sala shunt
Hi Salas!
I want Salas shunt for my DAC, you can hepl me on cricuit??
I use: +- 5v!
Thank you very much
))))))
Yes, we must've posted in the same time! LOL!
Hi Salas!
I want Salas shunt for my DAC, you can hepl me on cricuit??
I use: +- 5v!
Thank you very much
Hey Salas, I missed that question.
According to the manual current draw is:
...for each channel.
I'm hoping I'll be able to fit in the case a bipolar set of regulators for each channelt (4 regs in total) but I'll probably start with one set for both channels first and see how it goes.
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Good luck.
Another Salas Simplistic Shunt!
Up and running this afternoon, so I'll leave it on for a couple of days, so that it feels at home, before I have a serious listen.
Set for 5V, using a 4V7 zener, and gives 5.06V out. Volts drop across the current set resistor is 1.9 Volts-ish, and the resistor is 10R2, so roughly 190mA.
This will be powering Vd of my B32, but will soon have the parts on the way for the two 15V supplies.
Once I've had a good listen, I'll report back!
Thanks again, Salas and Ikoflexer
Up and running this afternoon, so I'll leave it on for a couple of days, so that it feels at home, before I have a serious listen.
Set for 5V, using a 4V7 zener, and gives 5.06V out. Volts drop across the current set resistor is 1.9 Volts-ish, and the resistor is 10R2, so roughly 190mA.
This will be powering Vd of my B32, but will soon have the parts on the way for the two 15V supplies.
Once I've had a good listen, I'll report back!
Thanks again, Salas and Ikoflexer
Attachments
Nicely done!
Now that you have it working, there are two things you can do to improve performance by quite a bit. First, use a quieter reference. If you could see the noise coming out of the zener, you wouldn't hesitate. This mod addresses the zener noise which is amplified by the bjt that drives the shunt mosfet. A 1000uF across the zener will decrease the noise, but it's still there. For 5V you can use two 2V LEDs and a diode.
Second improvement can be had by using a super-beta bjt to drive the shunt mosfet, such as mpsa18.
Now that you have it working, there are two things you can do to improve performance by quite a bit. First, use a quieter reference. If you could see the noise coming out of the zener, you wouldn't hesitate. This mod addresses the zener noise which is amplified by the bjt that drives the shunt mosfet. A 1000uF across the zener will decrease the noise, but it's still there. For 5V you can use two 2V LEDs and a diode.
Second improvement can be had by using a super-beta bjt to drive the shunt mosfet, such as mpsa18.
Splendid advice, you seem to know how to appeal to me!
I have two 2.4V leds sorted out, and ready to drop, but will be having a listen to the base version first. I also have a bag of MPSA18 from another project, which I can use.
When it comes to the hfe of the bjt, how high is too high? I ask as I do not want to get in osciallation. The BC550C I'm using at the moment is about 520ish, which was the lowest in the bag.
With this version, which we call v1, there is little chance of oscillation. The mpsa18 will have quite a bit higher hfe than the bc550c, and it didn't oscillate for me. But it's easy to try and see for yourself.
A third improvement, use as small an output cap as you can get away with, and short, thick, cables to the load. The best is to have no output cap, but that leads to oscillation sometimes.
I think you have enough tweaks now to keep you busy for a while. Let us know your impression once it settles a bit.
A third improvement, use as small an output cap as you can get away with, and short, thick, cables to the load. The best is to have no output cap, but that leads to oscillation sometimes.
I think you have enough tweaks now to keep you busy for a while. Let us know your impression once it settles a bit.
Just use 2X2.2 Vf leds and jumper the rest. In what position and for what circuit it sounds good? Can you expand on what you compared it with? Thanks.
Another Salas Simplistic Shunt!
Up and running this afternoon, so I'll leave it on for a couple of days, so that it feels at home, before I have a serious listen.
Set for 5V, using a 4V7 zener, and gives 5.06V out. Volts drop across the current set resistor is 1.9 Volts-ish, and the resistor is 10R2, so roughly 190mA.
This will be powering Vd of my B32, but will soon have the parts on the way for the two 15V supplies.
Once I've had a good listen, I'll report back!
Thanks again, Salas and Ikoflexer
Nice p2p straight DIY work. Will be nice to have a concrete opinion about its suitability for 5V digital. About higher Vout analogue its adequate. Thanks, and we see forward for your reports.
Iko, do you see any extension in the phase turn onset frequency in hf with the MPSA18 in your sim on V1 VS 550C?
Sorry guys, I just got home from an extended trip to Ikea
salas, not only in the HF; the output impedance becomes lower (by some amount) from low to high freq.
As far as which version, for those who are wondering, it's your choice. Tham has tested both v2 and v1.5, and many others have been testing v1.
Here's a summary of what's going on in this thread for some time.
shunt regulator v1
* very hard to get this one wrong, and very hard to make it oscillate
* low noise (find the lowest noise zener and bypass it with a 1000uF electrolytic
* excellent ripple rejection and very good output impedance across the audio range
* there are variations for high current or low current
* has been built and tested by many
shunt regulator v1.5
* reasonably stable
* using n-channel mosfets
* low noise, exc. ripple rejection, and low output
impedance extended to higher frequency; flat output impedance and phase plot across the audio frequency
* built by me and one other member; so, not so extensively tested
* low or high current
shunt regulator v2
* like v1.5, but even lower output impedance all across
* stable as long as one is careful about details (uses RF transistors)
* built by me
* ripple in the order of 10-30uV, difficult to measure
Tham, it would help other members here to hear what your subjective experience with these different versions is.
Also, if anyone else has built any of these, please come back with a little feedback (doesn't matter if it's negative or positive), you'll help everyone. If negative, we can fix what's wrong. If positive, others will get inspired, and we'll get encouraged to make it even better.
I've looked at a lot of regulators and I can tell you, we have some winners here.
salas, not only in the HF; the output impedance becomes lower (by some amount) from low to high freq.
As far as which version, for those who are wondering, it's your choice. Tham has tested both v2 and v1.5, and many others have been testing v1.
Here's a summary of what's going on in this thread for some time.
shunt regulator v1
* very hard to get this one wrong, and very hard to make it oscillate
* low noise (find the lowest noise zener and bypass it with a 1000uF electrolytic
* excellent ripple rejection and very good output impedance across the audio range
* there are variations for high current or low current
* has been built and tested by many
shunt regulator v1.5
* reasonably stable
* using n-channel mosfets
* low noise, exc. ripple rejection, and low output
impedance extended to higher frequency; flat output impedance and phase plot across the audio frequency
* built by me and one other member; so, not so extensively tested
* low or high current
shunt regulator v2
* like v1.5, but even lower output impedance all across
* stable as long as one is careful about details (uses RF transistors)
* built by me
* ripple in the order of 10-30uV, difficult to measure
Tham, it would help other members here to hear what your subjective experience with these different versions is.
Also, if anyone else has built any of these, please come back with a little feedback (doesn't matter if it's negative or positive), you'll help everyone. If negative, we can fix what's wrong. If positive, others will get inspired, and we'll get encouraged to make it even better.
I've looked at a lot of regulators and I can tell you, we have some winners here.
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