I personally would use them without hesitation. If I were being overly picky... I'd make sure that both rails were evenly balanced with resistance (one 0R47 on each side if they're not already stuffed), but ... it likely won't matter in any practical sense. My 
Let's do the numbers:
3 x 0.33R in parallel = 0.11R
Assume 2A current:
V = 0.11R x 2A = 0.22V
Each 0.33R: I = 2A/3 = 0.667A, P = 0.667A x 0.33R x 0.667A = 0.147W
2 x 0.33R and 1 x 0.47R in parallel = (2/0.33R + 1/0.47R)^-1 = 0.122R
Assume 2A current:
V = 0.122R x 2A = 0.244V
Each 0.33R: I = 0.244V/0.33R = 0.739A, P = 0.739A x 0.33R x 0.739A = 0.180W
Each 0.47R: I = 0.244V/0.47R = 0.519A P = 0.519A x 0.47R x 0.519A = 0.127W
Comparing the two, the difference in resistor voltage drop and power supply output voltage is 0.244V - 0.22V = 0.0.024V. Difference is very small. The 0.33R+0.47R combination will have slightly lower voltage output but the ripple will also be slightly lower. If the voltage difference is a bother, keep both 0.47R in one channel (V+ and V- in one channel).
All 0.33R - each resistor dissipates 0.147W
2 x 0.33R and 1 x 0.47R - each 0.33R dissipates 0.180W and 0.47R dissipates 0.127W
Resistors are 3W so the higher dissipation of 0.180W is not a problem.
3 x 0.33R in parallel = 0.11R
Assume 2A current:
V = 0.11R x 2A = 0.22V
Each 0.33R: I = 2A/3 = 0.667A, P = 0.667A x 0.33R x 0.667A = 0.147W
2 x 0.33R and 1 x 0.47R in parallel = (2/0.33R + 1/0.47R)^-1 = 0.122R
Assume 2A current:
V = 0.122R x 2A = 0.244V
Each 0.33R: I = 0.244V/0.33R = 0.739A, P = 0.739A x 0.33R x 0.739A = 0.180W
Each 0.47R: I = 0.244V/0.47R = 0.519A P = 0.519A x 0.47R x 0.519A = 0.127W
Comparing the two, the difference in resistor voltage drop and power supply output voltage is 0.244V - 0.22V = 0.0.024V. Difference is very small. The 0.33R+0.47R combination will have slightly lower voltage output but the ripple will also be slightly lower. If the voltage difference is a bother, keep both 0.47R in one channel (V+ and V- in one channel).
All 0.33R - each resistor dissipates 0.147W
2 x 0.33R and 1 x 0.47R - each 0.33R dissipates 0.180W and 0.47R dissipates 0.127W
Resistors are 3W so the higher dissipation of 0.180W is not a problem.
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Thanks for the responses and breaking down the math! I'm trying to absorb and retain this kind of stuff, but my grey matter seems to be hardening more and more these days and it's getting difficult.
I ended up finding a few 0.33's that are 5 watt mixed up with the 0.47's in my stash, so I'll just use those. I don't see any issue with the higher watt rating. It'll at least make it visually symmetrical, so I don't twitch every time I look at the board.
I ended up finding a few 0.33's that are 5 watt mixed up with the 0.47's in my stash, so I'll just use those. I don't see any issue with the higher watt rating. It'll at least make it visually symmetrical, so I don't twitch every time I look at the board.
Finally, assembled PSU for my Aleph Jzm. Took longer than expected due to initial lack of idea how to mount the transformer.
Run transformer wires through bottom holes of the shield assembly as planned and then twisted them. Initially I thought all wires are too long; however, after twisting, soldering to PSU plate and mounting rectifiers it turns out the length was just right.
The transformer is mounted on 1/2 inch stands from eBay. Just enough space between transformed and bottom plate to run the wires. Bolts inside the spacers are M5; the #10 should also work. All hardware other than spacers was from Lowes.
Tested the PSU without load- the output is +/- 28.3 V. That was the most amazing (and rewarding) part 🙂
Run transformer wires through bottom holes of the shield assembly as planned and then twisted them. Initially I thought all wires are too long; however, after twisting, soldering to PSU plate and mounting rectifiers it turns out the length was just right.
The transformer is mounted on 1/2 inch stands from eBay. Just enough space between transformed and bottom plate to run the wires. Bolts inside the spacers are M5; the #10 should also work. All hardware other than spacers was from Lowes.
