GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Melquiades Amplifier
In the Thread: Planning my DSET

Post Subject: Its about noisePosted by anthony on: 1/8/2019

N-set wrote:
Congratulations on the build!

anthony wrote:
Yours uses all toroids, or mostly so, which are more efficient than the EI that I use.

Why have you chosen EI vs toroids? The latter emit less.

Cheers, Jarek

Hi Jarek,

Yes, toroids can leak less magnetic flux than EI if they are wound such that the entire core is covered, but is flux leakage a problem if you are able to keep the transformers away from sensitive circuits? Toroids come into their own when you are forced to mount the transformer near the circuits, but otherwise EI have them covered on most fronts.

Toiroids

are smaller for the same power rating
are more efficient transformers of power than EI
if carefully made can have low flux leakage
are high bandwidth devices so more noise on the power line is transferred into the circuit
have no gap and will hum when there is DC on the mains

are larger for the same power rating
have a gap and do not hum when you have DC on your mains (unless there is so much that the core becomes saturated)
are lower bandwidth devices so act as a low pass filter for mains noise (we really only need to pass 50/60Hz - the rest is unwanted)
leak some flux so they should be kept further separated from the sensitive circuits

Personally, I would use EI in just about every situation for audio...unless I had no option but to tuck the transformer in tight to a sensitive circuit.

Cheers,

Anthony

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