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Pass ACA Class A Power Amplifier Review

BDWoody

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Hard to know what to compare it to or why only if one doesn't want, or dare, to find out.
By evading the comparison, Amirm renounces to meet his own claim.
He acts unprofessional and knows it.
He becomes mediocre at best.

Doesn't want or dare?
Are you serious?
This is a place where good value of any kind is recognized. Likewise, a poor product can't hide behind testimonials, no matter how much people want to believe...

I'm sorry your amp isn't as nice as you want it to be... not sure what you are trying to prove with this obstinacy...
 

readerA

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that's the point.
I don't want you to believe.

You're the pros, you're the nerds. You shouldn't be satisfied with believing. You should make sure it's bullshit even though you already believe it is, before you (sorry, that was Amrim) publicly determine it is.

I totally absolutely don't care wether you or Amrim or whoeveronearth like what I like.

But, as you can see, it upsets me quite a bit when anyone spreads shabby comments under the veil of holy measurements, then claims thoroughness (by lecturing the builders about how to conduct a subjective evaluation of audio products)

Himself: «On ASR Forum and myself, we are 100% in the camp of following established guidelines for subjective evaluation of audio products.»

And, to be honest, yes of course was I disappointed that the ACA didn't measure the same as a XA200.8 even though I was expecting it not to. I'd been all the more curious to read what a audio-expert from outside the diyaudio-context had to say about it.
But this?
 

DonH56

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I have not read all of this (ASR seems to be over run with it lately). Here's the history as I recall it.

Amir (@amirm) does not, or very rarely, does DBT-type listening tests. They are a pain and would take a lot of time. He focuses on measurements, the objective side. A year or three ago there was a rising tide of posters asking for some sort of listening test, any sort of subjective comparison, and IIRC Amir rather reluctantly agreed to post his impressions when he could. That is all they are, his impressions, with no claim to do rigorous DBT/ABX testing. In fact one of his objections (again IIRC) is that he would be attacked for exactly that; providing an impression without implementing the full rigor of DBT methodology. It's a no-win scenario.

It is nice to have a purely subjective listening test IMO in case something obvious jumps out but if they were left to others that's fine too. History tells us we will never convince confirmed subjectivists anyway; there is always an excuse for not hearing what another hears. When (sighted, uncontrolled) listening is placed over and above all rational science the arguments begin (or continue).
 
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DonH56

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Fixed it for you. :cool:

OK, I tweaked it a little. Didn't use the word "peeking", though, sounded too voyeuristic... :)
 

readerA

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I have not read all of this (ASR seems to be over run with it lately). Here's the history as I recall it.

Amir (@amirm) does not, or very rarely, does DBT-type listening tests. They are a pain and would take a lot of time. He focuses on measurements, the objective side. A year or three ago there was a rising tide of posters asking for some sort of listening test, any sort of subjective comparison, and IIRC Amir rather reluctantly agreed to post his impressions when he could. That is all they are, his impressions, with no claim to do rigorous DBT/ABX testing. In fact one of his objections (again IIRC) is that he would be attacked for exactly that; providing an impression without implementing the full rigor of DBT methodology. It's a no-win scenario.

It is nice to have a purely subjective listening test IMO in case something obvious jumps out but if they were left to others that's fine too. History tells us we will never convince confirmed subjectivists anyway; there is always an excuse for not hearing what another hears. When listening is placed over and above all rational science the arguments begin (or continue).

Sure, I agree to all of that. Still, amirms subjective conclusions are nothing but destructive. He did not bother to take care. Reading his comments, I imagine him turning that thing on, crank the volume pot full open, and turns it off again. 5 seconds. Sorry, time's up, nobody requiring him to anything more (or less) than that. (And even then would he have heard way more than "barely anything".)
 

DonH56

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You're a far more elegant fellow than I.

I am quite sure not. I wanted to include some sort of Thomas/Amir joke but there's been far too much of that lately and I need to get back to work. New PC mandated by IT, just takes a couple of hours they said, bah! :mad: My schedules don't include days of IT hell trying to get everything running again on a new PC. I suppose I've more time to post nonsense whilst it loads, dies, loads again, updates this, updates that, restarts...
 

BDWoody

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that's the point.
I don't want you to believe.

You're the pros, you're the nerds. You shouldn't be satisfied with believing.

What I believe are the objective test results. I only have to believe he is not lying about them. As a nerd, these measurements let the unit speak for itself in a technical sense.

What he identified in his uncontrolled listening pretty much obviated the need for anything deeper...at least for me.
 

DonH56

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Sure, I agree to all of that. Still, amirms subjective conclusions are nothing but destructive. He did not bother to take care. Reading his comments, I imagine him turning that thing on, crank the volume pot full open, and turns it off again. 5 seconds. Sorry, time's up, nobody requiring him to anything more (or less) than that. (And even then would he have heard way more than "barely anything".)

There was no plan to "take care" in the sense of doing DBTs and all that jazz. It is pretty clear what and why he is doing it to those of us who've been here a while. Perhaps he could qualify it better, or just leave them off again. The focus is on the measurements; if you don't like the subjective part, skip them. That is what I do with most other reviews elsewhere anyway.
 

SIY

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So here you are, escaped from diyaudio :).

But now I have an extra initial!

Still using the Equal Opportunity preamp. To be honest, I don't think I can design a better one- yet.
 

