Those two have very tiny pads on the underside so they don't look perfect. However, the solder is through the vias and up on the top side. The connections are good and well grounded.
It's normal behavior, as Nelson said in post #920. The output capacitors are charging and discharging. Your soldering and assembly looks wonderful. It's not the inline filter.
This might be a great opportunity for someone to create a brand new PCB layout of "ACA Mini with Prevent-a-Thump" by blending together Nelson's ACA Mini circuit design, and the circuit design of one of the anti-thump contrivances that already exist and are known to work well. Then people who are disappointed with the existing ACA Mini and its incomplete elimination of all thumps, can build the brand new PCB and get no thumps at all: Paradise! Nirvana! The Promised Land! Utopia!
I'm reasonably confident that adding prevent-a-thump would require the PCB to grow (so it wouldn't be quite so "mini" & cute), and I'm very sure the parts cost would be higher. Unless you could talk the Store into stocking the new board AND full kits, builders of the new PCB would have no choice but to buy all the components themselves, including the output MOSFETs and the input JFETs. Still, an enthusiastic person may want to launch the project anyway, perhaps for her own benefit even if no one else decides to buy and build an "ACA Mini with Prevent-a-Thump". There are already two dissatisfied owners, @A Jedi and @barryso which proves there are already potential builders / customers out in the world, with even more to come as the store sells hundred(s) kits, which are then built and listened to, critically.
I'm reasonably confident that adding prevent-a-thump would require the PCB to grow (so it wouldn't be quite so "mini" & cute), and I'm very sure the parts cost would be higher. Unless you could talk the Store into stocking the new board AND full kits, builders of the new PCB would have no choice but to buy all the components themselves, including the output MOSFETs and the input JFETs. Still, an enthusiastic person may want to launch the project anyway, perhaps for her own benefit even if no one else decides to buy and build an "ACA Mini with Prevent-a-Thump". There are already two dissatisfied owners, @A Jedi and @barryso which proves there are already potential builders / customers out in the world, with even more to come as the store sells hundred(s) kits, which are then built and listened to, critically.
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That will require an actual engineer lol. I'm just a happy builder with enough cursory knowledge to (hopefully) not kill myself 
I'm not in any way dissatisfied with the amp camp mini. It's a great amp. It's fantastic with my horn speakers.
I just commented about noises/thumps when disconnecting wires when the standby switch is off and the power brick is plugged in. Removing speaker connections and/or rca's can create noises and/or thumps when the amp is plugged in. Unplugging the power cord from the amp and waiting a minute or two before changing wires prevents these noises.
It's not a complaint, it's an observation. There is no noise whatsoever when using the standby switch so there's no issue day-to-day.
The wires don't get changed all that often so waiting a bit after pulling the plug, when necessary, isn't really a problem. No reason to build another version of this amp to "fix" what is absolutely a minor inconvenience. Would rather take that time to build another amp.
I just commented about noises/thumps when disconnecting wires when the standby switch is off and the power brick is plugged in. Removing speaker connections and/or rca's can create noises and/or thumps when the amp is plugged in. Unplugging the power cord from the amp and waiting a minute or two before changing wires prevents these noises.
It's not a complaint, it's an observation. There is no noise whatsoever when using the standby switch so there's no issue day-to-day.
The wires don't get changed all that often so waiting a bit after pulling the plug, when necessary, isn't really a problem. No reason to build another version of this amp to "fix" what is absolutely a minor inconvenience. Would rather take that time to build another amp.
Especially RCA's. They make a big noise if you insert/pull RCA's with the DC source on, and the on/off switch, actually a sleep mode, does not prevent this.
While I'm thinking about ACA mini, I should mention in advance that the ACA Mini Essentials kit shipped to the store uses matched Toshiba 2SJ74 and 2SK370 both Gr grade. The Gr chosen because it has the right bias without degeneration, and the 2SK370 being the 2SK170 in a smaller package.
So when you get this kit, be happy to have matched Toshibas...
So when you get this kit, be happy to have matched Toshibas...
Hello guys. I am interested in this amp, having read the thread , and really enjoying my Mark Johnson ACA Racam currently. The ACA Mini has a lot of appeal to me.
I have taken onboard comments about having boards made. I have made preliminary enquiries with one of the forums layout Meisters.
Am I OK to make a small run of clone PCBs?
How do I go about it all without treading on any toes/ upsetting anyone ?
Of course if I am totally wrong with this please say and I shall desist.
My thoughts were to have a layout done and the gerbers will stay with me. I shall do a small run of PCBs and sell the spares at a cost to cover my costs. I'm not wanting to make money. Or I charge a little more and make a donation to the forum.
Am I OK to proceed?
Regards.
Jim
I have taken onboard comments about having boards made. I have made preliminary enquiries with one of the forums layout Meisters.
Am I OK to make a small run of clone PCBs?
How do I go about it all without treading on any toes/ upsetting anyone ?
Of course if I am totally wrong with this please say and I shall desist.
My thoughts were to have a layout done and the gerbers will stay with me. I shall do a small run of PCBs and sell the spares at a cost to cover my costs. I'm not wanting to make money. Or I charge a little more and make a donation to the forum.
Am I OK to proceed?
Regards.
Jim
There is no point to doing that unless you plan to make some meaningful changes that would differentiate your board from the original. A number of boards has just been shipped to the DIY audio store and they will be for sale very soon.
Thanks for the input . I realise the offering from the Store with your very generous offerings Mr. Pass. Being in the UK the shipping is very costly and I thought I may be able to relieve some of the load on the store's inventory of this kit, I think it will be very popular, if I made a board for myself !
Shall give it some thought.
Best regards
Shall give it some thought.
Best regards
I'll put up a "built" shot after I build it....! Thank you Nelson!
