Mundorf M-Tube in Tube Amplifier Power Supply

Is anybody have experience using Mundorf M-Tube in tube amplifier power supply?
How do they compared to other capacitors like: ClarityCap  TC600, Audio Note Kaisei, Elna Cerafine?
I have used the Mtube as well as Clarity TCs and Elna’s The clear winner in overall performance are the TC caps. However, they are very large and require a huge chassis. I use the best 4 pole Kelvin style Clarity TC Caps.  They are simply the best cap I have used in my power supplies. Better than any electrolytic I have tried. Far more open, smooth, resolving and dynamic. I have not tried the Kaisei caps however.

The Mtube caps are my second choice thus far. They are not as good as the TCs, but in my experience a jump up in sound quality from Elna, Nichicon etc....
Hi @grannyring ,

Thank you for information.
How can you describe a difference between Mtube and Clarity TC?
Do Clarity TC have a better tone?
Many ears ago I tried to use Solen capacitors in power supply and I don't like synthetic tone of Solens compared to electrolytic capacitors like Nichicon.


I never liked the cheaper Solen caps as they sound rough and untidy if you will.  Clarity TCs are more refined and buttoned up then MTube caps. They have more top and bottom end extension and have a sense of ease and control that the Mtube can’t match. 
Thank you!
It looks like I can squeeze 50uF ClarityCap TC600 under the hood of my integrated amplifier.
Hi @grannyring ,

I installed two ClarityCap TC600 50uF capacitors (one per channel) to 300B B+ of my amplifier.
You can see it in my system pictures.
I didn’t remove old Nichikon capacitors I just put ClarityCap as bypass to Nichikons with 20 Ohm resistor for separation.
The sound (with zero break-in) is listenable, not bad at all.
The sound-stage on complex music is more stable. The instruments separation is better.
In general, amplifier is quitter.
High frequencies more extended, and detailed. Cymbals sound a little bit dirty. But flutes, violins sound more smooth. Bass has a more weight.

How much time takes break-in of ClarityCap TC600 ?


I guess I would have replaced the electrolytics and just used the Clarity. The mix may not sound as good as desired. The Clarity TC caps can replace electrolytics of much higher value. I would just remove the Nichicons from the circuit and go 100% Clarity TC for best sound.

Give the TCs some 150 hours to break in.

Hi @grannyring ,

Power supply CLC filter in my amplifier is one for both channels.   
I use 20 Ohms resistors to separate left and right channel B+.
Previously both channel B+s where the same point - the capacitor after the choke. 
After a break-in, I will try to remove Nichicons (and probably 20 Ohms resistors)  as you told.
I will check what does sound better for me.

I'm also thinking  about changing Nichicons in input and driver stages power supply to Munforf M-Tubes 30uF (I don't have enough space for ClarityCap T600 in my amplifier).

Hi @grannyring ,

Thank you for advice!

1. I run these new ClarityCap capacitors for 4 hours with Frubaby2 connected to amplifier input + 5 hour with normal music playing.
So far so good. The difference between ClarityCap T600 and Nichicons is very impressive! It is more significant than difference between Hashimoto vs James Audio output transformers!
High frequencies are very extended, detailed and smooth, bass is deeper and has more weight. Much more details, air and separation between musical instruments, bigger sound-stage. In general sound is more "analog" with less grain and haze. Image of musical instruments (like piano) are more stable and have more body.

2. Next step to remove Nichicons and 20 Ohm resistors between choke and ClarityCap (output B+).

3. After that, I will exchange Nichicons to Mundorf 30uf in driver B+ and input B+.
I need 4 capacitors (2 per each channel).

4. I know some people blame ClarityCap T and Mundorf M-Tube capacitors for bright and too analytical sound. But I think the issue is modern speakers with very bright tweeters that these people are using. They need amplifier with hazed, muddy high frequencies to make these speakers sound right.



