

[Billy Budapest]

Have you read what the manufacturer says the box does?

Yes. When I stated it “does what they say it does,” I meant the objective measurements show it performs the filtering they claim, but the filtering doesn’t matter as it doesn’t affect the measured signal coming out of the actual audio gear. Regarding the company’s subjective claims, that’s marketing puffery that I dismiss out of hand anyway.

 

[Billy Budapest]

It does something, which is a plus when comparing it to other similar devices. But what it does has little to none relation to what they say it does.

To their subjective claims, agreed, but that’s not what I was commenting on. As I said before, I viewed that as puffery and dismissed it out of hand.

 

[Killingbeans]

Some of these inverters put out 10%thd at 20khz to 25khz. You don't believe that might impact your audio equipments ability to operete properly.

I don't care about what others or myself believe. I care about the probability of something being a waste of time.

Do you have verifiable data showing how well designed audio gear fails to stop said distortion from being audibly superimposed on the output?

And for what its worth. I have created blind tests for subjects and 100% they immediately call out what topology they are listening too. So, the world is not devoid of people doing as such.

Equally well performing topologies? If none of them had bizarre in/output impedances, wonky frequency responses or oodles noise and/or distortion, then I highly doubt that the test was properly conducted. Again, nothing personal. Just the most likely explanation.

It seems to me there is a difference between making noise and overlaying it on a sine wave as opposed to creating a sine wave with noise embedded in the totality of the wave.

Nope, those two things are precisely the same thing. Any signal is a sum of sine waves. Doesn't matter how the individual ones got there. They don't have a "signature" other than their frequency and phase.

 

[antcollinet]

You don't believe that might impact your audio equipments ability to operete properly.

Why would it.

Audio equipment works internally on DC. That DC is created from the AC by circuits that apply massive filtering to the noise on that AC (Harmonic distortion on the mains is pretty much completely irrelevant to the AC to DC Conversion) Certainly much higher levels of filtering than will be applied by the Puritan.

And then the subsequent circuits are carefully designed (if the designers have any degree of competence) to reject any remaining noise still further. It is why DACS and AMPS are regularly achieving SINAD in excess of 120dB in spite of being connected to noisy mains circuits without any filtering.

 

[Kingrex]

Have any nay sayers listened to a filter. I always hear a change. Most of the time I don't like it. So I ask for engineering analysis to explain what I hear. The respone is, I don't know how to measure why your hearing, so your not hearing it??? What sort of answer is that. A forum full of people that don't own a stereo extrapolating from flawed data what people with stereo hear. I guess others were right that the engineering analysis on this site is not mature enough yet. Hopefully technology improves over time. Or at least the degreed scientist are interested enough to engage and measure.

 

[Kingrex]

I guess I should log off now. Nothing to learn an I'm sure I will be deleted and banned. Be well.

 

[antcollinet]

I guess I should log off now. Nothing to learn an I'm sure I will be deleted and banned. Be well.

Well certainly nothing to learn for those without the interest to listen and attempt to understand the information they are being freely given.


On the other hand, you could stick around for more than about 5 minutes and try to engage in good faith discussion rather than the nonsense in your last two posts.

 

[Kingrex]

You know what, I don't want to give up that easy. I shouldn't let armchair engineer that know nothing distract me. If your a degreed engineer and can help explain why certain filters change the sound based on unknown distortions on the power line, I hope you can help. I know from 5 different people using inverters that a Puritan 156 has a fairly profound impact on what they hear. Is this a 20khz switching noise or some other unknownndiatortion riding on the wires. Where would you focus testing.
FWIW, you can see distorted sine wave when the inverter is under load. What distortion, I don't know. Just a flat top sine wave. Is the puritan helping remove the flat top???

 

[NTK]

And I'm asking for the scientific approach. Has anyone inserted a actual device that creates noise outside a simple frequency generator that dumps noise onto a line.
It seems to me there is a difference between making noise and overlaying it on a sine wave as opposed to creating a sine wave with noise embedded in the totality of the wave.
I'm not a scientist. I only obseve we see what we measure. But do we measure what we are actually trying to see

Been there, done that.

