same case with just one specimen , or it is same with both?
presuming that you're building stereo ....... not mono , not multichannel
Both measure the same!
I checked it 1:3 as cinemag sugested and I get 2.77x gain!
check again ...... without loose wire
decent drive and appropriate loading .....
decent drive is , say , everything up to 75R and appropriate loading at autoformer output - no less than 20K
I am using complementary 2sk170V/2sj74V @12mA using a 50R pot so output impedance should be very low.
Tomorrow I will listen to the 1:3 setup....
That makes sense, especially as a utility preamp, you don't want to high of an Rout.
I should have clarified- I am thinking of using this into a hiZ input, such as the Salas 6V6 buffer to get just a little bit of a boost.
I should have clarified- I am thinking of using this into a hiZ input, such as the Salas 6V6 buffer to get just a little bit of a boost.
can we use below audio transformer iron preamp:
(LM-NP-1001-B1L - Audio Transformer, 600 ohm, 600 ohm, Through Hole, LM-NP-1000 Series)
http://in.element14.com/bourns/lm-np-1001-b1l/transformer-line-matching-1-1/dp/1929741
its power level is given as "- 45.0 to + 3.0 dBm"
not much clear with its current or voltage ratings.. can use this for preamp for 6db gain..?
(LM-NP-1001-B1L - Audio Transformer, 600 ohm, 600 ohm, Through Hole, LM-NP-1000 Series)
http://in.element14.com/bourns/lm-np-1001-b1l/transformer-line-matching-1-1/dp/1929741
its power level is given as "- 45.0 to + 3.0 dBm"
not much clear with its current or voltage ratings.. can use this for preamp for 6db gain..?
Last edited:
Could you please tell what parameters to look for selecting a transformer for voltage gain in preamp.. from the iron pre it seems to be a 600ohm:600hom.. ie. 1:1 turn ratio (can we look for a 1:2 turn ratio for gain more than 6db).. what other parameters do we need to look for
it needs to be linear ...... not just on paper , as many of these small and cheap thingies are
connected as autoformer , 1:1 is becoming 1+1 , having 2V/V gain , which is 6db
if you take 1:2 , it is becoming 1+2 , giving 3V/V gain , which is 9.5db
there is waste number of possible xformers ....... if you take 600CT:600CT , that's practically 4 windings of 150R (nominally) ......
you can use that one as 1:1+1+1 , resulting in 1+3 , having gain of 4V/V , which is 12db
and that's where I think you need to stop with gain , because Rout of entire shebang is really going up
connected as autoformer , 1:1 is becoming 1+1 , having 2V/V gain , which is 6db
if you take 1:2 , it is becoming 1+2 , giving 3V/V gain , which is 9.5db
there is waste number of possible xformers ....... if you take 600CT:600CT , that's practically 4 windings of 150R (nominally) ......
you can use that one as 1:1+1+1 , resulting in 1+3 , having gain of 4V/V , which is 12db
and that's where I think you need to stop with gain , because Rout of entire shebang is really going up