VRDN: bipolar regulator PCB for line level ckts: ±11V to ±20V @ 1.5A with "De-Noiser"

Member
Joined 2011
Paid Member
Please take a look at post #1 of this thread.



_
 

Attachments

  • post_1.png
    post_1.png
    59.3 KB · Views: 310
I've seen a lot of Qs on this thread about transformers, but not my question. My plan is to use one VDRN to power a Waynes Linestage. I bought an audio-grade Toroidy dual transformer. I think I know how to connect the secondaries, one set to each input.

But I don't understand how to connect the primaries to the power inlet. The Toroidy has only two wires for the primary. I'm looking at the diagram for the First Watt F5. This seems to have 4 wires for the primary.

My best guess is the "load" wire from the mains input runs through once CL60 thermistor to one of the primary windings, and the "neutral" wire runs to the other primary wire (just straight connection).

Do I need two CL60s? If I trace the F5 diagram, and assuming the C9 is an open circuit/air gap (i.e. not installed), then I see two circuits (main - transformer - main) and each circuit has a single CL60 on it.

And what do I do with the safety cap (C9 in the diagram)? That works to isolate the two primary transformer windings from each other (once it is charged). I only have one primary winding.

The toroidy is this one: https://sklep.toroidy.pl/en_US/p/TT...grade-transformer-TSAS50VA-voltage-to-50V/382.

Also, the F5 power supply has a CL60 thermistor from a ground point on the board to chassis ground and mains ground. I'll certainly connect mains ground to chassis ground, but I don't recall a ground connection on the VDRN. Obviously the VDRN is not the F5 power supply, so of course there are differences. What I don't know is if this is an intended difference (i.e. the VDRN should not be connected to chassis ground), or if I missed something in the build.

F5PSUschematic.jpg
 

PRR

Member
Joined 2003
Paid Member
The 4-wire connection is for choice of 120V or 240V supply.

That transformer is 240V-ONLY. I hope that what you have in your wall.

Putting the TH part between the two windings is a neat way to keep the builder out of trouble from extra wires. Since you don't have extra wires, you simply put the TH part in series with the one winding.
hbadger---42.gif
 
Success!

Except for a ground fault with an RCA jack (now fixed, but can I talk with the person who designed these? Like that little plastic collar is really the best way to insulate??) it works flawlessly.

Many many thanks to all the forum members who helped me with this project, directly or indirectly. This never would have happened without you.

Also a quick shout-out to Gianluca at Modushop, who made the case for me (and who generally provide a lot of support for DIY Audio). The case was a joy to work with; it has so many well-thought out and helpful little features, and Gianluca was very helpful with some of the design of the cutouts (and machined them).

IMG_20220305_173443.png



IMG_20220305_173713.png



IMG_20220306_093936.png
IMG_20220306_093952.png


IMG_20220306_094008.png

I'll probably cross-post in the Waynes's linestage thread.
 
Yes, select switch is in the back to keep the face clean. Also, I don't have much audio equipment-- the shame of my setup is the main input is my cell phone playing spotify or my synth. I doubt I will use the RCA inputs, they are "just in case" -- so I don't have a lot of use for the switch.

The two inputs you ask about are 3.5mm jacks, one for each of these inputs. The synth wants a dedicated input because it outputs +/- 10V, and I need to dump some of that to ground before it hits the preamp circuit. Cell phone is (probably?) closer to +/- 1V.

I have two LEDs above them, one blue and one white. This lets me code 3 indicators of what input is on. You see the blue spot on the radiator in the badger photo? Blue LED, middle 3.5mm jack.
 
Congratulations, @hbadger! I really like the way you've used the perforated steel "floor plate" to keep mains wiring tidy.
I don't want to be critical, but that's potentially dangerous, since the holes are likely not smooth and could, over time, erode the insulation, and then you get a short. When you do mains wiring with metal boxes, electrical codes usually require the use of some kind of relief around the entry and exit points for this reason.
 
  • Like
Reactions: 1 users
Hello folks, I would like to build the VRDN and first step was ti get board from jlpcb. After upload of gerber files get the message :
Detected 4 layer board of 62x142mm(2.44x5.59 inches) .
Your upload has finished processing. Enter the project details below and we'll move on to checking all the individual layers to make sure that they're correct.

asking to fill a layer sequence as show below :
1657449300521.png

where appear 4 dropdown menu ( TopLayer, InnerLayer1,InnerLayer2,BottomLayer) . Since I'not expert about gerber composition is it possible to have a suggestion on the correct selections to insert?? Thanks in advance
 
I’ve run BA2018 at 15v, 18v, and 24v. For a while I had the impression that 18v sounded best, but I’m not entirely sure if that is actually happening. All voltages sound great.

BA2018 runs about 50-60mA per channel. I have one running from a 500ma single secondary AC wall wart, and everything works perfectly. I have another running from a 50VA 18+18 transformer. Whatever you can easily get will most likely work very well.
Hi 6L6,

What is the required wallwart vac for 18vdc for the ba2018?

Thanks