Hi......
...plese for the tube experts out there,just have simply question,plese help me to become right data ,to put together a simpy anode folower for 6sn7gt tube,to become a plate current about 8-10mA,for best linearity and good sound.So plese tell me how much must be B+ voltage,how big anode resistor and how big cathode resistor for good operating point?
I will use one triode for bouth chanels,so half triode per chanel.
Plese for help!!!😕
...plese for the tube experts out there,just have simply question,plese help me to become right data ,to put together a simpy anode folower for 6sn7gt tube,to become a plate current about 8-10mA,for best linearity and good sound.So plese tell me how much must be B+ voltage,how big anode resistor and how big cathode resistor for good operating point?
I will use one triode for bouth chanels,so half triode per chanel.
Plese for help!!!😕
6SN7GT operating points.....
...sorry just forget to mention.I will use this anode folower for output stage of my cd player,this will be directly fited with signal from dac that is about 1,5Vrms.I just have see this simply schematic from Decware audio,for 12au7 tube,but becouse I have some 6sn7gt tubes at home I would try this with this tube in the same configuration.
😉
...sorry just forget to mention.I will use this anode folower for output stage of my cd player,this will be directly fited with signal from dac that is about 1,5Vrms.I just have see this simply schematic from Decware audio,for 12au7 tube,but becouse I have some 6sn7gt tubes at home I would try this with this tube in the same configuration.
😉
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Hi,
My guess is that a 250VDC B+ was used. Just don't expect the circuit to drive long (capacitive) cables and heavy loads.
Ciao, 😉
My guess is that a 250VDC B+ was used. Just don't expect the circuit to drive long (capacitive) cables and heavy loads.
Ciao, 😉
I use 6SN7 with +U 280-290 v, R anode 25-27 kohm, U anode 120-130 v, R cathode 510-560 ohm, U cathode 3 - 3.5 v.
...Hi Boys....
...thanks for answers.So I have at home some toroid transformer with secondary 180V,so after recitification I can become about 250V B+.So I hope this will be Ok for the 6sn7gt tube.So plese in this case,how big than I must choose the anode resistor and Cathode resistor to become the plate current to about 8-10mA.I have read in some internet projects,that good operating plate voltage for 6sn7gt will be 160-180V?
What do you mean about that???
...thanks for answers.So I have at home some toroid transformer with secondary 180V,so after recitification I can become about 250V B+.So I hope this will be Ok for the 6sn7gt tube.So plese in this case,how big than I must choose the anode resistor and Cathode resistor to become the plate current to about 8-10mA.I have read in some internet projects,that good operating plate voltage for 6sn7gt will be 160-180V?
What do you mean about that???
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Cathode resistor around 1k should do it for 8mA; You can use 200V or more on the plate. I suspect you will need a very clean B+ with this approach, you should plan on some good RC filtering, which works out well since you can allow the RC filter to drop 50V and still have 200V for the plate.
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After rect. You will have about +230 v. If You will want 160-180 anode v and 8 ma current, You must use anode res. about 8-10 kohm, that is too small load for 6SN7. Good load is about 20 kohm and more. And Your current must be about 4 ma, that is not good. Better go to mode 120-130 v, with 20 kohm and 5-6 ma. Cathode res - less 470 ohms. Problem is that Your main transformer is not suitable, IMO.
This circuit is not an anode follower.
It is an ordinary common cathode circuit and it has gain about 20 dB or a bit more.
Because you have quite high input level (1.5 Vrms) you actually do not need gain.
Therefore simple cathode follower would may be best, or a real anode follower with gain of 0 dB.
Below is the cathode follower with 8 mA anode current. This kind of circuit is very linear. The distortion is below 0,1 % at 3 Vrms out.
It is an ordinary common cathode circuit and it has gain about 20 dB or a bit more.
Because you have quite high input level (1.5 Vrms) you actually do not need gain.
Therefore simple cathode follower would may be best, or a real anode follower with gain of 0 dB.
