Good to know for next time. I tried turning the plastic while holding the metal shaft with a bit of force and the glue held strong. Here is my ATX power supply setup if anyone is curious. 12v (yellow cables) goes to fuse box and then to amp. Ground straight to amp. One 12v cable was used for the remote signal. I also put an ampmeter on the power line to keep an eye on it. Tomorrow once the fuses arrive I power this baby up.
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Does that ampclamp measure DC amps?
What types of fuses did you order? You can simply replace the on-board fuses with a smaller single fuse instead of inline.
What types of fuses did you order? You can simply replace the on-board fuses with a smaller single fuse instead of inline.
Good point. It’s only AC so it won’t work. The fuses are AGU which fit in my inline fuse holder. Didn’t know I could have replaced the ones on the amp. Lesson learned for next time.
The only AGU fuses that I've seen that were remotely reliable were the Bussman or Littelfuse brand and only when used in a good quality (not enclosed) fuse holder and not with CCA wire. For what you're doing here, any AGU should be OK but not in a car install with high current draw.
Well initital testing complete. Channels 1 and 2 working fine but the pots need a little cleaning (didn’t clean them yet because I wasn’t sure if they were dirty). The pots on Channels 3 and 4 were fixed. No more noise when adjusting the levels. I touched all the switches and found the culprit. Its the input select switch that chooses if the input comes from channel 1-2 or channel 3-4 RCAs. Upon touching it it made the RIGHT channel of 3-4 cut out or muffle. I then ran all 4 channels simultaneously at medium volume for an hour. 10A inline fuse held up fine. Amp seems to be working perfect. I am worried that when installed in a car that bad switch might cause trouble given the bumps and vibrations that are normal in a car environment. Also would like to push the amp a little harder to test it. Is it ok to install the 15A inline fuse and push it. If it blows then I pushed it too hard. But I saved the ATX power supply that is rated at 18A.
Also to confirm so you don’t recommend AGU fuses for car installs?
Also to confirm so you don’t recommend AGU fuses for car installs?
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The AGUs are OK for relatively low currents if the guidelines I gave are followed.
You can use the 15 amp fuse.
For the dirty switch, you can try using a couple of drops of contact cleaner into is and working it back and forth but the ones that are not giving a problem, I'd leave them as is.
You can use the 15 amp fuse.
For the dirty switch, you can try using a couple of drops of contact cleaner into is and working it back and forth but the ones that are not giving a problem, I'd leave them as is.
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Thanks for your fuse advice. I looked up and read your great articles on fuses and wiring. I was unaware of how slow fuses blow when the current is slightly over the rating. Knowing this has made me reassess my statement above about pushing my amp hard with the 15A fuse. I bought cheap no-name Chinese AGU fuses. I feel better using the 10A fuse as I hope it will blow faster if it reaches the ATX's limit of 18A.
Now about the car install, I plan on installing this 404 and possibly a 702. The 404 has 2 onboard 20 amp fuses and the manual recommends a 50 amp fuse on the B+ line. The 702 has a 60 amp onboard fuse and the manual recommends an 80 amp B+ line fuse. My plan was to run 8 gauge CCA for the 404 and 4 gauge for the 702. Your article recommends Maxi Fuses for my setup but you seem to also like ANL fuses. What kind of fuses and holders do you recommend? I like this one, but it has a set screw for the cable. I also like your idea of using speaker terminals for a Maxi fuse. Also ANL fuse holders seem like a solid option because of the screw terminals.
As for the switch, by contact cleaner I assume you mean the Deoxit D5.
Now about the car install, I plan on installing this 404 and possibly a 702. The 404 has 2 onboard 20 amp fuses and the manual recommends a 50 amp fuse on the B+ line. The 702 has a 60 amp onboard fuse and the manual recommends an 80 amp B+ line fuse. My plan was to run 8 gauge CCA for the 404 and 4 gauge for the 702. Your article recommends Maxi Fuses for my setup but you seem to also like ANL fuses. What kind of fuses and holders do you recommend? I like this one, but it has a set screw for the cable. I also like your idea of using speaker terminals for a Maxi fuse. Also ANL fuse holders seem like a solid option because of the screw terminals.
As for the switch, by contact cleaner I assume you mean the Deoxit D5.
Yes on the D5.
CCA wire is likely responsible for damage top more terminals than anything else.
The inline fuse size is determined by the wire being used. The wire sizes and fuse sizes on the site are for copper. CCA is rated for less. Some say 60% of actual copper wire.
Set screw terminals are OK as long as you use copper wire, they're good quality and tightened well.
MAXI and ANL are both good. I prefer terminals that use ring terminals and screws. Crimped and soldered ring terminal provide very low resistance. The ring terminal and screw provide a lot of contact area.
Speaker terminals for a MAXI fuse? I don't remember that.
CCA wire is likely responsible for damage top more terminals than anything else.
