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March Audio P452 Purifi Based Stereo Power Amplifier

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bigguyca

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#81
Thank you :)

Update done

Also the dimensions of the P451 were actually incorrect as we have very recently increased the size of the case.

View attachment 82780

View attachment 82781
W or watt is correct

W rms or W RMS can be calculated, but is a meaning less number. If you are going to produce power amplifiers then it would be good to learn the correct use of these terms. It would also be a service to others who also often misuse these terms. Watts rms is a particularly unfortunate term because it results from an actual, although meaningless, calculation.

Even PS Audio, run by Paul McGowan who you called an idiot, or was it stupid, in another thread, uses the correct term.

Watt, Watt rms, Watt RMS, W rms, w rms, and similar variations are incorrect.

Bob Cordell, in his book, Designing Audio Power Amplifiers, 2nd Edition, uses the term, "Continuous average sine wave power." That's a mouthful, but just power or average power or just plain W or watt, seems good. W rms is not correct and should be avoided.

https://www.amazon.com/Designing-Audio-Power-Amplifiers-Cordell/dp/1138555444/ref=sr_1_1?crid=3R2V9G0UYFDWG&dchild=1&keywords=bob+cordell+designing+audio+power+amplifiers&qid=1602439857&sprefix=bob+cor,aps,219&sr=8-1

A or amp is correct

Amp, or Amps, or the like is incorrect.

ohm is correct

Ohm or Ohms, or the like is incorrect

In technical writing adding an "s" to the units (ohm to ohms) is also incorrect, but is so common that it isn't worth noting.
 
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#82
That's great, I'm so close to pulling the trigger and ordering one too!
What other kit or what setup do you have @soundman414 ?

My current setup is the Adam Audio T7Vs, an Emotiva XSP-1 and a Bluesound Node 2i... But that's going to change soon.

I am going to keep the Bluesound as a digital source, but I got the Gustard P26 pre-amp to replace the Emotiva, I also got Sparkos Labs discrete opamps to replace the LM49860 chip opamps in the Gustard, I ordered a Topping D90 for my DAC, of course I got the P452 from March Audio and I also purchased the Wharfedale Evo 4.4 towers. lol quarantining has given me a lot of time to save up and get a proper 2 channel rig. I'm psyched to get it all together.
 

amirm

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#83
In technical writing adding an "s" to the units (ohm to ohms) is also incorrect, but is so common that it isn't worth noting.
??? Plural versions of these units is certainly correct. Here is NIST's own page on Ampere: https://www.nist.gov/si-redefinition/ampere-introduction

The ampere (A), the SI base unit of electric current, is a familiar and indispensable quantity in everyday life. It is used to specify the flow of electricity in hair dryers (15 amps for an 1,800-watt model), extension cords (typically 1 to 20 amps), home circuit breakers (15 to 20 amps for a single line), arc welding (up to around 200 amps) and more. In daily life, we experience a wide range of current: A 60-watt equivalent LED lamp draws a small fraction of an amp; a lightning bolt can carry 100,000 amps or more.
 
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March Audio

March Audio

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Thread Starter #84
W or watt is correct

W rms or W RMS can be calculated, but is a meaning less number. If you are going to produce power amplifiers then it would be good to learn the correct use of these terms. It would also be a service to others who also often misuse these terms. Watts rms is a particularly unfortunate term because it results from an actual, although meaningless, calculation.

Even PS Audio, run by Paul McGowan who you called an idiot, or was it stupid, in another thread, uses the correct term.

Watt, Watt rms, Watt RMS, W rms, w rms, and similar variations are incorrect.

Bob Cordell, in his book, Designing Audio Power Amplifiers, 2nd Edition, uses the term, "Continuous average sine wave power." That's a mouthful, but just power or average power or just plain W or watt, seems good. W rms is not correct and should be avoided.

https://www.amazon.com/Designing-Audio-Power-Amplifiers-Cordell/dp/1138555444/ref=sr_1_1?crid=3R2V9G0UYFDWG&dchild=1&keywords=bob+cordell+designing+audio+power+amplifiers&qid=1602439857&sprefix=bob+cor,aps,219&sr=8-1

A or amp is correct

Amp, or Amps, or the like is incorrect.

ohm is correct

Ohm or Ohms, or the like is incorrect

In technical writing adding an "s" to the units (ohm to ohms) is also incorrect, but is so common that it isn't worth noting.
Thank you for your extremely rude post.

I am quite aware of the technical definitions thank you very much and I don't require your corrections. Fully aware its actually average.

You need to remember that often the audience in a forum is used to certain terminology even if it isn't always 100% technically correct. This isn't a technical paper or journal.

Plural and adding "s" is perfectly correct BTW. Even if it were wrong I'm not sure why you would differentiate and not correct that as its "so common" yet be so offended by "rms".

So thanks for you pedantry but frankly bugger off mate. ;)

I actually wouldn't have minded you mentioning this as you have a valid point and I'm all for getting things technically correct, but implying a lack of knowledge on my behalf and the way you have gone about it is offensive.

