I just got notified by DIYAudio of a new post in this thread. I am amazed how long it has been since I last visited here. There were reasons for this, there are always reasons, usually dealing with something that cannot be delayed any longer. So you do it, and something else follows, and so on and so forth. By the time you get back there are 200 additional posts. Amazing!
The second amazing issue is that I read about 300 or so posts before starting to post, and now I have an equal number to read. The third amazing thing is how far out of mind the ACA kit can get, it is stored somewhere (I know where) but out of sight out of mind. Oh well, life is like that.
Sorry guys
The second amazing issue is that I read about 300 or so posts before starting to post, and now I have an equal number to read. The third amazing thing is how far out of mind the ACA kit can get, it is stored somewhere (I know where) but out of sight out of mind. Oh well, life is like that.
Sorry guys
Often amps come and go, but ACA is in my system on regular basis. It is not that old (1 year), but I really like it. Especially, it is my first build, including chassis (I did not count how many holes I made, more than 300). Due to fact I like "slim" design units PCB's are not from diy audio store, but made by diyaudio enthusiast in Germany.
Front panel is teak wood (polished and oiled), everything else is aluminum. PSU's are Lenovo units, providing 20V, dual mono unit, sharing only power cord.
In fact, this (last) Saturday, ACA was playing (at full power, of course
) at my daughter's birthday. As being "fed" by reasonably big Yamaha receiver (rxv 1700 - used as preamp), most people did not believed what actually is powering speakers.
Of course, none of it wouldn't be possible without extensive help and experience of other members of diyaudio forum!
Next in line is Babelfish J, coming soon.
Front panel is teak wood (polished and oiled), everything else is aluminum. PSU's are Lenovo units, providing 20V, dual mono unit, sharing only power cord.
In fact, this (last) Saturday, ACA was playing (at full power, of course
) at my daughter's birthday. As being "fed" by reasonably big Yamaha receiver (rxv 1700 - used as preamp), most people did not believed what actually is powering speakers.Of course, none of it wouldn't be possible without extensive help and experience of other members of diyaudio forum!
Next in line is Babelfish J, coming soon
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+1 Very nice dude!
I wish I had 1/100th of the talent that most of you guys have. I can barely follow the directions...
@TungstenAudio: thanks. It was my first diyaudio build, and I was not limited in time or dimensions (often a problem when buying premade enclosure). There are still a thing or to to make/improve, but as it sits - I am satisfied. Thank you very much!
@mraudioguru: that is exactly what I was thinking before start. ACA is just THE RIGHT THING to make, having optimal number of parts to make it a beginner's project, exactly as was Mr. Pass idea.
@oc11: well, to my surprise, it is not that cool as I was thinking it will be. I can not find photos at this moment from when I was measuring finished amp, but I did find some from testing phase. Anyway, temperature of complete amp inside rack was cca 50 deg C (so 122 deg F), and I decided it is not best idea to keep it in rack, so it is on top now. Also, I have made some kind of wooden stand for it (like wooden brick, oak wood, I couldn't find teak wood that big), but I removed it for safety reasons (my kid's birthday). I guess that temperature now is 42-43 deg C (cca 110 deg F), so really nice.
Here are two photos few minutes ago. It was really difficult to cut that one peace of aluminum heatsink into four pcs, than grind them (by hand) to make them same thickness, and drill all holes, and thread most of them. 90% of that was done on kitchen table. Not to mention holes on top cover, or frame made of aluminum L and U profiles.
Well worth the effort.
@mraudioguru: that is exactly what I was thinking before start. ACA is just THE RIGHT THING to make, having optimal number of parts to make it a beginner's project, exactly as was Mr. Pass idea.
@oc11: well, to my surprise, it is not that cool as I was thinking it will be. I can not find photos at this moment from when I was measuring finished amp, but I did find some from testing phase. Anyway, temperature of complete amp inside rack was cca 50 deg C (so 122 deg F), and I decided it is not best idea to keep it in rack, so it is on top now. Also, I have made some kind of wooden stand for it (like wooden brick, oak wood, I couldn't find teak wood that big), but I removed it for safety reasons (my kid's birthday). I guess that temperature now is 42-43 deg C (cca 110 deg F), so really nice.