Tested the PSU without load- the output is +/- 28.3 V. That was the most amazing (and rewarding) part 🙂
Hi there.
Getting around to start my build. I didn't realize the difference between the schematic text on the CL60/AC Cap Board - 120 vs. 240. I accidentally installed the components with the 240 text up on one of the boards. Just making sure that I can just ignore the text on the 240 one and reference the correct 120 one as my guide. For example, the mark for 120A on the 120 side is on the top right - I am just going to ignore the 0B on the top right of the 240 board and pretend it is 120A. I realize that I can pull the parts out, but I suck at that and usually end up overheating stuff. Anyone see any concerns here? My OCD isn't that bad, knowing that one is upside down won't be an issue.
Thanks for your advice.
Jim.
Getting around to start my build. I didn't realize the difference between the schematic text on the CL60/AC Cap Board - 120 vs. 240. I accidentally installed the components with the 240 text up on one of the boards. Just making sure that I can just ignore the text on the 240 one and reference the correct 120 one as my guide. For example, the mark for 120A on the 120 side is on the top right - I am just going to ignore the 0B on the top right of the 240 board and pretend it is 120A. I realize that I can pull the parts out, but I suck at that and usually end up overheating stuff. Anyone see any concerns here? My OCD isn't that bad, knowing that one is upside down won't be an issue.
Thanks for your advice.
Jim.
I did the same thing on my first build with these. Works fine. Just make sure it's installed per the 120VAC side silkscreen instructions, which appears correct to me in your photo.
If using the rhthatcher snubber boards also, be sure to drill out center holes so the bolt head passes through the snubber board to the rectifier base below. Also, if your rectifiers have a metal base, be sure to add space between the snubber board and the rectifier base so it won't short. Made that mistake as well.
If using the rhthatcher snubber boards also, be sure to drill out center holes so the bolt head passes through the snubber board to the rectifier base below. Also, if your rectifiers have a metal base, be sure to add space between the snubber board and the rectifier base so it won't short. Made that mistake as well.
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Thanks for your prompt reply and advice @birdbox Much appreciated. I am using the Thatcher snubbers with rectifier bridges that have metal bottoms. I wasn’t exactly sure how all these parts fit together and some of the other do’s and dont’s. I thought I saw some previous posts that I need to review before I do anything else.
I was also considering directly connecting everything with wires and solder instead of quick disconnects or terminal blocks. But I wasn’t sure if I was just asking for trouble.
Anyways, thanks for all the wisdom.
Jim.
I was also considering directly connecting everything with wires and solder instead of quick disconnects or terminal blocks. But I wasn’t sure if I was just asking for trouble.
Anyways, thanks for all the wisdom.
Jim.
Hi there,
Starting to figure out the process of mounting the PSU components to the perforated chassis. Specifically, I am using the Thatcher V8 dual mono build. Was wondering a couple things:
1. Connecting the transformers - I am going to mount vertically with the AnTek vertical mounts. They are metal. Can I connect the mounts with metal screws/washers/nuts?
2. What about connecting the transformer to the mounting bracket? Looks like they gave me two rubber gaskets with the transformers, assume that creates separation from the mount?
3. Snubbers/rectifiers - thanks for the "drill out the hole in the PCB trick" - do I need any washers at all for the rectifiers-to-chassis connection, nylon or otherwise? I was just going to mount the rectifiers so that their metal bottoms are touching the perforated chassis and use one metal screw and one metal locknut.
4. For the CL-60 PCB's - looks like there are three holes there for mounting. Assuming I need some kind of spacer between the PCB and the chassis. Does this need to be metal or nylon or doesn't matter?
5. For the PCB with all the capacitors - I know this need to be elevated with spacers - does it matter if the spacers are metal or nylon?
6. Also for the PCBs with the capacitors, because one of the holes is labeled as ground - assuming the metal screws/washers/nuts will make the connection?
7. Is there anything not covered above that strictly needs to be be either isolated with nylon stuff or specifically metal-to-metal connection?
8. I am using M4 screws for everything since it seems like that is the size of the perforations. I saw that there are various M4 assorted connection kits on Amazon with various nuts/washers/screws. Some with hex head, some Allen, some black, some stainless. Anything that you found to be the most appropriate?
Sorry, I know this is a lot. Thanks in advance for any info you can provide.
Jim.
