Hi,
I have some pain to source at good (reasonable) price a NOS 6072A !
Are there please any reasonable NOS model and serious shop in Europe for this ?
Look at at Jan Music with no success
!
I would like to try first this tube as I'm beginner before jumping to some more problematic tubes like the 3DA (easier to source) and expensive because the layout !
I have some pain to source at good (reasonable) price a NOS 6072A !
Are there please any reasonable NOS model and serious shop in Europe for this ?
Look at at Jan Music with no success
! I would like to try first this tube as I'm beginner before jumping to some more problematic tubes like the 3DA (easier to source) and expensive because the layout !
D,
NOS 6072a seems very expensive nowadays...
Then there is EH ones here --> EH 12AY7 / 6072A Electro Harmonix / Russia - Vorstufenröhren:
or EH 6072A/12AY7, 15,80 € or
12AY7/6072A TAD Premium Selected - TAD Vorstufenröhren SELECTED Tube
D3A I have at home... unused. You can have them
NOS 6072a seems very expensive nowadays...
Then there is EH ones here --> EH 12AY7 / 6072A Electro Harmonix / Russia - Vorstufenröhren:
or EH 6072A/12AY7, 15,80 € or
12AY7/6072A TAD Premium Selected - TAD Vorstufenröhren SELECTED Tube
D3A I have at home... unused. You can have them
Hello,
basically you could use nearly every tube as a output stage, as long as it is suitable for audio use ( linear characteristics, check datasheets ). You will have a strong negative feedback anyway which would take care of distortion ( though it will be higher than that of a Opamp ).
Balanced-Ouput DACs and Tubes and Aikido
Have a look at the " Balanced DAC & Filtered Broskie cathode follower ".
Be sure to chose a operating point with enough headroom ( about -4V UG1 if your DAC has a output of each +- 2,5V ) to make sure that you don´t draw grid current..
I wanted to build a tube output stage myself but it is pointless for me since I already use DIY tube amps with my DAC. If you intend to use a transistor amplifier with your DAC and hope for some tube distortion, you may build your tube output buffer
But remember, most tubes require a high voltage in order to operate properly, DC heater ( you might need to elevate the heater potential of the upper tube ) and a clean power supply.
In terms of output distortion, noise it will perform worse than a Opamp though..
Best regards,
basically you could use nearly every tube as a output stage, as long as it is suitable for audio use ( linear characteristics, check datasheets ). You will have a strong negative feedback anyway which would take care of distortion ( though it will be higher than that of a Opamp ).
Balanced-Ouput DACs and Tubes and Aikido
Have a look at the " Balanced DAC & Filtered Broskie cathode follower ".
Be sure to chose a operating point with enough headroom ( about -4V UG1 if your DAC has a output of each +- 2,5V ) to make sure that you don´t draw grid current..
I wanted to build a tube output stage myself but it is pointless for me since I already use DIY tube amps with my DAC. If you intend to use a transistor amplifier with your DAC and hope for some tube distortion, you may build your tube output buffer
But remember, most tubes require a high voltage in order to operate properly, DC heater ( you might need to elevate the heater potential of the upper tube ) and a clean power supply.
In terms of output distortion, noise it will perform worse than a Opamp though..
Best regards,
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Thank you,
Great paper!
Basicly I wanted to make a tube(s) pre with an unity gain 12ax7 tube and a sota traffo output... And yes to add some H2 and nice distorsion before a solid State amp (85 db speaker).
Because both I'm beginner and it's a too costy project, I would go for a good output with a TDA1541 chip. I'm sure a oap amp is quieter! Btw have a lot of pleasure listening an Audial AYA 2014 TDA1541 dac.
For some reason I don't want to go for a balanced dac chip.
I would like to try a not too much expensive 6072A to make it à la Thorsten Loesch, this tube is easier for a beginner; Even a 6922 à la Zanden would be an hassle for me for a diy project and a first one with tubes ! So not talking yet of a 3DA whic is a good tube for a tda1541 if you know enough about wild horses and layout .
I can buy a brand new 6072A Electro Harmonix and should do (20 euros - with shipping-Stixx's link)). But if I can find a no too bad NOS 6072A adding a little plus money... (60 to 80 euros?) why not. If too rare at this price or not worth to pay x3 or x4 for the a too little added quality in relation to the brand new one: better to forgett the NOS ?
Great paper!
Basicly I wanted to make a tube(s) pre with an unity gain 12ax7 tube and a sota traffo output... And yes to add some H2 and nice distorsion before a solid State amp (85 db speaker
).Because both I'm beginner and it's a too costy project, I would go for a good output with a TDA1541 chip. I'm sure a oap amp is quieter! Btw have a lot of pleasure listening an Audial AYA 2014 TDA1541 dac.
For some reason I don't want to go for a balanced dac chip.