I did  step 2 - removed Nichicon capacitors 2x100uF and 2x20 Ohm resistors (one resistor per channel) between choke and ClarityCap (output B+).
I don't like results. Bass become lightweight. As result too light tonal balance and
less information from lower mid-range to deep bass, less body of instrument.
Probably sound without  Nichicons a little more clean and airily, but the difference in very small.
Probably 100uF is not enough for 2x 300B tubes in class A with total idle current 130mA?  Before adding ClarityCaps output stage B+ capacitance was 200uF and when Nichicons and ClarityCaps were used together - 300uF .    
So, I going to return  Nichicon capacitors 2x100uF and 2x20 Ohm resistors back.

I'm not disappointed at all. It was a good experience for me.

I just added a scheme of power supply update and a general  scheme of my amplifier to "my system" page.
Nice work! I am sure your comments are spot on regarding your particular amps design and capacitance needs.  Always best to try and learn! Great job!
Hi @grannyring ,

I installed Mundorf 30uF Mtube capacitors in driver and input tubes B+ instead of old
100uF Nichicons.
The first impression was good - warm tonality, fast bass and micro-dynamics.
But now I recognize that my amp sounds too forward and too much emphasis mid-range and vocals. The high frequencies extension is not as god as in was with Nichicons too.
Does is a typical Mundorf Mtube sound or these capacitors need more break-in time?

Alex....since you are using a 4 poles type electrolytic caps.   The Clarity tc series are ok.  I strongly recommend the Jensen 4 poles.  In the 4 poles series ( Mundorf, Clarity, F&t, BHC, Sprague) the Jensen 4 poles IMHO is the best  electrolytic caps.  Better bass responds, more dynamic, transient, especially the sound stage, imaging will lock better.  Remember not all 4 poles are equal; i only recommend the 500volt +.   Happy Listening! 
Hi @zipost ,

Thank you for recommendation. Maybe I will try 4-pole Jensen later.

But what is wrong with Mundorf M-tubes?
There are polypropylene type two-pole type:
There are not the same to 4-pole Mlitics:

1.Probably 30uF capacitance is to low for 6f6g driver tubes?
2. Or probably capacitors need more break-in time?
3. Or it is these  capacitors specific sound signature that doesn’t much well to my system sound?

Which store does sale  4-pole Jensen now?
Part Conexions and Hificollective don't have them in stock.

Jensen do make the 50uf 550v, you can integrate it with your circuit.  I assume that this is the first cap on a clc designs.  Pm me if you have any questions.  
Funny, I found the Clarity TCs to sound the best by a good margin in my preamp builds. I suppose it comes down to use, design and preferences.  
I have not heard the Audio Note Kaiser, but read they are very good sounding. 
Hi @grannyring ,

Yes ClarityCap are great!
But I don't have enough space under the hood of my amplifier to put  ClarityCap in drivers (6f6g) and input (6sn7) tubes B+s.
So, I decided to try Mundorf Mtube 30uF capacitors in these positions. (I don't have space for bigger non electrolytic capacitors).
What I don't like in sound after installing Mundorf capacitors:
Images of instruments in sound-stage become too forward. I also feel that amplifier emphasis mid-range too much.

My thoughts and questions about it are:

1. A focus of instruments is not as stable as with 100uF Nichicons. So I think it is probably 30uF capacitance too low for 6f6g driver tubes?

2. Or probably, Mundorf Mtube capacitors need more break-in time? 

3. Or maybe, it is the specific sound signature of these capacitors that doesn’t much well to my system sound?


Hi @zipost ,

I use CLCRCRC filter: C1-L-C2-R1-C3-R2-C4
C1 is 30uF Mundorf polypropylene. I used it for many years and I like results. I don't want to use bigger capacitor because it is not good for my expansive GEC 5u4g.
C2 is 2x 100uF Nichicon - 300B output B+.  I used it for many years. Now I bypass them with 2 x50uF ClarityCap and I like result a lot!
C3 is 2x 30uF Mundorf polypropylene -  6f6 driver. (Previously I used  100uF Nichicon)
C4 is 2x  30uF Mundorf polypropylene - 6sn7 input.  (Previously I used 100uF Nichicon).

So, all my previous questions are about C3 and C4.

Alex...i pm and left you my recommendation.  it’s my opinion & how i would approach your diy 300b projects.  let me know if you have any questions. 
Bottom line, I didn't like the sound of my system with Mundorf M-tube capacitors.
So I returned Nichicons VZ(M) capacitors back.
I leaved one Mundorf M-tube  capacitors on position after rectifier tube, that I have used there for years.