Starting to figure out the process of mounting the PSU components to the perforated chassis. Specifically, I am using the Thatcher V8 dual mono build. Was wondering a couple things:
1. Connecting the transformers - I am going to mount vertically with the AnTek vertical mounts. They are metal. Can I connect the mounts with metal screws/washers/nuts?
2. What about connecting the transformer to the mounting bracket? Looks like they gave me two rubber gaskets with the transformers, assume that creates separation from the mount?
3. Snubbers/rectifiers - thanks for the "drill out the hole in the PCB trick" - do I need any washers at all for the rectifiers-to-chassis connection, nylon or otherwise? I was just going to mount the rectifiers so that their metal bottoms are touching the perforated chassis and use one metal screw and one metal locknut.
4. For the CL-60 PCB's - looks like there are three holes there for mounting. Assuming I need some kind of spacer between the PCB and the chassis. Does this need to be metal or nylon or doesn't matter?
5. For the PCB with all the capacitors - I know this need to be elevated with spacers - does it matter if the spacers are metal or nylon?
6. Also for the PCBs with the capacitors, because one of the holes is labeled as ground - assuming the metal screws/washers/nuts will make the connection?
7. Is there anything not covered above that strictly needs to be be either isolated with nylon stuff or specifically metal-to-metal connection?
8. I am using M4 screws for everything since it seems like that is the size of the perforations. I saw that there are various M4 assorted connection kits on Amazon with various nuts/washers/screws. Some with hex head, some Allen, some black, some stainless. Anything that you found to be the most appropriate?
Sorry, I know this is a lot. Thanks in advance for any info you can provide.
Jim.
1. yeah, inspect appropriate pics, you'll see details
2.bracket,rubber,Donut, rubber, plastic/metal dish, washer, screw nut
3.paste in between bridge and base plate, screw, washer, split washer, nut
rest is for Boyz knowing exact pcb
2.bracket,rubber,Donut, rubber, plastic/metal dish, washer, screw nut
3.paste in between bridge and base plate, screw, washer, split washer, nut
rest is for Boyz knowing exact pcb
4 - I like to use nylon spacers (cylindrical spacers) and metal hardware. Screw head on top, washer, split washer, nut under the 10x10mm grid swiss cheese bottom plate. See pic for spacer example from Amazon
5/6 - same as #4 - note that one of the screws should be metal for the "Chassis GND" hole. That needs to be metal for sure.
7 - don't think so. But post some pix from various angles before applying power.
8 - M3 or M4. Since you're in USA - 6/32 from Lowes or Home Depot works, too. I got a kit on amazon with M3/4/5 hex/Allen hardware in a few assorted lengths. Then when they run low I top up the specific fastener as needed. Don't forget to split washers and standard washers. Again Amazon, Lowes, Home Depot are all fine.
5/6 - same as #4 - note that one of the screws should be metal for the "Chassis GND" hole. That needs to be metal for sure.
7 - don't think so. But post some pix from various angles before applying power.
8 - M3 or M4. Since you're in USA - 6/32 from Lowes or Home Depot works, too. I got a kit on amazon with M3/4/5 hex/Allen hardware in a few assorted lengths. Then when they run low I top up the specific fastener as needed. Don't forget to split washers and standard washers. Again Amazon, Lowes, Home Depot are all fine.
4) You just want it to be secure as that has 120VAC lines. You don't want anything to short to ground. However you connect to perforated plate, as long as it's secure, and no shorts, many options work.
5) Doesn't matter as long as the "chassis ground" makes a good connection. You could rely on metal standoff to do it with locking mechanism, and/or add a chassis ground wire to a separate bolt with locking mechanism so it can't come loose. Just be sure the PSU PCB is properly grounded through that on board ground lift CL-60.
6) See "5)" above.
7) Long as its strong and won't break, won't matter.
8) Those bezos bookstore kits are great. I personally like the button head cap, but I have all variants on hand in both M3 and M4. Can never have too many well organized nuts/bolts kits.
Looks like Randy beat me to the post 😀
5) Doesn't matter as long as the "chassis ground" makes a good connection. You could rely on metal standoff to do it with locking mechanism, and/or add a chassis ground wire to a separate bolt with locking mechanism so it can't come loose. Just be sure the PSU PCB is properly grounded through that on board ground lift CL-60.
6) See "5)" above.
7) Long as its strong and won't break, won't matter.
