Still waiting for my order of 15uF ceramics to arrive. 🙂 Meanwhile, I have a question regarding...
Does this apply to any cap (other than C14 and C17) or just the ones for the positive voltage regs? What about the caps for the input (C18) and output (C19) of the negative reg U5? Same connection? Sorry for this newb question. I gotta be careful and sure because I've been bitten by an exploding cap that was installed in reverse earlier in this project, remember? 😱
BTW, thus far we've been talking about 1N5818 diode for this application. Would any (even not so similar) diode such as 1N4002 or UF4002 work just as well?
Thanks! 🙂
Does this apply to any cap (other than C14 and C17) or just the ones for the positive voltage regs? What about the caps for the input (C18) and output (C19) of the negative reg U5? Same connection? Sorry for this newb question. I gotta be careful and sure because I've been bitten by an exploding cap that was installed in reverse earlier in this project, remember? 😱
BTW, thus far we've been talking about 1N5818 diode for this application. Would any (even not so similar) diode such as 1N4002 or UF4002 work just as well?
Thanks! 🙂
You want the diodes to physically absorb heat... electrically they are doing nothing, so as long as they can withstand the voltage across them, any will be OK.
The stripey end always goes to the positive end of the cap so that the diode is reversed biased and non conducting.
The stripey end always goes to the positive end of the cap so that the diode is reversed biased and non conducting.
Thanks, good to know! 🙂 And can I also install more than one diode on a single cap so as to have more heat spreading?
Yes, always. That I'm sure of now. 🙂 BTW, will installing the diode not introduce any inductance issues similar to my concern about the long leads which reduces the ability of the pre-reg cap to suppress HF? Just want to be sure that it is totally OK, or if there is any detrimental side effect it is negligible.
Lastly, I'm noticing that when I measure the output ripple on the regs, it starts out a little high, like 3.5mV. After about an hour or two, it goes down to 2.5mV or even 2mV sometimes. Is this normal or is it just a coincidence - maybe the mains supply just became cleaner after a while?
I also tried turning off the power with the probes still attached. In that state I'm still seeing close to 2mV ripple on the output! What gives? 😕 Now I'm not sure anymore if I can trust my scope.
Thanks again! 🙂
You can use as many diodes as you want... no inductance issues as the diodes not "in circuit" feeding anything.
It's normal to see noise when the unit is off, just stray pickup. As always it's what's across the reg outputs when it's on that matters.
It's normal to see noise when the unit is off, just stray pickup. As always it's what's across the reg outputs when it's on that matters.
Thanks, that's really good to know! 🙂
I have now installed the 15uF ceramics. They turned out to be too large to install two ceramics in parallel, so my final choice had to be 15uF ceramic plus 10uF Rubycon ZLG. The thing with cramped spaces is you never know until you try it with the actual part on hand.
The test results on the scope and RMAA are not much different than before. Problem is, I can't really trust my scope for making judgments on the merits of component changes when the differences are very small.
This project is almost done. I just have to install the "heat spreading diodes" and the better resistors (I couldn't resist buying the Vishay/Dale CPF series which are touted as low noise and 100 ppm TC and can tolerate up to 230 deg.C of heat. Since I was placing an order for the 15uF ceramics anyway, I decided I might as well buy the better resistors.). 🙂
I have now installed the 15uF ceramics. They turned out to be too large to install two ceramics in parallel, so my final choice had to be 15uF ceramic plus 10uF Rubycon ZLG. The thing with cramped spaces is you never know until you try it with the actual part on hand.
The test results on the scope and RMAA are not much different than before. Problem is, I can't really trust my scope for making judgments on the merits of component changes when the differences are very small.
This project is almost done. I just have to install the "heat spreading diodes" and the better resistors (I couldn't resist buying the Vishay/Dale CPF series which are touted as low noise and 100 ppm TC and can tolerate up to 230 deg.C of heat. Since I was placing an order for the 15uF ceramics anyway, I decided I might as well buy the better resistors.). 🙂
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Yes!!! Finally! 🙂 What a long project this was! That's mainly because I could only do it at night and on weekends (I'm a programmer by day and hobbyist recording engineer/artist by night). Been too long on this project. I gotta make music now!
My 1010 is sounding awesome and I have learned a lot! Thank you so much!!!
I'm so grateful for all your help, I can't seem to thank you enough! I really appreciate your generosity with your knowledge and your patience in answering all my questions. Thank you for staying on this thread till the very end! 
Sorry, my worrisome nature has gotten the best of me again. I thought I had no more questions but I still have. 😛 It's regarding the RC snubber...
I have one in the wall wart wire and one inside the 1010. The one in the wall wart wire is located halfway along the wire that plugs into the power input jack of the 1010. So there is a distance of about 4 feet from where the snubber is located on the wire to the point where the plug connects to the 1010's power input jack. All this talk about lead inductance has got me wondering if I made a mistake in doing it that way. Should I have placed the snubber as close as possible to the plug that connects to the 1010 and not a far distance away?
Thanks! 🙂
I have one in the wall wart wire and one inside the 1010. The one in the wall wart wire is located halfway along the wire that plugs into the power input jack of the 1010. So there is a distance of about 4 feet from where the snubber is located on the wire to the point where the plug connects to the 1010's power input jack. All this talk about lead inductance has got me wondering if I made a mistake in doing it that way. Should I have placed the snubber as close as possible to the plug that connects to the 1010 and not a far distance away?
Thanks! 🙂
The network in the 1010 will stop any trace of ringing caused by resonance from entering the unit... and the network in the lead only does good. It's better if it were in the wall wart rather than in the lead, but it's no big deal... I can promise you won't have any issues at all with ringing on the transformer secondary winding with all the damping etc you have in place.
You mean inside the wall wart enclosure where the transformer is? I've been trying to figure out how to open the enclosure without destroying it, but it's hard because there are no screws. Seems like it's glued together. So I decided to just put the snubber in the wire. So if my only choice is to put it in the wire, would it actually be better to place it as close to the transformer as possible rather than close to the plug connecting to the 1010?
Yes inside... but if they are glued you can't do that so in the wire is fine. And yes, I would put it as near the tranny as possible.
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