Audio Science Review Tests and Amplifier protection systems

Alan March

Alan March

Founder of March Audio
Staff member
A new test of our P501 amplifier has landed on Audio Science Review forum. The testing was performed by a Korean member @thin bLue. He is a member here too and we have discussed technical matters and measurement techniques, but the review is completely indepenant performed with his Audio Precision AP525 analyser :
www.audiosciencereview.com

Marchaudio P501 Mono Block Power Amplifier Review

(Photo from Marchaudio) I saw some of ASR members request about review this Amp. And for my personal curiosity I asked to Company to lend one for review. After I finished measurement, I asked company how to return. But the Company gave me right to dispose of it. Disclaimer This is a review and...
www.audiosciencereview.com www.audiosciencereview.com

Ignoring all the silly nonsense that Amir, ASRs owner is trying to drag me into on the thread, an interesting request came from a member regarding the protection systems of our amps.

He wanted me to short out the amp whilst at maximum power output! I think he is expecting the amp to explode in flames, but our amps are far more sophisticated than that. The output current is non intrusively monitored and if any fault conditions occur it instantly shuts the amp down. So if an accident occurs, yes I have accidently shorted speaker lead myself :eek:, then absolutely no harm will come to the amp. It will just gracefully and instantly cut the output.

Here is the video!

 
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Hey Alan

I have just been banned from ASR. That guy BD Woody thinks I'm in New York, Amsterdam and Australia. One of them was right.

Its so funny. Amir is a total narcissist. He can't ever be wrong. His methods are stupid and he twists and squirms trying to justify them. Amir is a jerk and ASR is a joke..

You are doing great work and I'll be buying some amps soon.

Ciao

J
 
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Hi @JasonWells and welcome to the forum.

Yes, I have been watching whats been happening. I can only shake my head in dismay. Its what Amir does, he bans anyone that disagrees with him. A very insecure individual and frankly technically incompetent. His responses to you are typical of what he does. Evasion and never addressing the points. Trying to discredit you and myself was his only option. Followed of course by banning.

He banned me because I criticised his speaker reviews. He banned Doug from Soundstage for the same. He banned Erin from Erins Audio Corner because he was doing a genuinely good job of testing speakers, unlike Amir.

Don't worry, there a only a small number of vocal fan boys that follow Amirs every word. I just ignore the place now. Amirs tests are so limited in scope and flawed in method that the information tells you virtually nothing about how a piece of kit might perform let alone sound. He actually thinks that SINAD into 4 ohm resistive load is all you need to know.

I think what annoys me these days is not really Amir, everyone knows what he is like (arrogant egotistical bully), but that what he is doing is just re-inforcing the view of ardent subjectivists that measurements are of no relevance. This is wrong, but using simplistic single measurements such as SINAD and thinking that tells you all you need to know is really dumb. The subjectivist viewpoint is 100% correct in this respect. Unfortunately what he is doing is so inept and limited in scope, it tarnishes the validity and genuine usefulness of measurement.
Just ignore it and move on.

Cheers

Alan
 
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Which one is it @JasonWells ?
Au or Amsterdamned?

I attracted a ban a few weeks ago… I expected one on Audiogon, so I was a bit surprised it was on ASR.
It was mostly a misunderstanding on language, but it was a shock.
 
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I was thinking I might have been banned, so from my perspective a locked thread is a decent outcome.

Where are you when you are not visiting NY?

I guess you run a VPN?
I was temporarily banned a few weeks ago, and could not even view threads.
And I need to pull off some biquad settings, so I either need to be overly cautious or have a backup plan.
 
Alan March said:
… an interesting request came from a member regarding the protection systems of our amps…
Click to expand...

Does “our amps”, mean exclusively the March Audio amps?
Or…
Is it all the Purifi variations have it… as Purifi built in the protection?

I am assuming it is the later case… and that they know what to do so they implemented it wholesale across their range.
 
Holmz said:
Does “our amps”, mean exclusively the March Audio amps?
Or…
Is it all the Purifi variations have it… as Purifi built in the protection?

I am assuming it is the later case… and that they know what to do so they implemented it wholesale across their range.
Click to expand...
Yes it's all the purifi modules.

To expand further on the systems capabilities, it also monitors all the power supply rails, 6 in total. They all have to be within normal range or it shuts down. It also monitors for DC on the output and mutes the amp if seen. There is also a "fatal" line that asserts in the event of catastrophic failure, ie the output transistors going short. This line tells the power supply to instantly shut down.

