diyAudio Power Supply Circuit Board v3 illustrated build guide

Hello,

I am still at a beginner level, so please forgive me if I may ask a stupid question.

My question is related to the maximum filtering capacity. I have seen a recommendation from Mr. Pass at the F5Turbo manual for a CRC with 40uf, then 0.067Ohm resistor bank, and again 40uF capacitance per rail. The manual for the power supply recommends capacitors from 10000uF to 15000uF. May I ask, why is that and can I may use these capacitors:
ECO-S1VA223EA Panasonic | Mouser

many thanks,
tom
 

6L6

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Tom -

That's a good question, as there is some conflicting information depending where you look.

The easiest thing to do is look at the total capacitance in the PSU as drawn by the designer, and then see what parts you can buy similar to that.

As for the capacitors, are you building an F5Turbo? You will be better served by capacitors with a 50V rating. Such as these - ECO-S1HP183EA Panasonic | Mouser
 
Hi,
Help please! Where would I add more capacitors to this board? I have two boards made with 8 in parallel each and would like to include them but I don't know where to connect. Need to use the caps I have on hand so larger value is not an option now. Building the Honey Badger- built my last amp 42yrs ago so I'm a little rusty

Max
 
Can someone post an overhead shot of the fully assembled power supply with mains. I am a newbie and I am trying to wrap my head around why the mains are connecting to the filter section before the diode bridge in the photo with the monolithic bridge(please explain what this is).
 

6L6

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I am a newbie and I am trying to wrap my head around why the mains are connecting to the filter section before the diode bridge in the photo with the monolithic bridge (please explain what this is).

The "Mains" refer to the wires connected to the AC wall plug. The "Primaries" of the transformer connect to the mains. The transformer then transforms the wall voltage down to out transformer voltage, in a Pass amp something like 18V - 24V. The wires with the lower voltage (which is still AC, just lower voltage) are the "Secondaries"

The lower voltage AC needs to be turned into DC - diode bridges do this - the array of 4 discrete diodes with heatsinks (per channel, totaling 8) take the AC on the secondaries and make it DC, which is not particularly clean and smooth, which is what the filter section is for - The big capacitors and resistor banks will make the rippily DC into very smooth DC.

The "Monolithic bridges" are the little square packages that have 4 diodes in the one package, and take the place of the diode section of the PCB. They have 4 connections so AC goes in, and DC comes out.

In the below photo you can see, from left to right -

Transformer and transformer secondary wires, connected to;

(2) monolithic bridges, connected to;

Filter section of the PCB. (which has the diode section removed)

IMG_2182.jpg



This page has TONS of awesome info that will help you figure out your PSU - although it's specific to a chipamp, the Pass style PSU is essentially the same, just much bigger. Building a Gainclone chip amp power supply.
 
Thanks for the clarification and thank you for the link. I did not realize those devices (monolithic bridges) actually contained diodes (they looked too small).

I realized the BoM is not intended for the HoneyBadger board at 63W. Is there any advantage in selecting diodes that are rated higher than the secondaries?
 

6L6

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?? The normal diodes are 200V 30A. So don't worry about them.

What needs attention is the capacitor voltage rating. The need to be rated higher than the rail voltage. The voltage ratings in that general area are 50V, 63V, 80V, 100V. Higher voltage ratings have some advantages, but you will be trading away capacity for a given volume. More uF is generally better.
 
A bit confused about these monolithic bridges - why show them if they don't ship with the PCB [edit - by which I mean, they are not part of the BOM for the power supply - you provide the bridge rectifier PCBs instead] ? Should I abandon the diyaudio rectifier PCBs and get these instead? They certainly look easier to work with than all the heat sinking, bolting etc (although admittedly still require heat sinking which you are achieving with the chassis in your pic).

As this is the build guide for the power supply that you guys sell, introducing new components that are not part of that kit / BOM is a bit counter-intuitive to me!

A final comment - from memory mine were shipped with the 2 filter PCBs already separated from each other, so the stuff in the guide above about not separating them for a lower noise PCB is not very helpful ;)
 
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What a hobby!

