Ok..I checked my pot install and got them at 0. So I started looking around for something I did wrong. I opened up the schematic and saw that q3 and q4 were different. Q3 being irfp9140 and q4 being irfp140. During stuffing the board, I overlooked this. I know my fault. So I have one one board both 9140 and on the other board 140. So question is, did I break it, or this this fixable by just removing and replacing them in the right spot?
Sorry for all my dumb questions.
Sorry for all my dumb questions.
Swap into correct positions. Be careful when sedoldering. There's an art to it and you should have a good solder sucker. Be very patient and give plenty of time for things to cool off in-between attempts to remove the solder. You don't want to damage anything trying to just remove the FETs.
https://www.diyaudio.com/community/threads/my-first-desoldering-adventure-what-do-i-need.411252/
I'd suggest cutting leads of FETs shorter so it's easier to get them out.
https://www.diyaudio.com/community/threads/my-first-desoldering-adventure-what-do-i-need.411252/
I'd suggest cutting leads of FETs shorter so it's easier to get them out.
I think there's a good chance that the FETs are okay thanks to the PSU protection mode. One simple test you can do, even with the transistors still on board, is to check that you do not have a short circuit between the gate and the other two leads (see below). Swapping them to the right spots and continuing with power on procedure is also my vote.
I have spare parts if something ends up needing to be replaced
I have spare parts if something ends up needing to be replaced
The mosfets can be tested with a multimeter once the incorrectly placed mosfets are removed from the pcb:
https://www.homemade-circuits.com/how-to-check-mosfet-using-digital/
A tester such as this would work too:
https://www.amazon.ca/Transistor-XI...7da2a7eee0c49be11f&psc=1&tag=googleshopc0c-20
https://www.homemade-circuits.com/how-to-check-mosfet-using-digital/
A tester such as this would work too:
https://www.amazon.ca/Transistor-XI...7da2a7eee0c49be11f&psc=1&tag=googleshopc0c-20
The ACA MinMax needs either a quad, or two matched pairs, of 2SJ74/2SK170. Is there any preferred Idss for these parts? I noticed Papa used GR grade 2SJ74 and 2SK370 parts in the ACA Mini.
https://www.diyaudio.com/community/threads/diy-aca-mini.379037/post-7079920
I'm trying to get these hard to find parts for another ACA MinMax build and I want to be sure I get the correct/ideal ones.
https://www.diyaudio.com/community/threads/diy-aca-mini.379037/post-7079920
I'm trying to get these hard to find parts for another ACA MinMax build and I want to be sure I get the correct/ideal ones.
Seller “punkydawgs” on ebay sells genuine Toshibas.
https://www.ebay.com/itm/2560703159...uid=3BXt12BJT3G&widget_ver=artemis&media=COPY
https://www.ebay.com/itm/2560703159...uid=3BXt12BJT3G&widget_ver=artemis&media=COPY
Sorry if my question wasn't clear. I'm curious what Idss to get for ACA MinMax.
Per Nelson's post linked above, GR would match the ACA Mini, but I don't think Punkydawgs has that low for sale. I also don't know if the higher power ACA MinMax will benefit from a different Idss. Is there an optimal range to try and get?
Per Nelson's post linked above, GR would match the ACA Mini, but I don't think Punkydawgs has that low for sale. I also don't know if the higher power ACA MinMax will benefit from a different Idss. Is there an optimal range to try and get?
Yes, thanks, however in posting just a link it wasn't clear if you were responding to my comment about them being hard to find (pointing out a location they can be purchased), or specifically identifying an Idss range.
Your link was to 6-9 mA Idss. I'll now assume the answer to the question is go with 6-9mA based on your response. However, I'm still just assuming. Just trying to spend my money wisely by buying the preferred range.
The store also has two options, 6-8mA and 8-11mA. I'm not smart enough to know what difference these choices will make in the circuit.
https://diyaudiostore.com/products/matched-jfets
Your link was to 6-9 mA Idss. I'll now assume the answer to the question is go with 6-9mA based on your response. However, I'm still just assuming. Just trying to spend my money wisely by buying the preferred range.
The store also has two options, 6-8mA and 8-11mA. I'm not smart enough to know what difference these choices will make in the circuit.
https://diyaudiostore.com/products/matched-jfets
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Your post said things like “hard to find” and “want to be sure I get the correct/ideal ones”, my apologies for trying to kill two birds with one stone by posting a specific and exact solution.
Hello good people.
How have run into a problem building my second amp while waiting for parts on my first. I paid close attention to how I put it together. I think it’s all good. Unless I missed something. My adhd and all. Here is the issue. I have not tried to adjust anything. All I did was plug it in, and flip the switch. The leds lit up. Everything looked ok. In about 10 seconds, the power supply when into protection and the leds started blinking. I turned it off and unplugged it. Looked and looked and didn’t see anything wrong. So I tried a different power supply. Same thing. Any help would be very much appreciated. In my next post, I’ll post all the pictures I can.
Thanks
How have run into a problem building my second amp while waiting for parts on my first. I paid close attention to how I put it together. I think it’s all good. Unless I missed something. My adhd and all. Here is the issue. I have not tried to adjust anything. All I did was plug it in, and flip the switch. The leds lit up. Everything looked ok. In about 10 seconds, the power supply when into protection and the leds started blinking. I turned it off and unplugged it. Looked and looked and didn’t see anything wrong. So I tried a different power supply. Same thing. Any help would be very much appreciated. In my next post, I’ll post all the pictures I can.
Thanks
Note the pics in my post. My potentiometers are installed backwards in the picture. Cross check to see if you made the same mistake as me.
https://www.diyaudio.com/community/...-retrofit-for-aca-chassis.404975/post-7663466
Also note that the "fix" for my issue didn't require desoldering. I just had to rotate the pot the opposite direction than the instructions as 6L6 is pointing out.
https://www.diyaudio.com/community/...-retrofit-for-aca-chassis.404975/post-7663466
Also note that the "fix" for my issue didn't require desoldering. I just had to rotate the pot the opposite direction than the instructions as 6L6 is pointing out.
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My pots only went in one way. I’m not sure how I could have installed them wrong.
Being turned up all the way could might be the case. Is there a way to measure them as they sit?
Being turned up all the way could might be the case. Is there a way to measure them as they sit?
Ok, you had the kit, so your installation is hard to mess up. I procured the parts myself and had the "in line 3" leads for my pots, so it was much easier to get them installed wrong. Your pictures look like you correctly install the pots at closer look.
Since you're first attempt got the MOSFETs mixed up, I think we can be sure that's not the case on your second attempt. I'm no expert, so I'll let the Nelson Brocks, Ben Mah's, and 6L6's on this site give you advice. I can only bring up the errors I made as a possible culprits.
Since you're first attempt got the MOSFETs mixed up, I think we can be sure that's not the case on your second attempt. I'm no expert, so I'll let the Nelson Brocks, Ben Mah's, and 6L6's on this site give you advice. I can only bring up the errors I made as a possible culprits.
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