8) Those bezos bookstore kits are great. I personally like the button head cap, but I have all variants on hand in both M3 and M4. Can never have too many well organized nuts/bolts kits.
Looks like Randy beat me to the post 😀
Just wanted to thank you all for your prompt responses! Much appreciated! Cheers @Zen Mod @rhthatcher @birdbox big help!
Hey folks. Just wanted to check in and post these pics that show my proposed layout of the power supply units on the perforated chassis. Couple notes: 1. I will use the thermal paste stuff that someone else recommended earlier between the snubbers and the chassis.
2. I will add the other spacers, nuts and bolts to the main PSU boards.
3. I currently put 1mm nylon washers between the chassis and the donut mounts. Seems like this is unnecessary and may actually be bad because the mount is now only supported at those two points instead of by the whole area of the mount. I just wasn't 100% on whether the mount needs to be isolated.
Any objections to what I have shown? And please let me know if you spot something off, this is my first build with a power supply.
Thanks all.
2. I will add the other spacers, nuts and bolts to the main PSU boards.
3. I currently put 1mm nylon washers between the chassis and the donut mounts. Seems like this is unnecessary and may actually be bad because the mount is now only supported at those two points instead of by the whole area of the mount. I just wasn't 100% on whether the mount needs to be isolated.
Any objections to what I have shown? And please let me know if you spot something off, this is my first build with a power supply.
Thanks all.
Hi folks!
Made some more progress on the PSU Build. I moved stuff in a bit to try and create some room on the sides. I think I have all of the wiring done between the transformers and the various PSU/CL60/Snubber Boards. The stuff that goes from the CL60's to the fuses and power entry module (PEM) is still temporary because I want to make sure that everything looks correct to y'all. One item of note is that I accidentally flipped one of the CL-60 boards to the 240V side, but hooked it up as if it were the 120V side (I mentioned this in a previous post and it sounded like this was ok), just wanted to point it out in case anyone spotted it.
Before I clean up the wiring and finalize the connections and plug it in to a dim bulb tester, I wanted to make 100% sure that everything looks correct.
I wasn't 100% on:
1. The PEM
2. if the different sets of 120A / 0 A, 120B / 0B, secondary pairs from the transformers and the snubbers are specific to the A and B inputs on the PSU PCB's. I tried to hook everything up in a consistent manner, but wasn't sure if there was a specific way that all of these needed to be hooked up.
Anyways, if you wouldn't mind taking a gander and letting me know if something looks awry, that would be great.
Thanks in advance for any help you can provide.
JIm.
Made some more progress on the PSU Build. I moved stuff in a bit to try and create some room on the sides. I think I have all of the wiring done between the transformers and the various PSU/CL60/Snubber Boards. The stuff that goes from the CL60's to the fuses and power entry module (PEM) is still temporary because I want to make sure that everything looks correct to y'all. One item of note is that I accidentally flipped one of the CL-60 boards to the 240V side, but hooked it up as if it were the 120V side (I mentioned this in a previous post and it sounded like this was ok), just wanted to point it out in case anyone spotted it.
Before I clean up the wiring and finalize the connections and plug it in to a dim bulb tester, I wanted to make 100% sure that everything looks correct.
I wasn't 100% on:
1. The PEM
2. if the different sets of 120A / 0 A, 120B / 0B, secondary pairs from the transformers and the snubbers are specific to the A and B inputs on the PSU PCB's. I tried to hook everything up in a consistent manner, but wasn't sure if there was a specific way that all of these needed to be hooked up.
Anyways, if you wouldn't mind taking a gander and letting me know if something looks awry, that would be great.
Thanks in advance for any help you can provide.
JIm.
Where is you chassis ground connected? Make sure that goes straight from PEM to a dedicated bolt with locking mechanism. Keep it as short as is practical. You dont want a long run off to a far corner of the chassis. Some folks would say you should solder the chassis ground wire onto PEM, so it can't accidentally be left disconnected. I solder that wire on (no FastOn connector, but you could solder the FastOn to the tab) for feel good factor. You can always disconnect at bolt on perforated plate if you must fully disassemble.
It looks like you have your line/hot mixed up with the neutral on one of your AC input boards.
I would put heat shrink over those faston connectors for your AC mains into the soft start CL-60 boards so they can not short. Better safe than sorry there.
