Hi friends
I am trying to understand something
I have looked over the schematic of the mark levinson 33H the base resistors consists of thick film (matal glaze) TF-20 resistors rated at 1W
What was the thinking of the designer since when it comes to resistor noise thick film are worse than thin film and off course wirewound resistor.
The only thing that film resistors are superior are rise time and higher bandwidth.
But since we have Ayrton-Perry wirewound wich has high bandwidth and rise time close to film resistors...
Still why the use of thick film instead of wirewound? since the 33H should be statement amplifier cost no object.
Do anyone use vishay mills or other Ayrton-Perry resistor in the signal path and can give me his opinion???
God bless you all
Nehoray
I am trying to understand something
I have looked over the schematic of the mark levinson 33H the base resistors consists of thick film (matal glaze) TF-20 resistors rated at 1W
What was the thinking of the designer since when it comes to resistor noise thick film are worse than thin film and off course wirewound resistor.
The only thing that film resistors are superior are rise time and higher bandwidth.
But since we have Ayrton-Perry wirewound wich has high bandwidth and rise time close to film resistors...
Still why the use of thick film instead of wirewound? since the 33H should be statement amplifier cost no object.
Do anyone use vishay mills or other Ayrton-Perry resistor in the signal path and can give me his opinion???
God bless you all
Nehoray
What could to your opininion be the problem with these resistors.
Noise doesn’t play any role with 0.29nV/rtHz, way below the amp’s output noise of >1uV/rtHz.
Rise time and high Bandwidth are not important either for this application IMO.
And Dale RN resistors that ML normally uses are not available in 1 Watt version.
Hans
First of thank you for replying my post !
I do appreciate it a lot.
However I'm not electronic technician to know in which part of the amplifier noise does not play rule. I would be more than happy if you explain it a bit more.
However what I do know that everything is matter and there is a sound signature for each type off resistor and it's play a rule of what sound character the amplifier will sounds like.
However I have no doubt that engineering is much more important than silver resistor or other exotic components.
Yes you are absolutely right that mark levinson like to use dale RN resistors in his amplifier.
And I love those resistors basically RN resistors uses same as wirewound resistor Ni-Cr metals
Unlike metal glaze that uses silver- palladium
I have right now very expensive tube dac and I have play around with it by changing resistors types in a lot of places including silver tantalum
Old black mills..tkd correct ohm...amtrans amrg
And more
Different resistors sound so different
Really night and day difference.
Well that is raining a question why I have wrote this thread in the first place.
Well the 33H was a real dream of mine for more than 20 year. I have bought a pair recapping it
Modified it's power supply and it's sounds amazing. It has ability of almost perfect power source.
Some say it's a perfect amplifier since it's sounds not warm or not cold actually it has no character
What I do miss in this amplifier is a bit more warmth and romantic sounding.
I know that for example instead of those darlingtons was fets it would be much more warmer sounding but since I'm not going to change its design...
The only thing that I can think of is those silver palladium resistors that are in the signal path.
Thank you once again for replying my post
God bless you
Nehoray
I do appreciate it a lot.
However I'm not electronic technician to know in which part of the amplifier noise does not play rule. I would be more than happy if you explain it a bit more.
However what I do know that everything is matter and there is a sound signature for each type off resistor and it's play a rule of what sound character the amplifier will sounds like.
However I have no doubt that engineering is much more important than silver resistor or other exotic components.
Yes you are absolutely right that mark levinson like to use dale RN resistors in his amplifier.
And I love those resistors basically RN resistors uses same as wirewound resistor Ni-Cr metals
Unlike metal glaze that uses silver- palladium
I have right now very expensive tube dac and I have play around with it by changing resistors types in a lot of places including silver tantalum
Old black mills..tkd correct ohm...amtrans amrg
And more
Different resistors sound so different
Really night and day difference.
Well that is raining a question why I have wrote this thread in the first place.
Well the 33H was a real dream of mine for more than 20 year. I have bought a pair recapping it
Modified it's power supply and it's sounds amazing. It has ability of almost perfect power source.
Some say it's a perfect amplifier since it's sounds not warm or not cold actually it has no character
What I do miss in this amplifier is a bit more warmth and romantic sounding.
