X, et all;
I changed R15 to 22 Ohms and R14 to 4.7 Ohms, and am planning to install the 2SA1837's now. Do the 2SA1837's and or the DN2540's need heatsinks?
I have some small clip on sinks I was planning to use if need be.
This is pre-amp use, not headphone amp fwiw.
I'm close to wrapping up the component build phase, then I'll slap it on a prototype board and give it a listen. Need to build a stepped attenuator too, can't forget that.
Do you know if there are any connectors for X141, X142, etc. that are available at Mouser or Digikey (domestic US)? Would prefer to use some easy connectors there instead of soldering until I put it in a proper case.
Cheers,
Gable
The connectors are somewhere in this thread. And yes available at Mouser. Make sure you get the through hole version. I don’t have part number off top of my head.
You can cheat and use standard 0.100in or 2.5mm pitch PCB header pins - the ones you can break off to size. Use two rows and put mating female header sockets (2pin) on top at diagonal. Middle two are input ad outer two are outputs. They all share a common ground - the star ground hub is at these pins. That’s what I am doing now in lieu of proper part.
You should add a heatsink to the DN2540 and 2SA1837. They will be a bit warm at the higher bias of circa 34mA and 45v/2 that is 750mW ea. Definitely at headphone amp bias they are hot.
You can cheat and use standard 0.100in or 2.5mm pitch PCB header pins - the ones you can break off to size. Use two rows and put mating female header sockets (2pin) on top at diagonal. Middle two are input ad outer two are outputs. They all share a common ground - the star ground hub is at these pins. That’s what I am doing now in lieu of proper part.
You should add a heatsink to the DN2540 and 2SA1837. They will be a bit warm at the higher bias of circa 34mA and 45v/2 that is 750mW ea. Definitely at headphone amp bias they are hot.
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Tried fitting the eBay PCB RCA jacks on the board tonight. Unfortunately the holes don't align very well. I'll be using separate panel jacks and hook up wire for the RCA connectors on this project after all.
Which RCA jacks did you try?
I bought the inexpensive (relatively, $10.00 USD/pair) RCA's from HifiCollective, and they fit well.
Low cost high quality straight gold plated RCA sockets | Hifi Collective
Cheers,
Gable
Hi Gable,
I just went back to try the RCA jacks I got from ebay again. They DO fit! I was trying to put them in the wrong side of the board before. DOH! I'm going to blame that on sleep deprivation.
On the connectors you are looking for, are you talking about the X111 and X112 8-pin to connect the main board to the RCA board? X141 and X142 are 2-pin connectors for power and led. Anyway, here's what I sourced from Mouser. I verified that they are the trough-hole and they fit on the board.
TE Connectivity 2178710-8 - Header
TE Connectivity / AMP 2205062-2 - Cable
I just went back to try the RCA jacks I got from ebay again. They DO fit! I was trying to put them in the wrong side of the board before. DOH! I'm going to blame that on sleep deprivation.
On the connectors you are looking for, are you talking about the X111 and X112 8-pin to connect the main board to the RCA board? X141 and X142 are 2-pin connectors for power and led. Anyway, here's what I sourced from Mouser. I verified that they are the trough-hole and they fit on the board.
TE Connectivity 2178710-8 - Header
TE Connectivity / AMP 2205062-2 - Cable
Haha, glad you got the RCA's figured out!
I have the 8 pin cable and the 8 pin connector is on the way. I think I need to review which connectors I think I need again when I get back in front of the board.
Cheers,
Gable