I might leave the leads extra long if the thermistors were being run at the top of their performance envelope but, otherwise, I'd just leave enough to allow some airflow and not heat the board or other close components unnecessarily. They do need heat to reach the desired resistance and perform as intended.
Ok, I made them flush with the caps to make it easier to solder them. ( flip board upside down and let the thermistor rest on top of work bench while soldering )
Does anyone have a part number for those green screw terminal headers used for the small Nelson Pass PSU input board? I want to make sure I get ones which are rated for this use.
Does anyone have a part number for those green screw terminal headers used for the small Nelson Pass PSU input board? I want to make sure I get ones which are rated for this use.
Pick a terminal that will accept your intended wire 16awg was your decision? Any terminal that will accept a wire that large will be more than adequate for the currents involved. Rhodium or gold contacts may make some people feel better but I doubt Nelson would bother.
If you want to try something different, Wago produces a line of board mount lever lock terminals that I've been tempted to try. I love their standard wire connectors.
If you want to try something different, Wago produces a line of board mount lever lock terminals that I've been tempted to try. I love their standard wire connectors.
I ended up using some I had on-hand. I checked out the Wagos, similar to Phoenix. Very nice connectors but not sure how they would attach to PCB and did not see a line of 'standard' connectors small enough to SMT or through-hole solder.
The holes on the power PCB are small so I'll most likely just solder the wire directly to the board. I'm curious though, what wire->board termination options would there be for those holes/pads? It's not the typical 2.5mm pitch between pins. Could I potentially use those end of wire pin connectors? I've never ordered them and not sure if they would fit into the diameter of the PCB holes. I could entertain using JST/Molex style connectors between the power board and the amp boards, as well as from the rectifiers.
The holes on the power PCB are small so I'll most likely just solder the wire directly to the board. I'm curious though, what wire->board termination options would there be for those holes/pads? It's not the typical 2.5mm pitch between pins. Could I potentially use those end of wire pin connectors? I've never ordered them and not sure if they would fit into the diameter of the PCB holes. I could entertain using JST/Molex style connectors between the power board and the amp boards, as well as from the rectifiers.
The amplifier and power supply boards around here pretty much assume a simple and straight forward direct solder connection. I use the terminal blocks / ferrules on the 120V AC hookup's, where it makes sense, i.e. rectifier board I'm using designed for it, transformer wiring, incoming AC power and switch, CL-60 circuit to chassis connection, purple transformer shield wire, and so on..
@roboDNA I was unclear by using "std" instead of the product name. Lever-nuts, and more specifically, the 221-4xx (12-22awg)and 221-6xx (10-20awg) series. The lever actuated pressure plate connection, ampacity, and the ability to use solid/stranded/fine-strand in a wide range of guages with a single connector. I use them as a wirenut alternative, terminal blocks using the snap-in cages and for all temp connections on ny bench. Allow for an open port and you've got a solid, hands free test point that securely holds a dmm lead.
The pcb mount models that interest me most are the 2604 series. Very expensive compared to the Phoenix screwless terminals but the Phoenix versions that I'm familiar with all use a push-in, spring loaded wire contact point. I grin and bear their use on a manufacturers board. Thankfully, thats a rarity. I NEVER use the push-in (back-stab) option on AC receptacles. UL approval of that garbage demeans the system imo and no professionals I know will use them.
None of that helps you here though. Faston spades (if they fit the hole??) may be the best alternative if you choose not to direct solder.
Wago should sponsor me. No mere convert, I have apparently strayed into Evangelist territory. 🤣
The pcb mount models that interest me most are the 2604 series. Very expensive compared to the Phoenix screwless terminals but the Phoenix versions that I'm familiar with all use a push-in, spring loaded wire contact point. I grin and bear their use on a manufacturers board. Thankfully, thats a rarity. I NEVER use the push-in (back-stab) option on AC receptacles. UL approval of that garbage demeans the system imo and no professionals I know will use them.
None of that helps you here though. Faston spades (if they fit the hole??) may be the best alternative if you choose not to direct solder.
Wago should sponsor me. No mere convert, I have apparently strayed into Evangelist territory. 🤣
I noticed the F5m schematic shows IRFP9140 for Q3, however the BOM shows IRFP9240. The datasheet specs are a bit different. They both still seem to be available, so I'm curious to find out why 9240 was ultimately chosen.
