Choke power supply- part 2


Back in 2008 I asked why choke power supplies were not more common. At the time, the majority of opinions were that choke power supplies were more expensive and so most manufacturer's chose not to use them. Today, with mega priced gear, I still question why manufactures are not more enamored of using them in their power supplies?

I am of the opinion that a choke power supply can sound spectacular and it does seem to offer several technical advantages...so why not more popular? Surely if it is still cost, that seems to make less sense as the price of top flite gear is now approaching six plus figures! Thoughts?

128x128daveyf

I seem to have misread @daveyf  question, and the responses of @cindyment are so inane, I had decided not to respond. But here goes anyway. All linear power supplies use a combination of chokes and caps after rectification to smooth the rectification pulses into a quasi DC output. The degree of ripple in that output is a consequence of the values of the components used. There have been choke input linear power supplies, which used to be used primarily in tube amps.

Charles Hansen used this type of choke input power supply in his Ayre V-1 and V-3 amps, but abandoned it for his later amps because of the high cost and weight penalties which would have made his products non-compeitive. You can google these amps for descriptions

It is inconceivable that someone would state that it makes no difference as to whether a choke is used before or after rectification.

IF Schiit has designed a new amp with maybe a choke input PS is not relevant until said product makes it to market.

 

 

Moffat is a wizard w ears and nickel in the transformer is expensive, get a quote….

i think it is great what Schitt is doing. The book Schitt Happened is excellent, especially the chapter by Mike…

I am a robot all choked up over part quality…

@oldears , you not understanding my responses does not make them inane.

What I said was:

Whether you put the choke on the input or the output the effect is the same. A transformer reflects the impedance from one side to the other based on the turns ratio

I did not say:

It is inconceivable that someone would state that it makes no difference as to whether a choke is used before or after rectification.

While the values are the same, the net effect w.r.t. choke regulation is the same. If you don’t believe me, work out a small signal model or simulate it. I assume you understand reflected impedance? To your point, when people talk about a choke regulated power supply, they usually mean larger inductors, than the typical minimum used for higher frequency harmonics of the AC line and noise. The transformer has enough bandwidth in this case to put a regulation choke on either side.

Your last post did not say anything I did not say already, I just put in more detail:

Output of a bridge rectifier is DC + harmonics of twice the AC frequency. The choke in combination with the capacitor forms a filter eliminating some of those harmonics, but the choke in combination with the load does as well. Hence, the output voltage can droop. So much for your high dollar, low resistance AC power cord.

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If you really want to learn more a about choke applications in power supplies find yourself an amp tech that worked on Fender amps from the 40’s and 50’s when Leo was going for cleaner and cleaner tone. Short story to effectively use choke tech I t requires massive high quality transformers which is a cost and supply chain issue. Unless you take the McIntosh approach and produce them in-house.