@Azookey, look back at post 7038. I posted a THD graph of the bridged ACA with both balanced and single ended drive. In post 7040 I posted THD analyzer and spectrum plots of both sides in single ended drive mode. The sides look different because the in-phase side is getting it's input from the output of the inverting side which is pre-distorted.
oc11's suggestion is an easy way of patching your gear together.
One other way is this sort of approach:
Balanced Transmitter
Then there's ZenMod's suggestion that the link above discusses to some extent, as well. Don't have a link to something more than that. Maybe ZM could point to some design detail that you could build?
if one already have proper differential/balanced signal from source/preamp , then nothing needs to be done on ACA side - just feed one channel from pin 2 of XLR, second from pin3 of XLR , pin 1 to GND
if one is not having diff./balanced signal from upstream , inherent ACA bridging concept** is good and valid as any other ...... maybe only decent ( read - not cheap) input xformer is going to sound better
**described in Build Guide
if one is not having diff./balanced signal from upstream , inherent ACA bridging concept** is good and valid as any other ...... maybe only decent ( read - not cheap) input xformer is going to sound better
**described in Build Guide
Aviatrix MLTL
Hello,
I've built Speakerdesignworks Aviatrix which I believe is somewhere in the 84db range for efficiency. Could be higher, but I was just going off the frequency response measurements on their page. I have no real circuit experience except for building the speakers. I wanted to build two AMP Camp amps as monoblocks for them. They have RCA in the back and not balanced. The speakers are between 6-8ohms. Do you think the two amps will push the speakers good for music and some movies? The speakers are rated for around 80wpc. I am also looking into Hypex amps. My bday is nextmonth and I will be building soon.
Hello,
I've built Speakerdesignworks Aviatrix which I believe is somewhere in the 84db range for efficiency. Could be higher, but I was just going off the frequency response measurements on their page. I have no real circuit experience except for building the speakers. I wanted to build two AMP Camp amps as monoblocks for them. They have RCA in the back and not balanced. The speakers are between 6-8ohms. Do you think the two amps will push the speakers good for music and some movies? The speakers are rated for around 80wpc. I am also looking into Hypex amps. My bday is nextmonth and I will be building soon.
Bigger speakers, yes. And a bigger amplifier.
Probably the main appeal of the ACA is that it is available as a full kit. Plus, it is not too expensive and not too big or heavy. On the other hand, there are a couple N. Pass designs available that are available as nearly full kits and will sound wonderful with a wider range of speakers. The M2x, for example, can be assembled from a pair of main PCBs w/ front end boards of your choice, a Universal Power Supply, and housed in a Deluxe 4U Aluminum Chassis with the aid of the Back Panel parts kit. You just need to add a transformer, and buy a small number of components to populate the boards.
In the Lego kit parlance, this is more of a 14+ skill level assembly, but extremely rewarding for being such. The F5 is an alternative that will fit into the same chassis and power supply. I would reserve the Aleph J for a special build with a larger chassis (Dissipante 4U, 400mm deep) and a full dual-mono power supply.
Probably the main appeal of the ACA is that it is available as a full kit. Plus, it is not too expensive and not too big or heavy. On the other hand, there are a couple N. Pass designs available that are available as nearly full kits and will sound wonderful with a wider range of speakers. The M2x, for example, can be assembled from a pair of main PCBs w/ front end boards of your choice, a Universal Power Supply, and housed in a Deluxe 4U Aluminum Chassis with the aid of the Back Panel parts kit. You just need to add a transformer, and buy a small number of components to populate the boards.
In the Lego kit parlance, this is more of a 14+ skill level assembly, but extremely rewarding for being such. The F5 is an alternative that will fit into the same chassis and power supply. I would reserve the Aleph J for a special build with a larger chassis (Dissipante 4U, 400mm deep) and a full dual-mono power supply.
I also agree that these would not be a good choice.
I have tried over 20 different pairs of speakers with my single, stereo ACA. I plan on posting a list, but needless to say, anything under 87db or so, didn't play well.
This is not a basic problem inherent with ACA, it simply does not produce enough power without a preamp to drive certain loads well.
Compare this with the F4 amp, also a NP design but one with 0 gain. It is reputedly (I have never heard an F4 in use) capable of producing exquisite music but it needs a very specific type of preamp, one capable of providing a significant amount of gain, to drive it. The amp is fine once you feed it properly. I assume it is the same thing with the ACA, feed it properly and it will excel.
Compare this with the F4 amp, also a NP design but one with 0 gain. It is reputedly (I have never heard an F4 in use) capable of producing exquisite music but it needs a very specific type of preamp, one capable of providing a significant amount of gain, to drive it. The amp is fine once you feed it properly. I assume it is the same thing with the ACA, feed it properly and it will excel.
I understand the concept of speaker efficiency, but when you say "didn't play well" are you referring simply to insufficient volume or is there an actual loss in fidelity? (and interesting to see my grammar plugin wants to change that to infidelity lol).
Sorry, I knew when I typed that, that I wasn't clear. The volume level just wasn't high enough or was high enough, but included too much noise or distortion.
I tried several different preamps too, so it wasn't a gain issue per se. IMHO, it was the lower efficiency of the speaker(s).
I think that might be referring to the SE Stereo / Bal Mono switch. If you choose to not build in this feature, (if I remember correctly) the kit has a plug for blocking the hole in the back plate of the made-to-measure chassis from Modushop.
I'm pretty sure that the single 400 VA tranny with dual secondaries will serve me just fine for the Aleph J I've just built. Compared with the original design intent, that's oversized. I'll let my ears decide.. yet to get in a proper listening test yet.
With the ACA as my guide, I've got no doubts. There's a fun warning for those into their ACAs. Bigger things await, with more fun to be had..
Speaker Efficiency
Just to add to the speaker efficiency discussion...
My speakers are ~87 db efficient (but easy to drive) and they do quite well with my single stereo 24v ACA. Granted my listening space is small and I try to keep the level down, but I feel there is power to spare with 8 watts.
I think its also worth considering the load the speakers present to the amplifier, not just how efficient they are. The ACA will go further with speakers that have less impedance swing through their frequency response. It doesn't seem to handle difficult loads very well, even if the speakers themselves are efficient.
Just to add to the speaker efficiency discussion...
My speakers are ~87 db efficient (but easy to drive) and they do quite well with my single stereo 24v ACA. Granted my listening space is small and I try to keep the level down, but I feel there is power to spare with 8 watts.
I think its also worth considering the load the speakers present to the amplifier, not just how efficient they are. The ACA will go further with speakers that have less impedance swing through their frequency response. It doesn't seem to handle difficult loads very well, even if the speakers themselves are efficient.
Huh. I attached photos. I have the empty hole where the rear switch would have been and a press fit plug which I assume goes there. The plug fits inside the hole, but there is no friction to keep it in place.
Attachments
