Amir is a critic without a clue, he made his site by convincing people he could differentiate between indistinguishable DACs, he should stick with that. On the amplifier side of the industry the technology and knowledge base are much more mature, his amp reviews sound like a class d fanboy stuck in the 70/80s THD wars. The ACA review is like a tiny nobody throwing rocks at a giant to get a few more hits.
I think this part: As a starter hobby amplifier to get some sound coming out of a speaker, with relatively few components, the Pass ACA Class A Amp does the job. Build it, have fun with it
No?
Jan
Not only is he obviously and demonstrably wrong, it's also obvious that saying so is in his best interest.
But it's not the content of your post (or lack thereof) what bothers me. What bothers me is your intent, coming into the forum and throwing out a little soundbite like this just to see if anyone gets emotionally turnt over it. Manipulative posts trolling for outrage should probably get moderated (deleted).
On top of that, I don't think Nelson needs or wants other people getting outraged on his behalf. Nelson, like any mature adult, can stand up for himself if he feels the need.
I have no problem Amir measuring the equipment. I like to see measurements too but enough to decide if a 10wpc amplifier can drive my 4ohms (with 2ohm dips) 82db speakers in a medium sized room. Or if I need a 200wpc amplifier to drive my 8ohm 93db speakers in a small room. That’s it. After this all I care is how it sounds to my ears.
To measure ACA or any other respectable designers’ amp and say this is not worthy enough to recommend is disrespectful only because the amp did not pass his tests. You can say "this is how it measures", that’s that. Don’t you really know Nelson Pass or other respectful designers can design an amp that measures better than anything if that was their only goal? It is not about the distortion, etc. measurements make the amplifier sound good or bad. If it sounds good to your ears, who cares about the measurements?
Alan Shaw is great speaker designer, no question. I like Harbeth speakers. I used to own a pair. I would buy it again. Don’t forget though, he is also a good business person. He wants to make sure he gets his point, “don’t worry about which amp, all amps will sound great on Harbeth” which may be true, I don’t know. He does not want different amp owners to decide on their Harbeth purchase based on the amp. He does not want them to ask this question themselves; if their XYZ 100wpc amp will drive his 6ohm 86db speakers good enough. He just says they all sound the same. "Just get a 100wpc amp that is free of problems and you are good to go". So, a 100wpc White Van amps (or is it only White Van speakers?) will sound the same as Pass Labs or Conrad or whatever good amps out there. That does not make sense to me.
To measure ACA or any other respectable designers’ amp and say this is not worthy enough to recommend is disrespectful only because the amp did not pass his tests. You can say "this is how it measures", that’s that. Don’t you really know Nelson Pass or other respectful designers can design an amp that measures better than anything if that was their only goal? It is not about the distortion, etc. measurements make the amplifier sound good or bad. If it sounds good to your ears, who cares about the measurements?
Alan Shaw is great speaker designer, no question. I like Harbeth speakers. I used to own a pair. I would buy it again. Don’t forget though, he is also a good business person. He wants to make sure he gets his point, “don’t worry about which amp, all amps will sound great on Harbeth” which may be true, I don’t know. He does not want different amp owners to decide on their Harbeth purchase based on the amp. He does not want them to ask this question themselves; if their XYZ 100wpc amp will drive his 6ohm 86db speakers good enough. He just says they all sound the same. "Just get a 100wpc amp that is free of problems and you are good to go". So, a 100wpc White Van amps (or is it only White Van speakers?) will sound the same as Pass Labs or Conrad or whatever good amps out there. That does not make sense to me.
In the interest of disclosure: several years ago I organized an AmpCamp in my town in Eindhoven, Netherlands. We had 16 teams of two and each team build a pair of ACA amps on a Saturday. People were very happy to have a chance to build a nice amp. I had designed and produced very nice looking single channel enclosures.
So, thanks to me, 32 monoblock ACA's have been build and auditioned. How many of you have actually build one? Or actually listened to one?
Jan
So, thanks to me, 32 monoblock ACA's have been build and auditioned. How many of you have actually build one? Or actually listened to one?
Jan
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Alan Shaw probably says that because it's basically true (just like papa saying a good speaker-cable is long enough to reach both the amp and the speaker).
Anyone deep enough in the hobby will "probably" check what amp sounds better (and connect every single one in his/her collection), and Alan Shaw knows this too I'm quite sure.
If the quote above is what you're referring to as him saying they "all sound the same", well, no. I read this as him saying any working amp is good to be connected. Not a word about sounding "the same"...
Anyone deep enough in the hobby will "probably" check what amp sounds better (and connect every single one in his/her collection), and Alan Shaw knows this too I'm quite sure.
If the quote above is what you're referring to as him saying they "all sound the same", well, no. I read this as him saying any working amp is good to be connected. Not a word about sounding "the same"...
ME!
But not in such a cool chassis...
(Although the modushop-chassis ain't uncool!)
And I like listening to it, really.
🙂🙂🙂
Let's have another looks at the 2 posts:
No Jan, can't agree on this one. 🙂
Reading the conclusion as a whole (and IMHO we should be doing that) tells me that Amir had not "said words indicating that it was a great didactic design for people learning to build amplifiers. "
His opinion / verdict / conclusion was less positive...
And just to add, my respect to Mr. Pass for his generosity to the DIY community and for his ongoing encouragement.