BTW the reason I called McGowan moronic was for doing exactly this when referring to Amir. He was moronic for saying things that were demonstrably and obviously untrue.
 
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restorer-john

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#85
...a lightning bolt can carry 100,000 amps or more...
AC/DC roadies carry plenty of amps (Marshall) and lightning bolts:

1602463541323.png
 
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#86
My current setup is the Adam Audio T7Vs, an Emotiva XSP-1 and a Bluesound Node 2i... But that's going to change soon.

I am going to keep the Bluesound as a digital source, but I got the Gustard P26 pre-amp to replace the Emotiva, I also got Sparkos Labs discrete opamps to replace the LM49860 chip opamps in the Gustard, I ordered a Topping D90 for my DAC, of course I got the P452 from March Audio and I also purchased the Wharfedale Evo 4.4 towers. lol quarantining has given me a lot of time to save up and get a proper 2 channel rig. I'm psyched to get it all together.
Nice setup, what are the Evo 4.4's like? They look pretty meaty!!
I also have the Bluesound Node 2 for streaming. I have the Chord Qutest DAC and currently thats all going through my Cyrus 8 DAC (Pre/Power) but currently thinking to get the P452 to upgrade/improve the power amp and then maybe at some point in the future switch to a dedicated Pre.
 
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#87
Nice setup, what are the Evo 4.4's like? They look pretty meaty!!
I also have the Bluesound Node 2 for streaming. I have the Chord Qutest DAC and currently thats all going through my Cyrus 8 DAC (Pre/Power) but currently thinking to get the P452 to upgrade/improve the power amp and then maybe at some point in the future switch to a dedicated Pre.
I'm not quite sure yet. I will pick those up this upcoming weekend and I have to wait until the amp comes in to hook it up. When I have everything together I'll give my impressions and some pics.
 
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March Audio

March Audio

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Thread Starter #88
Nice setup, what are the Evo 4.4's like? They look pretty meaty!!
I also have the Bluesound Node 2 for streaming. I have the Chord Qutest DAC and currently thats all going through my Cyrus 8 DAC (Pre/Power) but currently thinking to get the P452 to upgrade/improve the power amp and then maybe at some point in the future switch to a dedicated Pre.
Our pre which will match the p452 in case format will be available in a few months.
 
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March Audio

March Audio

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Thread Starter #90
Have you detailed the features this will offer?

Where are you with your active speakers?
We are keeping the detailed info about the pre under wraps for the time being, sorry.

We put the speaker project on hold at the beginning of covid for several reasons. The project was ready but obviously the world situation was a little uncertain and we were frankly too busy building amps :) !

We have some more resource now and things have calmed down so the passive speaker will be out imminently. BTW we have finalised on the Bleisma T34B beryllium tweeter over the "A" magnesium.

The active is still a few months away, along with a floor stander ;)


Sointuva speaker prototype
20201014_083651.jpg
 
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restorer-john

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#95
Totally look like that photo. Do you know, I've never eaten a dumpling. They hopefully taste better than they look.

I think the driver surround look is growing on me. It's nowhere near as jarring as when I first saw it. I remember when Sony first made the APM square drivers. That was a visual shock and it took a while to become "normal". I guess the same can be said when speakers went from pleated, doped fabric surrounds to foam/rubber.
 
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Thread Starter #96
Totally look like that photo. Do you know, I've never eaten a dumpling. They hopefully taste better than they look.

I think the driver surround look is growing on me. It's nowhere near as jarring as when I first saw it. I remember when Sony first made the APM square drivers. That was a visual shock and it took a while to become "normal". I guess the same can be said when speakers went from pleated, doped fabric surrounds to foam/rubber.
Oh they are delicious.

When you hear these drivers you will instantly forgive and forget weird surrounds ;)
 
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#98
Any idea if I could trigger/turn on this power amp when I switch my Cyrus 8.2 DAC (amplifier) on? I'd plan on using the Cyrus as a Pre. I know Cyrus has an MC-BUS but I'd imagine that's proprietary and couldn't be used to wake up the March Amp @March Audio?
If you have any electronics skills this may be of interest - perhaps there's an opportunity here for someone?

http://www.funkster.org/e/hack/mcbus
 

ririt

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#99
I get a combo of March Audio amps in the past weeks: one mono and one stereo purifi amp (P451 & 452) to power the front stage on my home cinema /hifi set-up and 2 stereo Hypex-based amps to power the surround speakers and the zone 2 ( P252 and P122). Associated with a Denon AVR 4700h in full preamp mode, the purifi amps nicely drive my Dali Rubicon LCR loudspeakers (Front stage). No hiss, no hum, just a superb sound! Moreover, my in-ceiling speakers are well managed by the Hypex amps.
The customer service from Alan was awesome. The design and the product’s finish are top notch. For those who are looking for state of the art class D amps, I strongly recommend this company!
 

toei

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MA: What case temperatures are you getting with your P452 units when stress testing after assembly?

[Yes first post - hopefully this isn't too cheeky for a newbie :p]
 
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