diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Tubes / Valves (http://www.diyaudio.com/forums/tubes-valves/)
-   -   Gyrator PSU's in tube amps (http://www.diyaudio.com/forums/tubes-valves/183510-gyrator-psus-tube-amps.html)

alexmoose 19th February 2011 09:08 PM

Gyrator PSU's in tube amps
 
Hey guys,

I am going to give my SE amp a makeover in the coming weeks. New OPTs, new PT, maybe even going PSE. A guitar playing friend has recommended the use of a gyrator in the power supply. It sounds like a great idea on paper, however I've noticed that very few hi-fi designs use them. I would use it to eliminate electrolytic caps from the amplifier entirely. Why aren't there very many hi-fi amps that use this fairly simple design?

Regards
-Moose

quikie22 20th February 2011 04:25 AM

A gyrator would present a dynamic impedance. In a guitar amp this would be desired as it creates the "voltage sag" that makes the guitar amp sound the way it does.

For hi-fi, a gyrator would be detrimental to the sound. Here we want to maintain a smooth, ripple free, low output impedance power supply that can handle transients easily. Try a voltage regulator or even a real CLC (capacitor-choke-capacitor) topology for the power supply. Google PSUD 2 to get the power supply designer.

kenpeter 20th February 2011 06:44 AM

A gyrator uses a capacitor to stand in for an inductor.
If you are trying to get rid of electrolytics, perhaps you meant a cap multiplier?
They are very similar circuits, yet react in opposite phase.

Both types have one issue in common. They do not store energy that can later
fill gaps in the ripple.

Wavebourn 20th February 2011 08:28 AM

No, it's not a great idea, to use gyrator in PS. Just a R-C with high time constant feeding one source follower is much better. A parametric shunt regulator shunted by relatively big capacitance with source follower is even better: it brings up output voltage slowly and softly, and stays on the level stabilized by the shunt regulator.

Voltage sag can be created by a single additional R-C filter.

av-trouvaille 20th February 2011 09:04 AM

What exactly is a parametric shunt regulator, and how would it look like in a schematic?

Joshua_G 20th February 2011 09:49 AM

Quote:

Originally Posted by av-trouvaille (Post 2475925)
What exactly is a parametric shunt regulator, and how would it look like in a schematic?

http://www.diyaudio.com/forums/power...hunt-regs.html

Wavebourn 20th February 2011 05:36 PM

Quote:

Originally Posted by av-trouvaille (Post 2475925)
What exactly is a parametric shunt regulator, and how would it look like in a schematic?

It is a voltage divider formed by two elements with different parameters of Volt/Ampere characteristic. Like, one CCS and one resistor, or one resistor and one Zener diode. Or even better: on e CCS and one Zener.


All times are GMT. The time now is 04:26 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2