Below is the cathode follower with 8 mA anode current. This kind of circuit is very linear. The distortion is below 0,1 % at 3 Vrms out.
An externally hosted image should be here but it was not working when we last tested it.
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hi artosalo......
....thank you for the answer and sxhematic.thanks to another members also.so now my question is?what transformer than I would need,to become plata voltage to abot 160 to 180 volts.so for the cathode folower design,if I understund this right,I will become output with 3Vrms,so is twice so much like from the dac only.I will mention also,that I would build this output stage,becose my player have no output opamps,its original design with direct dac output with 1,5Vrms.the player is cambridge audio Track 1 with TDA1305T dac.so i just will to become more output to become more dynamik and higher output signal.
....thank you for the answer and sxhematic.thanks to another members also.so now my question is?what transformer than I would need,to become plata voltage to abot 160 to 180 volts.so for the cathode folower design,if I understund this right,I will become output with 3Vrms,so is twice so much like from the dac only.I will mention also,that I would build this output stage,becose my player have no output opamps,its original design with direct dac output with 1,5Vrms.the player is cambridge audio Track 1 with TDA1305T dac.so i just will to become more output to become more dynamik and higher output signal.
You can use that 180 V toroid you already have.
The output level I mentioned, 3 Vrms is just and example and value I used for simulation.
You can connect this circuit directly to dac and get some 1,3...1,4 Vrms out.
This circuit has some - 0,6 dB gain (0,93 times the input signal).
The output level I mentioned, 3 Vrms is just and example and value I used for simulation.
You can connect this circuit directly to dac and get some 1,3...1,4 Vrms out.
This circuit has some - 0,6 dB gain (0,93 times the input signal).
...yes,now I see where is the problem.I must go with transformer that have for about 250V secondary,so after that I will have about 350V on B+,in this case it is posibile to have than 180V anode voltage.In any case I will not build some another tube buffer with gain for about 0,98 or lower.I have some Musical Fidelity X10-D totaly modifyed,but I just see that there is missing some dynamic in the music.I just put the Decware option like a solution,becouse my good friend have his Zen cd player with almost the same output stage and this sound just incredibile.So thats the reason I have become the idea to put some verry simply output stage together with 6sn7 tube,becouse I have about 10 tubes from this model at home,I have become this from one of my friends.
Hi,
With 250VAC secondary and a full wave bridge you'll end up close to 327VDC.
350VDC is too optimistic since there always some loss from diodes, RC filtering, etc.
Ciao, 😉
With 250VAC secondary and a full wave bridge you'll end up close to 327VDC.
350VDC is too optimistic since there always some loss from diodes, RC filtering, etc.
Ciao, 😉
....yes you are right.I just put the data without calculation and just for example.
Im truly thinking now about to go with maybe some 12au7 tube in the design,becouse they maybe need lower voltage for B+ and with some good Nos 12au7 tube the sound will be good.Like I have say before I have MF X10-D buffer at home totaly havy modifyed,with some shinkoh resistors,Mundorf silver gold oil capacitors and other stuf,but I just dont get some good dynamic out of the player.I have try some 20 pairs of 6922,ecc88,6dj8 tubes from nos to new production,but Im not realy happy.My good friend told me that I must tray with some 6H30p tube,that this tube sound bether than any other tube in his tube output stage in his cd player.But Im not fimilar with this tube and I just see that they are expansive,some Nos can cost up to 200 euro pro piece.I just dont want to complicate the thing so much.So if someone have some good solution for me for one verry simply cd output stage with one tube for bout chanel I will be happy for some help.🙂
Im truly thinking now about to go with maybe some 12au7 tube in the design,becouse they maybe need lower voltage for B+ and with some good Nos 12au7 tube the sound will be good.Like I have say before I have MF X10-D buffer at home totaly havy modifyed,with some shinkoh resistors,Mundorf silver gold oil capacitors and other stuf,but I just dont get some good dynamic out of the player.I have try some 20 pairs of 6922,ecc88,6dj8 tubes from nos to new production,but Im not realy happy.My good friend told me that I must tray with some 6H30p tube,that this tube sound bether than any other tube in his tube output stage in his cd player.But Im not fimilar with this tube and I just see that they are expansive,some Nos can cost up to 200 euro pro piece.I just dont want to complicate the thing so much.So if someone have some good solution for me for one verry simply cd output stage with one tube for bout chanel I will be happy for some help.🙂
Hi,
Generally spoken I still have to hear a ECC82/12AU7 that I actually like.
