Gold mine of DI¥ audio tubes schematics from Japan

[Soundhappy]

Updates for Diyers audio hobby tubes audio articles HOME

 

[astouffer]

That 6AQ5 being driven by the jfet is interesting.

 

[MagicBus]

What would be the output impedance of this jfet?

 

[Soundhappy]

That 6AQ5 being driven by the jfet is interesting.

Yes interesting flea watt's amplifier ,updated lower distortion version is possible..

 

[directdriver]

The way the interstage transformers is connected is very curious. I assume there's some feedback involved? The secondary is getting negative supply for fixed bias but that one end is also connected to the primary!

 

[dreamth]

@directdriver
No , it's just a step up autotransformer.Follow the dot!

 

[directdriver]

it's just a step up autotransformer. Follow the dot!

Ah, you're right! The way it's drawn threw me for a loop! But what's the benefit of connecting as an autoformer instead of a traditional interstage transformer? Since there is no global feedback, neither would cause oscillation anyway. I believe the NC10 is a 1:1 ratio transformer so neither connection would have step up gain. I prefer the signal to be magnetically coupled even if it's less "pure" but I personally like transformer coloration.

 

[dreamth]

less iron and copper needed and usually better frequency transfer ...

 

[PRR]

...I believe the NC10 is a 1:1 ratio transformer....

Follow the dots. The input is one dot/winding. The output is three dots/windings. 1:3 ratio.

 

[analog_sa]

Looks like one of those slightly bizarre part applications only the Japanese are capable of

The NC10 basically replaces a grid choke with some added gain. It's main function appears to be a low dc path for biasing and the gain is just an added bonus.

Imo this part sounds much better with no dc current flowing which may be another reason for choosing the unusual application.

 

[zintolo]

Nelson Pass has this configuration in his SIT-3 with (IIRC) an Edcor PC600/15k.
https://www.firstwatt.com/pdf/prod_sit3_info.pdf

 

[nicoch58]

Yep Nelson and Zm use a lot...but I thinks for NP add a schade too.

 

[Soundhappy]

More articles to inspire Diyers hobby with audio tubes circuits HOME

 

[Soundhappy]

+
どうもありがとうございます
Domo arigato gozaimasu

 

[Soundhappy]

Looks like one of those slightly bizarre part applications only the Japanese are capable of

Japanese learned a lot's from old Western Electric and RCA schematics book's

 

[Soundhappy]

Does opamp with tubes amplifier Diy schematics from Japan was inspired by work of Sir Adrianus Van Doorn show at

European Triode Festival Berlin 2014 ?

 

[Demonkleaner]

Cool stuff Soundhappy! Especially those MV rectifiers.
Thank You

 

[Soundhappy]

Enjoy! 遠い昔のラジオ少年 HOME

Thomas Edison - World's Greatest Innovator. English Subtitles on Vimeo

Kanazawa Phonograph Museum on Vimeo

 

[Windcrest77]

I finally got around to pulling down many of these schematics, and read over hundreds more. It took all week. The one thing I come away with is of these thousands of schematics, they all use incredibly good transformers! For crying out loud even the beginner projects here use Tango and Hasimoto and ISO, etc.! Damn, builders in Japan sure do have a lot of great iron available, even for their beginner projects.

 

[gideon1990]

They sure do love lots of high quality iron