The inline fuse size is determined by the wire being used. The wire sizes and fuse sizes on the site are for copper. CCA is rated for less. Some say 60% of actual copper wire.
Set screw terminals are OK as long as you use copper wire, they're good quality and tightened well.
MAXI and ANL are both good. I prefer terminals that use ring terminals and screws. Crimped and soldered ring terminal provide very low resistance. The ring terminal and screw provide a lot of contact area.
Speaker terminals for a MAXI fuse? I don't remember that.
Wow I had no idea how poor CCA cable is. Only reason I was going to use it was because I had laying around. I will likely not use anymore. The 4 gauge cable does have a CCA marking but the 8 gauge cable doesn’t say anything with regards to CCA or OFC. Any way of knowing? Also what are your thoughts on plain OFC vs tinned OFC?
When I apply the D5 to switch should I move the actuator back and forth a few times?
When I apply the D5 to switch should I move the actuator back and forth a few times?
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If you use much larger CCA than you need AND use it only between disposable terminals (fuse and distribution blocks) but I would NOT use it going into an amplifier's terminal blocks which may be impossible to replace. Use copper cable between terminal/fuse/distribution blocks and amp terminals.
Scrape the 8g deeply. if it's CCA, you will see the aluminum. Try the same with the known CCA wire to see what I'm expecting you to see.
Don't waste money on OFC wire. It serves no purpose in use, only during the manufacturing process. Do your own research on sites that know wire, not audio sites where there is more snake-oil nonsense on wire than on wire sites.
Tinned wire is typically more expensive and generally made for marine applications but it typically very good wire.
If you want good all around wire and don't need a fancy insulator, buy welding cable with a neoprene or EPDM insulator. It's available in red and black. McMaster has it.
Scrape the 8g deeply. if it's CCA, you will see the aluminum. Try the same with the known CCA wire to see what I'm expecting you to see.
Don't waste money on OFC wire. It serves no purpose in use, only during the manufacturing process. Do your own research on sites that know wire, not audio sites where there is more snake-oil nonsense on wire than on wire sites.
Tinned wire is typically more expensive and generally made for marine applications but it typically very good wire.
If you want good all around wire and don't need a fancy insulator, buy welding cable with a neoprene or EPDM insulator. It's available in red and black. McMaster has it.
Excellent info on wires. I found this one which has good reviews on amazon and Home Depot and is the best deal I could find. Can I run a single 4 gauge wire for both amps and then in the trunk split it with another fuse and feed 4 gauge to the 702 and 8 gauge to the 404?
Also the switch appears to be working fine after applying the D5. Thank you Perry!
Also the switch appears to be working fine after applying the D5. Thank you Perry!
Yes a distribution block combined with a fuse block.
Now back to amp repair. Ive seen that you can upgrade these amps to make them produce more power and class A. What do you think? Worthwhile project?
Also I believe these amps have the darlington transistors vs normal MOSFETs. Which is considered the he better option for sound quality?
Now back to amp repair. Ive seen that you can upgrade these amps to make them produce more power and class A. What do you think? Worthwhile project?
Also I believe these amps have the darlington transistors vs normal MOSFETs. Which is considered the he better option for sound quality?
I believe the mods are pointless. I'm sure that others will have polar opposite opinions.
Darlingtons are series-connected bipolar transistors (look up the datasheet) in one package. FETs are a completely different type of device.
Darlingtons are series-connected bipolar transistors (look up the datasheet) in one package. FETs are a completely different type of device.
Thanks for that. I was thinking something along those lines. I was interested in getting an inexpensive o-scope. I read some folks have liked this one.
https://www.amazon.com/dp/B07QML4LJ
What do you think?
https://www.amazon.com/dp/B07QML4LJ
What do you think?
For any meaningful amp repair work, you need a scope that can (at the very least) accurately display a 200kHz signal. Most of the cheap scopes can't even accurately display the low-frequency square waves in a switching power supply. I doubt that the scope you linked to would be of much use for repair work. The cheapest scope I know of that will work (And needs a computer to work with) is about $100.
Understood. I'll save up for that hobby then so I can do it right. In the meantime, I was hoping to get your advice on my final power setup for the car. I've decided to only install the 404 but want the option to later add the 702. So I was thinking of running 4awg power to the trunk (~17ft) to a fused distribution block and then feed 8awg to the 404. I was going to put a 50amp fuse by the battery and repeat a 50amp fuse at the distribution block. If I add the 702 I would change the battery fuse to a 120-130amp fuse and leave the 50amp distribution block fuse but add an 80amp for the 702. I was thinking about this one for the battery fuse holder but with a 50amp ANL. And this one for the fused distribution block.
For the second one, if it uses bushings to make it suitable for two different wire sizes, those bushings will sometimes cause excess heating. For your application, they're not likely to be a problem. After running it as hard as you intend to run it for an hour or so, check the temperature of the blocks and confirm that the screws are still tight.