The only challenge I see for first time builders is going to be the biasing procedure. In the article it says "Initially the values will be at or close to 0 volts" so I was about ready to hit the kill switch when VO started climbing on initial turn on. It was a long process and I lost my build partner (12 year old son) at this point. I bet a video showing the bias procedure would be helpful to new builders
You know it has to be that way, or the spatial qualities will get confused.
The red PCBs (example photo in post #462 above) were prototypes, "risky builds" of a new layout.
https://www.diyaudio.com/community/threads/free-pcb-clone-of-aca-mini-to-a-good-home.380272/
It now seems that the boards work pretty well; I imagine that other risk builders who got a free board, will complete their amp pretty soon and post photos + listening impressions. After a couple more victory stories have appeared, we can call the ACA Mini Almost Clone a success.
Maybe a member "Volunteer V" might decide to run a Group Buy for these.
These are clones of the original PCBs Nelson gave out as prizes during the Virtual Burning Amp festival. They are NOT clones of some other PCB having some other X by Y dimensions to fit into premade picture frames.
https://www.diyaudio.com/community/threads/free-pcb-clone-of-aca-mini-to-a-good-home.380272/
It now seems that the boards work pretty well; I imagine that other risk builders who got a free board, will complete their amp pretty soon and post photos + listening impressions. After a couple more victory stories have appeared, we can call the ACA Mini Almost Clone a success.
Maybe a member "Volunteer V" might decide to run a Group Buy for these.
- V would collect names and quantities and money from buyers.
- V would send me some of the money, and then
- I'd ship the boards to V
- V would label and pack and ship out finished boards to buyers.
These are clones of the original PCBs Nelson gave out as prizes during the Virtual Burning Amp festival. They are NOT clones of some other PCB having some other X by Y dimensions to fit into premade picture frames.
We’ll do it! My family is in for helping. Being our first group buy, we would like to do a limited number and ship to only CONUS addresses. If it’s a success we could do another and possibly broaden the parameters.
I was just thinking I'd launch my first foray into a group buy, but instead I'll settle for being the first to be added to the list.
Many thanks, @KevinHeem !
Kind regards,
Drew
By "genuine transistors" I assume you mean the Harris 520/9520 output transistors, since the K170/J74 pairs are available from either Toshiba or LS at the diyAudio Store. Mark has sent out a number of free boards, and there will be others commenting on their successful builds using Vishay or IR parts for the outputs. I suggest you give those reviews a minute to come in before making a decision. Otherwise you're probably looking at a long wait for kits to make it to the store.