Hi,
The output strength of the signal also depends on what you put in but it will easily give you more than 2VRMS.
In fact I even think some people talked about attenuated the signal in the first link I posted higher up. Which can easily be done with a resistive divider.
Ciao, 😉
The output strength of the signal also depends on what you put in but it will easily give you more than 2VRMS.
In fact I even think some people talked about attenuated the signal in the first link I posted higher up. Which can easily be done with a resistive divider.
Ciao, 😉
....hi Frank...
....thanks a lot for all your answers and help.I the nex week or two,i will build this stage and report back how it sounds.Till than,thanks to other members for the answers allso!🙂
....thanks a lot for all your answers and help.I the nex week or two,i will build this stage and report back how it sounds.Till than,thanks to other members for the answers allso!🙂
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With my 250vac/160ma sec with full bridge diode I get 357volts with no load, after applying a load of 2@6N3C I get at plate on both 348volts and on the preamp of 6SJ7 I get 290v dropping to 120 volts on the plates. go figure
Hi Frank...
...so Im just to put parts together and than see waht is missing to order some parts to complete the linestage.Plese be so nice and help me with power supply for the linestage.I just buy a totoid power transformer with 200V 0,15A secondary and I have at home a pair of hammond 1,5H / 56ohm chokes and a few Mundorf HV capacitors.I have in mind to do the rectifications with 1N4007 diodes and than put the + line thru first capacitor after diodes(47uF/450V)than one choke than one capacitor (100uF/450V),and than second choke and than last capacitor( 220uF/450V) and than some bleeder resistor.What do you meen about this power supply for this line stage??Will it be OK??I think I will end between 250-260V B+ .
Im not thinking to use some tube rectifier,becouse in some design,I just have noticed that,the tube rectifier make the bass verry soft and not firm and fast.
I have tray in the past some tube rectifier from diferent brands and models and I was newer happy.For me the diode fullwave rectifier bridge works much bether.
What do you mean about this??
😕
...so Im just to put parts together and than see waht is missing to order some parts to complete the linestage.Plese be so nice and help me with power supply for the linestage.I just buy a totoid power transformer with 200V 0,15A secondary and I have at home a pair of hammond 1,5H / 56ohm chokes and a few Mundorf HV capacitors.I have in mind to do the rectifications with 1N4007 diodes and than put the + line thru first capacitor after diodes(47uF/450V)than one choke than one capacitor (100uF/450V),and than second choke and than last capacitor( 220uF/450V) and than some bleeder resistor.What do you meen about this power supply for this line stage??Will it be OK??I think I will end between 250-260V B+ .
Im not thinking to use some tube rectifier,becouse in some design,I just have noticed that,the tube rectifier make the bass verry soft and not firm and fast.
I have tray in the past some tube rectifier from diferent brands and models and I was newer happy.For me the diode fullwave rectifier bridge works much bether.
What do you mean about this??
😕
...thanks Frank for the answer.I will order now some good resistors and input caps,and than build this stage.Thanks a lot for help!
To use 1N4007 is not good idea, IMO. Better use the same brand, but fastest, I forgot....,or HER 108, or BYV26E with switching less than 70 ns. For better filtering first cap can be 100 uF / 47 uF is for tube rect./. Second cap / if You will connect OT/ can be 330 uF or more/, next 220-330 uF /if You will connect prestage/......My advice is for +U for one channel.
If Your idea is for two channels, Your caps are small for sucking energy for both channels in strong and power moments, IMO. But You can try Yours and my...
If Your idea is for two channels, Your caps are small for sucking energy for both channels in strong and power moments, IMO. But You can try Yours and my...
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...hi azazzelo....
...thanks for the advice.I just think becouse this is only a line stage and the total current maybe will be only for about max. 20mA,that in this case the 100uF capacitors are OK.I could do all three cap with 100uF is no problem,I have this at home.🙂
...thanks for the advice.I just think becouse this is only a line stage and the total current maybe will be only for about max. 20mA,that in this case the 100uF capacitors are OK.I could do all three cap with 100uF is no problem,I have this at home.🙂
Sorry, I think for tube amp. Yes You can use 100 and more uF-s, but first cap can be 100 uF for better filtering, for avoid humm / /filling in filtering will be more/, with 47 mF You can sense.
