@tubes4all, but 0.07 mm instead of 0.5 mm would make it look a lot worse than it really is from the core loss perspective. I don't need to read better. Who is the troll?
In the article they are considering the loop at 100Hz for 1.6T in 2 quadrants. The example with HWR core 90/44 at 100Hz for 30W output signal, Bac is less than 0.15T in one quadrant and far away from any sign of saturation. At 1W it becomes tiny.....0.022T!!!!
In the article they are considering the loop at 100Hz for 1.6T in 2 quadrants. The example with HWR core 90/44 at 100Hz for 30W output signal, Bac is less than 0.15T in one quadrant and far away from any sign of saturation. At 1W it becomes tiny.....0.022T!!!!
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Guys this is actually a great conversation, and I would really, really like to see it continue. A bit of friendly advice would be to moderate the tone a bit. There is a lot of expertise here, and experts don't always agree, maintaining civility despite significantly different view points is key.
Also I don't see much if any evidence of trolling here, so it would be great to see less name calling, and more acceptance that participants may have differing (and possibly incompatible) viewpoints about the matter being discussed.
And finally there is the ignore option, should you not be able to find any other way to participate respectfully.
This is a great opportunity for many of us who are interested and don't have a lot to say, let's keep it going. 😀 😀
Also I don't see much if any evidence of trolling here, so it would be great to see less name calling, and more acceptance that participants may have differing (and possibly incompatible) viewpoints about the matter being discussed.
And finally there is the ignore option, should you not be able to find any other way to participate respectfully.
This is a great opportunity for many of us who are interested and don't have a lot to say, let's keep it going. 😀 😀
This thread is now reopened. One member has been banned for inappropriate use of the forum, and several posts have been removed for being off topic or personal.We would now like to see this sanitised thread stay that way.
I don't have much expirience with nano comparing with the silicon steel, I wonder if someone could inlight on the subject.
Just talking about the core material.
Just talking about the core material.
Marek, the CC400 core is too big. One SET CC-320 is sufficient. At the moment, I'm using a single Nanocrystal CC-200 with a 211 tube at 55mA, but using double CC-200 would work perfectly with GM70. I have used in 211SET full power, with a perfect sound
You should check the airgap; nobody knows the properties of your core. Please refer to the picture bleow, but it should be less than 0.3mm.
For me, the important thing about this core is:
Nanocrystalline core output transformers have a wider and more linear frequency response.
They also have low distortion, resulting in more accurate and natural sound reproduction. Thanks to their improved performance in high and low frequencies, nanocrystalline transformers can provide increased resolution and transparency in reproducing subtle details and nuances of music.
However, this transparency has the drawback that the entire amplifier design must be developed around this transformer core. I'm not sure if using silver wire is a good idea with this core.
The power supply (PSU) and signal stages all need to be designed specifically for this transformer, otherwise it can lead to fatigue.
OPT GM70, > 60H and P/S > 28. Like many friends here, I prefer more load than less.
You should check the airgap; nobody knows the properties of your core. Please refer to the picture bleow, but it should be less than 0.3mm.
For me, the important thing about this core is:
Nanocrystalline core output transformers have a wider and more linear frequency response.
They also have low distortion, resulting in more accurate and natural sound reproduction. Thanks to their improved performance in high and low frequencies, nanocrystalline transformers can provide increased resolution and transparency in reproducing subtle details and nuances of music.
However, this transparency has the drawback that the entire amplifier design must be developed around this transformer core. I'm not sure if using silver wire is a good idea with this core.
The power supply (PSU) and signal stages all need to be designed specifically for this transformer, otherwise it can lead to fatigue.
OPT GM70, > 60H and P/S > 28. Like many friends here, I prefer more load than less.
It's quite the inverse, nanocrystalline cores have a worse frequency response potential than their HiB GOSS alternatives for the same Afe. The reason for this is the lower saturation flux density and lower stacking factor. These require a higher amount of turns to achieve the same power output and Idc vs L capabilities.
Considering flux density formulas are linear, I find it appropriate to calculate the core potential by multiplying the stacking factor difference with the max flux density difference. If we take 1T and 0.78 stacking factor for nanocrystalline, compared with 1.6T and 0.93 SF for HiB,
the potential factor should equal (1.6 / 1) x (0.93 / 0.78) = 1.9 times worse power capabilities potential than its HiB counterpart. This of course is a rule of thumb formula of mine.
The HF extension should be indifferent of the core choice, as interleaving takes cares of the HF behavior.
