How much gain in sound quality from upgrading the power supply in an headphone amp ?
Aug 8, 2015 at 9:29 AM Thread Starter Post #1 of 9

ginetto61

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Hi !
i have a weird question.  I wonder how much can be gained in sound quality by replacing caps in a power supply of an amp with better quality ones, and maybe a little bigger.
The amp in question is a Schiit Audio Magni 2 (not Uber).
I like extremely the amp ... is very very nicely built and cute.  Much smaller than what i imagined.
And also i like its sound through my k501 that i use for their nice midrange.
The caps to be replaced are these ones in the picture:
 

 
Looking inside better i see 2 fixed 15V regulators ... 
 

 
So i guess the circuit works with a dual +/-15VDC 
Could it be beneficial to bypass the regulators on board and provide the pcb with very very clean +/-15VDC from a high quality external ps ?
Leaving maybe 2 Nichicon FG caps 25V/2200uF as a buffer inside the chassis ?  
I believe in the importance of a very clean low noise power supply. 
Could i gain something in noise reduction, dynamics, or whatever ?
Thanks a lot and kind regards,
gino
 
Aug 8, 2015 at 6:55 PM Post #2 of 9
If the regulation is on the inside of the amp - as you point out, then, no - you're not going to notice much, if any improvement with an external power supply.  You might if you resorted to a true, audiophile linear-regulated power supply with ripple performance down into the microvolts.  However, to utilize that kind of quality power supply, you couldn't simply plug it in like another walwart.  You'd have to find out on the PCB where the linear regulation feeds into the rest of the PCB and tie the power supply into that section rather than plug it in from the outside.
 
Silk purse out of a sow's ear?  Sorry, but the analogy is probably pretty close.  The Magni is so inexpensive already that anything you mention is really outside of the bounds of practicality.
 
 
P.S. You're not going to have any kind of audible difference by upgrading the caps, either - even less so than if you figured out how to sandwich in a better external power supply. 
wink.gif
 
 
Aug 9, 2015 at 3:20 AM Post #3 of 9
If the regulation is on the inside of the amp - as you point out, then, no - you're not going to notice much, if any improvement with an external power supply.  

 
Hi and thanks a lot for the very kind and valuable advice.
I have already discovered one issue.   The AC adapter coming with the Magni 2.   It is a transformer from 220 VAC to 14 VAC.  
The Magni is connected now to the stereo outs of my tv for some break-in.   I switched off the Magni with its switch and this caused a big transient noise in the tv.
Conclusion ... the supplied ac adapter has very bad isolation.   The transient caused by switching off the Magni arrived unsuppressed to the tv directly 
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I am sure that a better transformer can give some benefits.
 
2nd point yes.  The regulation is inside the amp and does not look high end. The idea would be to provide the needed +/-15VDC from an external high quality power supply, bypassing completely the internal rectification and regulation stages. 
 
You might if you resorted to a true, audiophile linear-regulated power supply with ripple performance down into the microvolts.  However, to utilize that kind of quality power supply, you couldn't simply plug it in like another walwart.  

I agree. I am thinking a completely new power supply and ditching the ugly ac adapter that i am using now. 
 
 You'd have to find out on the PCB where the linear regulation feeds into the rest of the PCB and tie the power supply into that section rather than plug it in from the outside.

I have been not clear in my 1st post. This is indeed what i would like to do.
I have seen some preamps with separate power supply 3 wires umbilicals feeding the circuits.  
The point where to feed is easily found ... the two caps after the regulators ... 
 

 
i can replace them with two Nichicon 25V/2200 uF to create a buffer. They will act as power reservoirs close to the circuit. 
 
 Silk purse out of a sow's ear?  Sorry, but the analogy is probably pretty close.  The Magni is so inexpensive already that anything you mention is really outside of the bounds of practicality.  P.S. You're not going to have any kind of audible difference by upgrading the caps, either - even less so than if you figured out how to sandwich in a better external power supply. 
wink.gif
 

 
This is where i am not so sure.   I can tell you that i have the strong feeling that the Magni circuit is very very good. The sound in the midband is good.
But before messing with the internals i think i will try a much better transformer ... the supplied one must be ****. 
A better transformer will provide better isolation from the mains and hopefully will have lower impedance secondaries (the current will flow better) and better regulation (not that i believe that the Magni needs lot of current ... but better more than less).
Unfortunately 16VAC is not a common value.  
 
I wonder if this amp can be powered with VAC different from the 16VAC like written on the back. If there is a range of VAC i mean.
For instance ... would 20 VAC too much ?   
because i have already a very good quality transformer .... i could swear about its quality.  
It provides great isolation from mains and it is quite powerful indeed (i.e. 25VA).
 