I would like to try a not too much expensive 6072A to make it à la Thorsten Loesch, this tube is easier for a beginner; Even a 6922 à la Zanden would be an hassle for me for a diy project and a first one with tubes ! So not talking yet of a 3DA whic is a good tube for a tda1541 if you know enough about wild horses and layout .
I can buy a brand new 6072A Electro Harmonix and should do (20 euros - with shipping-Stixx's link)). But if I can find a no too bad NOS 6072A adding a little plus money... (60 to 80 euros?) why not. If too rare at this price or not worth to pay x3 or x4 for the a too little added quality in relation to the brand new one: better to forgett the NOS ?
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I would forget about "NOS" tubes...leave them for the guys who like to pay a lot of $$$ because they believe in their religion..
If you want to build a catode follower output stage, don´t forget that the max. gain is <1 ( nearly 1, unity gain ). You have a strong negative feedback through the catode resistor which will barely make a difference if you compare eg. a super expensive Telefunken E88CC or a cheap E88CC from JJ.
If you want to build a catode follower output stage, don´t forget that the max. gain is <1 ( nearly 1, unity gain ). You have a strong negative feedback through the catode resistor which will barely make a difference if you compare eg. a super expensive Telefunken E88CC or a cheap E88CC from JJ.
That would be an excellent choice: high transconductance, medium gain, and linear.
Thorsten Loesch uses the 6072A for basic mods with tda1541 ! 6922, D3A are goods but problematics for beginners ! because too high high transconductance ?
T. Loesch use the "drift" of the dac chip current output than passive i/v of the TDA1541 to load the tube and one of the easiest to do that is the 6072A according to him and many experienced diyers with both this dac chip and tubes ! Though with experiences you can uses any good tubes :cd-77 is 5687 iirc and a Mulard ??? !
Could an ECC99 a good competitor or in the same family than the 6922, 3DA ?
The new EH 6072A is 17 euros here, so why not follow T. Loesch shematics and advices ?
T. Loesch use the "drift" of the dac chip current output than passive i/v of the TDA1541 to load the tube and one of the easiest to do that is the 6072A according to him and many experienced diyers with both this dac chip and tubes ! Though with experiences you can uses any good tubes :cd-77 is 5687 iirc and a Mulard ??? !
Could an ECC99 a good competitor or in the same family than the 6922, 3DA ?
The new EH 6072A is 17 euros here, so why not follow T. Loesch shematics and advices ?
A ECC99 is excellent from my calculations, very linear and also easy to obtain I´ve read his name in another forum and he doesn´t have quite a "good reputation" when it comes to electrical design ( at least there have been a few discussions about him in other forums too ) . I don´t want to go into further details but some people have "strange ways" of building stuff and the more you understand about electrical engineering, the better you can see if there is some truth behind
Like I said before, basically you can use nearly every tube as a output buffer, eg. even a EL84.
You need to know the following points first:
1) the RMS Output of your DAC :
Assuming that most DACs will push about 2V RMS, you need a tube which can perform well at at least 2v * 2^0.5 = 2,83V
The grid would need a negative voltage of -2,83V UG1 as a bias. But wait, what happens if you really drive the tube +- 2,83V peak on the grid ? You can draw grid current once you reach 0V UG1...not something we want, right ? Let´s say that we add at least +0,5V as a safety measure to prevent this effect, we will need at least -3,3V UG1.
This is why I would chose a tube which can operate linear at about -4V UG1 or higher
We can expect a very low voltage swing from a catode follower, in fact the output voltage is slightly lower than the input ( <1 ; unity gain ).
This is why you could also use eg. a stronger Triode at -52V UG1 as a buffer...but this would be overkill
Next we need to consider the Ufk ( isolation between the catode and the heater ), some tubes will require you to elevate the heater potential.
Some tubes are very linear but prone to oscillating ( I know from experience ), this is where you actually need to know how to use them
Best regards,
I´ve read his name in another forum and he doesn´t have quite a "good reputation" when it comes to electrical design ( at least there have been a few discussions about him in other forums too ) . I don´t want to go into further details but some people have "strange ways" of building stuff and the more you understand about electrical engineering, the better you can see if there is some truth behind Like I said before, basically you can use nearly every tube as a output buffer, eg. even a EL84.
You need to know the following points first:
1) the RMS Output of your DAC :
Assuming that most DACs will push about 2V RMS, you need a tube which can perform well at at least 2v * 2^0.5 = 2,83V
The grid would need a negative voltage of -2,83V UG1 as a bias. But wait, what happens if you really drive the tube +- 2,83V peak on the grid ? You can draw grid current once you reach 0V UG1...not something we want, right ? Let´s say that we add at least +0,5V as a safety measure to prevent this effect, we will need at least -3,3V UG1.
This is why I would chose a tube which can operate linear at about -4V UG1 or higher
We can expect a very low voltage swing from a catode follower, in fact the output voltage is slightly lower than the input ( <1 ; unity gain ).
