Rafa, thanks for that comment. Confirms what I thought / picked up along the way.
I remember why I placed the SMPS inside the ACA...(apart from wanting that short DC bus to both ACA PCB's
)... -> to avoid switching around 4 amps of current. I kind of hoped that switching 400mA to SMPS will sort-out the turn on / turn off issues. The 24V rail build up is nice and smooth - I can tell that by observing the LED's. By the way, has anyone else increased the drop-down resistor to 15K with blue LED's??
@Rafa, there's some maths there to be checked... eagerly awaiting your tick of approval...
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No. Just use the volume control on your preamp or dac.
Input sensitivity on the 1.6 design is more like 2.25V RMS by the way...it has only 10-11dB of gain.
Best,
Anand.
Thanxs Anand, as I actually drive the 1.6 with a Dcb1 my target is to increase sound volume changing the actual 2volts dac with a higher voltage one. This will keep sound purity and avoid to introduce an active pre. In other words i prefer to change the dac instead of the dcb1. Makes sense?
ad010685 - That is a good plan.
The ACA gain, being somewhat lower than other amps, will benefit from a source with more output voltage or a preamp with gain.
I use a DAC that has a preamp output, it can swing 6v rms into the RCAs and 12v rms into the XLR, with this output I have no gain issues.
The ACA gain, being somewhat lower than other amps, will benefit from a source with more output voltage or a preamp with gain.
I use a DAC that has a preamp output, it can swing 6v rms into the RCAs and 12v rms into the XLR, with this output I have no gain issues.
Yup, I have changed the LED resistor - can't remember to what value, but I've also changed to a diffused blue LED. It's less directional than the Superbrights and more pleasing to the eye.
PS:
I'm assuming the kits come with Superbright LED's, because that's what I saw in the BOM. I built my own ACA from the ground up (own PCB's, etc.), so I could choose all the components myself.
I remember why I placed the SMPS inside the ACA...(apart from wanting that short DC bus to both ACA PCB's
By the way, has anyone else increased the drop-down resistor to 15K with blue LED's??
@Rafa, there's some maths there to be checked... eagerly awaiting your tick of approval...
Thanks for that, I think I’ll give it a go sometime.
Cheers,
Matt
Ha! Sounds good. I’ll just re-wire the whole house so I don’t need the power switch! Seems reasonable.
In all seriousness though, thanks Rafa for your recommendation. I think that I will just have the “wire work around” on hand, in the event that I need single ended bridged monos, and dedicate the rear switch for on/off. Or drill a hole in the back panel and install both switches there.
Is the metal toggle switch that is included in the kit easy to wire for power only?
Thanks again.
Well, I'm far from an expert here. But I can shed my limited knowledge on this: with the 10K, the current to the LED is 2.4mA. Depriving it of more current will yield a slightly less bright LED. Some sources say that, apparently, not dimmed by much in regards to visual perceived luminosity.
At any rate, the 15K will leave 1.6mA which is, apparenlty, still a good value to actually light up the led. One could try a 20K pot and measure if there is a cut-off value at which point the LED won't light at all? Or confirm that it is actually dimming linearly? The issue is that the charts show values from 0 to 45mA... so varying between 1.6 and 2.4mA falls into ranges of the graph that I find hard to predict.
Hard to say, sorry if this was of little use, best regards,
Rafa.
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just wire entire house via ACA switch
The switch is definitely rated for 240V AC and I think 10A. I know I thoroughly checked its rating before I decided to switch the mains voltage. I also used a cap&resistor snubber.
It is made by C&K - the brand I exclusively use.
Balance control
Greetings all.
I have 2 ACA kits ordered and expect them later this month.
Plan is to build them as fully balanced monoblocks to use in a minimalist system.
CD transport/Schiit Gungnir DAC/Pre amp TBD/ACA monoblocks/Omega Super 3XRS or Caintuck Betsy Baffle high efficiency, full range speaker system for critical listening primarily.
May skip a pre amp unless using the balance controls for overall volume is too unhandy.
I would like to add balance control to the picture.
I've searched this thread using every phrasing I could think of, but get no hits on adding balance control except for one unanswered similar question, to each amp.
While I am confident in my ability to assemble the ACA's, I'm an electrician, not an electronics man. Could someone tell me if balance control could be built into the ACA's and if so specifically how to do it?
Edit: If already answered, please refer me to the applicable posts.
Really excited about this project. Quite a departure from the high power A/B amp, medium efficiency multi driver speaker systems I've always had.
Greetings all.
I have 2 ACA kits ordered and expect them later this month.
Plan is to build them as fully balanced monoblocks to use in a minimalist system.
CD transport/Schiit Gungnir DAC/Pre amp TBD/ACA monoblocks/Omega Super 3XRS or Caintuck Betsy Baffle high efficiency, full range speaker system for critical listening primarily.
May skip a pre amp unless using the balance controls for overall volume is too unhandy.
I would like to add balance control to the picture.
I've searched this thread using every phrasing I could think of, but get no hits on adding balance control except for one unanswered similar question, to each amp.
While I am confident in my ability to assemble the ACA's, I'm an electrician, not an electronics man. Could someone tell me if balance control could be built into the ACA's and if so specifically how to do it?
Edit: If already answered, please refer me to the applicable posts.
Really excited about this project. Quite a departure from the high power A/B amp, medium efficiency multi driver speaker systems I've always had.
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