Okay thanks for your ideas, board size was stated in the post, with the pic, best to take any further discussion offline and leave this thread devoted to the design at hand. As Mark has stated this design is not intended for use with a center tapped transformer.
I had contemplated designing a new PS for the Hafler’s, we can continue that idea in the Hafler mod thread where it belongs.
I had contemplated designing a new PS for the Hafler’s, we can continue that idea in the Hafler mod thread where it belongs.
What is the purpose of R11,12 and C17,18 on the original board. Are they necessary? I didn't populate those parts because the pics in the original build guide by 6L6 left them out. If it matters, I'm using bridge rectifiers.
...edit... are the the 'snubbers' that are not necessary for class A?
...edit... are the the 'snubbers' that are not necessary for class A?
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dual mono grounding
have seen different ways that people execute grounding on single chassis dual psu builds. Generally into two camps;
1. IEC earth, both PSU Grounds (w\ CL-60), and both transformer shields on one star point
2. IEC earth, one PSU Ground (w\CL-60), and transformer shield from same PSU channel on one star and the other PSU & transformer shield on another star
Is either of these likely to be better than the other from a hum or otherwise perspective?
Would it make any sense to do the following instead?
IEC earth to it's own point, as short as possible.
One PSU Ground (w\CL-60) and that same channel transformer shield to one star and another star of the same for the other channel.
Further, if I had to choose on having a shorter ground wire from the PSU or a shorter shield cable from the Antek transformer, which would you choose? I'm packaging all this in a 4U so not a lot of room and will have to pick. Leaning toward a shorter transformer shield cable since I'll already be lifting the PSU ground off earth by a a CL-60. Reasonable?
appreciate the input.
have seen different ways that people execute grounding on single chassis dual psu builds. Generally into two camps;
1. IEC earth, both PSU Grounds (w\ CL-60), and both transformer shields on one star point
2. IEC earth, one PSU Ground (w\CL-60), and transformer shield from same PSU channel on one star and the other PSU & transformer shield on another star
Is either of these likely to be better than the other from a hum or otherwise perspective?
Would it make any sense to do the following instead?
IEC earth to it's own point, as short as possible.
One PSU Ground (w\CL-60) and that same channel transformer shield to one star and another star of the same for the other channel.
Further, if I had to choose on having a shorter ground wire from the PSU or a shorter shield cable from the Antek transformer, which would you choose? I'm packaging all this in a 4U so not a lot of room and will have to pick. Leaning toward a shorter transformer shield cable since I'll already be lifting the PSU ground off earth by a a CL-60. Reasonable?
appreciate the input.
Hello all. Sorry if this had been asked previously.. I assume I can use one side of this board to build up a linear psu for an Amp Camp Amp? With +18vac input (from one toroidal secondary) though a bridge rectifier it’ll output about 23 point something volts DC based on the one I built for my AlephJ. Not quite the 24VDC asked for but probably rough enough?
Thanks,
Andrew
Thanks,
Andrew
I remember when I was testing the Meanwell 24V SMPS, it sagged only few millivolts under the full load caused by 2 ACA modules, I think the current draw was something like 3.5A or a bit more... but no voltage drop, impressive!
I suggest you go with 240VAC / 2 X 20V (21)V AC, or 230V AC / 2 X 19V (20)V AC transformer.
That should give you approximately 2 x 24V DC ... or around 2 X 25V DC, depending on your rectification choice: a bridge rectifier, or 4 X low drop (dual?) didodes.
The input JFETS should be okay (only just...) with that voltage.
I suggest you go with 240VAC / 2 X 20V (21)V AC, or 230V AC / 2 X 19V (20)V AC transformer.
That should give you approximately 2 x 24V DC ... or around 2 X 25V DC, depending on your rectification choice: a bridge rectifier, or 4 X low drop (dual?) didodes.
The input JFETS should be okay (only just...) with that voltage.
Andrew - 18V transformer, bridge (discrete diodes if you want to use the bridge section of the PCB), (3) 0.47ohm 3W resistors, and two big capacitors. That should give you a supply that yields something near 23V and will work perfectly, merely set the DC balance pot to 1/2 of your actual supply voltage and enjoy! 
I use filtered IEC's. I'm not sure if they really help much, but I've been happy with my PSU's and I don't see the price increase for the filtered module as being big enough to be a problem.
I'm following the First Axiom of DIY: If some is good, then more is better.
Opinions will likely range from... use what you have around... to use megabuck stuff.
I use 16AWG in that spot.
I think this was what I got. Make sure to select stranded vs. solid (IMO).
Remington Industries 16UL1007STRKIT UL1007 16 AWG Gauge Stranded Hook-Up Wire Kit, 300V, 0.0508" Diameter, 25' Length Each: Amazon.com: Industrial & Scientific
You can get boxes of various brands. I got packs of 16 and 22 AWG in 6 or 8 colors. Some (cough) light, quick accidental touches to the insulation with a soldering iron didn't burn it, which made me happy.
I use 16AWG in that spot.
I think this was what I got. Make sure to select stranded vs. solid (IMO).
Remington Industries 16UL1007STRKIT UL1007 16 AWG Gauge Stranded Hook-Up Wire Kit, 300V, 0.0508" Diameter, 25' Length Each: Amazon.com: Industrial & Scientific
You can get boxes of various brands. I got packs of 16 and 22 AWG in 6 or 8 colors. Some (cough) light, quick accidental touches to the insulation with a soldering iron didn't burn it, which made me happy.
i'm no expert but i too used stranded 16awg wire. I went on ebay and searched "PTFE 16 AWG" and found a guy selling 5ft lengths of 5 colors of milspec wire tinned copper for very affordable. Was a real joy to work with. Definitely more per foot than a bundled kit from amazon but want to say it was still only like 10-15$.
I'd urge you to avoid PVC insulated wire even though it may be the least expensive you'll find. It is harder to work with because of its strong memory (hard to get it to keep a bend where you want it to, springs back to the shape it's used to) and melts too easily.
16 AWG stranded is what I use in this application as well.
16 AWG stranded is what I use in this application as well.