Considering flux density formulas are linear, I find it appropriate to calculate the core potential by multiplying the stacking factor difference with the max flux density difference. If we take 1T and 0.78 stacking factor for nanocrystalline, compared with 1.6T and 0.93 SF for HiB,
the potential factor should equal (1.6 / 1) x (0.93 / 0.78) = 1.9 times worse power capabilities potential than its HiB counterpart. This of course is a rule of thumb formula of mine.
The HF extension should be indifferent of the core choice, as interleaving takes cares of the HF behavior.
Also, Celsius, what is the primary DC resistance of your 211 OPT? You should have a rather large number of primary turns to reach the required inductance on the smaller core, also to stay well below max flux density.
What is the primary inductance of your OPT?
What is the primary inductance of your OPT?
50AE: this is my next step with HIB C core, now I am looking the source. 😉
Well theory is the beginning if follow the theory you finish with a Solid Stage amp. I do not listen numbers, the sound of the Nanocrystalline is very very detailed. and yes to the rest I agree with you, bigger size is mandatory. all cores have their sound signature, is one stage more.
Daanve:
DCR
Monolith Magnetic 8.5k 240R
Lundalh LL9202 11k >1000R
My OPT
C Dual core 14k 168R 100mA
C Single core 14k 122R 50mA ( 211 low power my favourite )
But in all cases, the transformers made by 50AE are really very good maybe one the best, follow this link where 50AE explain very good
https://www.diyaudio.com/community/...ussion-on-winding-output-transformers.310327/
This is a good threads,
Well theory is the beginning if follow the theory you finish with a Solid Stage amp. I do not listen numbers, the sound of the Nanocrystalline is very very detailed. and yes to the rest I agree with you, bigger size is mandatory. all cores have their sound signature, is one stage more.
Daanve:
DCR
Monolith Magnetic 8.5k 240R
Lundalh LL9202 11k >1000R
My OPT
C Dual core 14k 168R 100mA
C Single core 14k 122R 50mA ( 211 low power my favourite )
But in all cases, the transformers made by 50AE are really very good maybe one the best, follow this link where 50AE explain very good
https://www.diyaudio.com/community/...ussion-on-winding-output-transformers.310327/
This is a good threads,
Ok, but a real 14k OPT requires more inductance (over 100H).
Also, I don't believe your single core transformer to be able to handle the anode swing for 15 watt which a 211 is capable of.
Also, I don't believe your single core transformer to be able to handle the anode swing for 15 watt which a 211 is capable of.
I have been looking a bit more at these nanocrystalline cores since this thread started. I have figured out a nice PP transformer for myself.
For SE I think FeSi C-cores are more convenient but effective permeability is not very different respect to FeSi cores of identical size once a good sized airgap is installed. As @50AE mentioned is all about lower induction and lower stacking factor.
DC resistance is not a problem at all even if 15W and nominal 100H are the target on CC-200 double core. This would require some 5600 primary turns with 0.8mm airgap (0.4 mm spacer) at 55 mA. Using 150 turns for the secondary it would result in a 11K/8R with 400R primary resistance and 0.23R secondary. It could be 24 primary layers using 0.28mm double insulation wire for the primary and 18 secondary layers all in parallel with 0.455 mm double insulation for the secondary plus 0.08 NOMEX between layers and 0.23 NOMEX between primaries and secondaries. 233-234 turns for each primary layer and 150-151 turns for each secondary layer. The total Rdc referred to the primary equates to 720R which is 6.5% of 11K. Total induction for 15W at 30Hz would be just over 0.9T. Pretty good!
As always, the main problem by far would be the geometry for good frequency response....more likely vertical sectioning will be required. So the calculation above needs to be re-adjusted to take into account the space robbed by the vertical spacers.
With FeSi a smaller core could be used to get the same numbers or the same size with less turns and more freedom for the geometry. However given the size of a 211 I don't think the double CC-200 would look too big....
For SE I think FeSi C-cores are more convenient but effective permeability is not very different respect to FeSi cores of identical size once a good sized airgap is installed. As @50AE mentioned is all about lower induction and lower stacking factor.
DC resistance is not a problem at all even if 15W and nominal 100H are the target on CC-200 double core. This would require some 5600 primary turns with 0.8mm airgap (0.4 mm spacer) at 55 mA. Using 150 turns for the secondary it would result in a 11K/8R with 400R primary resistance and 0.23R secondary. It could be 24 primary layers using 0.28mm double insulation wire for the primary and 18 secondary layers all in parallel with 0.455 mm double insulation for the secondary plus 0.08 NOMEX between layers and 0.23 NOMEX between primaries and secondaries. 233-234 turns for each primary layer and 150-151 turns for each secondary layer. The total Rdc referred to the primary equates to 720R which is 6.5% of 11K. Total induction for 15W at 30Hz would be just over 0.9T. Pretty good!