This is why you could also use eg. a stronger Triode at -52V UG1 as a buffer...but this would be overkill
Next we need to consider the Ufk ( isolation between the catode and the heater ), some tubes will require you to elevate the heater potential.
Some tubes are very linear but prone to oscillating ( I know from experience ), this is where you actually need to know how to use them
Best regards,
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http://www.diyaudio.com/forums/tubes-valves/197920-thorstens-tube-stage-tda1541a-3.html#post2743267
and
http://www.diyaudio.com/forums/tubes-valves/197920-thorstens-tube-stage-tda1541a-2.html#post2742817 ?
http://www.diyaudio.com/forums/tubes-valves/197920-thorstens-tube-stage-tda1541a-4.html#post2744076
Mogliaa with e180f tube http://www.diyaudio.com/forums/tubes-valves/197920-thorstens-tube-stage-tda1541a-6.html#post2747723
And finally in the mouth of T. Loesch : "They have more in common than different. AMR would use 6072A if we could get enough in the open market. A simple Hybrid Mu-Follower or a Gomes stage are both very clean, low output impedance etc. I would have used a Gomes stage as in the AMR designs, but it would not fit..." : http://www.diyaudio.com/forums/digital-source/30025-decoupling-tda1541a-20.html#post2661834
So I want to walk in this trace... 3cg could be great though expensive. 17 euros for a 6072A would be nice for my low money !
and
http://www.diyaudio.com/forums/tubes-valves/197920-thorstens-tube-stage-tda1541a-2.html#post2742817 ?
http://www.diyaudio.com/forums/tubes-valves/197920-thorstens-tube-stage-tda1541a-4.html#post2744076
Mogliaa with e180f tube http://www.diyaudio.com/forums/tubes-valves/197920-thorstens-tube-stage-tda1541a-6.html#post2747723
And finally in the mouth of T. Loesch : "They have more in common than different. AMR would use 6072A if we could get enough in the open market. A simple Hybrid Mu-Follower or a Gomes stage are both very clean, low output impedance etc. I would have used a Gomes stage as in the AMR designs, but it would not fit..." : http://www.diyaudio.com/forums/digital-source/30025-decoupling-tda1541a-20.html#post2661834
So I want to walk in this trace... 3cg could be great though expensive. 17 euros for a 6072A would be nice for my low money !
AHAHA Oliver, I can recognize your free mind here
I believe here I can explain it to you ! It's a question of vocabulary ! (if it's really a question from you)
Swap the word "God" by "Experienced"
Swap the word 'understand" by "experiment" (go out the house to listen to a CD-77, a simple CD-777, etc).
Swap the word "Truth" by "prove"
... and the prophety will work much better !
I don't say it will be for you an epiphany, but you will understand, knowledge and experience stay an important factor. This is why it's often better for beginners like I am and you still are to follow such best diyer like Pedja, Thorsten, John.
Now, I'm the first to love liberty, break all my device to adapt them by fine tunning to the rest of the hifi system or bad experiments, but Oliver, please: show me better than those guys with TDA1541 and I will follow them, whatever you call them : democrats, diyers, modests non shown Genius, etc !
It's not about religion it's about the final result ! Instead critics the way I do, show me a better way I can copy and firstly prove it : if the device I listen is better than the one of those experienced guys (who share) I trust you.
The rest is words & music... just phrases...
Never forgett you talk to a french : we invent official state atheism, we are found of liberty and I am the first to live to be free.... ! Myself I don't trust in any religion but the culture !
BTW I find the intelligence is better when shared, so I'm the first not to Godism the others people and have a big doubt as soon as I listen a prophety ... or an anti prophety!
I believe here I can explain it to you ! It's a question of vocabulary ! (if it's really a question from you)
Swap the word "God" by "Experienced"
Swap the word 'understand" by "experiment" (go out the house to listen to a CD-77, a simple CD-777, etc).
Swap the word "Truth" by "prove"
... and the prophety will work much better !
I don't say it will be for you an epiphany, but you will understand, knowledge and experience stay an important factor. This is why it's often better for beginners like I am and you still are to follow such best diyer like Pedja, Thorsten, John.
Now, I'm the first to love liberty, break all my device to adapt them by fine tunning to the rest of the hifi system or bad experiments, but Oliver, please: show me better than those guys with TDA1541 and I will follow them, whatever you call them : democrats, diyers, modests non shown Genius, etc !
It's not about religion it's about the final result ! Instead critics the way I do, show me a better way I can copy and firstly prove it : if the device I listen is better than the one of those experienced guys (who share) I trust you.
The rest is words & music... just phrases...
Never forgett you talk to a french : we invent official state atheism, we are found of liberty and I am the first to live to be free.... ! Myself I don't trust in any religion but the culture !
BTW I find the intelligence is better when shared, so I'm the first not to Godism the others people and have a big doubt as soon as I listen a prophety ... or an anti prophety!
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