5 : Excellent 4 : Good 3 : Average 2 : Bad 1 : Terrible

PSU for High end audio without electrolytic capacitors

Posted 13th February 2010 at 06:18 PM by Nazar_lv
Updated 1st April 2014 at 09:45 PM by Nazar_lv

---

From article https://s-audio.systems/diy/psu-without-electrolytic-eng
----------------------------------------------

Electrolytic capacitors are constant part of power supply of audio devices, but in terms of sound he does not bring anything good, dispersion of sound quality-type of electrolytic capacitor is very large. Sonically the best types of electrolytic caps are Nichicon KZ, FG, Panasonic Pureism, Black Gate FK, NX, Elna Cerafine, Silmic II, Silmic,but the attempt to eliminate from PSU electrolytic capacitors was very successful, instead is used "electronic capacitor" (right side of the circuit).
It is global negative feedback free electronic substitutes, that has a low and stable impedance 0,1...0,2Ohm (equivalent to cap 40000u) in the band to megahertz shunting NP0 0,1 microfarads Murata GRM31 in close to chips, it completely detach regulator (317\337) from load, therefore we have the ideal transient response when load "changes", and dont have noise and output impedance modulation. Output capacitors 0.1-10u SMD NP0/X7R is needed for HF bypass (>1Mhz), caps on 317/337 out (not less than 1u) is needed for 317/337 stability. R1-C3, R9-C7 forms LPF that eliminates HF noise produced by swithching of diodes working on cap filter.

Calculation of this schematic is not difficult, according to the desired output voltage and maximum output current calculate values of resistors R4, R6 and R2, R10, respectively, from the formulas below

R4=240*(Uout-Ueb) / 1.25
R2=(1,25-Ueb) / (0.3/Uout)+Iload
where Uout-output voltage V, Ueb-emitter-base voltage VT1, VT4 V, Iload- load current А.

This structure of regulator-"electronic capacitor"(follower) provides in a comparison with the best series audio electrolytic capacitors significantly better results.

-------------------
original article is here
Article, schematic etc. for DIY use only, completely or partially may not be copied, reproduced or published elsewhere without author's permission

Attached Thumbnails

 

Posted in Uncategorized

Views 19726 Comments 14

Comments

1. 	Good point but this is nothing new. It's also two different situations, low current and high currents.
   	Posted 15th February 2010 at 02:50 PM by peranders

2. 	what are you talking about?
   	Posted 15th February 2010 at 03:05 PM by Nazar_lv

3. 	Using a regulator is quite normal if the current is rather low and the purpose is to create a low output impedance in an artificial way using feedback and active devices. An another thing is to increase the PSSR. You have maybe heard of the super regulators and this approach make it possible (with fast devices) to get an extremely low output impedance high up in frequency.
   	Posted 15th February 2010 at 03:16 PM by peranders

4. All NFB regulators have inductive output impedance, placing electrolytic capacitor especially low-esr types creates a resonanses in output impedance (if the is yet a film or ceramic capacitor we will have more and stronger resonances). Impulse response to change the load current especially with low noise regs (M5230, M5290 etc) is very bad (one solution to this problem is use after regulator CRC filter,but it has its drawbacks), and output impedance and noise is a function of load current, as load changes noise and output impedance will be correlated with load changes (correlated to our music). Proposed schematic completely eliminates all problems with regulators and capacitors, and have stable resistive output impedance at frequencies up to 500-1000Khz (then the capacitive), stability of the output impedance at audio frequencies is a very important thing for sound quality and tonal balance.

   Posted 15th February 2010 at 05:10 PM by Nazar_lv Updated 15th February 2010 at 05:13 PM by Nazar_lv

5. 	The LM317/337 has negative feedback so I don't follow you completely.
   	Posted 16th February 2010 at 01:45 PM by peranders

6. 	of course LM317/337 has NFB, but load is not connected to 317 read carefully
   	Posted 16th February 2010 at 03:25 PM by Nazar_lv

7. 	Why do you insert a resistor and then increase the output impedance on purpose? Personally I prefer to have a low output impedance from deep bass and through the whole audio band up to MHz.
   	Posted 16th February 2010 at 03:33 PM by peranders

8. 	that resistor(R2,R10) and 317\337 has no relation to output impedance. In real world output impedance of power supply should not be above 5 ohms, 0,2ohm in this design is 20 times lower, it is important that the impedance was stable in the audio band. In this scheme is very simple to reduce the output impedance from 0,2ohm to 0,05ohm (also not introducing a global negative feedback)
   	Posted 16th February 2010 at 03:56 PM by Nazar_lv Updated 16th February 2010 at 04:01 PM by Nazar_lv

9. 	Hi.I have 4.7uf 40v ero 5mm mkt1826 4pcs of polyester capacitors.Can i use them?Is it good to use them instead of 100nf caps?Thanks
   	Posted 22nd October 2011 at 05:10 PM by umut1001

10. 	no, 100n is 1206 NP0 close to chips
    	Posted 23rd October 2011 at 09:53 AM by Nazar_lv

11. 	Hi Nazar, Maj I use these - ECHU1H104JC9 PPS Film Chip Capacitor 0.1uF @ Regards, Ignat
    	Posted 25th January 2012 at 05:52 PM by niamex

12. 	PCB Power Amplifier try RENKUS HEINZ-model P-1500
    	Posted 17th November 2012 at 10:53 PM by ricardo rocha

13. 	Hi I think elna silmic is the best capacitor for coupling and power without feedback and Elena silmic II Gives you a real voice ... Even for very good DAC The filtered voltage + wima mks4 + 10nf ceramic cap... tanks
    	Posted 13th August 2013 at 06:26 AM by afshindiy

14. 	Hi Nazar! What is the value of C3 and C7? Cheers!
    	Posted 19th April 2014 at 02:09 PM by flyboi

Nazar_lv

• Join Date Oct 2009
• Location Banderstadt
• Posts 210
• Blog Entries 5

• Blog Categories

  Local Categories

  • Uncategorized
• Recent Comments

  • PCM58, the best 18bit parallel DAC by miklos
  • PSU for High end audio without electrolytic capacitors by flyboi
• Recent Entries

  • "Nazar`s regulator", variants
  • First article about DEM (TDA1540, TDA1541)
  • PCM58, the best 18bit parallel DAC
  • MASH
  • PSU for High end audio without electrolytic capacitors
• Recent Visitors

  • BillBr
  • concker
  • DocTony
  • ermine22
  • Morde
  • sontero
  • tmsandj
  • trimer1
  • vlucian
  • zoranaudio