Ok so if I wire the amp the way I see it in the pics from this link as long as I don't flip the switch it runs as a Stereo amp? By the way thanks for your help.
aca16
Oh! Duh, I'll just omit the back switch and the XLR completely.
You can certainly leave both the XLR jack and switch out. You can see from the pics that they wire "into" the circuit, so if you omit them, no harm no foul.
Alright, I got both of mine finished and up and running.
Initially the output seemed a bit low but I had some filters installed in Foobar and that was the issue. With that fixed, the power is adequate playing from PC and from vinyl and with some extra gain on my preamp.
The sound is fantastic even after just a few hours of use so I'm sure they will break in a bit more. I listen to a very wide range of music and I had to a chance to everything from jazz to electronic music of various types. The only downside is that I have a huge library of music I collected over the years and they are mostly MP3's of dubious quality and those files just sound really bad. Playing from vinyl or my much smaller high res library sounds incredible now.
I two Mark Audio 10p's with a Planet10 cabinet, a sub that I built that contributes just a little to the low end, a Schiit Freya preamp and, Rega RP1 with a Hagerman Bugle2 phono preamp. As you can see I've been super busy this year collecting audio stuff
Thanks to everyone who helped put all this stuff together and to every one who helps us newbies out by giving us a chance to build a kit and answering all our questions.
I also happen to collect all the important parts of an F5 so at some point I'll give that a try.....
Kevin
Initially the output seemed a bit low but I had some filters installed in Foobar and that was the issue. With that fixed, the power is adequate playing from PC and from vinyl and with some extra gain on my preamp.
The sound is fantastic even after just a few hours of use so I'm sure they will break in a bit more. I listen to a very wide range of music and I had to a chance to everything from jazz to electronic music of various types. The only downside is that I have a huge library of music I collected over the years and they are mostly MP3's of dubious quality and those files just sound really bad. Playing from vinyl or my much smaller high res library sounds incredible now.
I two Mark Audio 10p's with a Planet10 cabinet, a sub that I built that contributes just a little to the low end, a Schiit Freya preamp and, Rega RP1 with a Hagerman Bugle2 phono preamp. As you can see I've been super busy this year collecting audio stuff
Thanks to everyone who helped put all this stuff together and to every one who helps us newbies out by giving us a chance to build a kit and answering all our questions.
I also happen to collect all the important parts of an F5 so at some point I'll give that a try.....
Kevin
Attachments
motospark -
The switch is not necessarily used to make it a monoblock, if you use the XLR, it's going to be bridged automatically. It is, however, used to make it bridged mono from the RCA inputs.
Stereo single ended, use RCA connectors on both RCA jacks and attach L and R speaker to the respective speaker posts.
Monoblock XLR, use the XLR jack and take speaker output from the two black posts.
Monoblock RCA, use the Left RCA for input, leave the right empty, flip the switch up, and take speaker output from the two black posts.
Another impatient newbie with two kits burning a hole in his pocket Question:
1.) For Monoblock RCA... I can build it exactly like the pictures, and with switch flipped its a Monoblock RCA?
2.) and the "leave the right empty" what exactly is meant by that? I understand it would only have one RCA input going IN RCA Left. Is that what is meant? Sorry for my newbieness
It is Alive . Damn this thing runs Hot, 1st bias set to 10.06 or so, give a take a few. Hey Thanks everyone who helped with the wiring details, I gonna cover it and let it run another 30 min, then check the Bias again. Then its time to listen, I'm using a WJung modified Adcom GFP-565 pre-amp hooked up to Vandersteen 2ci. This should be interesting.
Oh I have another question, should I be using the same Bias settings 10v as the version 1.5 for my 1.6?
I guess since I'm asking questions, how hot is your running, after 1st Bias set to 10v and change I'm reading on the outside fins 123 f. Is this normal?
Mark
Oh I have another question, should I be using the same Bias settings 10v as the version 1.5 for my 1.6?
I guess since I'm asking questions, how hot is your running, after 1st Bias set to 10v and change I'm reading on the outside fins 123 f. Is this normal?
Mark
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I biased my ACA amps at 12V (more like 11.8V) - which is the suggested point for the 24V power supply and yes, they do run hot - as in very hot. I'll have to check the bias again just to be sure. But right now I'm very happy listening to them bridged via XLRs from my Classe Five preamp, even with 86dB Wharefedale speakers.