A bit confused about these monolithic bridges - why show them if they don't ship with the PCB [edit - by which I mean, they are not part of the BOM for the power supply - you provide the bridge rectifier PCBs instead] ? Should I abandon the diyaudio rectifier PCBs and get these instead? They certainly look easier to work with than all the heat sinking, bolting etc (although admittedly still require heat sinking which you are achieving with the chassis in your pic).

As this is the build guide for the power supply that you guys sell, introducing new components that are not part of that kit / BOM is a bit counter-intuitive to me!

A final comment - from memory mine were shipped with the 2 filter PCBs already separated from each other, so the stuff in the guide above about not separating them for a lower noise PCB is not very helpful ;)

While confusing, it is good they listed an alternative. You don't want to use the monolithic bridges on a high current supply so the heatsinks might be necessary for your build. Don't abandon the PCB as it is modifiable.

I am not 100% on this but I believe the DIYAudio store was a grassroots startup by enthusiasts and I doubt they make much profit after other fees are considered. I am sure an updated BOM and build guide will be released at some point which will include input from the site. One thing that they should add in the BoM is an editable section in the spreadsheet for transformer values that could give optimal values for the other components (not necessarily part numbers as this would be too intensive). It would also be cool to see new designers come forward and get kickbacks for their board sales.

Don't sweat the boards being separate just make sure to mount them adjacent to each other. There is no foil going from one PCB to the other so they need to be bridged regardless.
 
Greetings Ihala,

I want you to know that I hear your frustration, I experienced a similar feeling with some of the "inconsistencies" I have come upon but HoneyBadger has hit the nail on the head. This is a community venture. The folks you tap for information are volunteers giving you and I their free time for free.

I'll take this opportunity to thank them again: THANKS! :hug:

I'm closing in on my third Nelson Pass project now and may soon be a supplicant for additional help. IF the whole world were as smart and as generous as the folks here it would be a better world indeed!

Cheers! :cheers:
 
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6L6

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As this is the build guide for the power supply that you guys sell, introducing new components that are not part of that kit / BOM is a bit counter-intuitive to me!

The simple reality is that there is about 144 different ways you could use this PCB in your amp project. And the same for somebody else in their amp project.

It's a very well though out, mostly universal, generic high-current bipolar PSU board. Some things are going to be very similar from amp to amp, but some will be different.

from memory mine were shipped with the 2 filter PCBs already separated from each other, so the stuff in the guide above about not separating them for a lower noise PCB is not very helpful ;)

They arrived separated? That's damage during shipping.

You don't want to use the monolithic bridges on a high current supply so the heatsinks might be necessary for your build.

?? The bridges can take lots of heat and lots of current. Much more than your transformer could ever apply. Heck - the factory built Alephs only had one bridge for the PSU and that was no problem.

One thing that they should add in the BoM is an editable section in the spreadsheet for transformer values that could give optimal values for the other components

?? Can you elaborate? I'm not sure what you are asking for.

I want you to know that I hear your frustration, I experienced a similar feeling with some of the "inconsistencies" I have come upon

Again, there are many, many different ways this PCB can be used in your project. because there are so many different parts that can be applied to the PSU. A simple and good example - lets say you had a transformer that was center-tapped instead of dual secondaries - I.E., 24v-0-24v instead of 0-24v, 0-24v. This would dictate the use of a single bridge. You could use one of the brigdes on the PCB, or use 2 diodes only on both sides of the discrete diode section and make a bridge using both sides of the PCB, or just snap it off all together and use a different part or parts - monolythc bridge, or perhaps some other discrete pieces you have laying around.
 
Please 6L6, don't get me wrong, you're a hero to me.

I put "inconsistencies" in the quotes because I am such a beginner that any sort of difference in parts can be a puzzle. What threw me at first was the many ways the grounding scheme could be executed but we've been through that already and thanks to your help I understand grounding a bit better now. Thanks! Plus, the confusion and its elimination is there in the thread for the next fellow who might experience what I did. That's cool.:wave2:

I read many, many threads from this community looking for such problems and explanations - they are quite helpful to me! :wrench::treasure:

I wanted to let HoneyBadger know he's not "seeing things" that the confusion is normal and at the same time repeat my thanks to you. I'm just trying to encourage everyone because this pursuit, this learning by forum, has been very enjoyable for me. I want it to continue!


:cheers: