I finally assembled my second ACA. Fun project and the kits made it very easy.
I have a question on the Parallel Input method of running them as monblocks. How do I connect the speakers? The manual makes it sound like I just run the ins and outs parallel to each other. That makes sense of the in, but tying the outs together goes against all I have been taught.
That is all.
I have a question on the Parallel Input method of running them as monblocks. How do I connect the speakers? The manual makes it sound like I just run the ins and outs parallel to each other. That makes sense of the in, but tying the outs together goes against all I have been taught.
That is all.
The photo in this link will show you the way. I believe it's also in 6L6's build guide.
Yes it is and yes it is!
Covered here in post #6522 https://www.diyaudio.com/forums/pass-labs/215392-amp-camp-amp-aca-653.html#post5595943
Alan
Yes the diagram in #6923 is correct. As long as both boards are working correctly, that will give you a 'Mono block bridged' ACA. (caveats not withstanding...)
Is the BOZ ok now? How are you combining the stereo signals into mono?
Alan
The diagram looks correct. The speaker connects between the two '-' output terminals of the amp, the + terminals being left unused (and these are in fact ground anyway).
The resistor feeding the input should be whatever was recommended in the design, which for two identical amps with identical gain would be around 33.5k for an 8 ohm resistive load. Use what was recommended though.
AMP Camp Amp completed today who hoo. Sounds so good!!
Happy Xmas Mr Pass what a treat.
So I'm feeding it Tidal via from a Nativ Streamer and a Cambridge DAC magic plus. It's outputing to a pair of Carfrae little big horns replicas I built - 106db/watt each of those takes a signal off the speaker cable to drive 170watt hypex plate amps and Seas subwoofer passive combo. So the little ACA is just driving Lowther DX4's. Plate amps and subs just fill in the lowest octave but also relieve the main amp of some of the hard work.
It's a substitute amp for my Audio Innovations 500 valve amp which operates push pull triode fashion but is in the repair shop. Happy swap for a while but couldn't do it permanently as I need phono and preamp too. Passive pre amp would work.
Happy Xmas Mr Pass what a treat.
So I'm feeding it Tidal via from a Nativ Streamer and a Cambridge DAC magic plus. It's outputing to a pair of Carfrae little big horns replicas I built - 106db/watt each of those takes a signal off the speaker cable to drive 170watt hypex plate amps and Seas subwoofer passive combo. So the little ACA is just driving Lowther DX4's. Plate amps and subs just fill in the lowest octave but also relieve the main amp of some of the hard work.
It's a substitute amp for my Audio Innovations 500 valve amp which operates push pull triode fashion but is in the repair shop. Happy swap for a while but couldn't do it permanently as I need phono and preamp too. Passive pre amp would work.
Preamp for ACA
I am new to this forum and am going to build an ACA. However, I think I will need a preamp for it. I have also been reading the threads for the Whammy headphone amp and it sounds as though it will function as a preamp also. Is this the only option or is the BA-3 also a possibility. This is a really awesome forum and I appreciate all the great information.
Thanks!
Bill
I am new to this forum and am going to build an ACA. However, I think I will need a preamp for it. I have also been reading the threads for the Whammy headphone amp and it sounds as though it will function as a preamp also. Is this the only option or is the BA-3 also a possibility. This is a really awesome forum and I appreciate all the great information.
Thanks!
Bill
Will the effect of separate SMPS?
I wanted to buy a LRS-100-24, but it was not available from a local supplier. The seller offered LRS-50-24 which can be put on each channel.
He also has the RS-100-24 model available, with a slightly less pulsation of 120 versus 150 for the LRS.
It will cost as two LRS-50-24.
Which option is the best? Or everything does not make sense and it is worth waiting for the delivery of the LRS-100-24.
Thanks.
I wanted to buy a LRS-100-24, but it was not available from a local supplier. The seller offered LRS-50-24 which can be put on each channel.
He also has the RS-100-24 model available, with a slightly less pulsation of 120 versus 150 for the LRS.
It will cost as two LRS-50-24.
Which option is the best? Or everything does not make sense and it is worth waiting for the delivery of the LRS-100-24.
Thanks.
I bought the LRS-150-24 (see post 6900 in this thread)
, I would have to check to be sure and I've not fired the amp up yet to see/hear if it's OK. But I don't anticipate any issues from the spec. If you are concerned you could implement a CRC.... Type filter on the output and tweek up the voltage on the psu to compensate.
, I would have to check to be sure and I've not fired the amp up yet to see/hear if it's OK. But I don't anticipate any issues from the spec. If you are concerned you could implement a CRC.... Type filter on the output and tweek up the voltage on the psu to compensate.
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Neel007 - Use whichever sounds better with your speakers. 90% of the time this is going to be bridged, but there's no right or wrong answer.
Centurion53 - Whammy works fantastic as a preamp. There's also other options in the works, but no promises as to when those will be available. This is an exciting time to be here at diyAudio! The ACA is a fantastic amp, you'll love it.
Centurion53 - Whammy works fantastic as a preamp. There's also other options in the works, but no promises as to when those will be available. This is an exciting time to be here at diyAudio! The ACA is a fantastic amp, you'll love it.
I'm with you. I just thought it was useful to bring some mathematics to the fore to let the number do the talking..
... but that to one side ... Merry Christmas all ... enjoy making your own music everyone.
My pair of ACA monoblocks did a great job with the fam' over at ours for Christmas Eve dinner pumping out some golden oldie Christmas faves.
Thanks again to everyone here at diyAudio and of course, the man who could easily be mistaken for
, Monsieur Pass himself... 
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It depends on how much power you need and the Ohm rating of your speakers. Here is the official document:
https://cdn.shopify.com/s/files/1/1006/5046/files/ACA_Monoblock_Operation_RevA.pdf
Parallel allows 2x the power into 4 Ohms, bridged is best for 8 Ohm loads.
Folks (esp. ZM, mjf, Indra1, Mooly and Alan4411):
Okay, I remain puzzled. I'm building an integrated amplifier consisting of a Bride of Zen preamp (now working brilliantly) and a single-ended bridged ACA. The bridged ACA sounds distorted. ZM suggested that I test each of the four ACA boards individually, which I've done, and each sounded fine on its own. But when two ACAs are linked together (see attached redrawn diagram) the sound is muddy. Weird.
Any and all wild-*** guesses appreciated.
Regards,
Scott
Okay, I remain puzzled. I'm building an integrated amplifier consisting of a Bride of Zen preamp (now working brilliantly) and a single-ended bridged ACA. The bridged ACA sounds distorted. ZM suggested that I test each of the four ACA boards individually, which I've done, and each sounded fine on its own. But when two ACAs are linked together (see attached redrawn diagram) the sound is muddy. Weird.
Any and all wild-*** guesses appreciated.
Regards,
Scott
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