Amp Camp Amp - ACA

Guys, have you seen this review/measurements thread?
I know the amp sounds good, but that tested unit seems almost broken?
Or what am I missing?
(Havent read the whole thread)
Pass ACA Class A Power Amplifier Review | Audio Science Review (ASR) Forum

As Nelson said at BAF2019, "it's entertainment".

And to paraphrase Rusty Crowe from "Gladiator", "are you not entertained?"

Measurements and specs have there place but placing appropriate reliance on your own ears is where I'd suggest you fall back to. If your ACA doesn't sound right to you, post some photos, describe the issue and do a voltage survey with your DMM. Report back the details and you'll get mountains of support and help here from people who enjoy listening to music.

Some places on the internet aren't that helpful. I'd suggest avoiding the grumps out there.
 
Originally Posted by bambadoo View Post
Guys, have you seen this review/measurements thread?
I know the amp sounds good, but that tested unit seems almost broken?
Or what am I missing?
(Havent read the whole thread)
Pass ACA Class A Power Amplifier Review | Audio Science Review (ASR) Forum

One thing that strikes me odd is the comment about how the reviewer could not get any real volume from the speakers for the listening test. The speakers used in the review were 86db sensitive and 8 ohm, my speakers are 88db sensitive 8 ohm full rangers plus I have 3db of BSC filter. They go beyond what I consider loud listening in my living room. Distortion or no what is so fundamentally different from my setup to what the tester used?
 
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PCB-connection tips?

Good morning!
I know I'll tear my ACAmp apart to try to implement some of the tweaks and improvements. Since this means connecting/disconnecting the board "many" times, I think it would be reasonable to work with PCB-connectors of sorts.

I bet the distances of the solder-points are according to some standard, but which?

I'll probably need something like a molex, solder-pin, quick-fix connector...
I've seen some in ACAmps, here in the forums, can I ask what part you were using?

thank you!
david
 
The speakers used in the review were 86db sensitive and 8 ohm, my speakers are 88db sensitive 8 ohm full rangers plus I have 3db of BSC filter. They go beyond what I consider loud listening in my living room. Distortion or no what is so fundamentally different from my setup to what the tester used?
This was also the part of the review I found most strange. The tester should redo this test and measure on speaker input if he gets full signal. A 5V RMS signal on 86 dB speakers should be louder than just background music?
 
diyAudio Chief Moderator
Joined 2002
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Room size and listening distance change sufficient power thresholds a lot. Listening habits are a significant factor as well. Users of high power amps usually listen loud and uncompressed in bigger rooms with moderate efficiency speakers of larger voice coils poised for impressive replay of also EDM and other power loving genres.
 
I used my ACA with fifty years old philips full range drivers. I was using B1 at that time.. And it was magical.. Unfortunately I don't have full rangers anymore for listening because of WAF issues (really big boxes!)....

I also used ACA with 87db three ways and used BA3 pre and it still delivers enough juice for speakers..

I think reviewer doesn't have enough input level to get sufficient spl.
 
diyAudio Chief Moderator
Joined 2002
Paid Member
ACA should be at its dynamic best on 95dB SPL/W/M speakers or more. Never pushed beyond 2-3V RMS output so it gives a moderate bloom of harmonic coloring in subjectively high enough peaks while getting progressively resolving in fade outs. Its blacker background than most tube amps and going to its linear best the other way than most higher SINAD performance solid state amps should be its two trick pony mojo.