And use fast diodes, dynamic will better.
And use fast diodes, dynamic will better.
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....Hi Frank and other guys....
....so I have today buy a pair of 6h30pi EH gold pin tubes from my friend that have this in his BAT player,he just sold the player and put the original Svetlana in!I buy this selected pair for only 10$,so I think this is a good deal.But now my question to Frank,can I use this tube in the same design of yours for 6sn7 with the same power supply???I have looked on internet and it seems that the best operating point will be around 120-150V on plate with 20-25mA current.So now my question is what for parts do I need or bether say,what value must this parts have that the design will work.Im build the original design with 6sn7 anyway,becouse I just ordered all the parts,but I just ask that becouse It will be good for some smal experiment to see how this 6h30pi tube compare to the legendary 6sn7.
What do you mean guys about this idea??😉
....so I have today buy a pair of 6h30pi EH gold pin tubes from my friend that have this in his BAT player,he just sold the player and put the original Svetlana in!I buy this selected pair for only 10$,so I think this is a good deal.But now my question to Frank,can I use this tube in the same design of yours for 6sn7 with the same power supply???I have looked on internet and it seems that the best operating point will be around 120-150V on plate with 20-25mA current.So now my question is what for parts do I need or bether say,what value must this parts have that the design will work.Im build the original design with 6sn7 anyway,becouse I just ordered all the parts,but I just ask that becouse It will be good for some smal experiment to see how this 6h30pi tube compare to the legendary 6sn7.
What do you mean guys about this idea??😉
Hi,
The same topology could be used for that valve.
No idea what it sounds like though. Some members of the forum say it's not all that great.
The idea of the preamp was born out of the general demand for a preamp (for CDP use) which had just a bit of gain and low output impedance.
In those days there were still plenty of good NOS 6SN7s around and they were relatively cheap, so...
If I had to rebuild that preamp now I'd probably look at the 6CG7 as it is essentially the same as the 6SN7 (and its cousins) in 9 pin miniature version.
Other candidates would be the Russian 6N6P or the JJ ECC99 for instance.
Ciao, 😉
The same topology could be used for that valve.
No idea what it sounds like though. Some members of the forum say it's not all that great.
The idea of the preamp was born out of the general demand for a preamp (for CDP use) which had just a bit of gain and low output impedance.
In those days there were still plenty of good NOS 6SN7s around and they were relatively cheap, so...
If I had to rebuild that preamp now I'd probably look at the 6CG7 as it is essentially the same as the 6SN7 (and its cousins) in 9 pin miniature version.
Other candidates would be the Russian 6N6P or the JJ ECC99 for instance.
Ciao, 😉
why do not you build line pre around 6V6 like Salas: http://www.diyaudio.com/forums/tubes-valves/102352-6v6-line-preamp.html
6V6 familly: 6V6, 6AQ5, 5AQ5, 6L31...
some of them you can buy for 1-2$...
6V6 in triode has the right MU - around 9
6V6 familly: 6V6, 6AQ5, 5AQ5, 6L31...
some of them you can buy for 1-2$...
6V6 in triode has the right MU - around 9
...so folks,just want to tell you,that I have finished the 6sn7 line stage and Im verry happy with the sound.Im using now 6cg7 tubes but with same circuit,becouse the 6sn7 and 6cg7 are the same tube,just that the 6cg7 is a miniature 9 pin version.Im using right now 6cg7 RCA tri mica with black plates and the sound is TOP!Truly deep bass with great control and a lot of detail in the midlle and verry silky top section.Im verry plased with the sound.So thanks to Frank for this trula simply and good design.
But now I have one more question!My Friend have some dac board with CS4390 dac chip and this dac have diferential voltage output.SO it is posibile to conect this dac with the dacs out R+,R- and L+,L- to this line preamp design and if yes HOW????
My good friend that have buy this dac board a time ago from me,He just want to build the same line preamp,becouse he is verry impresed how good this sounds.
So plese for help again guys.
😉
But now I have one more question!My Friend have some dac board with CS4390 dac chip and this dac have diferential voltage output.SO it is posibile to conect this dac with the dacs out R+,R- and L+,L- to this line preamp design and if yes HOW????
My good friend that have buy this dac board a time ago from me,He just want to build the same line preamp,becouse he is verry impresed how good this sounds.
So plese for help again guys.
😉
Hi,
Glad to hear you like the sound of the preamp.😎
I'm not familiar with the Crystal/Cirrus Logic chip but if it does not require I/V conversion then you could take the -L and -R output from the chip before the coupling caps and feed that through a pair of appropriately sized coupling caps to the input of the stereo preamp.
You also want to pull the opamp(s) behind the DAC chip so they don't feed back any signal to the preamp stage.
The preamp inverts signal polarity so that is why you want to take the signal off the - rails.
Ciao, 😉
Glad to hear you like the sound of the preamp.😎
I'm not familiar with the Crystal/Cirrus Logic chip but if it does not require I/V conversion then you could take the -L and -R output from the chip before the coupling caps and feed that through a pair of appropriately sized coupling caps to the input of the stereo preamp.
You also want to pull the opamp(s) behind the DAC chip so they don't feed back any signal to the preamp stage.
The preamp inverts signal polarity so that is why you want to take the signal off the - rails.
Ciao, 😉
Hi,
Just wondering, but I fail to see how fast switching diodes in PS rectification can improve "dynamic" ?
Could you pls elaborate on this?
TIA, 😉
Just wondering, but I fail to see how fast switching diodes in PS rectification can improve "dynamic" ?
Could you pls elaborate on this?
TIA, 😉
....hi Frank...
...thanks again for your answer.What I have in mind and its the problem with the CS4390 DAC chip,is,that this have balanced voltage output,so the i/v conversion and the opamps are allready build in ,in this dac chip.My friend use now the lundahl output transformer to become from balanced input conversion to unbalanced output.So now he have the idea just to replace the transformers with this line preamp stage.So He will need some conversion from balanced input to unbalanced output??
Is this posibile with this design???😕
...thanks again for your answer.What I have in mind and its the problem with the CS4390 DAC chip,is,that this have balanced voltage output,so the i/v conversion and the opamps are allready build in ,in this dac chip.My friend use now the lundahl output transformer to become from balanced input conversion to unbalanced output.So now he have the idea just to replace the transformers with this line preamp stage.So He will need some conversion from balanced input to unbalanced output??
Is this posibile with this design???😕
Hi,
Your friend could still use his transformers to go from balanced out to single ended out. He may end up with too much gain though depending on the step-up ratio of the transformer model.
Or he could take the output as I described in the posting above. Use analog ground (AGND) for the signal return path.
In the latter case the output level would be roughly half of the full output, i.e. 1 VRMS instead of 2VRMS which isn't a problem since the preamp stage amplifies the signal more than sufficiently to drive the input of the amplifier.
Examples:
Different chip, same principle:
Introduccion a SPDIF
CD DAC Lampucera lampizator
Ciao, 😉
Your friend could still use his transformers to go from balanced out to single ended out. He may end up with too much gain though depending on the step-up ratio of the transformer model.
Or he could take the output as I described in the posting above. Use analog ground (AGND) for the signal return path.
In the latter case the output level would be roughly half of the full output, i.e. 1 VRMS instead of 2VRMS which isn't a problem since the preamp stage amplifies the signal more than sufficiently to drive the input of the amplifier.
Examples:
An externally hosted image should be here but it was not working when we last tested it.
Different chip, same principle:
Introduccion a SPDIF
CD DAC Lampucera lampizator
Ciao, 😉
.....Frankk,thanks again for the help.Yes now I understund the case.He will just take the L- and R- outputs from the dac and feed this in the preamp stage.This would give some lower output signal,but bether lower than to much when this come in the amplifer.
Thanks verry much.I will report back how its work in a cuple of days.In the mean time I will try some 6H30Pi tube in my preamp to compare this with 6cg7.
Have a good time!🙂
Thanks verry much.I will report back how its work in a cuple of days.In the mean time I will try some 6H30Pi tube in my preamp to compare this with 6cg7.
Have a good time!🙂
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