Subjective listening impressions: more punch, more dymanics, less less noise, I am not sure that I am under the placebo efect but can not come back to LM317 or LT1085....
Special thanks to Rod Coleman, also thanks to Salas & Iko for kind support & help.
Special thanks to Rod Coleman, also thanks to Salas & Iko for kind support & help.
I am happy to hear the music's good!
I say - LM317 is no use anywhere in audio....
They are noisy - and there is capacitive coupling to the cathode. I know this is a small effect, but given that it is just as easy to do a transistor heater supply (current or voltage) - I would always avoid the noisy parts.
With directly heated tubes, the difference can be heard immediately!
With directly heated tubes, the difference can be heard immediately!
Not to self-promote, but Rod's comment makes me think of my CFP cap multiplier. Maybe something like this is what you had in mind?
http://www.diyaudio.com/forums/powe...ntokens-cfp-cap-multiplier-3.html#post2376286
- keantoken
http://www.diyaudio.com/forums/powe...ntokens-cfp-cap-multiplier-3.html#post2376286
- keantoken
More compact PCB for +V12R med. The blue elements are big MKP capacitors which can used alternative.
I'm not familiar with the requirements for filament power. My circuit will withstand 300mA before beta droop sets in. You would need to get the right filament voltage beforehand, and the multiplier will take away ~1.3V from this.
Furthermore, as long as the capacitors are appropriately rated, the circuit will work at any output voltage, as in normal operation the voltage across them cannot exceed a few volts. If the current demands are low enough, the 1k resistor can be increased, improving filtering.
If changes are needed I think they will be trivial.
- keantoken
Furthermore, as long as the capacitors are appropriately rated, the circuit will work at any output voltage, as in normal operation the voltage across them cannot exceed a few volts. If the current demands are low enough, the 1k resistor can be increased, improving filtering.
If changes are needed I think they will be trivial.
- keantoken
"You would need to get the right filament voltage beforehand" ... Do you meant this cap multiplier should be used after a voltage regulator ?
I have used cap multipliers in the past with spectacular results but I placed them before a 317 reg.
I have used cap multipliers in the past with spectacular results but I placed them before a 317 reg.
Since 317 regulators themselves are noisy, it makes much more sense to place the capacitance multiplier, which is quiet, after the regulator.
It looks to me that for heaters the above combo will do. The 317 voltage can be made to come up slowly, which is healthy for the tubes' heaters.
For audio circuits, the best possible combo will be 317 regulator followed by capacitance multiplier, followed by Salas Shunt Regulator.
So using the Salas shunt after the gyrator is the best choice.
We should not put anything after the shunt because we want to use it´s inerent low output impedance.
Series Reg (317) into CMX is basically a Teddy Reg - well developed designs on "Pinkfish Media" site.
Indeed. Adding a shunt after the TeddyReg, one will get what I believe is the best possible regulator for audio.
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