 
So to end all my ramblings 1st move will be to try a much better transformer (or AC adapter as they say) and do not touch anything inside.
 
After that 2nd step would be to study the possibility to use an external very high quality dual power supply +/-15VDC (i will have to make a hole for the 3 wire umbilical cable). A solution like this one here for instance with an xlr power cable feeding the Magni.
 

 
http://forum.audiogon.com/cgi-bin/fr.pl?rprea&1202765651
 
Thanks a lot again.
Gino
 
Aug 9, 2015 at 8:17 AM Post #4 of 9
You're headed down the wrong road.  An AC adapter is perfect for the Magni since dual regulation is onboard.  It ensures that the highest voltage is available to the amp and all of the quality is completely controlled from the inside on the PCB.  Isolation is already present if the AC walwart is separate and away from the amp.  Besides, a turn-off transient means nothing with respect to the amp or the quality of its power supply.
 
Let me state it more clearly: you are better off searching for a better amp than anything you propose.  It's not going to make a noticeable difference unless you're interested in a placebo.
 
Aug 10, 2015 at 7:37 AM Post #5 of 9
Hi and just a question ... then why the Uber version ?
the two circuits looks the same to me. 
I am sure that even just a recapp of the power supply with something better will improve sound. 
Clearly you do not like modifications ... that is fine.
I had the opportunity to listen to a cd player before and after modding ... there was simply no comparison.
I was amazed ... and that experience told me that modding can do amazing things.
Regards, gino 
 
Aug 10, 2015 at 8:36 AM Post #6 of 9
  Hi and just a question ... then why the Uber version ?
the two circuits looks the same to me. 
I am sure that even just a recapp of the power supply with something better will improve sound. 
Clearly you do not like modifications ... that is fine.
I had the opportunity to listen to a cd player before and after modding ... there was simply no comparison.
I was amazed ... and that experience told me that modding can do amazing things.
Regards, gino 

 
Uhhhhhhhhhhhhh you are talking to someone who does a lot of diy amp stuff. That guy def knows his stuff and is no stranger to modification. 
 
The issue with any audio device is there are times when good capacitors are absolutely crucial, and there are times when you should not even bother. 
 
Capacitors in the power delivery system of an amplifier only need to be of good quality. They do not and should not be audio grade capacitors. If anything you would want to use low tolerance Panasonic caps or something along those lines.  
 
The only thing you can hope to achieve by modding the power caps in this case is maybe a quieter sound stage and a cleaner sound in general. But we are talking less than a 5% improvement. 
 
-----------------------------
 
I would also be willing to bet that the CD player you listened to was not using audio grade caps for the power system. If the power capacitors were swapped it was probably because the guy felt like if he was replacing the audio caps that he might as well do the power caps as well. 
 
If that were the case, I can almost promise you he used low tolerance caps in the power system. Using something like nichicon FG caps would just be stupid. 
 
------------------------------
 
And the magni 2 uber just uses slightly different parts and just puts out a bit more power. That is it. 
 
Aug 10, 2015 at 9:19 AM Post #7 of 9
Uhhhhhhhhhhhhh you are talking to someone who does a lot of diy amp stuff. That guy def knows his stuff and is no stranger to modification. 

 
Hi and of course i did not mean to offend anyone.
However, as a principle, ANY unit can be improved. And in particular cheap units that are the result of some kind of comprimise to keep the price down.
A good pot costs like the all Magni 2.
Let me state again that as i see an UBER version of the Magni 2 i have the strong feeling that the basic version can be improved.  
A better pot, a better power supply .... these come to my mind.
 
 The issue with any audio device is there are times when good capacitors are absolutely crucial, and there are times when you should not even bother. Capacitors in the power delivery system of an amplifier only need to be of good quality.
They do not and should not be audio grade capacitors. If anything you would want to use low tolerance Panasonic caps or something along those lines.  
The only thing you can hope to achieve by modding the power caps in this case is maybe a quieter sound stage and a cleaner sound in general. 

 
And this is exactly what i am looking for.   I do not have at hand instruments to measure the noise.  But i am more than sure that replacing the power supply on board with something really serious and external can make a difference ... audible difference. This can also be seen in some high end preamps for instance like the Threshold but many others have separate power supplies. And of course very low noise ones. 
 
 But we are talking less than a 5% improvement. 

this is open to discussion ... like we cannot quantify the sound quality we cannot quantify improvements.
I believe in measurements ... unfortunately i have not seen any on the Schiit Audio.  But better parts can only be better ... if you replace a cap with a better one you cannot get a worse sound.
 I would also be willing to bet that the CD player you listened to was not using audio grade caps for the power system. If the power capacitors were swapped it was probably because the guy felt like if he was replacing the audio caps that he might as well do the power caps as well. 

