| ja2dhc |
Does someone explain the difference of sonics between
ORIENTED core and Not-ORIENTED core of Output
Transformers with E-I shape core. |
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| oldeurope |
Hello ja2dhc
More Henry at same size.
Kind regards,
Darius |
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| Doug Kim |
Sonics still same?
Doug |
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| EC8010 |
| A grain oriented core (such as a C-core or a toroid) will saturate more sharply than a non-oriented core (such as an EI core). |
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| Tweeker |
Cores (for audio and power transformer applications) mostly use Grain Oriented Silicon Steel. C-core and toroids have all of the flux parallel to the grain, whereas the is not the case in some regions of the EI.
Non oriented steels have lower saturation density, although this is improving. These steels are often used in motors. |
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| ja2dhc |
| quote: | Originally posted by Tweeker
whereas the is not the case in some regions of the EI.
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Thanks Tweeker. That point is my concern. What is the
impact to sonic caused by this irregular flux path ? |
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| Geek |
Hi,
| quote: | Originally posted by ja2dhc
Thanks Tweeker. That point is my concern. What is the
impact to sonic caused by this irregular flux path ? |
I have taken a professionally wound bobbin and filled it with M4, M6 and some garbage from a cheapo-of-el-cheapo power tansformer.
Above 100Hz, I couldn't hear much difference and above 1KHz, none.
Below 100Hz, BIG difference. M4 was clean and full, M6 tight, but not as deep and the garbage was... well... garbage.
I have no idea if this helps, just the results of an impromptu bench test :)
Cheers! |
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| richwalters |
Commercial good quality stuff M6, the BH curve hasn't really improved for decades.
Quote:- Below 100Hz, BIG difference. M4 was clean and full, M6 tight, but not as deep and the garbage was... well... garbage.
No not really, when iron gets close to saturating on the BH curve the 2nd harmonic becomes dominant and the MI industry knows that lower fundamental lower f1 notes can't be reproduced on smaller bookshelf systems. So 2nd harmonic sounds with fuller bass on small box LS systems. Result, big bass extension systems can often sound too heavy reproducing both harmonics. One have it both ways but one needs to back off on the bass control.
E&I cores saturate smoothly as permeability is higher due to inherent airgaps within stacking laminations. An advantage with p-p tube o/p trannies as out of balance currents can be tolerated without performance problems.
Not all CD's and sound source studio techniques are uniform. The music market assumes most listeners have smaller bookshelf systems.
true/false ?
Question:-
How may audioforum users have bass speaker systems i.e 5Cuft (140Lit) or larger that can get down to 25Hz ?
richj |
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| kevinkr |
| Pair of 11 cu ft bass modules.. Usable output down to about 35Hz.. (Jensen Ultraflex/Onken) Dropping rapidly below 30Hz... |
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| EC8010 |
| My last loudspeakers were transmission lines that had a bit of a bump at 20Hz. The new loudspeakers will be open baffles and will fall away at 18dB/oct from 40Hz; I'm hoping the lower Q resonance will be better. |
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| smoking-amp |
"How may audioforum users have bass speaker systems i.e 5Cuft (140Lit) or larger that can get down to 25Hz ?"
Use two speakers in the cabinet, one sealed in front of the other, and drive the back one with a little more signal so the front one is unloaded on its back side. Then stuff the back chamber with a dense wet honeycomb of paper soaked with a fluorocarbon fluid that vaporizes/condenses at room temperature.
Don |
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| EC8010 |
| quote: | Originally posted by smoking-amp
"How may audioforum users have bass speaker systems i.e 5Cuft (140Lit) or larger that can get down to 25Hz ?"
Then stuff the back chamber with a dense wet honeycomb of paper soaked with a fluorocarbon fluid that vaporizes/condenses at room temperature. |
Won't the nitrile rubber surround dissolve? |
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| Tweeker |
| quote: | | Thanks Tweeker. That point is my concern. What is the impact to sonic caused by this irregular flux path ? |
I cannot speak to the sonic differences solely attributable to the difference in core shape. I can say an EI needs about 20% more material to carry the same power due to it. However, once the EIs limits are nearing, it does saturate more gradually. Another major variable here is the air gap. C and EI cores always have one, C cores must be ground and assembled with much care if it is to be minimized. Toroidal transformers can be built without one, giving much lower leakage and more inductance, however, there is no free lunch, it also makes them very sensitive to current imbalance, DC. Some toroids for use in audio sometimes have a distributed air gap.
Toroids have much to recommend them in applications where you can be sure there is no DC, such as in SRPP or parafeed OPTs. |
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| SY |
| quote: | Originally posted by EC8010
Won't the nitrile rubber surround dissolve? |
Can't remember who it was, but someone came out with a fluid like that enclosed in a bag, suitable for stuffing into a speaker box. |
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| dave slagle |
| quote: | Originally posted by Tweeker
Another major variable here is the air gap. C and EI cores always have one, C cores must be ground and assembled with much care if it is to be minimized. Toroidal transformers can be built without one |
While this is technically true in that a gapless toroid core could be assembled from stamped O's of material, the typical tape wound method of assembling a toroid still has a gap. I'll admit that it is effectively quite small but it is still there.
dave |
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