sowter 9050 or Lundahl LL1660 line out transformer?

[Shoog]

I have used a toroidal as a parafeed interstage. It worked and sounded good, but I needed to push 30mA through the driver just to get the top end up to about 35Khz. To much interwinding capacitance.
It works but not recommended.

Shoog

[piero7]

Originally Posted by dice45

Matt,

Sowter 9050 or LL1660PP: It depends what you want to achieve.

For the 6SN7 (R_p= 7k) the Sowter 8650 or 9050 certainly is better suited as the tube should face a load of atleast 15k.

With the 8650 you get 185R (+ secondary DCR) as output resistance, with the 9050 417R plus sec.DCR.

I am not sure if the 6SN7 is the right choice if you want to use the LL1660; it only has a stepdown turns ratio of 2.25 in PP to line out mode. You end up at about 3k output resistance then. Better use a 5687 or a juicy 12B4A to drive the LL1660.

Sonics: i haven't heard either in my system, but i heard the LL1660 in Thomas Mayers system and liked it very much; Thomas even recommended the thing for single-ended mode.

Sowter makes any custom job you want, Lundahl does not. But in general the sonic reputation of Lundahl is considerably better (exceptions exist).

I have decided to use the LL1660 PP for my preamp project; i will use a 12B4 to drive it and i guess the Lundahl driven by the right tube will be dramatically better than the Sowter. Moreover, it has way higher safety margins concerning isolation voltages. The only Sowter i considered was the 9111 but this baby has to be used in parafeed mode which i want to avoid: parafeed needs a cap to block the CD; this is a coupling cap. I strive to avoid coupling caps in my system.

Could you post schematic diagram of your preamp with 12B4+1660 please?

[Gordy]

piero7, please note that you have quoted a message from 14th September 2002!
Good luck with that!

[piero7]

thanks gordy I didnt notice it was so old