Has anyone using LC input in their power supply?

jarthel · 27th June 2007, 04:00 AM

as title.

Based on my experienced with tubes and from what I have read and simulations using PSUD2, it will provide stable current at the cost of lower voltage.

As I said, I've only used this with tube projects so I would like to get people's experiences using them with SS.

Thank you

Gordy · 28th June 2007, 03:40 PM

It's just as valid in solid state, however once the voltage and current starts to be significant, such as in a power amplifier, the size and cost of the choke becomes significant too !

Try it with a preamp, and let us all know how you get on.

Hartono · 28th June 2007, 03:50 PM

Ayre brand amplifier use them.

jarthel · 28th June 2007, 04:29 PM

Quote:

Originally posted by Gordy
It's just as valid in solid state, however once the voltage and current starts to be significant, such as in a power amplifier, the size and cost of the choke becomes significant too !

Try it with a preamp, and let us all know how you get on.

I've seen power amp (aleph amps) projects where people have used CLC. it's easy enough to turn it into LC

apassgear · 28th June 2007, 04:47 PM

No problem with SS I have used LC on Aleph 4 with excellent results but reverted to CLC for rail voltage reasons.

AndrewT · 28th June 2007, 04:58 PM

Hi,
as the PSU voltage comes down and the current goes up, then LC supplies (choke input) become uneconomic.

The very big and heavy and most expensive in the range of Musical Fidelity used to use LC (they called it choke regulated) PSU.

Keep in mind that the DCvoltage from the transformer becomes 0.9*Vac instead of 1.4*Vac.

BUT the voltage holds very steady and hum free with small changes in current, until the operating current drops below the regulating current then voltage rises from 0.9 to 1.4 times and ClassAB can end up with 50% overvoltage if designed incorrectly.

apassgear · 28th June 2007, 06:30 PM

Good point Andrew.

LC should be used only for class A amps.

jnb · 28th June 2007, 11:47 PM

As currents go up (or rather, impedances go down), you may need less inductance, so - you could take a fair sized power transformer core and wind relatively few turns of somewhat heavy gauge wire on the bobbin, before stacking the laminations for DC.

Probably one of the easier winding excercises available.

apassgear · 28th June 2007, 11:57 PM

The lamination needs a gap in order not to saturate it with DC.

jarthel · 29th June 2007, 12:22 AM

I wasn't thinking of using it for power amps. mainly for preamps as preamp transformer at higher VA (higher voltage but needing to maintain the same current requirement) is not a lot more expensive.

it is probably uneconomical for power amps. but it seems it would work with the F4 (the amp i'm planning to build) as the manual says it's Class A. I guess it's easy enough to check prices from the local supplier

27th June 2007, 04:00 AM	#1
jarthel diyAudio Member Join Date: Jan 2002 Location: somewhere in Australia	Has anyone using LC input in their power supply? as title. Based on my experienced with tubes and from what I have read and simulations using PSUD2, it will provide stable current at the cost of lower voltage. As I said, I've only used this with tube projects so I would like to get people's experiences using them with SS. Thank you

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28th June 2007, 03:40 PM	#2
Gordy diyAudio Member Join Date: Nov 2006	It's just as valid in solid state, however once the voltage and current starts to be significant, such as in a power amplifier, the size and cost of the choke becomes significant too ! Try it with a preamp, and let us all know how you get on.

28th June 2007, 03:50 PM	#3
Hartono diyAudio Member Join Date: Nov 2002 Location: currently in China	Ayre brand amplifier use them.

28th June 2007, 04:47 PM	#5
apassgear diyAudio Member Join Date: Nov 2002 Location: Viña del Mar, Torreon	No problem with SS I have used LC on Aleph 4 with excellent results but reverted to CLC for rail voltage reasons.

28th June 2007, 04:58 PM	#6
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, as the PSU voltage comes down and the current goes up, then LC supplies (choke input) become uneconomic. The very big and heavy and most expensive in the range of Musical Fidelity used to use LC (they called it choke regulated) PSU. Keep in mind that the DCvoltage from the transformer becomes 0.9Vac instead of 1.4Vac. BUT the voltage holds very steady and hum free with small changes in current, until the operating current drops below the regulating current then voltage rises from 0.9 to 1.4 times and ClassAB can end up with 50% overvoltage if designed incorrectly.

28th June 2007, 06:30 PM	#7
apassgear diyAudio Member Join Date: Nov 2002 Location: Viña del Mar, Torreon	Good point Andrew. LC should be used only for class A amps.

28th June 2007, 11:47 PM	#8
jnb diyAudio Member Join Date: Dec 2006	As currents go up (or rather, impedances go down), you may need less inductance, so - you could take a fair sized power transformer core and wind relatively few turns of somewhat heavy gauge wire on the bobbin, before stacking the laminations for DC. Probably one of the easier winding excercises available.

28th June 2007, 11:57 PM	#9
apassgear diyAudio Member Join Date: Nov 2002 Location: Viña del Mar, Torreon	The lamination needs a gap in order not to saturate it with DC.

29th June 2007, 12:22 AM	#10
jarthel diyAudio Member Join Date: Jan 2002 Location: somewhere in Australia	I wasn't thinking of using it for power amps. mainly for preamps as preamp transformer at higher VA (higher voltage but needing to maintain the same current requirement) is not a lot more expensive. it is probably uneconomical for power amps. but it seems it would work with the F4 (the amp i'm planning to build) as the manual says it's Class A. I guess it's easy enough to check prices from the local supplier