So along with the current limiting, 25 amps for the 1et400 and 40 amps for the 1et7040, it's about as comprehensive as you can get.
 
Holmz said:
I was thinking I might have been banned, so from my perspective a locked thread is a decent outcome.

Where are you when you are not visiting NY?

I guess you run a VPN?
I was temporarily banned a few weeks ago, and could not even view threads.
And I need to pull off some biquad settings, so I either need to be overly cautious or have a backup plan.
Click to expand...
Just clear your cookies if it happens.
 
JasonWells said:
I see you guys down under are out too. You did well though. It's good to see the usually strong teams arent dominating. Makes it much more interesting.
Click to expand...
Yes Aussies are out but we have our second team (well first to be honest) to support. We hail from England originally and emigrated to Oz about 12 years ago. We are dual citizens will be up at 3 am on Sunday morning watching England v France.

I think that's going to a stressful game to watch.
 
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JasonWells said:
Hey have you seen they have locked the thread.
Jeez what total jerks.

J
Click to expand...
Totally expected. @Holmes was absolutely correct when he was trying to explain to Amir how his behaviour comes across. Amir has an axe to grind with me and it biases any reviews of our products. It's so obvious to others. It damages his reputation and ASRs.

There was nothing wrong with how @thin bLue presented the information. It was just Amir trying to find an excuse to make out the P501 wasn't performing as well as it obviously does.

You are just the latest person in a long line who have pointed out the same flaws in Amirs testing methodology. He won't change though. He is right, everyone else is wrong.

As I said, just ignore ASR. There is nothing scientific going on there.
 
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Alan March said:
Totally expected. @Holmes was absolutely correct when he was trying to explain to Amir how his behaviour comes across.
Click to expand...

To be fair it may not be his (Amir’s) behaviour as much as just a wholesale dog pile scrum of the group writ large.
But since it is his forum, I would have expected some moderation of the ad hominem attacks by others.


Alan March said:
Amir has an axe to grind with me and it biases any reviews of our products. It's so obvious to others.
Click to expand...

Ok… ^This^ is hard to cogently argue against.


Alan March said:
It damages his reputation and ASRs.
…
Click to expand...

It certainly does not help it.
Seeing Erin booted was a bit of a shock.

AudioGon hates ASR.
AudioGon hate Amir
Amir hates Alan
etc…
Where is Rodney King when we need him?
 
Holmz said:
I was thinking I might have been banned, so from my perspective a locked thread is a decent outcome.

Where are you when you are not visiting NY?

I guess you run a VPN?
I was temporarily banned a few weeks ago, and could not even view threads.
And I need to pull off some biquad settings, so I either need to be overly cautious or have a backup plan.
Click to expand...
Based in UK currently. Vpn into our business systems. Gotta run.
 
Holmz said:
To be fair it may not be his (Amir’s) behaviour as much as just a wholesale dog pile scrum of the group writ large.
But since it is his forum, I would have expected some moderation of the ad hominem attacks by others.
Click to expand...
You would, but Amir is happy to let it happen because I had the audacity to criticise his methods.

Also one of the moderators BD Woody is a particularly nasty piece of work. Before I was banned he was personally abusive towards me via PM. He also threatened that unless I stop criticising Amirs testing methods he would ban me.
 
Alan March said:
You would, but Amir is happy to let it happen because I had the audacity to criticise his methods.

Also one of the moderators BD Woody is a particularly nasty piece of work. Before I was banned he was personally abusive towards me via PM. He also threatened that unless I stop criticising Amirs testing methods he would ban me.
Click to expand...

OK - but it would be a bit stupid to anoint admins that were not loyal to a fault.
 
Alan March said:
Yes it's all the purifi modules.

To expand further on the systems capabilities, it also monitors all the power supply rails, 6 in total. They all have to be within normal range or it shuts down. It also monitors for DC on the output and mutes the amp if seen. There is also a "fatal" line that asserts in the event of catastrophic failure, ie the output transistors going short. This line tells the power supply to instantly shut down.

So along with the current limiting, 25 amps for the 1et400 and 40 amps for the 1et7040, it's about as comprehensive as you can get.
Click to expand...
Hey Alan, is that current limiting rms or peak?
 
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