As always, the main problem by far would be the geometry for good frequency response....more likely vertical sectioning will be required. So the calculation above needs to be re-adjusted to take into account the space robbed by the vertical spacers.
With FeSi a smaller core could be used to get the same numbers or the same size with less turns and more freedom for the geometry. However given the size of a 211 I don't think the double CC-200 would look too big....
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Good design, but indeed HF bandwidth will be the challenge.
My 211 OPT had about double Afe and 3440 primary turns.
Experimenting with sectioning and interleaving thickness it hardly hit -2 dB at 20 kHz.
You would do well with -3 dB @ 20 kHz.
My breadboard build was EL34 - 1:1 IT - Elrog 211 (1000V@60mA).
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daanve: Thank you for your attention. Personally, I appreciate enlightening threads or ones with good intentions. If all the questions are ultimately meant to call someone foolish, I don't see the usefulness in that.
But in all cases mi answer is : P/S 38 ( 8ohm) with 60H give around -0.7db at 20hz as I said before for my personal speaker is ok, NOT FOR COMMERCIAL USE
well maybe open a new discussion about how many watts do you need, for my 96db I run 211 over 12w maybe a little less.
follow with Marek :
for GM70 I think that dual CC-200 is ok. P/S 27 ( 8ohm ) over 60H but never is a problem bigger only for my bones.
I don't know your experience but is easy to have mistakes and begin to winds again, and again, and again.
I have a 1000 turns bobbin to check permeability same times each core give different measures.
But in all cases mi answer is : P/S 38 ( 8ohm) with 60H give around -0.7db at 20hz as I said before for my personal speaker is ok, NOT FOR COMMERCIAL USE
well maybe open a new discussion about how many watts do you need, for my 96db I run 211 over 12w maybe a little less.
follow with Marek :
for GM70 I think that dual CC-200 is ok. P/S 27 ( 8ohm ) over 60H but never is a problem bigger only for my bones.
I don't know your experience but is easy to have mistakes and begin to winds again, and again, and again.
I have a 1000 turns bobbin to check permeability same times each core give different measures.
Celsius, when discussing 211 OPT's I think it is important to indicate the individual application.
211 tube has ~ 15 watt output power; when you use it in a lower power mode, and you get away with 60H that is OK but it is not representative for a mature 211 OPT.
My remarks were not meant to call someone foolish; I hope that's behind us in this thread 😉
211 tube has ~ 15 watt output power; when you use it in a lower power mode, and you get away with 60H that is OK but it is not representative for a mature 211 OPT.
My remarks were not meant to call someone foolish; I hope that's behind us in this thread 😉
I am not sure about GM70 never have been in my target but I have read Monolith Magnetic OPT data
Primary load 6100 Ω
Winding ratio (4/8 Ω ) 39.05 / 27.56
Bandwidth (-3 dB @ 1W, sec. grounded) 7 – 103,000 Hz
Core saturation 22 Hz @ 30W rms
Primary inductance 45 Hy
Primary DC resistance 188 Ω
Not very difficult, but 30w at 22hz need a lot of iron 🙂
daanve: Thanks for your reply. I never see threads as a competition, but as a way to share knowledge.
Primary load 6100 Ω
Winding ratio (4/8 Ω ) 39.05 / 27.56
Bandwidth (-3 dB @ 1W, sec. grounded) 7 – 103,000 Hz
Core saturation 22 Hz @ 30W rms
Primary inductance 45 Hy
Primary DC resistance 188 Ω
Not very difficult, but 30w at 22hz need a lot of iron 🙂
daanve: Thanks for your reply. I never see threads as a competition, but as a way to share knowledge.
GM70 capable to load even 6k.
At 1.1kV/100mA operating point the estimated power about 30W/about 5% THD/.
It seems like a good project. 24 layer for PP maybe 6 primary groups
Nanocrystalline material just needs a little more iron. Today, after our chat I checked my small OPT CC200 and found that it saturates the core at over 4W at 35hz gap 0.4mm, while the same core made of amorphous material works correctly at 10W.
For larger loads, using nanocrystalline material becomes more complicated due to the size. However, this core with 300B is one of the best ones I've listened to.