PCB?
A PCB for Frank's preamp? Oh my, why would you when point to point wiring is so easy? I'da know, cause this is easier for me?
Your thoughts on this would be grand. Could have errors as I have not spent much time on it. I have new amps, speakers and now to round out the project I added a DIY pre. All projects in the oven cooking in the kitchen. The speakers and amp are ready for assembly and I'm concurrently working on them.
Cheerio!
A PCB for Frank's preamp? Oh my, why would you when point to point wiring is so easy? I'da know, cause this is easier for me?
Your thoughts on this would be grand. Could have errors as I have not spent much time on it. I have new amps, speakers and now to round out the project I added a DIY pre. All projects in the oven cooking in the kitchen. The speakers and amp are ready for assembly and I'm concurrently working on them.
Cheerio!
Attachments
Power?
I found this schematic(Aburquerque Power supply) searching through DIY(and Frank's pre) too.
I have not yet done a PCB for PWR but I think I could muster one in a jiffy. Oh no! Solid state PWR! Why? Hey guys I'm hard core on sound but there has to be a limit. My ears have limitations. I hop yee-all understand. I know it is not everybody's cup of tea when it comes to DIY valves.
Aburquerque Power:
I found this schematic(Aburquerque Power supply) searching through DIY(and Frank's pre) too.
I have not yet done a PCB for PWR but I think I could muster one in a jiffy. Oh no! Solid state PWR! Why? Hey guys I'm hard core on sound but there has to be a limit. My ears have limitations. I hop yee-all understand. I know it is not everybody's cup of tea when it comes to DIY valves.
Aburquerque Power:
Attachments
SUGGESTION
If you already have this 6SN7s at hand and are willing to make it, just take a quick look at the RPA preamp on my webpage www.tubeaudio.8m.com
The line stage of the RPA uses ECC82, but since the sub is the same, you can copy all values and make it with the 6SN7.
It will sound way, way, better. Maybe you should first try the original schematic posted, and than change to the suggested RPA line stage, just to understand why I wrote the above.
For the power supply, try to stay unregulated, with chokes and eventually a tube rectifier (like 5Y3).
Regards,
Alex
If you already have this 6SN7s at hand and are willing to make it, just take a quick look at the RPA preamp on my webpage www.tubeaudio.8m.com
The line stage of the RPA uses ECC82, but since the sub is the same, you can copy all values and make it with the 6SN7.
It will sound way, way, better. Maybe you should first try the original schematic posted, and than change to the suggested RPA line stage, just to understand why I wrote the above.
For the power supply, try to stay unregulated, with chokes and eventually a tube rectifier (like 5Y3).
Regards,
Alex
Alex's line stage looks like a CCD line stage I was going to do. If you look at the TCJ article here and here you might find further explanation.
CCDGC
Yes, I use those or a similar type of gain stages troughout my preamp designs, since I like them very much.
Broskie gave it a name - CCDGC. At the time internet in Serbia was a very disputable affair
Anyway, this is not about "who did it first" but about the fact that the topology is one of the very best.
Regarding the PCB, I was surprised to find out that a lot of those who have made the line section of the RPA preamp have used my PCB design, care of a good friend - Elvis (his site is nowhere to be found, he seems to have vanished from internet tube life) to whom I sent the design files.
When it comes to the other "similar" schematics, yes I do not like the superfluous caps (I cannot see a valid purpose for the one before the grid of the first triode). And, what I actually do not like is that the first triode draws too little current, while the second actually drives too much current (yes, there is such a thing as too much current, even for cathode followers).
Well, if you want to have the first one draw more, and the second one draw less, in the end there is no reason why should they not drive the same current (in counterphase, thus "constant current draw"). Eventually I stumbled upon the Broskie line stage and adopted his "additional" resistor on the cathode follower as a good idea. Else, I would have ommitted it just like in the gain blocks of the phono stage...
