can explain better ?
Is that pressure band on side cores going inside?
That is a shorted turn... :-(
You need to align pressure band parallel to winding loops to make shorted turn. Right now it works as expected.
I really had to commend you for the above comment, my first thought upon seeing that picture. I have darker thoughts which I will not share here.. Some reputable transformer vendors actually do get custom bobbins and cores made for their products. And I agree with your comments on core area/magnetics etc as well. Nice to see a nice rational post here once in a while.
That needs some clarification.
In Europe we have actually four standard ranges of c-cores: SM, SG, SE and SU.
SM, SG and SE are double core / single bobbin configurations.
SU is single core / dual bobbin (configuration used by Lundahl).
For a specific audio transformer it is not difficult to select the right core(s) when you know what is needed in terms of power and winding space.
For example:
SM85b and SG89/29 are both rated for 160 watt / 50 Hz (M6), however SM85 has some 50% more core weight and only halve the winding space.
Most important property of the SE series (not so different from SG otherwise) is that the same bobbins can be used as for EI, so an SE150a bobbin will fit an EI core with 41,2 mm stacking height.
I agree that the three core Audionote is poor engineering.
Tango had a U-808 "budget" output transformer which was EI.
About all high quality Japanese audio transformers are wound on c-cores, and for a reason.
Every time someone mentions Bob Carver, this picture pops into my mind. Thanks for putting a smile on my face today.
If those Monoliths are anything like my S-833 Monoliths they will have GREAT bass. Those things shake the walls with ease, all the way down to sub-sonics.
<picture snipped>
Every time someone mentions Bob Carver, this picture pops into my mind. Thanks for putting a smile on my face today.
I had to laugh as well! I was less than impressed with the amplifier in person. It was certainly imposing in a way, it sounded muscular, but not my cup of tea.
Obviously the nightmare with the big Carvers was re-tubing. I gave up on 300bs as soon as I discovered that 4P1Ls sounded great as output tubes. Re-tubing was just so expensive, and the lifetime of 300bs wasn't as good as that of the 4P1Ls anyway. Re-tubing with 4P1Ls is the job of a few dollars. I have 150. It's not even an issue. You can't own a tube amp without re-tubing. It's an expense that has to be factored in because it will happen.
Hello!
It seems that a lot of theoretical talking has taken place in the last time
Here is an practical example of a pure 300B amplifier with one of the candidates discussed:
VinylSavor: Custom 300B Amplifiers
Should be a classical core.
It seems that a lot of theoretical talking has taken place in the last time
Here is an practical example of a pure 300B amplifier with one of the candidates discussed:
VinylSavor: Custom 300B Amplifiers
Should be a classical core.
Another beautifully done amplifier from Thomas. No mention was made on the transformer, so according to MM the core could be: "a high grade SiFe or Metlas amorphous dual C-core..."
Maybe I have missed something in the thread but everyone is only talking about core losses and behaviours on a theoretical basis. The title is about single ended amps. Here we have a magnetization due to the current that should change a lot concerning the magnetization curves and also the structure of distortions - or not?
Hello everyone,
I am an unconditional power triode is my Blogg: Officina Tron-audio Switzerland
you will find a section with DIY describing a multitude module dedicated to audio.
as here for a dedicated driver Mu-Follower: Officina Tron-audio Switzerland: Pilote Mû Follower for Single-End
or here with the project description 300B Officina: Officina Tron-audio Switzerland: Projet 300B Officina
I let you watch and read. If needed if you want more information you can contact me via blogg or so more directly here: antony.turchi@tron-audio.ch
Best regards. Tony
I am an unconditional power triode is my Blogg: Officina Tron-audio Switzerland
you will find a section with DIY describing a multitude module dedicated to audio.
as here for a dedicated driver Mu-Follower: Officina Tron-audio Switzerland: Pilote Mû Follower for Single-End
or here with the project description 300B Officina: Officina Tron-audio Switzerland: Projet 300B Officina
I let you watch and read. If needed if you want more information you can contact me via blogg or so more directly here: antony.turchi@tron-audio.ch
Best regards. Tony
I find the theoretical discussions very useful indeed. On the one hand we want subjective opinions, because few of us are in a position to compare several OPTs to each other. When we are spending hundreds of euros/dollars we want as much information as possible.
But on the other hand, we need this kind of theory on amorphous cores, for instance, and what kind of bass losses and/or treble gains we might expect. I think the last lot of posts on this have been very helpful.
What I see from my point of view is that for single ended amps the core stays magnetized 100% of the time because of the permanet current. So, what about zero flux conditions? These seem to be not so relevant for SE amps as the core stays in a more or less linear region of the curve. Maybe the experts can say more about this.
Do we really need such cores like finemet which are designed for true high frequency apllications in SE amplifiers? I doubt, but I think the market crys for them as exclusive is often more interesting.
Do we really need such cores like finemet which are designed for true high frequency apllications in SE amplifiers? I doubt, but I think the market crys for them as exclusive is often more interesting.
Docali take a read of this thread: P-SET EL34.
It gets interesting especially when smoking-amp pops in (#23); he has some good clarifications.
Finemet cores are not designed for SE amplifiers as none of the high quality materials are; audio is simply not interesting for industry to develop. We pick what is available.
In my opinion Finemet does make sense, also in a SE application because it simply sounds better than silicon steel; it also outperforms amorphous in permeability.
Audiophiles continue to call these better materials "boutique"; better to say that the modern materials like amorphous and Finemet are currently state-of-the-art and silicon steel is "yesterday".
Please note that with good quality silicon steel (HiB; thin laminate) very good transformers can be made, but the modern materials can take the quality a step beyond.
It gets interesting especially when smoking-amp pops in (#23); he has some good clarifications.
Finemet cores are not designed for SE amplifiers as none of the high quality materials are; audio is simply not interesting for industry to develop. We pick what is available.
In my opinion Finemet does make sense, also in a SE application because it simply sounds better than silicon steel; it also outperforms amorphous in permeability.
Audiophiles continue to call these better materials "boutique"; better to say that the modern materials like amorphous and Finemet are currently state-of-the-art and silicon steel is "yesterday".
Please note that with good quality silicon steel (HiB; thin laminate) very good transformers can be made, but the modern materials can take the quality a step beyond.
Thanks Pieter for the link.
You say "modern materials can take the quality a step beyond" But, what are the objective metrics that can be measured with some device that supports this in the audio range?
We can see examples of vendors having their transformers with diffenrent core materials while not changing the remaining design (assuming that). What is the metric which shows us the difference?
If I remeber numbers for frequency response metrics well the traditional core is better especially in the low frequency region.
You say "modern materials can take the quality a step beyond" But, what are the objective metrics that can be measured with some device that supports this in the audio range?
We can see examples of vendors having their transformers with diffenrent core materials while not changing the remaining design (assuming that). What is the metric which shows us the difference?
If I remeber numbers for frequency response metrics well the traditional core is better especially in the low frequency region.