This Blog is about revising/upgrading the vintage Quad 33 to 909 amplifiers and the Revox taperecorders.
Audio electronics and High End Hifi are also absolutely "on-topic" here.
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Monday, October 22, 2007
K4700 & Toroïdal transformer in the Quad 405
On general request: a picture of the Velleman K4700 and the 2x 36V 300VA Toroïdal transformer mounted in a Quad 405.
Several articles on both subjects have been published on this blog. You'll have to scroll down a long way....
I think if the transformer is in a good shape, it shouldn't make any difference to our ears whether it is toroidal or the other.
After all, the sound doesn't use the ac voltage at all, it uses the dc voltage. Every thing is well filtered by the 10000uF and if necessary we can add small caps on each rail on each board (like from 0.1uF to 100mF) the +50v and the -50v. I have no problem with mine, but with time xfo can become tired, the varnish of the wires inside might deteriorate (I don't have experience nor knowledge of xfo's lifetime so it is a thought only). Maybe I can be put right by more knoledgeable people than me.
Just to put me right myself, I found from a good source that yes the original kind of transformer is difenitly better than the toroidal when both in perfect condition. Aparantly the toroidal can introduce some kind of noise.
Does the toroid have a positive effect on sound? or does it just get rid of a buzzing tx please? Lee.
ReplyDeletehello, in my case, i changed the transformer to toroid. the sound became more clean & quiet. maybe someone don't like that. :D
ReplyDeleteI think if the transformer is in a good shape, it shouldn't make any difference to our ears whether it is toroidal or the other.
ReplyDeleteAfter all, the sound doesn't use the ac voltage at all, it uses the dc voltage. Every thing is well filtered by the 10000uF and if necessary we can add small caps on each rail on each board (like from 0.1uF to 100mF) the +50v and the -50v.
I have no problem with mine, but with time xfo can become tired, the varnish of the wires inside might deteriorate (I don't have experience nor knowledge of xfo's lifetime so it is a thought only).
Maybe I can be put right by more knoledgeable people than me.
Daniel
Sorry, I wrote "from 0.1uF to 100mF.
ReplyDeleteWe should read 100uF not 100mF.
Daniel
Just to put me right myself, I found from a good source that yes the original kind of transformer is difenitly better than the toroidal when both in perfect condition. Aparantly the toroidal can introduce some kind of noise.
ReplyDeleteDaniel