Anyway, the RPA actually has a 5670 implementation of this stage, and over the years several different versions were implemented with various tubes by various people, every time with good results.
Yes, I use those or a similar type of gain stages troughout my preamp designs, since I like them very much.
Broskie gave it a name - CCDGC. At the time internet in Serbia was a very disputable affair
Anyway, this is not about "who did it first" but about the fact that the topology is one of the very best.Regarding the PCB, I was surprised to find out that a lot of those who have made the line section of the RPA preamp have used my PCB design, care of a good friend - Elvis (his site is nowhere to be found, he seems to have vanished from internet tube life) to whom I sent the design files.
When it comes to the other "similar" schematics, yes I do not like the superfluous caps (I cannot see a valid purpose for the one before the grid of the first triode). And, what I actually do not like is that the first triode draws too little current, while the second actually drives too much current (yes, there is such a thing as too much current, even for cathode followers).
Well, if you want to have the first one draw more, and the second one draw less, in the end there is no reason why should they not drive the same current (in counterphase, thus "constant current draw"). Eventually I stumbled upon the Broskie line stage and adopted his "additional" resistor on the cathode follower as a good idea. Else, I would have ommitted it just like in the gain blocks of the phono stage...
Anyway, the RPA actually has a 5670 implementation of this stage, and over the years several different versions were implemented with various tubes by various people, every time with good results.
The problem with 1Nxxx is not noise! It's the fact that they are solid state diodes. Some people tend to solve the problem by aggravating it (in my opinion) by using ultrafast recovery diodes...
Actually, there is just no comparison between tube rectifiers and ss diodes. To try and hear is to believe. Since I plugged my first GZ34, I cannot imagine doing a power supply with ss diodes...
And the worst thing there is that actually the GZ34 is not the best sounding rectifier -- actually, its somewhere in the lower half when sound is compared. Direct heated tube rectifiers generally sound way better than indirect.
Some will find these statements offending, but most probably they have not tried tube rectifiers for themselves. Sometimes it is better to try than blindly believe what you hear/say of read!
That said, democracy teaches us to be tollerant of those who use SS diodes
Re: CCDGC
I have good number of Sylvania 6SN7 made in Canada, in original packaging! I’ll look at the RPA line stage. Thanks!
I’m going to check it out tonight, cheers.
I couldn’t agree more. Will do! And yes it will be a solid state power supply for certain.
Thank you folks for the input. I’ll be back with some results or more questions.
Alex Kitic said:
I have good number of Sylvania 6SN7 made in Canada, in original packaging! I’ll look at the RPA line stage. Thanks!
I was not aware of it. I’ll snoop around on DIY to see if I can find it. Thanks!leadbelly said:
athos56 said:
I’m going to check it out tonight, cheers.
Boy, you certainly like your RPA. I’ll do some looking into that.Alex Kitic said:Broskie gave it a name - CCDGC. At the time internet in Serbia was a very disputable affair
Regarding the PCB, I was surprised to find out that a lot of those who have made the line section of the RPA preamp have used my PCB design.
ray_moth said:
I couldn’t agree more. Will do! And yes it will be a solid state power supply for certain.
Thank you folks for the input. I’ll be back with some results or more questions.
mosfets said:
If you don't know about the original thread, I recommend that you read it:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=12042
So now we have three line stages from Frank. From a paper stand point, it is kinda hard to make a decision. I may end up making two ala the post "running in circles" as the ultimate project looks similar to another I buillt years ago.
I've cemented my decision typing this post. Athos56 post #15: I'll build boards for both options. It's funny, I've over looked that diagram a hundred times thinking somebody was depicting A & B channels of the same
I've been mulling over these threads for months now. The more I read the less I can see.
Thanks a mint chaps!
I've cemented my decision typing this post. Athos56 post #15: I'll build boards for both options. It's funny, I've over looked that diagram a hundred times thinking somebody was depicting A & B channels of the same
I've been mulling over these threads for months now. The more I read the less I can see.
Thanks a mint chaps!