I also noticed the BOM shows 2 IRFP9240 and 2 IRFP140. Is that for when a monoblock is built?
I also noticed the BOM shows 2 IRFP9240 and 2 IRFP140. Is that for when a monoblock is built?
Thanks for the info. I'll check out those connectors so I can use them in the future, but considering all the great advice I've gotten here, I'll hard wire on my first build and re-visit options on my second build. I had no idea it was such a rabbit hole with all those connector options 🙂 At least now I know.
Here is an example from www.Mouser.com that may work. Check the "pitch" spacing on your board and its footprint. https://www.mouser.com/ProductDetail/Wurth-Elektronik/691216710002?qs=w/v1CP2dgqr8TDL32Rr4aQ==
other sizes and variations are available as well.
other sizes and variations are available as well.
It looks like I had some headers just like the mouser part# 710-691216710002 you suggested. I'll order more of those, thanks. And yes, they do fit well.
I do see 10mm pitch Wurth headers which have 1 position instead of 2, so I can get those for CT and G.
I guess one benefit is being able to quickly disconnect parts when testing/troubleshooting. I plan on testing my PSU and rectifiers before connecting the amp boards.
P.S. I did not intend to state the holes are too small on the PCU board, they are not... my bad.
I do see 10mm pitch Wurth headers which have 1 position instead of 2, so I can get those for CT and G.
I guess one benefit is being able to quickly disconnect parts when testing/troubleshooting. I plan on testing my PSU and rectifiers before connecting the amp boards.
P.S. I did not intend to state the holes are too small on the PCU board, they are not... my bad.
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What do you have in hand? If you look at the distortion graph below, I believe Pass originally chose Harris part. The harris 9240, IR 9140 and the fairchild part are all good in that the distortion is very linear. The IRFP (Vishay?) is not linear so you probably won't see that in the kits.
I received IR9140's in my kit. They sounded terrific. Due to the price of these kits, I suspect the part chosen to go out is whatever is the most affordable or easily available at the time.
Good idea.
What about these for 10mm pitch screw headers for the CT and G on the PSU board?
Mouser 710-691254810002
Mouser 710-691254810002
My powered studio monitors have XLR/TRS/RCA inputs. I plan on using 1/4" TS cables out of my soundcraft mixer into ts->rca converter cables. Should I consider adding TS inputs on the F5m to ensure the best signal quality or is the converter cable just the same? ( my mixer is XLR or TS unbalanced output )
1/4" TS on the amp wouldn't be a bad idea, however there would be no inherent advantage to it aside utilizing cables you already have.
Making a cable set with RCA on one end and 1/4" TS would likely be the very best solution, however these doohickeys work beautifully if you want to use RCA/RCA cables...
Making a cable set with RCA on one end and 1/4" TS would likely be the very best solution, however these doohickeys work beautifully if you want to use RCA/RCA cables...
Just curious, is an RC snubber preferable on the 2 rectifiers? I'm using an one Antek AS-3218. I made a Kicad footprint for the rectifier so I can make a daughterboard but wont' bother if the snubber is overkill. ( I'll attach the transformer directly to the rectifiers using spade connectors if snubber is not required )
Overkill? Not at all, in fact, a great idea.
Something like this works wonderfully.
https://www.etsy.com/listing/144585...907&click_sum=2ae70b6e&ref=shop_home_active_9
Something like this works wonderfully.
https://www.etsy.com/listing/144585...907&click_sum=2ae70b6e&ref=shop_home_active_9
Is the white silk screen area after the Rs= meant to write-in the calculated value for RC? I think my Nelson Pass PS kit comes with the RC net in the middle PCB in that picture right? ( so I would just need 2 snubber daughterboards? ) If it's just 2 caps, a resistor, the rectifier and an M4 center hole, that it should be simple.
Information on Mark Johnson's Quasimodo test jig for transformer snubber is here:
https://www.diyaudio.com/community/...rmer-snubber-using-quasimodo-test-jig.243100/
https://www.diyaudio.com/community/...rmer-snubber-using-quasimodo-test-jig.243100/