I'd be interested in a similar PSU with the following changes.
fixed input 120V/240V by switch.
Fixed output voltages set by jumper. 280V - 320V - 400V.
Open loop no feedback design.
No start delay
Ability to start into 6000uF.
1 ampere output current.
Right now I do this with 12V SMPS feeding DC-DC boost converters but an all in one solution would be nice.
fixed input 120V/240V by switch.
Fixed output voltages set by jumper. 280V - 320V - 400V.
Open loop no feedback design.
No start delay
Ability to start into 6000uF.
1 ampere output current.
Right now I do this with 12V SMPS feeding DC-DC boost converters but an all in one solution would be nice.
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Medium to high power: https://www.aliexpress.com/item/1005003336586371.html
low power: https://www.aliexpress.com/item/1005001756069951.html
Good for VU meters or nixies: https://www.aliexpress.com/item/33040159635.html
Here's the PSU for my preamp 🙂 The picture is before it was completely wired.
low power: https://www.aliexpress.com/item/1005001756069951.html
Good for VU meters or nixies: https://www.aliexpress.com/item/33040159635.html
Here's the PSU for my preamp 🙂 The picture is before it was completely wired.
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Get yourself a cheap 12.6 v dc supply , prefferably transformer plus rectifier.Then use Dave's zvs to boost it to your desired voltage:
https://highvoltageforum.net/index.php?topic=1439.msg10989#msg10989
You can follow the topic for devellopement, but I'm not going to take credit on Dave's genious simple zvs circuit.It has some advantages over simpler zvs circuits like no start-up faillure.The efficiency is pretty high, over 90% and its output sinewave-ish
I needed it for a luxman cl 34 clone's 390v anode supply.
https://highvoltageforum.net/index.php?topic=1439.msg10989#msg10989
You can follow the topic for devellopement, but I'm not going to take credit on Dave's genious simple zvs circuit.It has some advantages over simpler zvs circuits like no start-up faillure.The efficiency is pretty high, over 90% and its output sinewave-ish
I needed it for a luxman cl 34 clone's 390v anode supply.
You don't really need the anode voltage to be regulated especially in class A tube preamps.
Yeah, that’s exactly the type of circuit I’m playing with. The only difference is my input voltage is higher - 48V. So I’m going to build a version with a separate FET driver chip. Anyway, given a stable input, the output will be predictable. And that’s all I need.
Ad the moment i use this one.
https://www.aliexpress.com/item/100...daa,tpp_buckets:668#2846#8115#2000&pdp_ext_f={"sku_id":"12000015963231639","sceneId":"30050"}&pdp_npi=2@dis!EUR!!45.69!!!!!@211b5db316551372258983283ee191!12000015963231639!rec
But heater and anode supply share ground. It is not possible to lift heatersupply.
There is a 30mV rimple at 62Khz. I like to compare if there is a change in sound when rimple is below 1mV.
I already tried LR8N with fet to bring down rimple, but rimple just got 15mV down(-3db).
Further i have not found a good smps diy design with great specs for hifi gear.
https://www.aliexpress.com/item/100...daa,tpp_buckets:668#2846#8115#2000&pdp_ext_f={"sku_id":"12000015963231639","sceneId":"30050"}&pdp_npi=2@dis!EUR!!45.69!!!!!@211b5db316551372258983283ee191!12000015963231639!rec
But heater and anode supply share ground. It is not possible to lift heatersupply.
There is a 30mV rimple at 62Khz. I like to compare if there is a change in sound when rimple is below 1mV.
I already tried LR8N with fet to bring down rimple, but rimple just got 15mV down(-3db).
Further i have not found a good smps diy design with great specs for hifi gear.
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You can always use linear regulators after smps if noise levels aren't good enough...Studer A827 did it 40 years ago and that was no 1 tape recording console .Apple computers used resonant smps since the 70's I think and they were famous for the audio processing found on their motherboards at some point.
Other than that if rimple doesn't go flat try reducing ripple instead 🙂
Most linear regulators do not function at 100khz rimple. And there are not so much regulators for 350V. I think kubato hv regulator has - 30db rimple surpression at 100khz. So using this one after smps will do the job. Now i need a smps schematic.
Why bother with that? 14v 63...100 watts r-core transformer, 12.6 v linear regulator supply both the fillament and the zvs booster giving 60...100khz sine output of whatever voltage you choose to wind. 2×7...10 primary litzwire turns ...any amount of turns you need in the secondary plus a voltage multiplier if you want less cap coupling in the transformer.
Here's for a fourth time posted here on the forum some of the Luxman cl 34 clone and its anode booster pictures. The zvs booster used 4 x 450 volts caps, 1200v 8 amps ultra high speed diodes and 32 amps schotky diodes ...so it was about 4 times bigger than it should have been...I abandoned it because I was very unskilled at finding a suitable shielded case.I listened to it , it sounded great and that was just all about it...I preffer smaller phono preamps though.
Here's for a fourth time posted here on the forum some of the Luxman cl 34 clone and its anode booster pictures. The zvs booster used 4 x 450 volts caps, 1200v 8 amps ultra high speed diodes and 32 amps schotky diodes ...so it was about 4 times bigger than it should have been...I abandoned it because I was very unskilled at finding a suitable shielded case.I listened to it , it sounded great and that was just all about it...I preffer smaller phono preamps though.
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Did you test passive filtering of this supply? I am thinking along RF chokes, s used here https://diyaudiostore.com/blogs/news/smps-dc-filter-new-stocks-have-arrived. Or maybe the 5900 line from Bourns.
Passive filtering is already used in most smps. Adding more passive filter is an option but when capacity becomes to high the smps will not start. If my smps has more then 100uf capacity connected, it do not start. Further i need then 400V rated capacitors.
I like to know what is the smps topology with the lowest rimple.
I like to know what is the smps topology with the lowest rimple.
You can have multiple series clc pi filter which will allow your smps to work with more capacitance and the filtering will be more efficient.
A simple solution would be to use 12vac wall wart into a reversed mains transformer.
You can use 12vac for heaters too with some valves.
Or even use 6VAC with reversed mains transformer and 6vac for heaters.
You can use 12vac for heaters too with some valves.
Or even use 6VAC with reversed mains transformer and 6vac for heaters.
The only real silent switcher is one followed by a linear regulator. Not absolute truth but nearly so.
So for real low ripple voltage a linear regulator is needed anyway. These regulators often dislike the high frequency ripple that switchers spit out. These 2 facts kind of defeat using an SMPS as frontend for low power PSU application in audio devices.
Lifting heater power supply is one of those things that are possible with linear stuff.
What is exactly gained by using SMPS? It can not be low cost as a simple low power R-core transformer for a preamp is not that expensive.
So for real low ripple voltage a linear regulator is needed anyway. These regulators often dislike the high frequency ripple that switchers spit out. These 2 facts kind of defeat using an SMPS as frontend for low power PSU application in audio devices.
Lifting heater power supply is one of those things that are possible with linear stuff.
What is exactly gained by using SMPS? It can not be low cost as a simple low power R-core transformer for a preamp is not that expensive.
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For valve circuits I use CRC filters.
Low power valves can have quite large resistors as the R part.
Low power valves can have quite large resistors as the R part.
Done it...depends on transformer's secondary impedance to get the voltages right...but you still need a voltage regulator.
https://www.gyraf.dk/gy_pd/g9/g9pd.htm
