Simplistic MosFET HV Shunt Regs

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You did very well and you did not pull out the chokes. They pre filter the ripple and the RF. I have actually made it with some prefiltering in mind. Says rectified and filtered on the schematics. How many mA you run through the CCS right now? How is the sound?
 

iko

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Joined 2008
Something must be wrong with my shunt implementation. The amp draws 110mA at idle, without the shunt. With the shunt, it draws 115mA, and the LEDs are not on. I think I'll scrap it and redo a new one.

Built a mosfet Maida tonight; is it me or the sound is somehow dry with the Maida?
 
Yes Maida sounds dry to me too.

Same impression here after some listening...
Though sonics have improved over my previous CRCRC, especially in rendering 3D-space of the recording and localization of instruments.

Maybe I should also try an HV shunt for my Aikido? It needs about 55mA so we are talking 100mA through the shunt? I'll do some calculating (which is not much :D ) and will post a schematic...
 

iko

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Joined 2008
salas said:
Curiously in between mishaps you had a stint with the shunt working OK, didn't you? Your LEDs maybe not working if their tail resistor isn't enough for dissipation and burned.


Turns out that the irfp9240 was kaput, the resistor was fine. More experimenting needed. Interesting that your impression of the Maida was this. Asked my wife for an impression; she is very unbiased, as she couldn't care less what circuit is used. While listening to the mosfet Maida she said "I can hear so many details, and is kind of cold." It's probably the lm317.
 
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ikoflexer said:
It's probably the lm317.

It is. Although a Maida its the most economic and fast solution so to regulate, it lends the typical tone of a series op amp reg. I got much aware of that in phono stages. Battery was nothing to tell home about too. I normally don't go developing some new circuit if what I already have satisfies me. To the contrary, the shunt lends a natural, full, harmonically correct tone.
See what Cygnus x1 had to say in another thread. I guess I can not put it into words better than him.
 
I took my shunt reg from post #69 (meant for another headphone amp consuming approx. 38mA) and simply //ed 100ohm with the existing R1 of 33ohm (equals 24.5ohm).

Connected to the psu of my Aikido (luckily still on the breadboard...) and working against a ballast resistor first everything fired up smoothly, LED's lit and everybody happy ;) .
Upon start up voltage rised to a certain value and then gradually dropped about 10V, adjusting the trimmer showed reaction and I dialed in about 205V.

After about 10min. (and cause it was about to seriously toast the ballast resistor) I connected the reg to my circuit, and interesting things happened... After I powered up again everything seemed fine until my cheap testing 'phones began to generate chirping noises like an ill chicken... like chirp --- chirp --- chirp.
It eventually stopped more or less, but setting the voltage now doesn't seem to have much effect, and every time I put the probe on + it goes "chirp" again (one only :D ).

So obviously something's not right... oscillation?

Salas, can you chime in....again... :lifesavr: