Hi!
Could somebody tell me What is the LL1517 good for?
Is it possible to use in tube circuit?
Something like the Raven preamp has in the input?
http://www.lundahl.se/pdfs/datash/1517.pdf
Tyimo
Could somebody tell me What is the LL1517 good for?
Is it possible to use in tube circuit?
Something like the Raven preamp has in the input?
http://www.lundahl.se/pdfs/datash/1517.pdf
Tyimo
Hi
The LL1517 is designed to be driven from a very low source impedance. The datasheet even mentions 'minus 18' as the optimum source. The frequency response is given when driven by a source resistance of 10 ohms, fed into 600R. Those are too low values for tubes. Ok, a white cathode follower may achieve a R out of 10 ohms and not distort to much when driving 600R, but that is about it in the 'tube world'.
Erik
The LL1517 is designed to be driven from a very low source impedance. The datasheet even mentions 'minus 18' as the optimum source. The frequency response is given when driven by a source resistance of 10 ohms, fed into 600R. Those are too low values for tubes. Ok, a white cathode follower may achieve a R out of 10 ohms and not distort to much when driving 600R, but that is about it in the 'tube world'.
Erik
Hi Erik!
I would connect it between the CDP and the tubepre.
I think a solid state CDP has low output imp, it isn't it?
Tyimo
I would connect it between the CDP and the tubepre.
I think a solid state CDP has low output imp, it isn't it?
Tyimo
CD-players do have low output impedances, but if it is as low as 10R I don't know. Best thing is to check your manual. It is also important to terminate this transformer with at least 600R. This can be a tough load, or introduce a LP cutoff in the output coupling cap (if present) is too low in value.
Chech the driving habilities of your CD-player! I don't know if the manual shows this information, however.
Chech the driving habilities of your CD-player! I don't know if the manual shows this information, however.
The manual doesn't shows this information.
I think I have to try it and I will terminate the transformer with 600R +10nF.
Greets:
Tyimo
I think I have to try it and I will terminate the transformer with 600R +10nF.
Greets:
Tyimo
How did it work out? Normally an output transformer will have to be able to look into 10 - 50K input impedance on the secondary,
and sometimes more.
I have made some measurements on a Sowter 3603 that also is specified for a 600R load. It worked perfectly into 1 K, but showed
very bad results into 10K+, with severe 100 KHz ringing.
and sometimes more.
I have made some measurements on a Sowter 3603 that also is specified for a 600R load. It worked perfectly into 1 K, but showed
very bad results into 10K+, with severe 100 KHz ringing.
I have used it Winther excellent resultat as gain transformer in Firstwatt B1, as Nelson Pass has designed. It is also usefull in Firstwatt M2...
I stay corrected. I didn´t think of the possibility to wire the 4 windings separately. I have allways thought of them as 2 inputs and 2 outputs,
but that does not have to be the case.
It takes some time to get the head around audio transformers, and the manufactures don´t help much in that regard.
but that does not have to be the case.
It takes some time to get the head around audio transformers, and the manufactures don´t help much in that regard.