I'll be curious to see how these stack up with my next project, the Aleph J.
I'll be curious to see how these stack up with my next project, the Aleph J.
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Oh ok .
From everything I've read thus far, normal operating temps should be 25 C (~45 F) above ambient. Also, you can safely set the bias to 12 V per side with the 24 V power supply (that's where mine is set).[/QUOTE
Ha! I was so into building the Amp I neglected to turn on the Air Conditioner, it was 83 in my apartment.
This Amp has a dead silent background, sounds so sweet so far. It drives my Vandersteen just fine, volume on my pre-amp is around 12 oclock.
Thanks Mr Zenith.
Hello,
Can anyone recommend some speakers that mate well with the ACA amp? I can build the design if it is not too complex, and don't mind buying something commercial if it is a sensibly priced.
Thanks!
If you want very efficient DIY you might look into PI speakers. Wayne’s designs are very efficient and sound very, very nice.
Pi Speakers - unmatched quality and state-of-the-art performance
I just finished the first of two amps. What happens when you don't know how to tell the difference between unpowered LEDs? Statistics seem to predict that you will build an amp with one red LED and one blue LED, and that's precisely what I did.
Thanks for the tip, maybe I'll test mine before installation
Cheers,
Matt
Thanks for the tip, maybe I'll test mine before installation
Cheers,
Matt
You can use a small value coin type battery to test them, low voltage. I made the mistake of trying a 9 volt battery and my Blue LED blew and died, well I did find it was blue but now I have to use the Red LEDs. I prefer Blue, Ill have to order some.
Mark
You can use a small value coin type battery to test them, low voltage. I made the mistake of trying a 9 volt battery and my Blue LED blew and died, well I did find it was blue but now I have to use the Red LEDs. I prefer Blue, Ill have to order some.
Mark
Thanks Mark. I'll use a current limiting resistor to prevent accidents.
Cheers,
Matt
My digital multimeter has a diode option and it lights up the led and tells you the current it is passing (usually around 2.5 or so volts). Maybe you guys can look into that option before assembling the ACAs as Christmas lights?
Great idea Rafa. I'm certain we have an LED tester here at work somewhere, I'll have to go find it...
Matt
LEDs need a current limiting series resistor.
There's no two way about it.
Unless the supply voltage is exactly what the Forward Voltage drop of a LED is, which is not the case in the world of DIYAudio.
Typical LED characteristics @20mA:
infra red Vf 1.2 V
amber / red 2.0 V
yellow 2.1 - 2.2 V
green 3.5 v
blue 3.6 V
white 3.6 - 4.0 V
How to calculate series resistor:
Rs = (Vs - Vf)/If
where
Rs is the current limiting series resitor
Vs - supply voltage
Vf - LED forward voltage (or the voltage drop across the LED)
If - the current flowing through the LED
20mA is a pretty high current, so use something like 10, or 5, or whatever you feel like it.
Higher current will make the LED brighter, its light more intense.
In the case of a blue that can be quite annoying, so bring that current down.
Example:
Vs = 24 V
LED blue, so Vf = 3.6 V
Desired current 4mA
Rs = (24 - 3.6)/0.004 = 5100 ohms
If you find that the light is still too bright increase the value of the resistor.
Simples.
There's no two way about it.
Unless the supply voltage is exactly what the Forward Voltage drop of a LED is, which is not the case in the world of DIYAudio.
Typical LED characteristics @20mA:
infra red Vf 1.2 V
amber / red 2.0 V
yellow 2.1 - 2.2 V
green 3.5 v
blue 3.6 V
white 3.6 - 4.0 V
How to calculate series resistor:
Rs = (Vs - Vf)/If
where
Rs is the current limiting series resitor
Vs - supply voltage
Vf - LED forward voltage (or the voltage drop across the LED)
If - the current flowing through the LED
20mA is a pretty high current, so use something like 10, or 5, or whatever you feel like it.
Higher current will make the LED brighter, its light more intense.
In the case of a blue that can be quite annoying, so bring that current down.
Example:
Vs = 24 V
LED blue, so Vf = 3.6 V
Desired current 4mA
Rs = (24 - 3.6)/0.004 = 5100 ohms
If you find that the light is still too bright increase the value of the resistor.
Simples.
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