Hey, getting ready to build up a few projects, and would rather have a pre-made PSU board rather than point to point for my regulators. Most likely going to run a few hundred mA at 12~15+- rails (24~30v rail to rail) using the LM317/337 chips. Any recommendations on a decent board (or even cheap kit with components/heatsinks incuded) for a decent price?
I was looking at this guy, and it seems to be a pretty decent deal, and inculdes everything but the transformer. heatsinks are a bit small, but I'm not going to be dropping a ton of voltage at this current, so I think they would work just fine for my purposes...
DIY Kit Adjustable Filtering Power Supply LM317 LM337 Voltage Regulator Module | eBay
Any suggestions? I would probably grab three of them. The only review seems to be from someone who isn't familiar with electronics, as this is one of the easiest to figure out circuits there is, and self explanatory to anyone who knows what they're looking at.
I was looking at this guy, and it seems to be a pretty decent deal, and inculdes everything but the transformer. heatsinks are a bit small, but I'm not going to be dropping a ton of voltage at this current, so I think they would work just fine for my purposes...
DIY Kit Adjustable Filtering Power Supply LM317 LM337 Voltage Regulator Module | eBay
Any suggestions? I would probably grab three of them. The only review seems to be from someone who isn't familiar with electronics, as this is one of the easiest to figure out circuits there is, and self explanatory to anyone who knows what they're looking at.
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The routing of the ground/sense is important to the final performance.
I can't see how he/she has routed those traces.
I don't like the capacitors across the rectifier diodes.
It needs a snubber from both sec to CT, not across the 4 diodes shown.
I can't see how he/she has routed those traces.
I don't like the capacitors across the rectifier diodes.
It needs a snubber from both sec to CT, not across the 4 diodes shown.
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Have a look at Power Supply for Preamps
A load of useful information on Rod Elliott's pages even if you don't buy pcb from him.
A load of useful information on Rod Elliott's pages even if you don't buy pcb from him.
That supply has two of the "standard" way regulators are designed in ground separation and output-bypass caps.
Have a look at these measurements and curves when increasing the bypass capacitor value and decreasing the output cap value, both in noise and impedance, and when using separate ground paths.
Simple Voltage Regulators Part 1: Noise - [English]
Simple Voltage Regulators Part 2: Output Impedance
I recently bought two 3x7 regulators from eBay, one of them having a correct ground layout.
Have a look at these measurements and curves when increasing the bypass capacitor value and decreasing the output cap value, both in noise and impedance, and when using separate ground paths.
Simple Voltage Regulators Part 1: Noise - [English]
Simple Voltage Regulators Part 2: Output Impedance
I recently bought two 3x7 regulators from eBay, one of them having a correct ground layout.
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Hi
I have received LM317/337 based PCbs yesterday.It's designed by my friend and Fm Omishra. It has a adjustable outputs using onboard trimmers. This is Rev1, earlier version has already been proven with phonostages and small preamps. Let me know if you are interested. I have enough PCbs.
You can see the pics in my last post here AD797 Phono Stage Build and Help Desk Thread | Page 51 | Audiokarma Home Audio Stereo Discussion Forums
Regards
Sachin
I have received LM317/337 based PCbs yesterday.It's designed by my friend and Fm Omishra. It has a adjustable outputs using onboard trimmers. This is Rev1, earlier version has already been proven with phonostages and small preamps. Let me know if you are interested. I have enough PCbs.
You can see the pics in my last post here AD797 Phono Stage Build and Help Desk Thread | Page 51 | Audiokarma Home Audio Stereo Discussion Forums
Regards
Sachin
I've actually got those pages printed out around here somewhere...
Is this the PCB you pictured? Sure looks like it.
AC-DC LM317 LM337 Adjustable Regulated Dual Power Supply Module Board DIY Kits | eBay
It does look to have a much better ground plane.
This will be running tube filaments in series across the rails (which will help pull a nice healthy current at all times, helping to keep regulation consistent, as well as help noise performance) as well as a few discrete CCS, and a few Opamp DC servo circuits, so those heatsinks *should* be okay, should only be dissipating 400~500mA at around 4~7v drop, but we shall see...
Yes, that's it. It has a better ground layout, not a ground plane. Sometimes ground planes are not such a good thing for audio, IMHO. The frequencies used are not that high to justify them. Instead of that larger tracks can bring more benefits and occupy the same space. Even more: they can allow using different size parts, even SMD. Bypasses can be easier too.
I can recommend this one:
Power Supply Board Kit, PCB, Based on LM317 & LM337 IC | eBay
A little more expensive, but worth it.
Power Supply Board Kit, PCB, Based on LM317 & LM337 IC | eBay
A little more expensive, but worth it.
It has two things that I would not recommend: grounds are not separated and the output cap is too large.
I uploaded the schematic corresponding to the other kit, and you can see the grounds are regrouped in a better way.
The output capacitor is also small, and the Adj pin cap bypass is larger. Look at the graph from TNTaudio on how regulator's output impedance is affected by that capacitor.
The output capacitor shouldn't be larger that 100uF and that capacitor shouldn't have a low ESR, If it does, a small resistor should be added, as on the schematic.
This other supply does not specify the adj cap value, and I wonder if it's even there.
Look also at this subjective test using the LM317 supply and different combinations for adj and output caps.
High End Audio - LM317
I uploaded the schematic corresponding to the other kit, and you can see the grounds are regrouped in a better way.
The output capacitor is also small, and the Adj pin cap bypass is larger. Look at the graph from TNTaudio on how regulator's output impedance is affected by that capacitor.
The output capacitor shouldn't be larger that 100uF and that capacitor shouldn't have a low ESR, If it does, a small resistor should be added, as on the schematic.
This other supply does not specify the adj cap value, and I wonder if it's even there.
Look also at this subjective test using the LM317 supply and different combinations for adj and output caps.
High End Audio - LM317
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