I canot tell what they did.  The sound was amazing.
 
If that were the case, I can almost promise you he used low tolerance caps in the power system. 

It is not only a problem of tolerance ... but lower impedance, ESR, etc.   a better cap is a better cap in general.
And some are so much better that they become object of cult like the Siemens Sikorel now Epcos. 
The power supply is very important always.  Like the exact transformer used.  
 
 Using something like nichicon FG caps would just be stupid. 

 
so you mean that who use them is stupid ? or just a marketing play ?
i have been recommended these caps here on this site by some members.  I would bring them in but it will be OT i guess. 
The FG cost quite more than the basic version ... there must be a reason and they sell them quite well also. 
 
And the magni 2 uber just uses slightly different parts and just puts out a bit more power. That is it. 

One thing i know for sure, looking at the pics. It uses a different  pot and some more caps in the PS.
I was worried about the pot being noisy but it seems ok ... no noise and not big unbalance.
I will try with the transformer and the ps caps ... and then listen 
In this way i will not modify the unit substantially.
One thing about price.  
The web is full of reviews about units performing like other units 2, 3 times their price.
This adds to confusion ... which is for instance the 200 USD headphone amp of reference ?
What means a unit performing at the 80% of a reference unit ?
they are just chit chat showing the huge confusion around.
I prefer to talk about good sounding units and worse sounding units.
The Magni 2 is already good sounding to me.  
If you take it and., as an example, replace the necessarily cheap pot with a high quality attenuator of same value you cannot make things worse.  it is impossible. 
And the sound will be surely better ... how much better ?   6-7%  at least  
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wink.gif

 
Thanks again.
gino 
 
Aug 11, 2015 at 12:07 AM Post #8 of 9
 
If that were the case, I can almost promise you he used low tolerance caps in the power system. 

It is not only a problem of tolerance ... but lower impedance, ESR, etc.   a better cap is a better cap in general.
And some are so much better that they become object of cult like the Siemens Sikorel now Epcos. 
The power supply is very important always.  Like the exact transformer used.  
 
 Using something like nichicon FG caps would just be stupid. 

 
so you mean that who use them is stupid ? or just a marketing play ?
i have been recommended these caps here on this site by some members.  I would bring them in but it will be OT i guess. 
The FG cost quite more than the basic version ... there must be a reason and they sell them quite well also. 
 
 

 
The poster was trying to explain this to you, but you missed it. 
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  Power caps are different than audiophile caps.  Fundamentally, electrolytic capacitors sound like cr*p in the signal path.  So certain electrolytic capacitors are made and classified as "audio grade."  They've been optimized to sound good, nothing more.  In fact, if you look up the data sheets for audio-grade electrolytic capacitors, you will very often find that ESR and ripple current is not even specified.  Why? Because the ratings are often terrible.  Even the most rudimentary power cap will often have better ESR and ripple current ratings than an "audio-grade" electrolytic.
 
Nichicon FG, ES, and KZ caps (there are others) are audio-grade caps.  Most likely, you would be swapping out better performing power capacitors for something worse if you used FG's.
 
Aug 11, 2015 at 4:08 AM Post #9 of 9
  The poster was trying to explain this to you, but you missed it. 
wink.gif
  Power caps are different than audiophile caps.  Fundamentally, electrolytic capacitors sound like cr*p in the signal path.  So certain electrolytic capacitors are made and classified as "audio grade."  They've been optimized to sound good, nothing more.  In fact, if you look up the data sheets for audio-grade electrolytic capacitors, you will very often find that ESR and ripple current is not even specified.  Why? Because the ratings are often terrible.  
Even the most rudimentary power cap will often have better ESR and ripple current ratings than an "audio-grade" electrolytic. 
Nichicon FG, ES, and KZ caps (there are others) are audio-grade caps.  Most likely, you would be swapping out better performing power capacitors for something worse if you used FG's.

 
Hi and thanks and ok ... i was completely missing this.
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  And  I am sincerely shocked 
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I was sure that the FG had better ratings ... if not why other people use them to get the best sound ???  i am honestly confused.
They are quite more expensive that normal series. 
So you say that normal caps are better than FG in a power supply ?  i should have known that before putting them in my usb to spdif converter.
It was a mod highly recommended here in another thread.
Ok ... i will fix my attention on transformers ... i would like to use one of the kind used by Schiit in the Asgard .... 
 

 
but i would never solder a transformer on the same pcb of circuits ... never in the world.
Impressive the amount of capacitance .... and they look of the same series of the Magni 2
If the Asgard were not so hot i would buy it.  I can stand the hot. 
Cold and good sound is possible ... so why go hot ????
Thanks again.
I am really puzzled by this caps story ... 
Regards, gino  
 

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