I built two ACA's amps a couple weeks back. Then a ACP+. Mind you the last time I did any soldering was back when Gas was 0.40 cents a gallon and the Dow was at 850! Like they say getting back into the flow was like riding an old bicycle. Everything was a piece of cake when it came to assembly of the kits.
I have an old Sony STR-D1011S integrated amp that I've had since the 90's. Hard to remember just how old it is, it has been around a long time, longer than my kids, ex-wives, ect. You get the picture. Anyway today I fired up one of the ACA amps and routed it to a pair of DCM CX-07 monitors rated at 80w and 90db. I was never impressed with them as they are the smaller set of speaker that the Sony drove. When the amp came online I was amazed at just how this little amp changed the tonal quality of these speakers. It was surreal. They sounded new and much larger. This little amp amazed me yet I found it to be a tad weak by itself, not bad although it's brother was on deck waiting to jump into the fray.
Next I added the second ACA amp! I ran them as Mono blocks Parallel. Threw some SRV on from my IPhone and holy crap a whole new world opened up. The bass was full and rich while the mid-range was strong. While the highs were clear and spot on. I never considered that these DCM's would ever perform this way ever! These two filled the house with music, good clean sound. No hum, no buzz, no static or popping.
Sooooo.....
Then I connected my ACP+ to the system.
I was gobsmacked, Period! I had no idea that they would or could sound so good.
I was hooked!
Building these ACA amp was just to kill time during Covid. I had no idea they would have such an impact on my music listening.
Many, many years ago I listened to a set of Klipsch speakers and knew of their history. Someday I figured I'd build myself a set, being part termite. During my research I'd heard of these ACA amps being compared to Tube amps for their quality of sound. Really? So I did some homework and then ordered two.
My speakers are a on going project. I'm mid way through building a set of Klipsch La Scala clones, sort of. The lower folding bass horn will be hybrid of a Peavy FH1 and the lower AL5 Klipsch size-wise. While they both have a similar 15" woofer and the FH1 will throw a little more bass by it's designed. A common complaint of early La Scala owners is lack of bass. The Squawker will follow the Klipsch AL5 in design but, the tweeter will sit freestanding on top of the squawker like an open baffle horn driver. All of the compression drivers/ woofers will be tied together using ALK universal crossovers.
This DIY stuff is additive, especially when working with a quality design, parts, and information.
Thank you Papa for offering these kits to inspire people(it worked), the diyAudio Store for shipping a quality complete kit. Along with all the members here that have inspired me with their builds and knowledge!
Thank you all....
Art
(An old Hack having some fun)
I have an old Sony STR-D1011S integrated amp that I've had since the 90's. Hard to remember just how old it is, it has been around a long time, longer than my kids, ex-wives, ect. You get the picture. Anyway today I fired up one of the ACA amps and routed it to a pair of DCM CX-07 monitors rated at 80w and 90db. I was never impressed with them as they are the smaller set of speaker that the Sony drove. When the amp came online I was amazed at just how this little amp changed the tonal quality of these speakers. It was surreal. They sounded new and much larger. This little amp amazed me yet I found it to be a tad weak by itself, not bad although it's brother was on deck waiting to jump into the fray.
Next I added the second ACA amp! I ran them as Mono blocks Parallel. Threw some SRV on from my IPhone and holy crap a whole new world opened up. The bass was full and rich while the mid-range was strong. While the highs were clear and spot on. I never considered that these DCM's would ever perform this way ever! These two filled the house with music, good clean sound. No hum, no buzz, no static or popping.
Sooooo.....
Then I connected my ACP+ to the system.
I was gobsmacked, Period! I had no idea that they would or could sound so good.
I was hooked!
Building these ACA amp was just to kill time during Covid. I had no idea they would have such an impact on my music listening.
