Nelson's PCB layout is shown in the .pdf document, so you can make a very accurate "clone" of the board if you can't find any for sale.
@Mark Johnson
Thank you Mark. Yes, I have seen this, but that will change the project from being easy, to being pretty difficult.
Is this a nice way of saying there will be no boards available, or are you just trying to ease my impatience?
Thank you Mark. Yes, I have seen this, but that will change the project from being easy, to being pretty difficult.
Is this a nice way of saying there will be no boards available, or are you just trying to ease my impatience?
I don't know what the Store (or anybody else) will do in the future. But I do know that energetic, resourceful, and highly motivated hobbyists CAN clone Nelson's PCB if they want to.
edit- another option of course is to assemble a consortium, pool your funds, and hire one of the PCB layout specialists here on diyAudio. Such as @Prasi and others whose names I can't recall off the top of my head.
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edit- another option of course is to assemble a consortium, pool your funds, and hire one of the PCB layout specialists here on diyAudio. Such as @Prasi and others whose names I can't recall off the top of my head.
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@ Mark Johnson
I do consider myself both energetic, resourceful, and highly motivated. But I also consider myself very busy, having 4 kids and a wife, so naturally I would prefer a board from the shop, but make no mistake, I will sit down and learn KiCad if I have to. 😛
@ Papa
Thank you kind Sir!
I do consider myself both energetic, resourceful, and highly motivated. But I also consider myself very busy, having 4 kids and a wife, so naturally I would prefer a board from the shop, but make no mistake, I will sit down and learn KiCad if I have to. 😛
@ Papa
Thank you kind Sir!
This one will probably be as big a hotseller as the ACA.
I like the fact that most of the mechanical work is out of the way with these heatsinks.
I'd suggest though to make holes in the PCB to improve airflow. Just some hole between each of the fins could help to keep things a tiny bit cooler. Or a square cutout maybe.
I like the fact that most of the mechanical work is out of the way with these heatsinks.
I'd suggest though to make holes in the PCB to improve airflow. Just some hole between each of the fins could help to keep things a tiny bit cooler. Or a square cutout maybe.
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It appears there are large blank regions on the PCB shown in Nelson's .pdf document; regions which have no top copper (red) and also no bottom copper (green). You could drill one of Nelson's existing PCBs in these areas, to provide your own ventilation ports. Here is an example, showing two holes per heatsink: eight holes total.
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Maybe if the board was slightly wider you could put solder points for Q3 and Q4 near the edge as well. This would make it so you could choose to use the onboard heatsinks or mount them to a large heatsink by soldering the mosfets on the edge of the board like you would with all of the other boards. Would be a convenient way to mount the amp into a chassis without having to worry about ventilation.
I have noticed a ton of vinyl going the pre-sale route and months out. I would be happy to pre-order. Not only do we know we are going to get a great project or kit but Nelson and team gets to control quality with some cash in hand. I will take it any way I can get. Thank you so much for the great projects!
you could mount the fets on a heatsink anyway, just extend with some wires 🙂
best,
st
Yes it was more an idea for convinience.I didn't know if they were making any changes to the board layout etc.
Hi
Amazing little amp, can’t believe I got this as a gift. Thanks!
What I really enjoy is the absence of turn on/off thumps, I have sensitive full range so that was always a concern with the original ACA.
I also like the jumper allowing you to hear a dominant 2nd order or 3rd order harmonic profile, this is genius.
One thing to be aware is that the switch is actually a stand-by switch so when flipped in the off position on the silkscreen the amp will actually be on. I found out later that this is written in the manual, very well made by the way.
I believe this ACA mini could be even more successful than it’s ACA predecessor and deserves a permanent sticky...
Thanks to all once again, I’m thrilled.
I’ll fix my amp on a piece of marble but here it is for now.
Eric
Amazing little amp, can’t believe I got this as a gift. Thanks!
What I really enjoy is the absence of turn on/off thumps, I have sensitive full range so that was always a concern with the original ACA.
I also like the jumper allowing you to hear a dominant 2nd order or 3rd order harmonic profile, this is genius.
One thing to be aware is that the switch is actually a stand-by switch so when flipped in the off position on the silkscreen the amp will actually be on. I found out later that this is written in the manual, very well made by the way.
I believe this ACA mini could be even more successful than it’s ACA predecessor and deserves a permanent sticky...
Thanks to all once again, I’m thrilled.
I’ll fix my amp on a piece of marble but here it is for now.
Eric
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Another one is built!
Initially I did not hear any difference with the jumper on or off, so I looked at the spectrum.
Without the jumper, I got about 0.5% @ 1kHz/1W/8ohm with the dominant H2:
This is with about 0.33V across source resistors; the distortion falls rapidly as the output stage bias - and heatsink temperature - increases. Also, note there is virtually no noise from the power supply.
With the jumper and with R11 = 1ohm, distortion halved to 0.2% with H2 remaining dominant:
I played with R11 and got lowest H2 at 0.1ohm, with distortion at about 0.05%:
Will check how H2 compensation behaves at lower levels - but also connect a better pair of speakers and listen to some music...
Initially I did not hear any difference with the jumper on or off, so I looked at the spectrum.
Without the jumper, I got about 0.5% @ 1kHz/1W/8ohm with the dominant H2:
This is with about 0.33V across source resistors; the distortion falls rapidly as the output stage bias - and heatsink temperature - increases. Also, note there is virtually no noise from the power supply.
With the jumper and with R11 = 1ohm, distortion halved to 0.2% with H2 remaining dominant:
I played with R11 and got lowest H2 at 0.1ohm, with distortion at about 0.05%:
Will check how H2 compensation behaves at lower levels - but also connect a better pair of speakers and listen to some music...
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Yup, the best thing is that in the manner of the ACP+ Preamp/headphone amp, the connectors are soldered on the board, so they are cheaper, and no wires flying out to connectors on a chassis, which are a major part of construction and construction confusion…
And no chassis required, which cuts the cost in half.. I expect to see a lot of these in college dormitory rooms. I think the open tower with an ACP+ below is the best look!
And no chassis required, which cuts the cost in half.. I expect to see a lot of these in college dormitory rooms. I think the open tower with an ACP+ below is the best look!
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I think that the ACP/miniAca open tower would also be perfect for bedrooms, with a RPi or similar SBC coupled with dac: you will have a super headphone/speakers setup 
At the moment the management is quite caught up in the transition to the new forum software, so any store topics are on hold
