Eminent Technology ET-2 Tonearm Owners

Regarding EI (there are several other "square" cores BTW) vs. toroidal transformers: Things are not that simple. While a toroidal has the advantage of a more simple "flowing" magnetic circuit, it's main "advantage" is the absence of an air gap - an economic advantage. This makes for considerably less iron for a toroidal, and more inductivity with less windings. This makes for a low (ohmic !) loss transformer, with low impedance windings.
However this creates disadvantages: The saturation of a toroidal is very sharp, and with the industry practice (and the practice of almost all audiophile transformer builders) of driving the transformers too close to the magnetic saturation point of the cores ("Efficient" ! Bling!) they are *the* achilles heel of excessive sonic mains sensitivity.
And within these issues DC on the mains (a strong disturbance of high variability) drives a toroidal transformers very easily into saturation, a massive disadvantage!
The last related disadvantage of a toroidal is the inherently lower ohmic loss: It produces (much) higher charging current spikes, which on their own magnetize the (hard limited) toroidal core much harder, and again pull away reserves from the iron core. Low loss is not per se better, on magnetic circuits it creates very audible problems.
A correct air gap of a well made EI transformer (not the usual cheap chinese ones) makes it much more linear, and it absorbs DC on the mains with much less hickups. And yes, it usually sounds better.
As does a well designed "artisanal" insulation transformer with EI core.
One example more of reality vs. hype and hypothesis.
And a toroidal "out of reserve" creates very strong hum fields BTW.

In my system, there is a low count of transformers (and an increasing count of batteries). The LFD, with some hum and interference problem in our test, has toroidal transformers ;-) Close to my phono front end (1m) there is only one transformer plus the phono stage transformer, if there is one.

^^^^^^^
Pegasus - I am not an amplifier-preamplifier-phono manufacturer; but someone who bases all products I own (not just audio) on design, construction, operability, reliability, and with my audio products together - making music (lets call this part implementation).

I don't tolerate downtime, hiccups, or operability problems especially with any products that are supposed to, with others as part of a whole - bring me pleasure for leisure activities. It has been my experience with all products (not just audio), that a good design to start does not guarantee a good implementation.
In fact.

The lesser design implemented well; can have better end results than a better design not implemented well.
The setting up of a vinyl turntable system - especially the tonearm - being a perfect example ?

Now I do own audio amplifiers with both type of transformers. It is my general understanding that a toroidal transformer by design is better to minimize hum and buzz. So it makes it ideal I would think for a preamp / phono design. But in reality my understanding is it is in fact much more difficult to implement a toroidal design. Harder to make. It stands to reason then that to implement this type of design will cost more.

Pegasus
The LFD, with some hum and interference problem in our test, has toroidal transformers ;-)

Interesting. Is this the one ?
LFD

There are toroidal transformers and then there are
toroidal transformers.

True Story

Was finishing the basement space adjacent to my main music room - to hold my extra gear and it became music room B.
I assembled some gear and started listening in the unfinished room space. This gives you a good idea "with your gear", how much damping and other room treatment is going to be needed. Now, with no music playing, whenever I would get up to change the lp or cd I would hear a hum as i walked close to the gear. I followed all the normal procedures to find and eliminate the hum. It was not audible at the listening position. It did not come from the speakers or individual components that were turned on. Frustration set in.

Then one day when I was standing between the speakers with no music playing my right ear got fixed on the hum. It was a transformer that I discovered was for the front door bell. It had been mounted to the side of one of wood beams supporting the main floor. Only visible from a certain angle. I followed the cord unplugged it and the buzzing transformer stopped. What relief ! My wife was not as happy as me about this event. I promised my wife I would re-locate it to the back of the house. But I like not having a door bell ....... There is a knocker on the door. But I also discovered that people have forgot how to use those things. They need to see buttons now.

Moral of the story and Lesson Learned for me.

When trying to eliminate hum and buzz...
Look straight ahead; look to the left; look to the right; look down.

Don't forget to look up.

btw... it was not a toroidal transformer :^)

My LFD MM0 looks like it has the same circuit board as the LFD Mistral, but has a double mono power supply fed by a very generous toroidal transformer. It's switchable between MM and MC, it seems to sound very good on both inputs. I saw that one was sold on ebay for 275£, and another one advertised in spain vor ca. 310€. These are extremely attractive prices. Sonically, to my ears it plays well into the 2000$ phono stage league.

Frogman - Wait, this is a trick question.....

If I provided "e) all of the above" - it would have made it too easy for all you sharpshooters on the thread.
Impressive thought process !

Pegasus
We suspected already during an earlier listening sessions, that the slowly increasing amount of dry air exiting the tonearm creates - a lot! - of static charge on the vinyl surfaces. And it had a considerable effect sonically. The ionizer, building up a certain reserve of air ions (smells also a bit like Ozone), seems to eliminate this problem. Hmmm...

An interesting comment Pegasus.

I have humidity gauge right next to the TT, One foot away. The needle doesn't move during the hours I am in there. But that is maybe too macro a level....

Have you ever tried a smoke pencil puffer under the sides of the manifold to see the air stream pattern ?

1) With a still record and
2) with a record in play which is playing big bass

Good air movement is ...good :^)

now where did I put that smoke pen ....

"Smoke 'em if you got 'em"
-
-

Pegasus
Regarding EI (there are several other "square" cores BTW) vs. toroidal transformers: Things are not that simple. While a toroidal has the advantage of a more simple "flowing" magnetic circuit, it's main "advantage" is the absence of an air gap - an economic advantage. This makes for considerably less iron for a toroidal, and more inductivity with less windings. This makes for a low (ohmic !) loss transformer, with low impedance windings.
However this creates disadvantages: The saturation of a toroidal is very sharp, and with the industry practice (and the practice of almost all audiophile transformer builders) of driving the transformers too close to the magnetic saturation point of the cores ("Efficient" ! Bling!) they are *the* achilles heel of excessive sonic mains sensitivity.
And within these issues DC on the mains (a strong disturbance of high variability) drives a toroidal transformers very easily into saturation, a massive disadvantage!
The last related disadvantage of a toroidal is the inherently lower ohmic loss: It produces (much) higher charging current spikes, which on their own magnetize the (hard limited) toroidal core much harder, and again pull away reserves from the iron core. Low loss is not per se better, on magnetic circuits it creates very audible problems.

What if;

You have two Solid State Amps Class A/B that both put out 100 wpc *** at 8 ohms and both have toroidal transformers.

Their specs look like this.

Amp A
2 - ohms - n/a
4 - ohms - 125 wpc
8 - ohms - 100 wpc ***
16- ohms - 50 wpc
32 - ohms - 25 wpc

Amp B

2 - ohms - 400 wpc
4 - ohms - 200 wpc
8 - ohms - 100 wpc ***
16- ohms - 50 wpc
32 - ohms - 25 wpc.

If both are driving full range speakers at a decent SPL level. These speakers dip to 2 ohms for the low bass requirement.

Question:

Is transformer saturation the right word to describe what is going to happen to Amp A first ?

Just asking ....