Hugo9000

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Just some thoughts that I decided to mention here and which shouldn't be inferred to be about anyone particularly in this thread (but if the shoe fits...haha!):

It's just so fascinating how people who clearly have a history come here with a username they don't use elsewhere, and pretend to be open and honest and disinterested parties, who state or imply that they only wish to improve this forum or a particular discussion. lol

I use a pseudonym, but I use the same one everywhere. If I want to get in an argument with someone across forums, they at least can see clearly that I'm the same crackpot/friend/enemy/nobody/whatever that they've previously encountered, and choose to respond or ignore me accordingly. Likewise, bystanders/readers in such threads also have the advantage of knowing there is a history there which may be relevant.

If people really think their views/beliefs/positions are valid, why are some of them continually hiding this history, and pretending to be someone or something they are not? And why do one or two particular people feel the need to keep coming back under new usernames? These are usually the ones that accuse the person they are stalking of being dishonest and/or hypocritical lmao!

If your point is valid, actual individual readers might agree with you. It's pretty sad when you think that making a dozen sock puppets to "agree" with you or act as a posse to harass someone you encountered in the past (in an AOL chatroom, or who worked for a company you love to hate or whatever the reason, or perhaps because they pointed out a flaw in some product you own/love/manufacture/reviewed/shilled/whatever) strengthens your position. You obviously know that it doesn't, and you obviously know that you place no value on the truth when you engage in such dishonesty. You can make 100 sock puppet accounts across all audio forums to "agree" with you and quote your other puppets to "support" your argument, but you would still be wrong. More sock puppets won't make you right, although if you're artful enough in your use of sock puppets, you might succeed in smearing your target if enough bystanders/readers think that there is actually some consensus against your target, rather than just one or two obsessed cyber-stalkers with a bizarre grudge.

Perhaps this belongs in its own thread, and would make an interesting discussion. I'll leave that up to @amirm and @Thomas savage
 
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amirm

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that's the point.
I don't want you to believe.
Yeh right.

I totally absolutely don't care wether you or Amrim or whoeveronearth like what I like.
Yeh right. :) Any other falsehoods we have to deal with regarding your intentions? People don't post in an argumentative way because they don't want anyone to believe them. They desperately need us to believe them or they would have wasted their time here.
 
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amirm

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But, as you can see, it upsets me quite a bit when anyone spreads shabby comments under the veil of holy measurements, then claims thoroughness (by lecturing the builders about how to conduct a subjective evaluation of audio products)

Himself: «On ASR Forum and myself, we are 100% in the camp of following established guidelines for subjective evaluation of audio products.»
First, you should avoid getting upset. It is just about audio and inanimate objects. You lose your objectivity when you speak from point of emotion.

As to your point, you cut out the context of what I said there. Someone mentioned the ACA sounds good. I asked if they had compared it to another amp and found that to be the case. If so, I lectured them :), on doing such tests in controlled manner. Finding sonic differences below amplifier limits is very hard to impossible. So we operate from the position of disbelief until supported otherwise.

In my case, I ran into said limits the moment I powered on this amp. It severely lacked power to drive the speaker I used. This kind of observation is not controversial since it is backed by objective measurements that show this amp is equiv. of trying to read by candle lights. Hence the reason the members here didn't demand me running a blind test to prove that.

As an analog I have used before, if you tell your doctor that rubbing garlic on your toes cured your cold, he would ask for controlled testing of that before prescribing it to his patients. But if you said that your nose was running when you had a cold, he would believe you. And not ask for a double blind test.

The notion that this is not understood by you, shows that you need to calm down, control your angst, and allow us to explain the failings in audio and how people become victim to it. We have all been there while you have not been where we are.
 

Thomas savage

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Hard to know what to compare it to or why only if one doesn't want, or dare, to find out.
By evading the comparison, Amirm renounces to meet his own claim.
He acts unprofessional and knows it.
He becomes mediocre at best.
@amirm your mediocre AND failed to invent the iPod ..

God knows why anybody listens to you ... bloody mediocre Emmy award-winning VPs coming here telling us what to think about audio.. the cheek , the audacity of it all.
 
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amirm

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@amirm your mediocre AND failed to invent the iPod ..
Yeh, I will never live that down. Good news is that I invented the wireless phone decades back in 1960s. I was young and my father had just bought this fancy new phone. When no one was around, I opened it and was fascinated by all the wires in there. I decided to cut all the wires and see what happens. Bam! I had a wireless phone! It no longer worked but it certainly was wireless.

I plan to go modify the Wiki on this and put a mention of myself in there....
 
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amirm

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Still, amirms subjective conclusions are nothing but destructive.
As they should be for anyone who thinks this amplifier is a gift from heaven because it has "class A" and "Nelson Pass" on it. It is anemic. Has lots of distortion. And wastes power for no good reason whatsoever. A lot of audiophiles are buying this amp not because they want to get into the hobby of electronics but to have an amp they think sounds superior to commercial offerings. It is time that they are no longer misled.

Remember, folks like you don't do controlled testing anyway so me testing the amp as I did, should fit your mantra well regardless.
 

Thomas savage

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Yeh, I will never live that down. Good news is that I invented the wireless phone decades back in 1960s. I was young and my father had just bought this fancy new phone. When no one was around, I opened it and was fascinated by all the wires in there. I decided to cut all the wires and see what happens. Bam! I had a wireless phone! It no longer worked but it certainly was wireless.

I plan to go modify the Wiki on this and put a mention of myself in there....
I bet that DAC of jk's took you right back to that memory.. big mess of wires lol
 

pma

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I would let them live. Does it make any sense to fight against people who love distorting heaters? It doesn't. Let them live, WE know what it is about. The endless fight only indicates to being unsure in your opinion and findings and knowledge.
 
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