Hello,
Don't seem to find much info on this.
I'm currently using shunt regulators (in combination with serie regulators) as PSU for my preamp. As the dissipation is too high for me to feel comfortable I was wondering to maybe leave this out. According to LTspice, it has no added value in suppresion below 1Khz.
Shunt current is 75ma, load current is 160mA (with max ripple of 2mA).
As I have 4 of these shunt regulators, it saves me more than 8W on dissipation.
What is a good rule of thump of the factor between shunt and load current, to have decent added value of the shunt regulator?
Any references to read?
Thanks
Ben
Don't seem to find much info on this.
I'm currently using shunt regulators (in combination with serie regulators) as PSU for my preamp. As the dissipation is too high for me to feel comfortable I was wondering to maybe leave this out. According to LTspice, it has no added value in suppresion below 1Khz.
Shunt current is 75ma, load current is 160mA (with max ripple of 2mA).
As I have 4 of these shunt regulators, it saves me more than 8W on dissipation.
What is a good rule of thump of the factor between shunt and load current, to have decent added value of the shunt regulator?
Any references to read?
Thanks
Ben
Attachments
Easy. Leave it out. Shunt regs can be fine for low current applications but become extremely inefficient and provide no benefit over a straight linear solution at more than a few tens of mA or so.
Recommendation from the Salas's UltraBiB shunt regulator build guide is that shunt should drain minimum 50 -100 mA over peak output current.
https://www.diyaudio.com/community/threads/salas-sslv1-3-ultrabib-shunt-regulator.322411/
IMO, it is not best option to supply such fine design as is Blowtorch preamplifier from the capacitance multiplier stage as a final stage of an overcomplicated PS. Capacitance multiplier has high output impedance and relies on output capacitor performance. Better option would be to supply preamplifier from the shunt output.
I would use Salas UBIB shunt or Jung-Didden super regulator. They bot have >120 dB ripple reduction and extremely low output impedance and noise across complete audio frequency band.
https://www.diyaudio.com/community/threads/salas-sslv1-3-ultrabib-shunt-regulator.322411/
IMO, it is not best option to supply such fine design as is Blowtorch preamplifier from the capacitance multiplier stage as a final stage of an overcomplicated PS. Capacitance multiplier has high output impedance and relies on output capacitor performance. Better option would be to supply preamplifier from the shunt output.
I would use Salas UBIB shunt or Jung-Didden super regulator. They bot have >120 dB ripple reduction and extremely low output impedance and noise across complete audio frequency band.
Ha, many including me would disagree. Shunt regulators are fantastic solution below 1 A, efficiency be damned. 🙂
I see shunt voltage regulator as a, sort of, push-pull regulator. It can source and sink current at its output. Usual series voltage regulator can’t deal efficiently with any back EMF from a reactive load, which would bring voltage at the regulator output above set point. Any sinking will be done only by small output capacitor and not by active regulator circuit. That makes distinctive difference in transient response.
I just dissabled the function of the shunt (opening the 4k4 resistor, see schematic), result: soundwise I don't seam to notice difference. Noise wise: with my ear to the woofer, I hear a hiss which was not there when the shunt regulator was active.
Jung-Didden, 🤔, I have a few boards laying, bud these are for 15V output voltage. I need about 27...30V output voltage. Let's see if I can figure out how to increase the output voltage and not blow up the opamp (AD825's). https://www.diyaudio.com/community/threads/super-regulator.247281/page-76#post-5282055
30V should be OK for AD825. Datasheet recommends +/-15 which of course is 30V, abs max is 36V.
Jan
Jan
Tandem regulators afford you the best of both worlds, without the excessive dissipation and the benefit of synergy
You have put a lot of effort, accompanied with great craftmanship, to build a no compromises preamplifier. Really great job. 👍
Few unfortunate component choices undermined final result. I don’t know if transformers are salvageable, but for a replacement I can recommend Toroidy audio grade. They are absolutely noiseless and have excellent performance. I notice that you have put great care to suppress any HF junk noise coming from the mains (transformers choice + 3 stage voltage regulators). Toridy audio grade have electrostatic screen between primary and secondary windings that shunts HF noise to the ground. Two 60 VA transformers with dual 30 V secondaries would be fine. As an example, here is PS noise measurement from my preamplifier which has Toroidy 60 VA transformers and Salas’ UBiB shunt regulators. All HF noise is at nV levels and visible peaks are from laptop internal switching PS circuits and from the USB. Checking up to 96 kHz, there is nothing above 100 nV level.
EDIT: this was meant to be posted in the other thread:
https://www.diyaudio.com/community/threads/silent-transformers-for-use-in-preamp.391955/
Few unfortunate component choices undermined final result. I don’t know if transformers are salvageable, but for a replacement I can recommend Toroidy audio grade. They are absolutely noiseless and have excellent performance. I notice that you have put great care to suppress any HF junk noise coming from the mains (transformers choice + 3 stage voltage regulators). Toridy audio grade have electrostatic screen between primary and secondary windings that shunts HF noise to the ground. Two 60 VA transformers with dual 30 V secondaries would be fine. As an example, here is PS noise measurement from my preamplifier which has Toroidy 60 VA transformers and Salas’ UBiB shunt regulators. All HF noise is at nV levels and visible peaks are from laptop internal switching PS circuits and from the USB. Checking up to 96 kHz, there is nothing above 100 nV level.
EDIT: this was meant to be posted in the other thread:
https://www.diyaudio.com/community/threads/silent-transformers-for-use-in-preamp.391955/
Last edited: