Dear Folks,
Does anyone do this 6N3 based preamp can share the schematic ? My friend give me 4 these tubes. I want to DIY the preamp and use in between the DAC and Power AMP (FET)
CK
Does anyone do this 6N3 based preamp can share the schematic ? My friend give me 4 these tubes. I want to DIY the preamp and use in between the DAC and Power AMP (FET)
CK
6N3 appears to be a rectifier tube. Would you care to post more information about the tubes in your possession?
6N3 is a chinese copy of the Russian 6N3P, which is a copy of the US 5670/2C51 dual triode.
There are a lot of 6N3 preamp and buffer designs on the net, just "google" 6N3 tube preamp schematic
There are a lot of 6N3 preamp and buffer designs on the net, just "google" 6N3 tube preamp schematic
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Take a look at:
Pre Amplifier for Rotel CDP Skematic diagram
as a start. This is to be used as a dac analog output stage.
Pre Amplifier for Rotel CDP Skematic diagram
as a start. This is to be used as a dac analog output stage.
Hello,
you think, it is possible to make changes to this preamp tube Preamplificatore valvolare stereo to adapt it to a DAC output?
Thanks so much
Hi,
It's hard to say, there is no schematic for this on the website, and it also depends on the type of DAC you have. It could be a I out dac, then you need a current (I) to voltage (V) converter stage, or it could be a V out dac, then you actually only need a preamp stage. It is possible that the preamp you give the link to could be used for both, but it is hard to say without a schematic. I suggest that you take a look at:
http://www.pearl-hifi.com/06_Lit_Ar...pers/Loesch_Thorsten/Tube Stages for DACs.pdf
And: https://www.by-rutgers.nl/IV-converter.html , this is based on opamps, but explains the I to V converter and low pass filters.
You could also take a look at: http://www.tubecad.com/2012/06/blog0233.htm
It could give you the information you need to proceed with your project.
It's hard to say, there is no schematic for this on the website, and it also depends on the type of DAC you have. It could be a I out dac, then you need a current (I) to voltage (V) converter stage, or it could be a V out dac, then you actually only need a preamp stage. It is possible that the preamp you give the link to could be used for both, but it is hard to say without a schematic. I suggest that you take a look at:
http://www.pearl-hifi.com/06_Lit_Ar...pers/Loesch_Thorsten/Tube Stages for DACs.pdf
And: https://www.by-rutgers.nl/IV-converter.html , this is based on opamps, but explains the I to V converter and low pass filters.
You could also take a look at: http://www.tubecad.com/2012/06/blog0233.htm
It could give you the information you need to proceed with your project.
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CK,
I'm not sure if you want to go the I to V converter route or what you want is a line stage to go between the output of your CDP and your power amp. Be careful of some of the 6N3 boards out there on eBay, they don't put nearly enough B+ voltage on the tubes to make them work properly (see link). Have your tubes tested if possible, there's no sense building something if the tubes you have are no good. The problem with the 6N3 and its 2C51 etc. western equivalents is that they have a unique pin-out so it would require some work to change an amp over to a more common 6DJ8 or 12AU7 tube for instance if you don't like the 6N3.
Cheers, Steve
Battle of the Cheap Line Stages – Part 2 | Wall of Sound | Audio and Music Reviews
I'm not sure if you want to go the I to V converter route or what you want is a line stage to go between the output of your CDP and your power amp. Be careful of some of the 6N3 boards out there on eBay, they don't put nearly enough B+ voltage on the tubes to make them work properly (see link). Have your tubes tested if possible, there's no sense building something if the tubes you have are no good. The problem with the 6N3 and its 2C51 etc. western equivalents is that they have a unique pin-out so it would require some work to change an amp over to a more common 6DJ8 or 12AU7 tube for instance if you don't like the 6N3.
Cheers, Steve
Battle of the Cheap Line Stages – Part 2 | Wall of Sound | Audio and Music Reviews
THANK YOU, for your advice me. My DAC is this https://it.aliexpress.com/item/Asse...t-384K/32627445751.html?spm=2114.13010608.0.0. 1Trc2p. Of course, no schematic it's hard modification.
Hello guys,
since there is no schematic on the net, I visually rebuilt the connections, I noticed that the schematic is much like Little Bear Tube preamp.
I want to try to improve it and I want to reduce the gain, what do you advise?
These are the values and schematic detected in my preamp Preamplificatore valvolare stereo
MPrivitera1:
Your schematic is 2 gain stages one after the other that's why there is too much gain. It is reduced by feedback through C3 and R5. You might be able to adjust the gain by reducing R5. BUT...Why have feedback in a line stage? IMHO this sounds bad! Start with a good feedback-free circuit in the beginning. The Chinese circuit I mentioned earlier is an implementation of Aikido circuit but it suffers from too little B+ voltage. B+ on that board is limited to about 60 volts. It probably needs about 150 to 200 volts to make the tubes work properly. PM me and I'll give you the values used on the Yuanjing board.
Cheers, Steve
Your schematic is 2 gain stages one after the other that's why there is too much gain. It is reduced by feedback through C3 and R5. You might be able to adjust the gain by reducing R5. BUT...Why have feedback in a line stage? IMHO this sounds bad! Start with a good feedback-free circuit in the beginning. The Chinese circuit I mentioned earlier is an implementation of Aikido circuit but it suffers from too little B+ voltage. B+ on that board is limited to about 60 volts. It probably needs about 150 to 200 volts to make the tubes work properly. PM me and I'll give you the values used on the Yuanjing board.
Cheers, Steve
Feedback in this amp will reduce distortion and eleminate tube dependecies. Normally
considered "a good thing".
considered "a good thing".
Hello Steve,
on 'input, 150k resistance I measured 160V ... but you sent an MP
Thank you
Petertub,
I think we fall on opposite sides of the feedback divide. I agree it is good, well a little bit anyway, on a push pull amp, I don't think it has a place in a line stage. Reducing gain by applying feedback is like stepping on the brakes to slow your car down instead of taking your foot off of the gas.
If by "tube dependencies" you mean sonic differences between various tubes isn't that why we love tubes in the first place?
All the best, Steve
I think we fall on opposite sides of the feedback divide. I agree it is good, well a little bit anyway, on a push pull amp, I don't think it has a place in a line stage. Reducing gain by applying feedback is like stepping on the brakes to slow your car down instead of taking your foot off of the gas.
If by "tube dependencies" you mean sonic differences between various tubes isn't that why we love tubes in the first place?
All the best, Steve
HELLO,
-Work update in progress; So, I deleted the volume potentiometer put out and put in its place du resistance from 47K, I put two input resistance from 470K in place of 10 K. I connected input a pot volume of 100k, replaced the capacitors 4 by 2,2uF (I had them all to a brand, put two and two WIMA Mundorf). The greatest effect obtained, at the time, is the Volume control now a regular and not too aggressive as before, perhaps pot original Linear and poor .... The sound, however, is not like very poorly defined and lacking in detail and recently extended the low Range ..... I accept your advice more
Under Now schematic llo with values....
-Work update in progress; So, I deleted the volume potentiometer put out and put in its place du resistance from 47K, I put two input resistance from 470K in place of 10 K. I connected input a pot volume of 100k, replaced the capacitors 4 by 2,2uF (I had them all to a brand, put two and two WIMA Mundorf). The greatest effect obtained, at the time, is the Volume control now a regular and not too aggressive as before, perhaps pot original Linear and poor .... The sound, however, is not like very poorly defined and lacking in detail and recently extended the low Range ..... I accept your advice more
Under Now schematic llo with values....
NFB will reduce the distortion caused by unlinear tube characteristics. All tubes ( and transistors) are unlinear, some more some less. It will
also make the amplification less dependent on the individual tubes,
instead amplification will be a factor of NFB.
Why make it more difficult than nessesairy 😕
Like this you can adjust the gain between 0 and ~20dB (1x...10x)
The Ne bulb is to prevent high voltage between cathode and grid at start-up.
Mona