I know that for example instead of those darlingtons was fets it would be much more warmer sounding but since I'm not going to change its design...
The only thing that I can think of is those silver palladium resistors that are in the signal path.
Thank you once again for replying my post
God bless you
Nehoray
It is correct, that each part have it's own sound signature. With resistors, however, the differences are so small that one only notice them if one only use the best components of the rest (especially elcaps) and also a first-class design and perfect GND management.
This model has deficiencies somewhere - maybe in the circuit design, maybe in the GND management - I don't know.
Check out fig. 5 (distortion waveform at low speaker impedance) under
https://www.stereophile.com/content...monoblock-power-amplifier-measurements-part-2
found under
https://www.stereophile.com/solidpoweramps/115/index.html
I have heard first time this power amp on the High-End exhibition 1998 (Gravenbruch-Kempinski close to Frankfurt/Main) on large Avalon loudspeakers - sound character was a bit harsh and crispy. Some years later I have heard this M33 monaural amps on Wilson's Watt-Puppy V - go to
https://www.stereophile.com/content/wilson-audio-wattpuppy-system-5-loudspeaker-wattpuppy-51-upgrade
against Aleph 1.2 and Halcro's DM38 - go to
https://www.stereophile.com/solidpoweramps/1197pass/index.html
and
https://www.stereophile.com/solidpoweramps/1004halcro/index.html
Sound quality of this both power amps was better in all respects especially in the high frequency area.
This model has deficiencies somewhere - maybe in the circuit design, maybe in the GND management - I don't know.
Check out fig. 5 (distortion waveform at low speaker impedance) under
https://www.stereophile.com/content...monoblock-power-amplifier-measurements-part-2
found under
https://www.stereophile.com/solidpoweramps/115/index.html
I have heard first time this power amp on the High-End exhibition 1998 (Gravenbruch-Kempinski close to Frankfurt/Main) on large Avalon loudspeakers - sound character was a bit harsh and crispy. Some years later I have heard this M33 monaural amps on Wilson's Watt-Puppy V - go to
https://www.stereophile.com/content/wilson-audio-wattpuppy-system-5-loudspeaker-wattpuppy-51-upgrade
against Aleph 1.2 and Halcro's DM38 - go to
https://www.stereophile.com/solidpoweramps/1197pass/index.html
and
https://www.stereophile.com/solidpoweramps/1004halcro/index.html
Sound quality of this both power amps was better in all respects especially in the high frequency area.
Thank you for replying my post
God bless you
I have red all your comments
Frankly I don't have a problem with the high frequency
I have a problem that this amp has no character
Regarding what you have mentioned about that resistors have a small differences
If you have red my previous post above I have played with resistor in my tube dac and the difference was night and day
For example I have became aware that carbon film and carbon composite are not my cup of tea and those amtrans let me down big time
Silver tantalum is specific location was unbearable and in other locations was unbeatable.
If you looked good over the schematic that I have send we are talking about 80 resistors that in my opinion needed to be replaced. So I don't think that the sound will be minor.
Having said that I have looked over the old levinsons such as the 27 which known for its warmish sounding all those base resistors are RN65 and not the tf20 resistors
As you have mentioned... yes electrolytic caps in the power supply can change but bypass them with good mkp makes more change
I will never forget the day that I tried it over my previous amplifier mbl 9007
It has poor quality 4 33000uf
I have replaced them with good epcos 47000 each
To tell you the truth it was waste of money
But when I bypassed each one with mundorf 4.7uf Supreme silver oil my jaw dropped I was in real shock it was night and day.
But still I can't forget the amp that was before the 9007.
It was mbl 8011 It didn't had the speed of the 9007 or the resolution but it has sweet tube harmonic sounding and that is what I'm trying to achieve or at least close to it.
God bless you
I have red all your comments
Frankly I don't have a problem with the high frequency
I have a problem that this amp has no character
Regarding what you have mentioned about that resistors have a small differences
If you have red my previous post above I have played with resistor in my tube dac and the difference was night and day
For example I have became aware that carbon film and carbon composite are not my cup of tea and those amtrans let me down big time
Silver tantalum is specific location was unbearable and in other locations was unbeatable.
