The Audio Standard Forum.

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Dr Bunsen Honeydew
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Re: The Audio Standard Forum.

Unread post by Dr Bunsen Honeydew » Sun Jan 14, 2018 2:49 pm

We are corrected :mrgreen:

Martin Taylor via outlook.com
12:06 PM (1 hour ago)

It amazes me that the forum which claims honesty, truth, accuracy etc., appears to make so little attempt at finding the truth and repeats poor or incorrect assumptions, including an engineer who rates himself above all others (Cawley) and a Turing machine with crayons who is allowed to spout rudeness against others without contributing a single thing of any interest himself (DQ). Then there’s all the hangers-on who worship everything you say, unintentionally absorbing the same incorrect advice.

So much for your laughable stance. Now for the proof. You are all wrong, despite my several attempts to explain how the P10 works. It doesn’t help that PS Audio call it a regenerator but I can understand their desire not to go into great explanations and put potential customers off.

The P10 is not a ‘big amplifier’, it does not convert all incoming power into DC and then create the AC waveform as in older models. It’s a tracking amplifier, or as I call it a waveform repairer. Even reviewers of the P10 get it wrong and PS Audio make no effort to correct them. You have to go back to the previous model, the PPP, in order to get the explanation. Here it is...

“Enter Bob Stadtherr, PS Audio's out-of-the-box thinker. He invented a way of converting the incoming AC signal into a 5-volt square wave by using a synchronization circuit. This square wave is perfectly in phase with the AC signal so it follows it accurately. Now a processor, a DSP chip running at 6.4kHz using Direct Digital Synthesis techniques, assembles a sine wave from the self-generated square wave. Next, the sine wave is fed to a digital-to-analog converter or DAC, the same kind as one would find in a CDP. The DAC here samples the sine wave and puts out an analog 2.5-volt signal again phase-locked with the incoming AC signal. Now we have a completely regenerated but downscaled likeness of the incoming signal which merely requires an amplifier to boost it to the necessary voltage.

Of course there is also a filter that cleans the low voltage analog signal before it is sent off to the power amplifier. Filtering of low voltages is far easier to achieve than on high voltages. As mentioned, the PPP uses 2.5 volts for the analog signal and from this signal, all remnants of DC coming from the DAC plus any remaining sampling noise of the DDS circuit are purged. The basic idea hence is to create an exact miniature replica of the incoming AC signal, clean it up, amplify it to the desired and now precisely stabilized level to pass it on to whatever device wants it. And because it can be done without bulky transformers -- the load is driven directly -- the source impedance can be very low.

Still, this technology is not yet the precise reason why the PPP is so much more efficient than its predecessor (which, incidentally, used the same minimize/filter/amplify technology). The real secret behind the efficiency resides in the power supply for the amplifier. In the P1000, PS Audio used a 200-volts DC power supply. This voltage was fed to a class A/B amplifier and the result was a 50 or 60Hz output. With the 200 volts, the amplifier would waste 50% of the used energy on a good day, more on a bad one. In the PPP, only 70 volts are used to feed the amplifier. That naturally lowers both heat and output voltage substantially. In order to elevate the output voltage, the PPP design now couples the 70-volt DC power supply and amplifier and AC-couples them hot to ride up and down with the incoming sine wave. That's a really bright idea. The resultant output is more than sufficient to produce a powerful and clean sine wave without the need for a high power supply voltage.”

Honestly, I don’t know why I bother but I’m not going to join your forum in order to post the correction. It should go without saying that any DC is going to upset the sensitive circuits generating the low voltage reference waveform. It also explains why you cannot change the output frequency as with older models, why you can switch it off and keep listening and why setting the output voltage to as close as possible the input voltage gives the lowest distortion output. The big transformer is there because you don’t want to try to repair the waveform for the entire local community.

But hey, who am I to correct such auspicious people as some of your members? I’m just an electronics engineer with a degree and a pair of ears.

Daniel Quinn
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Re: The Audio Standard Forum.

Unread post by Daniel Quinn » Sun Jan 14, 2018 2:50 pm

The manufacturer will say a dc blocker is not needed.

You're degrees are irrelevant ,you are a charalatan
Even a stroke didn't result in me liking AOS

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Dr Bunsen Honeydew
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Re: The Audio Standard Forum.