Impact of AC Distortion & Noise on Audio Equipment

This is an ASR research project to see what impact AC noise and distortion has on performance of audio equipment. I have been wanting to write this article some three years ago and finally getting a chance to do the testing and release it. As you will see, the heart of this study is a special...

www.audiosciencereview.com

 

[antcollinet]

If your a degreed engineer

Check

and can help explain why certain filters change the sound based on unknown distortions on the power line, I hope you can help.

Ah - that might be more difficult.

Why don't you at least consider the possibility that they don't?

See - what we recognise here is that our auditory system is flawed. In particular, it is subject to perceptive bias (See the psychoacoustics section of the forum for more on that topic)

But in summary

What we hear is impacted by what we know, what we believe, how we feel, our life experiences, what we see etc etc. No-one is immune to this if they are human - it is how we are built. In fact we would be unable to function if our senses were not filtered by our subconscious brain. Everyone is subject to this, it happens at the subconscious level, and it is not possible to avoid it - even when we are aware it is happening.

Without controls (Blind level matched comparisons), you can never be sure whether what you are hearing is due to perceptive biases..... or not. It may be you are genuinely hearing a difference in the sound-waves reaching your ears, or it may just be your subconscious playing tricks on you.

Couple that to a situation where the measurements say it is very very unlikely that there is a difference to be heard by almost anyone, then the balance of probabilities becomes heavily weighted towards bias. Any uncontrolled perception of difference in that situation can reasonably be challenged.... or just ignored.

 

[GXAlan]

Have any nay sayers listened to a filter. I always hear a change. Most of the time I don't like it.

It would easy to measure the before and after. For all we know, Amir’s power could be unusually clean and yours could be unusually dirty and your downstream electronics could be unusually good or bad at filtering out these problems.

The point still stands that for any amount of money you have allocated toward power cleaning, you would have been better off getting better speakers or a better room….

 

[amirm]

Have any nay sayers listened to a filter. I always hear a change.

I do too. But if I do the test blind and repeat to avoid chance, that difference vanishes. Have someone test you a dozen times and see if you can guess correctly if the filter is in the loop all of the time. If not, then you have answered your own question.

 

[BlackSpider777]

Hi everyone,
I bought the PSM136 few weeks back to replace my Furutech TP80ES distributor box. Please don't hate me but i did notice a difference with the Puritan.
I guess my power was dirty to begin with.

Cheers.

 

[Frank Dernie]

And I'm asking for the scientific approach. Has anyone inserted a actual device that creates noise outside a simple frequency generator that dumps noise onto a line.
It seems to me there is a difference between making noise and overlaying it on a sine wave as opposed to creating a sine wave with noise embedded in the totality of the wave.
I'm not a scientist. I only obseve we see what we measure. But do we measure what we are actually trying to see

If anybody working for me had designed a mains powered device that needed some sort of separate equipment added so that it worked properly when plugged into a plausibly noisy mains supply they would be looking for another job.

If there are hifi devices which genuinely sound different with mains treatment they are, in my opinion, badly designed and should be avoided, as should any other product designed by the same person.

It is easy to check anyway, if any device alters the signal in the audible frequency range we have measuring devices more sensitive than human hearing that can detect this alteration, be it adding noise or changing amplitude frequency or phase of the electrical signal.

 

[antcollinet]

Hi everyone,
I bought the PSM136 few weeks back to replace my Furutech TP80ES distributor box. Please don't hate me but i did notice a difference with the Puritan.
I guess my power was dirty to begin with.

Cheers.

Please don't hate me, but if you didn't compare blind and repeated, it is far more likely that the difference was not in the sound waves reaching your ears, but created in the wetware between them. (see my previous post 3 above yours, and @Amir's directly above).

Cheers.