If you looked good over the schematic that I have send we are talking about 80 resistors that in my opinion needed to be replaced. So I don't think that the sound will be minor.
Having said that I have looked over the old levinsons such as the 27 which known for its warmish sounding all those base resistors are RN65 and not the tf20 resistors
As you have mentioned... yes electrolytic caps in the power supply can change but bypass them with good mkp makes more change
I will never forget the day that I tried it over my previous amplifier mbl 9007
It has poor quality 4 33000uf
I have replaced them with good epcos 47000 each
To tell you the truth it was waste of money
But when I bypassed each one with mundorf 4.7uf Supreme silver oil my jaw dropped I was in real shock it was night and day.
But still I can't forget the amp that was before the 9007.
It was mbl 8011 It didn't had the speed of the 9007 or the resolution but it has sweet tube harmonic sounding and that is what I'm trying to achieve or at least close to it.
I have no idea what you dislike on the distortion figures, way lower than the Pass Aleph.
You must be aware that this amp has in fact two amps connected in bridge, thereby canceling all even harmonics.
And the speaker has no ground connection because of that.
Mind you, Nelson Pasd has a ML 33 by himself.
Hans
Sorry, which fig 5 are you referring to ?
Read this, it will confirm my words.
https://www.stereophile.com/solidpoweramps/115/index.html
Hans
Read this, it will confirm my words.
https://www.stereophile.com/solidpoweramps/115/index.html
Hans
Fig 5 of Measurement part 2.
As also stated in the measurement part 2:
Don’t get what you are trying to tell, that it isn’t a bridged amplifier, or that the distortion sucks ?
When looking at fig 9 you will see that the distortion in fig 5 is 0.009%, so what ?
Fig 6 tells that at 50Hz 200Watt distortion in mainly third harmonics.
This is simply one of the best amps ever made.
Hans
When looking at fig 9 you will see that the distortion in fig 5 is 0.009%, so what ?
Fig 6 tells that at 50Hz 200Watt distortion in mainly third harmonics.
This is simply one of the best amps ever made.
Hans
From Stereophile:
Comparing the two best amplifiers I've ever heard to one another, I reckon one has to be better. But if I seem uncomfortable in proclaiming the Levinson to be better than the Krell, I am—until I heard the No.33H, I never would have guessed the FPB 600 had an equal. These two amps are so close in character that another listener could very easily call it the other way. I can't imagine anyone being less than satisfied with either. Yet to my ears, no matter how slightly, the No.33H sounded like the better amp.
Comparing the two best amplifiers I've ever heard to one another, I reckon one has to be better. But if I seem uncomfortable in proclaiming the Levinson to be better than the Krell, I am—until I heard the No.33H, I never would have guessed the FPB 600 had an equal. These two amps are so close in character that another listener could very easily call it the other way. I can't imagine anyone being less than satisfied with either. Yet to my ears, no matter how slightly, the No.33H sounded like the better amp.
Dear Hans
I have made this test before I have purchased my 33H
The levinson sound smoother and more musical
The krell was faster and with better bass slam
Personally I prefer the levinson.
And nowadays it's sound better than ever.
Besides recapping it, I have changed the old rectifier diode to ultrafast soft recovery vishay for the input power supply.
And as for the output power supply I have change the the rectifier diode to the mur7040
Since it's 140A rectifier and it's so massive
I let myself to go even crazier. All the power supply capacitors that sitting on the current gain board next to the output transistors
Instead of the original 330uf chemi-con
I install mundorf 1500uf
Now it feels that it has effortless dynamics
I have made this test before I have purchased my 33H
The levinson sound smoother and more musical
The krell was faster and with better bass slam
Personally I prefer the levinson.
And nowadays it's sound better than ever.
Besides recapping it, I have changed the old rectifier diode to ultrafast soft recovery vishay for the input power supply.
And as for the output power supply I have change the the rectifier diode to the mur7040
Since it's 140A rectifier and it's so massive
I let myself to go even crazier. All the power supply capacitors that sitting on the current gain board next to the output transistors
Instead of the original 330uf chemi-con
I install mundorf 1500uf
Now it feels that it has effortless dynamics
Attachments
BTW
I have made a test with the mbl 9007 that I gave to my brother
I have changed it's output rectifier to cree zero recovery SIC diodes and is by far the best diodes that I have use for amplifier output sound so dynamic and explosive. Better low end control.