First, the most important advantage of Nichicons capacitors is more organic sound.
More bass and treble extensions and more even sound without highlighting any frequencies.
They also have more natural tone.
On other hand Mundorf M-tube  capacitors have more energetic bass and a little bit more transparent sound. I don't like how  Mundorf M-tube capacitors emphases mid-range. The sound became not natural.

I lived ClarityCap in my amp. They work good in my amplifier.
I also recognized how is important to isolate B+ of output and driver and B+ of right and left channels.

Here is continue of the power supply capacitors story.

CalrityCap capacitors sound really impressive, they have some WOW factor. But I always had feeling of something artificial, like sound was processed by some studio equipment. There are a lot of air, extended high frequencies, smooth sound but I can hear a little bit plastic colors in tone. Other important drawback of CalrityCap - it give a very deep but diffused bass and on some records that kills a rhythm of music.

I decided to try power supply capacitors solution suggested by @zipost st. He suggested me to try AN Kaisei capacitor after the rectifier and Jensen 4-pole capacitors in 300B B+.
As result, I ordered both Kaisei and Jensen capacitors. I received Kaisei first and put it after a rectifier tube instead of Mundorf M-tube. After a short and not full break-in (10 hours with Frybaby2 on input of my amp) I did some comparison.
With Kaisei the sound become even more airy, smooth, with beautiful mid-range, big sound-stage, less plastic coloration. But mid bass punch was weaker compared to Mundorf and it doesn’t worked together with CalrityCap that also has a similar issue.
I think AN Kaisei is very similar to CalrityCap T600. It has extended, clear and smooth high frequencies, big sound-stage. The advantage of Kaisei is more natural tone. The advantage of CalrityCap is deeper bass.
Than, I installed Jensen 4-pole capacitors instead of CalrityCaps. Bass become more defined and punchy, with very good sense of rhythm, more natural tonal balance. Focus of instrument become much better. Details and separation were as good as with CalrityCaps.
But, some good things that CalrityCaps gave were lost: a lot of air and high frequency extension, big sound-stage, very smooth high frequencies. OK, we have take into account, that Jensen 4-pole capacitors haven’t passed a full break-in.

But I didn’t wait, and after some chat with @zipost I changed cathode resistors of 300b from 50 Watt metal body Mills to Ohmite Gold and constant resistor in my L-pad volume control from Shinkoh 0.5 Watt Tantalum to 2 Watt Audio Note Tantalum Silver. @zipost strongly recommended me to rid of from metal body Mills resistors and go to Ohmite Gold, and now I understand why. The bass became strong, dynamic, fast with a lot of weight, slam, texture. The overall sound became more mature, real!
I never compared directly cathode (auto) bias to fixed bias in the same amplifier, but sound with Ohmite Gold cathode resistors has all qualities that people usually associate with "fixed bias" sound.
2 Watt Audio None Tantalum Silver in volume control gave me high frequencies smoothness and detail clean and clear from any noise. Cymbals sound is extremely clear without dirt and distortion and well focused. Mid-range is very clear with a lot of small musical details and noticeably better musical flow.
Yes, the sound is still changing and improving. All new parts has to path a full break in. But so far, I’m impressed by results.

I would like to thank @zipost and @grannyring for help.
It was a very interesting experience to try all this great parts ( CalrityCaps T600, Jensen 4-pole and Kaisei capacitors, Ohmite Gold and AN Silver Tantalum resistors ) in my amplifier.


Hi @erik_squires ,
I run Clarity Cap about 20 hours of noise (Frybaby2 connected to my amplifier input).
Noise break in - is approximately 5-10 times faster than regular music playing break-in.
In addition to that I played about 20+ hours of music.
In comparison Jensen 4-pole had less break-in in my setup.
I don’t want to put tags - that this capacitor is good and that is bad. All these capacitors I used,
including Mundorf M-Tube, are very good. Just in each setup you need to find the right combination that will suite for your personal taste.

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I use CC TC600 in phono preamp power supply. I agree with everything you say. The odd thing was the plastic coloration seemed to disappear after about 25 hours. Nice system by the way. Sounds great. 
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