Here are two photos few minutes ago. It was really difficult to cut that one peace of aluminum heatsink into four pcs, than grind them (by hand) to make them same thickness, and drill all holes, and thread most of them. 90% of that was done on kitchen table
. Not to mention holes on top cover, or frame made of aluminum L and U profiles.Well worth the effort
.Attachments
@elb. If you read this thread (and I know it is extremely large) you will find out any number of changes and alterations that have been used by people in their ACA units, 1.6 and prior versions. Some things are agreed upon: 1. The increase in voltage to 24 volts is beneficial for the performance of the ACA. 2. Lots of people have had issues with low output from the ACA when used without a preamp, it is therefore generally accepted that a preamp is a very good addition to the system particularly when used with certain types of speakers. I think you should feel free to try the mods suggested by TungstenAudio and see if you like them and feel they improve the sound. Let your ears decide. Remember one of the reasons Mr. Pass started the ACA kits was to foster experimentation and to propagate knowledge about amplifiers.
@oc11.
Thank you for the explanation.
I have just recently built the ACA as per the excellent build guide.
Fired it up and it works.
I have no problem with the output.
The sound quality of this little amp is wonderful and I will leave the modifications to the experts.
ACA 1.6 Questions
Hey All
My wife is out of town and I finally have some uninterrupted time to work on my ACA 1.6 bridged balanced monoblocks, which have been collecting dust while I did absolutely critical things like mop the floor. Now that I have 3 of the 4 boards stuffed, it's the obvious time to ask questions, right?
Build Guides: I've found two, links below:
ACA Build Guide v1.0, dated Dec 11 2013
ACA Build Guide v1.5, dated March 31 2018
Thanks loads to 6L6 for these guides!!
Within the ACA Build Guide v1.5 there is a reference to doing a guide for v1.6, which by the way is the kit that I have. I didn't locate a v1.6 guide, so proceeded to build using the v1.5 and comments in that build thread. I've attached a pic of the boards I'm stuffing.
First question: There is an extra 39.2k resistor in each kit. I see no where on the board for this. Please tell me I have just won the resistor lottery and I can use these two extra resistors for my next project.
Second question: Does a separate v1.6 guide exist? It seems the v1.5 guide was just modified to accommodate the v1.6 build changes, which is fine.
Third question: How in the world could "Orville" not be in the running for the v1.6 name????
Hey All
My wife is out of town and I finally have some uninterrupted time to work on my ACA 1.6 bridged balanced monoblocks, which have been collecting dust while I did absolutely critical things like mop the floor. Now that I have 3 of the 4 boards stuffed, it's the obvious time to ask questions, right?
Build Guides: I've found two, links below:
ACA Build Guide v1.0, dated Dec 11 2013
ACA Build Guide v1.5, dated March 31 2018
Thanks loads to 6L6 for these guides!!
Within the ACA Build Guide v1.5 there is a reference to doing a guide for v1.6, which by the way is the kit that I have. I didn't locate a v1.6 guide, so proceeded to build using the v1.5 and comments in that build thread. I've attached a pic of the boards I'm stuffing.
First question: There is an extra 39.2k resistor in each kit. I see no where on the board for this. Please tell me I have just won the resistor lottery and I can use these two extra resistors for my next project.
Second question: Does a separate v1.6 guide exist? It seems the v1.5 guide was just modified to accommodate the v1.6 build changes, which is fine.
Third question: How in the world could "Orville" not be in the running for the v1.6 name????
Attachments
ACA 1.6 Build Guide
Amp Camp Amp V1.6 Build Guide - diyAudio Guides
See Step 39 for the extra resistor use
Amp Camp Amp V1.6 Build Guide - diyAudio Guides
See Step 39 for the extra resistor use
Thank you, oc11, I completely missed that. Appears lots of stuff - info, links, and equipment - has been added to the diystore since I last looked.
You'll probably need a some kind of preamp. I'm using speakers with similar sensitivity and without preamp the ACA is at full volume for "normal" listening level. At the moment I'm using an O2 to add some gain until I come up with a better solution.
Other more knowledgeable-DIYA-types will know more.
Other more knowledgeable-DIYA-types will know more.
Got my stereo ACA going nicely at first go (one channel at least first off, the other channel I had to carefully check my home milled boards for a wee short.) I am yet to make plates for top and bottom so have had the heatsinks sitting flush against the bench - it felt towards the hot side and I had been thinking I might need a fan.
However, I used a couple of pencils to lift both sinks off the flat surface and was very surprised at the drop in temperature - incredible what allowing for a bit of passive air circulation will do!!!
However, I used a couple of pencils to lift both sinks off the flat surface and was very surprised at the drop in temperature - incredible what allowing for a bit of passive air circulation will do!!!