Also thanks to Amir for measuring gear (I very much support measuring stuff, and his website is a great resource).
Kudos to you too for holding the AmpCamp in Eindhoven and encouraging DIY! Wonderful to see you engage all the folks across various age groups. 🙂
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Well said Mr. Pass! 😀
I think your audience is a bit more hands on too... they build things of all shapes and sizes... but mostly these objects are quite heavy and can get a bit hot!
I think your audience is a bit more hands on too... they build things of all shapes and sizes... but mostly these objects are quite heavy and can get a bit hot!
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I cannot give the link because it takes you to a different page (I guess they changed the forum so links have changed).
Here is a challenge then.
If, in a controlled experiment with all variables accounted for (incl. differences in frequency reponse and within the power range appropriate to the amps) under instantaneous A-B relay switchover, driving any Harbeth speakers, if you can positively identify an amplifier by sound alone, I will give you, FOC, a pair of brand new Harbeth speakers, up to and including a pair of M40.1 in any veneer you fancy.
I am quite confident that under controlled conditions, these fabled amplifier differences disappear and that I will never be parting with my money!
However, I don't have the time to play around. You have to conceive of the test, design the switch over system and bring it to us here and we'll cooperate fully. There are plenty of examples of carefully constructed tests over the past 30+ years to draw on that meet my critera, and every one of them comes to the same conclusion. As far as this 'amp matching to Harbeth speakers' issue goes, it is a non-issue. As dead as the dodo. I cannot comment on the amp matching for other speaker brands. We take care to make our speaker an easy load: other speaker designers may be less consumer-focused.
NO CORRESPONDENCE PLEASE - CALL ME WHEN YOU HAVE THE WHOLE PLAN EXECUTED!
Amplifiers should be selected not for "sound quality" (whatever that is) but for facilities, design integrity, durability, after care and likelyhood of being able to source service parts in 5 or 10 years. Also, if you're really serious, a quick peek at the financial standing of the brand might tell you if they are likely to have the financial resources to weather the economic downturn of the next few years which is effecting the whole consumer electronics sector. Some of the most likely surviving (UK) brands rarely advertise, rarely exhibit, have relatively old-fashioned designs, use standard parts, have been around for a generation and are rock solid businesses. They deserve to be respected and supported because they will be there to look after you in 10+ years.
There are some very difficult times ahead for the consumer industry: now is a time to be cautious."
Alan A. Shaw
Designer, owner
Harbeth Audio UK
Challenge from Harbeth's Alan Shaw - Speakers • Canuck Audio Mart Hifi and Audio Forum
Ok, you got me.
I‘ll never be able to organize something like that, and if I could I probably still wouldn‘t even though harbeth has a reputation of beautiful price-tags afaik, and still … remember nelson‘s characterization of some FW‘s?
To me, it sounds like a fun contest, if this would happen around the corner, I‘d attend.
I‘ll never be able to organize something like that, and if I could I probably still wouldn‘t even though harbeth has a reputation of beautiful price-tags afaik, and still … remember nelson‘s characterization of some FW‘s?
To me, it sounds like a fun contest, if this would happen around the corner, I‘d attend.
Nice marketing, but unnecessary I already liked your speakers. So is this challenge meant to show that amps all sound the same or that Harbeth speakers are not revealing? Your marketing challenge is limited here while it may be impossible to identify amps by sound you can certainly say which sounds better. If we reverse the challenge and ask people to identify harbeth speakers by double-blind sound alone what would happen? (Hint:if I had money on it I’d be keeping it too). Interesting you talk about the need for consumer support in the industry but downplay the importance of a huge market segment.
I promise. I am not trying to get you or someone else. I did open this thread because Nelson Pass can’t defend himself or he cares what others think. I opened here because he is a well respected designer and this is his/ours forum under his name. I love his amps regardless how they measure. I like Harbeth speakers too. I am a member in ASR also but I don’t think that simple measurements and/or comments that make any designers’ work worthless is fair.
This is a public forum so I assume it is OK to express my views.
Would like to see the complete context surrounding the "all amps sound the same " statement . Difficult to envision someone in the business saying such a thing as a blanket statement . If this is the case , we can trash many descriptive terms used in reviews and describing our gears sonic characteristics. Just buy according to load needs , cosmetic appeal and away we go .
If the amplifiers all have low output impedance, flat frequency response, low distortion, and are not driven beyond their capability, they will have to sound the same. Amplifiers that err from these requirements will sound different. As an example, tube amps may sound different if they deviate from the requirements I listed above.
Of course, your opinion of an amplifier may influence your perception of its sound, so double blind testing at matched volume levels is the only legitimate way to test for perceived differences.
I don't know if it is a modern thing or just something I notice now because of the internet but why do so many people make blanket statements that their preference is the requirement for everyone?
The two words that need to be used much more are "for me" or "I prefer". They dismiss any amp that can't rattle the walls.
My 20 watt M2 clone could drive me out of the room. It played crystal clear to the end of the volume knob. My 6 watt or so tube amp goes plenty loud enough for comfortable listening... wait for it... for me.
Which brings me back to my earlier point of 'why test the amp if all the published specs are outside what you consider mandatory?'. It would be like reviewing a style of music that you dislike.
I built one with the circuit boards from here, for under $100, mounted to a cutting board. That was probably about 10 amps ago. Yeah, it is a gateway drug 🙂
Music should be fun, if it isn't then they are doing it wrong.