How did you sim the DN2540 without an ".INC" command?
I'm fairly sure thats not a standard Linear Tech library part.
Where did you go to find the library with the DN2540?
How did you sim 6DJ8 (rather than NH6DJ8) without wiring
up heaters.. I see no terminals added for that purpose?
I'm fairly sure thats not a standard Linear Tech library part.
Where did you go to find the library with the DN2540?
How did you sim 6DJ8 (rather than NH6DJ8) without wiring
up heaters.. I see no terminals added for that purpose?
hey kenpeter,
It´s your circuit that doesn´t work not mine, so take it easy!
You can E-mail me if you want some help with LTSpice.
Say thank you instead😉 . Maybe you haven´t gotten so deep into LTSpice yet. ".four" command is fourier-analyze. You can check the figures under "View"/"Spice error log".
www.revintage.se/Draft14.asc
It´s when you bypass/or substitute with LEDs you get the severe THD!!!! Off coures I tried your schematic first and as I suspected it did not work to well. One of the reasons was that you bypassed the "unused" cathode to ground! But if you like 2%THD it´s OK.
About the added 12V you already have it for heating your 12AU7 so there are no extra parts!
And if you want a low-mu tube go for 6H30.
And for this circuit DN2540 or whatever you got at hand is good enough.
Sunrise: You are so right, it´s in the ballpark of 5mA/triode.
Why add distortion and tube noise? Just use one side (the hot, or +). You will lose 6 db but if your inputs are unbalanced then it should be ok; there nominal input should be 14 db lower than the 2volt out (not sure why you want a gain of 1) In pro recording studios you usaully drop the level 14 db as well as go from balanced to unballanced. This is usaully done with a resistor pad (3 or 4 resistors, thats it) the cheapeast easiest cleanest quietest flatest (you get the point).
It´s a free country, you can add any model in the libraries. You are also free to rename them if you want to!
A small lead: Why not check Supertex for models.......
revintage said:
Yes, you will only be able to listen to music if you buy $250 worth of transformers. Edcor makes a 1:1 nickel core transformer for $20, or a steel core for about $10. As good as the Lundahl? Probably not. But probably closer than you think. Otherwise, tie the negative signal to ground and call it a day.
A mic input maybe won´t be able to cope with the 2Vrms level. Couldn´t find at what level they measured distortion?
But surely Edcor and many american manufacturers have transformers at low prices that will work and will be likable to play music through.
A somewhat cheaper alternative is LL1544A(max 2V before core saturation) at 160USD/pair. Thank godness I live in Europe where Lundahl prices are lower😎.
If you want to tie the negative signal to ground, you must do it through a cap.
But surely Edcor and many american manufacturers have transformers at low prices that will work and will be likable to play music through.
A somewhat cheaper alternative is LL1544A(max 2V before core saturation) at 160USD/pair. Thank godness I live in Europe where Lundahl prices are lower😎.
If you want to tie the negative signal to ground, you must do it through a cap.
oh boy.... a lot of answers again.....guys thanks .... you are very helpfull.....
@kenpeter - "If low parts count is going to be a consideration here at all?"
yes - it is in consideration....but most of all what i would like is to have a tube out of that Wolfson dac. and not to loose to much voltage when doing that.... so i would like at the output of the dac to have a minimum od 1Vrms if possible.....
and quality - in my opinion WM8740 is a very nice dac that deserves to have a tube output that can match its quality....
@revintage - i like that 6H30 tube circuit better...... less complicated and with a nice tube in it too.....
so is it the one to go????
@kenpeter - "If low parts count is going to be a consideration here at all?"
yes - it is in consideration....but most of all what i would like is to have a tube out of that Wolfson dac. and not to loose to much voltage when doing that.... so i would like at the output of the dac to have a minimum od 1Vrms if possible.....
and quality - in my opinion WM8740 is a very nice dac that deserves to have a tube output that can match its quality....
@revintage - i like that 6H30 tube circuit better...... less complicated and with a nice tube in it too.....
so is it the one to go????
I like the 6H30 that is so neutral, some call it laid back......
C2 must be adjusted in circuit with load as it seems critical.
About the circuit I am sure it can sound OK. But I have never tried anything like that myself, nor had I seen anything like it until kenpeter showed the embryo yesterday.
C2 must be adjusted in circuit with load as it seems critical.
About the circuit I am sure it can sound OK. But I have never tried anything like that myself, nor had I seen anything like it until kenpeter showed the embryo yesterday.
or maybe i will go with the 6DJ8 circuit and use 6N23P tube.... they are nice when used on 5mA current......
don't worry - i am waiting for WM8740 to come home - to try them in a cheap dac concept.....
i have some E88CC at my home and also maybe i can find some 6N23P (they are very similar but it seems to me that they are more linear in 5mA region)......
6H30 is the one i would like to try the most..... but actually don't have them - so i will have to buy them.,....
will see.....
if the design works i think it is the one to go...... one or the other.....
i have some E88CC at my home and also maybe i can find some 6N23P (they are very similar but it seems to me that they are more linear in 5mA region)......
6H30 is the one i would like to try the most..... but actually don't have them - so i will have to buy them.,....
will see.....
if the design works i think it is the one to go...... one or the other.....
I got no objections to 6H30. But I want to know what model is
being used? 6H30 is not listed in the standard dmtriodep.inc
from Duncan's page. Yours has been updated or something???
being used? 6H30 is not listed in the standard dmtriodep.inc
from Duncan's page. Yours has been updated or something???
Kenpeter,
You have to add it yourself to dmtriode.inc! There are no updates to rely on. This one I borrowed from Andrei:
.subckt 6H30 P G K
Bp P K I=(0.391133693m)*uramp(V(P,K)*ln(1.0+(-0.0187352739)+exp((5.147858602)+(5.147858602)*((12.74287762)+(-184.3951189m)*V(G,K))*V(G,K)/sqrt((23.72646407)**2+(V(P,K)-(13.80558026))**2)))/(5.147858602))**(1.205889167)
Cgp G P 6.0p
Ci G K 6.3p
Co P K 2.5p
.ends 6H30
Lots of useful models at www.intactaudio.com/forum/viewforum.php?f=15&sid=59139eebb3c8e1c9ce4eef777da4d3e7!
You have to add it yourself to dmtriode.inc! There are no updates to rely on. This one I borrowed from Andrei:
.subckt 6H30 P G K
Bp P K I=(0.391133693m)*uramp(V(P,K)*ln(1.0+(-0.0187352739)+exp((5.147858602)+(5.147858602)*((12.74287762)+(-184.3951189m)*V(G,K))*V(G,K)/sqrt((23.72646407)**2+(V(P,K)-(13.80558026))**2)))/(5.147858602))**(1.205889167)
Cgp G P 6.0p
Ci G K 6.3p
Co P K 2.5p
.ends 6H30
Lots of useful models at www.intactaudio.com/forum/viewforum.php?f=15&sid=59139eebb3c8e1c9ce4eef777da4d3e7!
oh man - that one would be expensier for sure 😀 .... i like better those simpler examples...... they are not making me nervous 😀
which one to go after???? i like 6DJ8 circuit because i have 4 tubes of that type.....
i like the 6n30 circuits because i like the tube..... and i don't have that one - i would have to buy it.......
aaaaaaa
😀
i like the 6n30 circuits because i like the tube..... and i don't have that one - i would have to buy it.......
aaaaaaa
😀
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