6CG7, 6SN7 are much better.
The MF X10-D is just a buffer. It won't make a big difference no matter what valve you use.
A few years ago I have presented a simple line stage with one 6SN7 per channel that was well received. It has a little gain and a buffer as well so it should be closer to what you're looking for I believe.
Ciao, 😉
Generally spoken I still have to hear a ECC82/12AU7 that I actually like.
6CG7, 6SN7 are much better.
The MF X10-D is just a buffer. It won't make a big difference no matter what valve you use.
A few years ago I have presented a simple line stage with one 6SN7 per channel that was well received. It has a little gain and a buffer as well so it should be closer to what you're looking for I believe.
Ciao, 😉
Hi,
http://www.diyaudio.com/forums/tubes-valves/141263-frank-s-6sn7-preamp-linestage-2.html
Posting #15, the one on the bottom where the two halves of the 6SN7 are direct coupled.
Use a coupling cap after the pot if you intend on using the volume control.
The original drawing is in a very, very long thread here somewhere:
http://www.diyaudio.com/forums/tubes-valves/12042-franks-ultimate-tube-preamp.html
I used a valve regulated PS but any well filtered PS will do.
Ciao, 😉
http://www.diyaudio.com/forums/tubes-valves/141263-frank-s-6sn7-preamp-linestage-2.html
Posting #15, the one on the bottom where the two halves of the 6SN7 are direct coupled.
Use a coupling cap after the pot if you intend on using the volume control.
The original drawing is in a very, very long thread here somewhere:
http://www.diyaudio.com/forums/tubes-valves/12042-franks-ultimate-tube-preamp.html
I used a valve regulated PS but any well filtered PS will do.
Ciao, 😉
Hi Frank.....
...thanks,verry nice from you.It looks like a verry good option.Plese tell me if it is posibile to not use any attenuator or volume pot on the input,becouse I will take the signal directly from my dac and put this on input of the tube stage.I will use some verry good input capacitors and grid leak resistors.Tell me if there must be some grid stoper resistor to or no in this case,becouse I will feed the input directly from dac output??
...thanks,verry nice from you.It looks like a verry good option.Plese tell me if it is posibile to not use any attenuator or volume pot on the input,becouse I will take the signal directly from my dac and put this on input of the tube stage.I will use some verry good input capacitors and grid leak resistors.Tell me if there must be some grid stoper resistor to or no in this case,becouse I will feed the input directly from dac output??
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Maybe this is also of interest for reading on the topic: http://www.diyaudio.com/forums/digital-line-level/157940-tubed-ccda-i-v-amp-tda1541.html
CCDA: constant-current-draw amplifier
CCDA: constant-current-draw amplifier
Hi,
@Bigun: TS may not need I/V conversion?
@Audiorado: just feed the signal straight to the 0.047microF cap and you'll be fine.
Ciao, 😉
@Bigun: TS may not need I/V conversion?
@Audiorado: just feed the signal straight to the 0.047microF cap and you'll be fine.
Ciao, 😉
....hi Frank.....
...thanks for answer.I decide to go with your design.Plese just one more question.You say,that you design have a litle gain to.So on the output how strong the signal will be??I will be happy with some 2,3-2,5Vrms on the output.So is this posibile with your design?🙄
...thanks for answer.I decide to go with your design.Plese just one more question.You say,that you design have a litle gain to.So on the output how strong the signal will be??I will be happy with some 2,3-2,5Vrms on the output.So is this posibile with your design?🙄
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