Unread post by Dr Bunsen Honeydew » Sun Jan 14, 2018 2:56 pm

"I am not going to join your forum" Do you seriously think I would let you even if you wanted to, when you ban me, block my product, all without reason (unless your own ;) )

But I thank you for your input, I made a presumption from what I knew, so the new circuit does things differently, so does Power Inspire for less than 1/10 the cost, and a NVA BMU does similar but better, again at about a 1/10 of the cost. You have got yourself in the pocket of a rip off merchant retailer, you want to waste your money, fine it is your money to waste, but you feed that slurpers pocket by recommending him, so he can feed off the less rich and snobbish members.

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Dave Cawley
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Re: The Audio Standard Forum.

Unread post by Dave Cawley » Sun Jan 14, 2018 3:14 pm

I understand that the DDS is PLL'ed to the incoming mains, nothing new there. I'll challenge PS Audio directly tomorrow on their claim "In the process of regeneration any problems on your power line such as low voltage, distorted waveforms, sagging power and noise are eliminated." that customers find untrue.

BTW I don't "rate myself above all others" but I was lecturing at AES in NYC a few months ago.
"if it measures well and sounds good, then it is good" : "if it measures badly and sounds bad then it is bad" : "if it measures badly and sounds good, then it could be improved" : "if it measures well but sounds bad then it is bad" © Dave Cawley

Geoff.R.G
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Re: The Audio Standard Forum.

Unread post by Geoff.R.G » Sun Jan 14, 2018 3:21 pm

I find Martin's explanation very interesting, I am not sure about some of the technicalities but never mind. I would however like to know what the RF noise created by "Ethernet by mains" adaptors does to the device. The noise is in the HF region and of particular annoyance to radio amateurs.

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Dr Bunsen Honeydew
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Re: The Audio Standard Forum.

Unread post by Dr Bunsen Honeydew » Sun Jan 14, 2018 3:39 pm

Oh and BTW Martin, why would you expect DQ to be polite to you when you banned him for supporting me and saying you had nor reason to ban me - you throw shit at people Martin and they will throw it back - human nature.

Lurcher300b
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Re: The Audio Standard Forum.

Unread post by Lurcher300b » Sun Jan 14, 2018 4:00 pm

Ok, so all that means is that unlike a simple way of regenerating mains (convert mains into DC, generate pure sine wave, use high power amplifier to amplify pure sine wave to 230v), they use a more efficient method, create sine wave locked to incoming mains, convert mains into lower DC voltage, use smaller amplifier riding on the incoming mains (via transformer), amplifier uses as a input the difference between the "perfect" sine and the actual sine, output is added to output AC. For those old enough to remember Peter Walker, its called current dumping.

Generally doesn’t make any difference to the points being made, the ability to remove mains problems is now limited by the frequency response of the correcting amplifier, which is the point I think Geoff is referring to. But there is still a large transformer that passes all the power that the load requires, and it will still saturate if there is an asymmetric supply.

Daniel Quinn
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Re: The Audio Standard Forum.

Unread post by Daniel Quinn » Sun Jan 14, 2018 4:17 pm

Unlike the doc, I don't care about people critiquing me personally, I would
Be mad if personal insults got to me , please call me what you like.

Martint ,I call you, because your opinions on HiFi are shite and dangerous
Even a stroke didn't result in me liking AOS

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Dave Cawley
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Re: The Audio Standard Forum.

Unread post by Dave Cawley » Sun Jan 14, 2018 4:18 pm

Lurcher300b wrote:
Sun Jan 14, 2018 4:00 pm
But there is still a large transformer that passes all the power that the load requires, and it will still saturate if there is an asymmetric supply.
But will that affect the output waveform in any way ?
"if it measures well and sounds good, then it is good" : "if it measures badly and sounds bad then it is bad" : "if it measures badly and sounds good, then it could be improved" : "if it measures well but sounds bad then it is bad" © Dave Cawley

Lurcher300b
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Re: The Audio Standard Forum.

Unread post by Lurcher300b » Sun Jan 14, 2018 4:46 pm

Dave Cawley wrote:
Sun Jan 14, 2018 4:18 pm
Lurcher300b wrote:
Sun Jan 14, 2018 4:00 pm
But there is still a large transformer that passes all the power that the load requires, and it will still saturate if there is an asymmetric supply.
But will that affect the output waveform in any way ?

I will refer you to my earlier "don't know" answer, but it will reduce the power handling capacity of that transformer, and likely increase the distortion on its secondary, so will consume more of the available error correction the tracking amplifier has available.

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