Yeah, I don’t know what the hell I was thinking, but thanks for your help. I believe those diodes came in the kit for the F5T from the store as well so I have a spare set for the next build 😉
LED Dropping Resistors Correct?
Hello again! I've completed the filter section for my first PSU of two for my dual mono F5Tv2.5 amp. I've omitted the snubbers, which I think is correct for my build. I'm wondering if I chose the correct LED dropping resistors though, 273-4.75K-RC which are 1/2W and ROHS compliant:
Here are some progress pictures:
Thanks!!
Hello again! I've completed the filter section for my first PSU of two for my dual mono F5Tv2.5 amp. I've omitted the snubbers, which I think is correct for my build. I'm wondering if I chose the correct LED dropping resistors though, 273-4.75K-RC which are 1/2W and ROHS compliant:
Here are some progress pictures:
Thanks!!
Looking fine from what I can see. One thing some screw up is the orientation of the LEDs. But you’ll soon find out if you did it correctly at first power up.
I, personally, would have omitted the 0v links closest to the rectifier boards, lots of ripple there so in theory a bad place to link gnds, they should only have one link position, preferably after smoothing. But then, it is done this way by 6L6 and prolly some greedy boyz too, and it works perfectly. I tried both ways, no discernable m/audible difference. So think you are good. Nice work!
Andy
I, personally, would have omitted the 0v links closest to the rectifier boards, lots of ripple there so in theory a bad place to link gnds, they should only have one link position, preferably after smoothing. But then, it is done this way by 6L6 and prolly some greedy boyz too, and it works perfectly. I tried both ways, no discernable m/audible difference. So think you are good. Nice work!
Andy
That makes total sense about the ripple, so I'm glad to hear that what I've done seems fine in practice. Thanks! My thinking in fully populating was that the less resistance the better, plus 6L6 populating them fully in the guide as you mention gave me confidence that I was on the right track. I'm hoping to finish the diode bridges tonight, but I need to sort out my placement and wiring a bit more before I'm ready to test, I think. I should probably wait to test the first PSU before I build the second one, but knowing me it could go either way haha. Thanks again!
I can verify that this is an easy screw-up. I misunderstood the direction on one, and had to flip it to get it lit. If I had looked carefully at the schematic, I would have gotten it right.
That's what I had to do, I couldn't really see the difference in either side on the silk screen that is supposed to mark it. I got paranoid after two of you mentioned them, and tested with my DMM. A connectivity check shows that both LEDs are oriented correctly, with the positive lead on the dropping resistor side and the negative lead on the ground trace side, I think I'm good!
Just realized I'm still waiting for some hardware to mount the bridge diodes to the heat sinks, so I can't finish the first PSU tonight after all. That will have to wait until this weekend. Oh well! Plenty of other stuff to work on.
See schematic linked in first post. You may want to double check one side, I think.
Careful. On one side the resistor is on the positive leg, on the other it's negative, if I remember correctly.
Oh geez, yeah I think I have them backwards on the negative rails now that you mention it. Thanks!!!
Output of DIYaudio power supply board
I know this will be a loaded question...
If one was to use the standard BOM used in this thread using an Antek AS3218 300VA 18V transformer, what voltages and currents are being delivered to the rest of the amplifier? I'm not sure if I have seen a spec on this.
I realize that the "good enough for Papa" uses the eight 15,000uF 25V caps and some builds are using eight 22,000uF 35V caps. What is different is being supplied to the amp? I have organic chemistry and molecular biology pretty well locked down, but electronics has been a bit of a struggle for me so far.
Thanks!
I know this will be a loaded question...
If one was to use the standard BOM used in this thread using an Antek AS3218 300VA 18V transformer, what voltages and currents are being delivered to the rest of the amplifier? I'm not sure if I have seen a spec on this.
I realize that the "good enough for Papa" uses the eight 15,000uF 25V caps and some builds are using eight 22,000uF 35V caps. What is different is being supplied to the amp? I have organic chemistry and molecular biology pretty well locked down, but electronics has been a bit of a struggle for me so far.
Thanks!
What amp am I building...?
I have boards for both the Aleph J and the F6, and using the diyAudio 4U chassis. I thought I would give both of them a shot.
I have boards for both the Aleph J and the F6, and using the diyAudio 4U chassis. I thought I would give both of them a shot.
Neat! They are fairly different sounding amps, you’ll enjoy the contrast.
18V secondaries are the ‘normal’ spec for these projects and will yield rails under load of about 23V. The AS3218 is perfect.
As for capacitors, in this application, there’s not much difference operationally between 15K uF and 22K uF. Maybe a bit more filtering, but not enough to worry about. Capacitor voltage rating is their maximum - you need at least 25V, a higher rating will lead to better capacitor life. I like 35V for these projects but have used 25V a number of times.
Remember that the PCB needs capacitors with 10mm snap-in leads and a maximum diameter of 35mm.
18V secondaries are the ‘normal’ spec for these projects and will yield rails under load of about 23V. The AS3218 is perfect.
As for capacitors, in this application, there’s not much difference operationally between 15K uF and 22K uF. Maybe a bit more filtering, but not enough to worry about. Capacitor voltage rating is their maximum - you need at least 25V, a higher rating will lead to better capacitor life. I like 35V for these projects but have used 25V a number of times.
Remember that the PCB needs capacitors with 10mm snap-in leads and a maximum diameter of 35mm.
Perfect, all makes sense - Thanks.
Yep I got the correct cap diameters and lead spacing.
Back to the salt mines.
Yep I got the correct cap diameters and lead spacing.
Back to the salt mines.
Do you guys recommend soldering wires from the transformers directly to the boards or the use of spades to connect them?
If you plan on changing in the future use some type of clamping device. I’m a believer in slobbering everything. Of course that leads to an all new build which is a good thing.
