John Curl's Blowtorch preamplifier part II

[SY]

If you want to be a pedant, it's actually "Sveriges riksbanks pris i ekonomisk vetenskap till Alfred Nobels minne." But I'm sure you weren't.

[gk7]

I don´t want to be a pedant ;-) but probably Alfred Nobels familiy is. From the Wikipedia article you linked in your post:

"Some critics argue that the prestige of the Prize in Economics derives in part from its association with the Nobel Prizes, an association that has often been a source of controversy. Among them is the Swedish human rights lawyer Peter Nobel, a great-grandson of Ludvig Nobel. Nobel criticizes the awarding institution of misusing his family's name, and states that no member of the Nobel family has ever had the intention of establishing a prize in economics."

[simon7000]

Well they do call you from Stockholm to tell you that you have won. (The call begins "This is the long distance operator calling from Stockholm..,") which is a bit different from the others sometimes. But you still get it at the same awards ceremony and are treated to all the same formalities.

Interestingly enough Herbert (78) and John (94) at one time lived about 3 blocks away from each other. Both would walk down the hill to what is now Carnegie Mellon.

Even as an undergrad John was a bit strange. The movie doesn't quite get his stomp right or his devotion to his always present attache case. It does illustrate his drinking.

[john curl]

I hope that Ed Simon or Rick Miller will give us further thoughts on power supply design. They both have worked on improvements to power supplies, and I trust that they have more to contribute.

[Jakob2]

Originally Posted by Nelson Pass

If you have any mismatch between the secondary coils with a common
ground, the core will tend to saturate when the amplifier is delivering DC
or low frequencies. The result is mechanical noise that critical customers
will complain about. Dual bridges and isolated secondaries avoid this issue.

Not to mention that the magnetic field radiated from the transformer will increase and will "look" much more nastier if the core approaches saturation.

So it might not only be a mechanical noise problem if any susceptible receiver loops are waiting.

[bcarso]

Originally Posted by Jakob2

Not to mention that the magnetic field radiated from the transformer will increase and will "look" much more nastier if the core approaches saturation.

So it might not only be a mechanical noise problem if any susceptible receiver loops are waiting.

Yes, absolutely, and the nasties will propagate much better.

[SY]

Originally Posted by john curl

I hope that Ed Simon or Rick Miller will give us further thoughts on power supply design. They both have worked on improvements to power supplies, and I trust that they have more to contribute.

You'll want to consider primary and secondary common and differential mode filtering, interwinding shielding, and snubbing (especially the secondaries). A broad-based approach to making quiet supplies is more effective than just focusing on one or two aspects and trying to rhodium plate them.

[john curl]

Duh! '-)

[PMA]

I am just watching "Sunset Boulevard"

[SY]

I don't think he's ready for his close up, Mr. DeMille.