DaveP said:The price of 6SN7 has got a bit silly, has anyone got any thoughts on using 6N7 for this app?
DaveP said:The price of 6SN7 has got a bit silly, has anyone got any thoughts on using 6N7 for this app?
When you know the tube runs with 5mA quiescent, you want the transformer to be specified for at least that, and the saturation current to be about twice. The output stage runs in class A so the peak current is about twice idle.Kingston said:How does one calculate the current the output transformer needs to handle? How is it in relation to the tube bias current?
That's the normal operating area.Also, that LL1680 has three separate current ratings, which one am I supposed to be looking at?
Recommended DC current (or Primary DC current for 0.9 Tesla): 5mA
You want the peak current the stage is capable of delivering to be less than that.Core Saturating DC current: 10mA
Not a normal condition. More than that and you fry the windings.Max standing DC current through any primary section: 50 mA
Amorphous metal is supposed to have superior magnetic properties. Some are evident, like lower losses, which have made them attractive for high-power transformers (I'm talking MVA's), hence have made the price drop consequently, making them somewhat less expensive than hi-Ni cores. Amorphous cores being superior for audio applications has not been demonstrated.Prices are not as exorbitant as I would have thought. about €90 for a standard model. But then €230 for "amorphous core" version, whatever that means.
abbey road d enfer said:You want the peak current the stage is capable of delivering to be less than that.Core Saturating DC current: 10mA
They have a softer curve, not as steep as non-gapped, but for a given voltage, distortion comes earlier, because the inductance is lower.Kingston said:abbey road d enfer said:You want the peak current the stage is capable of delivering to be less than that.Core Saturating DC current: 10mA
RE: distortion
I wonder if these air-gapped SE output transformers have a softer clipping/saturation point than non-gapped transformers.
has anyone got any thoughts on using 6N7 for this app?
But 40~18K Hz., <1dBu is not great
volker said:Not sure what the "current sourcing effects" are that you mention.
The advantages of a transformer are that gain is higher since the xfmr impedance is very high, supposed to be several times the actual load, and output swing is not limited to B+ because of the energy magnetically stored in the core.Kingston said:about SE output transformers in general,
how do they affect the tube curve in comparison to a simple plate resistor? Since the signal is formed directly across the transformer primary, will this have any plate choke like current sourcing effects making the plate curve more linear?
Is there any advantage in using SE output transformer other than not needing a plate resistor and a coupling cap?
when using an SE output transformer I still need to bias the tube optimally using datasheet plate curves. But what is the "plate resistor"?
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