Unfortunately there isn't any SIC diodes in DO-05 case otherwise I would install them in the 33H
If you aware of any please let me know
I have made a test with the mbl 9007 that I gave to my brother
I have changed it's output rectifier to cree zero recovery SIC diodes and is by far the best diodes that I have use for amplifier output sound so dynamic and explosive. Better low end control.
Unfortunately there isn't any SIC diodes in DO-05 case otherwise I would install them in the 33H
If you aware of any please let me know
Distortion into lower impedance load shown on fig 5 which is dominant 2nd but you insist that even harmonics are cancelled. Confusing.
Agree, never question about this.
Last edited:
To answer your question, compare the bridged distortion to a single channel in the amp.
For 200Watt into 2R see image below, a simulation of the 33H showing the bridged output's distortion in Blue and a single channel's distortion in Red.
Be aware that in the sim both channels are 100% identical, but the smallest differences will let the even harmonics rise.
Hans
For 200Watt into 2R see image below, a simulation of the 33H showing the bridged output's distortion in Blue and a single channel's distortion in Red.
Be aware that in the sim both channels are 100% identical, but the smallest differences will let the even harmonics rise.
Hans
Attachments
That is because in tube amps voltages are much higher.
And the higher the voltage on a resistor, the more it's voltage dependent distortion is coming into play.
In a transistor amp, the highest voltage in the signal chain usually comes on the feedback resistors, therefore being the most critical resistors in the amp.
The base resistor you are referring to have to handle substantial currents but never more than 1Volt, therefore totally uncritical and even then, because sitting at the end of the chain, reduced by the amp's substantial loop gain.
Warmth of sound usually means lots of even harmonics, can be very agreeable, but it adds something that was not there in the first place.
Apart from feedback resistors, I don't think that will improve anything on the Dale's.
Hans
High THD value can sound very good as long only low order components present - extrem low THD value can sound bad - e.g. harsh and sharp in the upper frequency range - if only high-order components present.
Therefore THD-N value isn't for me of interest in order to get best sonic quality - only the waveform of distortion (fundamental notched out) is crucial for me, which sound character is to be expected.
Check out in this case this thread:
https://www.diyaudio.com/community/...st-possible-thd-n-really-the-best-way.367692/
and post #22 under
https://www.diyaudio.com/community/...usical-fidelity-a1.398447/page-2#post-7334213
Of course, this statement is not true for electronic music and hard techno beats so as rock/heavy metal.
Sorry to say, but the text you wrote is so totally unfounded and completely besides truth.
Let’s finalise by agreeing that we won’t be able to agree.
Hans
Let’s finalise by agreeing that we won’t be able to agree.
Hans
Dear Hans
I have red your comment
Please inlight my eyes
If you look over the schematic of the current gain you will see that the tf20 resistors starts even at the beginning of the schematic (driver stage if I'm not mistaken) so there is a chain of those resistors uses. (Open it by pdf and search tf20 and you will see the chain I'm talking about)
However by your last reply I understood that those resistors need to pass substantial amount of current and low current noise resistor is needed
Further more when it comes to current noise as long as the value of the resistor is decreases the current noise increases.
And those values are very low 1R and 5R
In that case don't you think that ayrton-perry wirewond resistors are superior by their low noise?
Your reply will be much appreciated
God bless you
Nehoray
I have red your comment
Please inlight my eyes
If you look over the schematic of the current gain you will see that the tf20 resistors starts even at the beginning of the schematic (driver stage if I'm not mistaken) so there is a chain of those resistors uses. (Open it by pdf and search tf20 and you will see the chain I'm talking about)
However by your last reply I understood that those resistors need to pass substantial amount of current and low current noise resistor is needed
Further more when it comes to current noise as long as the value of the resistor is decreases the current noise increases.
And those values are very low 1R and 5R
In that case don't you think that ayrton-perry wirewond resistors are superior by their low noise?
Your reply will be much appreciated
God bless you
Nehoray