You do realize those are wildly different circuit designs? You do realize they MUST be different circuit designs, else the same amount of heatsinking would be required on both. Which clearly, from your photos, is not so. Conclusion: they aren't the same circuit.
Nope, it is the same circuit, but cut in half and layed out to mono boards, obviously requiring different heat sinks. But it is the same schematic as Papa created.....with one optional unused addition in this case and multi turn pots instead of the single turn pots. I have one, too.
Wow, thanks for the explanation. Take the design that needs extremely little heatsinking, enabling extremely inexpensive enclosure/chassis, . . . . but put it into a not inexpensive enclosure with wild excess gobs of heatsinking. Okay.
Not completely unlike installing a cool running class-AB amplifier into a Modushop Deluxe 4U chassis with ginormous bohunker heatsinks, to be fair.
Not completely unlike installing a cool running class-AB amplifier into a Modushop Deluxe 4U chassis with ginormous bohunker heatsinks, to be fair.
Yeah. It costs more.. but.. it looks cool and is easier and safer to handle... and still costs a good amount less than a standard ACA. FYI, Bubba177 used a chassis bought cheap as part of a non functional ACA. My chassis cost about $60 including shipping. It's DIY. We make what we like, not what's the cheapest. 🙂 I could not see putting a less than good looking amp or some kind of chassis kludge on my office shelf!
I like the case. It is still small and very nice looking. Also, it's going to be hard to keep the cost under $60 if you are actually using a chassis.
Mr. Johnson, wow I am so sorry to offend you, I had no idea you would get so upset over a 70 year old man keeping his mind engaged by tinkering in this hobby. I will rename it a tale of one aca mini and one steampunk minnie. Peace out.
Indeed. Not your normal encouraging sentiments Mark. Well done guys for your mono ACA Minis. Definitely more WAF/pet/child friendly. Fugly!
Fugly!
certainly not enough porn for proper Fugly!, but you got it for obvious amount of joy in making it
🙂
Well, things have changed in a month. It now runs about $100 with shipping. I bought two when I got mine so I could run a pair in bridged mode. Shipping was $75 for two. It is now more than that for 1. :-( But still less than a 2U Mini Dissipante used in the ACA. One important caveat. You need to mill or drill your own vent holes. This unit has none as is. https://www.aliexpress.com/item/2251832837354663.html?spm=a2g0o.order_list.0.0.29e11802OWBDJA
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Still not terrible. I was looking into a Chinese chassis for a project that I want to do. Shipping has gotten so expensive that it now ends up making some items cost-prohibitive. Thank you for sharing your project 🙂
Yeah, even at $100 it's $50 less than an ACA case, a bit smaller (64x150x180 internal vs 80x150x200 internal) but plenty big! You can build an ACA Mini in a nice case for $75 ish less than a regular ACA.
Bridge mode capability with a single ended input and fancy connectors will push the price to the high end of that difference.
And you'll need to drill all the holes, including cover vents.
I had some of the parts I needed lying around so saved on connectors, jumpers, switches, etc. Those can add up.
I'm gonna post my own thread on the build as soon as I get the time. I'm on rev 3 of the boards right now. Pictures are rev 2 which work great but rev 3 is improved for ease of build and also fixes a problem in the bridge inverter that required a workaround in r2.
I can't speak for bubba177 but I've bought Vishay MOSFETs and Linear JFETs and also, by far the best deal in the universe, the essentials kit for the ACA Mini in the DIYAudio store. That kit gives you properly selected JFETs, the Harris MOSFETs and a free trivet at a really good price!
I will order that kit when it comes back in. It is pretty inexpensive. 🙂
I could use some troubleshooting assistance. I got the kit from the store (both parts) and put it together last weekend. It was working well, sounded great. I turned it on tonight and it plays distorted for a second, then okay, with the led dimming in the same rhythm - as though the power supply is pulsing. I actually got two sets of kits so I tried out the unused power supply, but got the same result. Any troubleshooting suggestions will be much appreciated. Thanks in advance.
Turn the switch off, wait a few moments and turn it back on. The power supply protection can balk at charging the the supply caps and biasing the amp both at the same time.