Are you going to twist the 120VAC AC pair (hot and neutral) from fuse box on? I think that's the most important pairs to twist. Also helpful to run those twisted AC pairs under the perforated plate since you're running the mains from back to front of chassis.
The pictures could be better. Shadows make some areas hard to see.
Overall, looks like a nice build!
It looks like you have your line/hot mixed up with the neutral on one of your AC input boards.
I would put heat shrink over those faston connectors for your AC mains into the soft start CL-60 boards so they can not short. Better safe than sorry there.
Are you going to twist the 120VAC AC pair (hot and neutral) from fuse box on? I think that's the most important pairs to twist. Also helpful to run those twisted AC pairs under the perforated plate since you're running the mains from back to front of chassis.
The pictures could be better. Shadows make some areas hard to see.
Overall, looks like a nice build!
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The red / black transformer pairs need to be connected carefully.
It looks like you paired them and twisted and tied the pairs together. Did you measure the pairs with a DMM to ensure they’re pairs?
Pick black or red as 120, and the opposite as 0. One pair is Pair A, one is Pair B. Then hook up according tv to the labels on the board.
Can you get a close up picture of one of those boards?
It looks like you paired them and twisted and tied the pairs together. Did you measure the pairs with a DMM to ensure they’re pairs?
Pick black or red as 120, and the opposite as 0. One pair is Pair A, one is Pair B. Then hook up according tv to the labels on the board.
Can you get a close up picture of one of those boards?
Hi there,
Thanks so much for the comments. I am going to try to address @birdbox and @rhthatcher comments here.
All of my connections to the PEM are temporary because I wasn't sure if stuff was correct. With all of the connections, I will be soldering (after crimping) and then following up with heatshrink and twisting. So that is still to be done, and 100% agree with your comments.
@birdbox comments:
1. Chassis ground is going to be connected directly to the chassis by just stripping enough wire to create a "circle" and I was going to connect to chassis with a screw, washers, lock washer and nut (the last picture indicates how I did this for the transformer ground). Thanks for the note about keeping is the wire short and not using the quick disconnect at the PEM.
2. The apparent mixup on the AC input boards is because I accidentally installed everything with the wrong side (240V) up on one of the boards. I just used the 120V silkscreen information. So I think it is correct, even though the silkscreen makes it seem wrong.
3. The 120VAC AC pair will absolutely be twisted and tied down between the open channel between all the boards.
@rhthatcher comments:
1. I did use the continuity check on each of the pairs to make sure that they were the correct pairs. I just wasn't sure if one pair was particularly "A" or "B". It sounds like it doesn't matter, so long as I am using actual pairs. I am doing a bad job explaining what my question is here.
2. I included some additional photos. Hopefully, that helps in any further evaluation.
Thanks again for all of your comments, this has all been really helpful.
Jim.
Thanks so much for the comments. I am going to try to address @birdbox and @rhthatcher comments here.
All of my connections to the PEM are temporary because I wasn't sure if stuff was correct. With all of the connections, I will be soldering (after crimping) and then following up with heatshrink and twisting. So that is still to be done, and 100% agree with your comments.
@birdbox comments:
1. Chassis ground is going to be connected directly to the chassis by just stripping enough wire to create a "circle" and I was going to connect to chassis with a screw, washers, lock washer and nut (the last picture indicates how I did this for the transformer ground). Thanks for the note about keeping is the wire short and not using the quick disconnect at the PEM.
2. The apparent mixup on the AC input boards is because I accidentally installed everything with the wrong side (240V) up on one of the boards. I just used the 120V silkscreen information. So I think it is correct, even though the silkscreen makes it seem wrong.
3. The 120VAC AC pair will absolutely be twisted and tied down between the open channel between all the boards.
@rhthatcher comments:
1. I did use the continuity check on each of the pairs to make sure that they were the correct pairs. I just wasn't sure if one pair was particularly "A" or "B". It sounds like it doesn't matter, so long as I am using actual pairs. I am doing a bad job explaining what my question is here.
2. I included some additional photos. Hopefully, that helps in any further evaluation.
Thanks again for all of your comments, this has all been really helpful.
Jim.
Please ponder this one. I'm not sure, but I dont think you "swap" the mains neutral and hot/line, just because you had the board upside down. I could be wrong, but I also could be right. Quadrouple check this one just in case.
I installed mine upside-down the first time and I did not "flip" the hot/line and neutral wires. Maybe I need to go fix that on my first amp if I'm wrong.