Winding a single secondary will not "increase" bass.
Bass performance in an output transformer is by inductive coupling, that is through the core.
A single secondary however will improve HF bandwidth compared to a tapped secondary because of the better capacitive coupling (all windings "used").
In my own output transformers I apply a different winding technique for multiple secondaries; these are without HF loss. Changing secondary impedance requires a bit of soldering instead of just connecting to another "tap".
Should we trust Mordan Jones when he writes stuff like this in his books?:
"The core of a poorly designed mains transformer can easily be saturated by the large current pulses drawn by a large resevoir capacitor...."
According to Faraday the flux density is related to the volt-seconds applied.
Well, I have some pretty nasty sounding 12AU7's, the best sounding variant being RCA 5814A TM BP.
jeff
As long as you don't mention the context of Morgan Jones' "stuff", YES we can trust him.
Constant magnetic field is generated by DC that is how all permanent magnets are working actually.
I must admit that my opinion regarding his book is exceptional good very straightforward and professional presentation of vital knowledges for a tube amp's designer.
On the practical side - yes I agree, I cannot see any reason to choose ECC82 over 6SN7.
On the theoretical side, it is worrying that MJ does not understand the basic physics of transformers: magnetic flux is related to volt-seconds and not to current. This is why we need a larger o/p transformer for higher output at lower frequencies.
On the theoretical side, it is worrying that MJ does not understand the basic physics of transformers: magnetic flux is related to volt-seconds and not to current. This is why we need a larger o/p transformer for higher output at lower frequencies.
MJ does not understand the basic physics of transformers?
Start learning yourself Dave, and start with Ohm's law....
Audio transformer theory does not cover all aspects; power supply transformers have their own issues.
This is correct:
Core Saturation - Transformers
"When a transformer's primary winding is overloaded from excessive applied voltage..."
Core Saturation - Transformers
"When a transformer's primary winding is overloaded from excessive applied voltage..."
That is a well known issue with SET where DC part of a class A amp output signal requires OT core being made larger with air gap to prevent saturation.
In a PP design magnetic field from a DC portion cancels each other.
Chokes and power trafos are SET OT's alike.
Well, apparently you did not read yourself the article you linked
Towards the end you read: ".....Yet another cause of transformer saturation is the presence of DC currrent in the primary winding.....".
Hundreds of autors will explain to you how current can saturate a core.
I advice, after you mastered Ohm's Law, to read a bit on the subject before posting.
Well, apparently you did not read yourself the article you linked
Towards the end you read: ".....Yet another cause of transformer saturation is the presence of DC currrent in the primary winding.....".
Hundreds of autors will explain to you how current can saturate a core.
I advice, after you mastered Ohm's Law, to read a bit on the subject before posting.
I would suggest you read the next sentence:
"Yet another cause of transformer saturation is the presence of DC current in the primary winding. Any amount of DC voltage dropped across the primary winding of a transformer will cause additional magnetic flux in the core."
Yes Ohm's Law applies - the DC voltage (small) dropped across the DCR of the primary winding (for a long time) is what cause the magnetic flux to increase.
...is an inevitable result of the current passing through the winding. Ohm's Law. And Ampere's Law.
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