Many, many years ago I listened to a set of Klipsch speakers and knew of their history. Someday I figured I'd build myself a set, being part termite. During my research I'd heard of these ACA amps being compared to Tube amps for their quality of sound. Really? So I did some homework and then ordered two.
My speakers are a on going project. I'm mid way through building a set of Klipsch La Scala clones, sort of. The lower folding bass horn will be hybrid of a Peavy FH1 and the lower AL5 Klipsch size-wise. While they both have a similar 15" woofer and the FH1 will throw a little more bass by it's designed. A common complaint of early La Scala owners is lack of bass. The Squawker will follow the Klipsch AL5 in design but, the tweeter will sit freestanding on top of the squawker like an open baffle horn driver. All of the compression drivers/ woofers will be tied together using ALK universal crossovers.
This DIY stuff is additive, especially when working with a quality design, parts, and information.
Thank you Papa for offering these kits to inspire people(it worked), the diyAudio Store for shipping a quality complete kit. Along with all the members here that have inspired me with their builds and knowledge!
Thank you all....
Art
(An old Hack having some fun)
Had fun building this one. No problems; works great. But question: Is there a reason why the panel connectors are wired to the pcbs with point-to-point wire, soldered at each end, rather than using header pins or something like that? Connecting to the pcbs with header pins instead of soldering would make the wiring and final assembly so much easier.
I made an ACA variant that uses only PCB mount connectors. No wires! It does make assembly easier and I haven't had any complaints. The store ACA could be redesigned to put connectors on a rear PCB, but redesign and re-release can be difficult when you already have inertia in a product (parts, stock, order page, build guide, pricing, troubleshooting, etc)
Thread here: ACA Redux | diyAudio
I have to pay tribute to this little big amp again... My M2x broke today... I thought ok I have a big commercial amp, 2x200w, I'll plug it in... but after only half an hour I turned it off, it was just bad. After the M2x unbearable. But what now? Then I remembered that I have two ACAs... quickly connected - yes, that's it, the usual sound pattern. Used as a bridged mono, they can drive my OB (according to simulation 92 dB sensitivity) without any problems. I can now take my time with the repair of the M2x. What a great amp!
I tried to make it this way and ultimately gave up. To do those little pins that go into the good quality headers like molex, and I mean do them well, you either need to use a moderately priced tool and be very experienced with crimping, or buy the precision tool for the job. I don't know if you've ever looked at the price of the certified crimping tools for these things, but it exceeds the cost of the whole ACA kit. This is why I imagine some amp kit suppliers supply the wires for their kits pre crimped. Bad solder is more obvious than a bad crimp.
You'd also have to (or at least you ought to) supply the kit with three different headers per board (one pin header, one socket header, one with different spacing) so you can't absently get them backwards when reconnecting it and blow things up. That ups the cost again. With the exception of the LED power they'd also have to have sufficient power handling. No tiny dupont headers.
In the end I just settled for attaching the LEDs with breadboard leads and a 2 pin dupont header so I can swap them out easily and left everything else soldered. I agree that case assembly with all the wire (especially that faceplate) is a pain in the butt.
I have started assembling 4 separate ACA boards for bridged amps with only XLR L and R connections using an existing 3U 400 mm enclosure.
Since I am not installing the position selector, do I still need the 39K resistor installed as per schematic to connect 2 boards in bridge?
thanks
https://cdn.shopify.com/s/files/1/1006/5046/files/ACA_wiring_-_All_Together_-_V18.pdf?v=1593415056
Since I am not installing the position selector, do I still need the 39K resistor installed as per schematic to connect 2 boards in bridge?
thanks
https://cdn.shopify.com/s/files/1/1006/5046/files/ACA_wiring_-_All_Together_-_V18.pdf?v=1593415056
in a bridged two channel amp, one amp provided the voltage gain, the other which is a slave channel only needs to invert the output signal of the voltage amplifying channel, hence the 39k , in my case the feedback resistor is 47k so i use the 47k is what i use..
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