Gold mine of DI¥ audio tubes schematics from Japan

[Soundhappy]

Just find sensei Sakuma Susumu ultra-simple 211 + 211 " rare pearl "

MJ0001_(5)211-para-single-power-amp_SakumaS.pdf - Google Drive

Genius design DHT amplifier

What Diyers the very best " diamant " interesting article example is ?

 

[Norelco]

Nice[emoji106][emoji106]

 

[Soundhappy]

New schematic diy projects are available today

MJ1708_(05)6BX7GT-5998A-PP-amp_SoyaS.pdf - Google Drive

MJ1708_(04)845-single-pre-main-amp_SakumaS.pdf - Google Drive

and few others...

Greetings 🙂

 

[Soundhappy]

Second part of new schematics was update. This one and more..

r-tec1708_(02)KT88(T)-single-amp_ShiodaH.pdf - Google Drive

Have fun 🙂

 

[audiowize]

I would be really cautious with these designs. Seeing an LM1085 setup to heat a 211 doesn't inspire much confidence in me.

 

[Soundhappy]

Good point in diy spirit you can open dedicated thread about this amplifier and share your better creative solution.
Is for inspire your way of making 😉
All tubes projects was build by Diyers , tested and work amplifiers.
Is not virtual software simulation is verified true analog only.
Sure not perfect for every body but generous gifts 🙂

 

[JoeAlders]

Exactly. To see measured characteristics gives me more confidence in the design.

 

[hpeter]

Mini Watters Project
µW obsession

 

[jazbo8]

The whole Passionate Tube Amplifier site is pretty good, especially the All Differential Push-Pull Amplifier section.

 

[hpeter]

http://our-house.jp/4-400/index.htm
just browsing around web, and suddendly this......
g2 gets some punishment... 2kv 😱 35w screen can survive that ? ( i hope)

 

[jazbo8]

The construction of the amplifier itself is also quite bonkers - don't try this at home, kids...🙂

Capacitor banks:

Transformer and Choke towers:

Heatsink and chimney for the 4-400A:

 

[Shinja]

He must be a crazy guy. He wrote some crazy experiments and circuits in his website. Worth reading or even looking pictures.
http://our-house.jp/vtm/index.htm

I want to try reducing heater power he trying if it does not much shorten valve life. How do you guys think? If the space charge is too less for the anode current,the cathode will be damaged by itself or the contaminated ion, IIRC? But how much? current, heater power, cathode thermal resistance and cathode temperature? In fact it should be avoided, I suppose...

 

[jazbo8]

I guess there is a limit, e.g, 15%, on how much you can lower the filament voltage before shortening the life of the tube. I think his experiments basically confirmed what the old texts said.

 

[hpeter]

reason, why it got my attention, is the use of similar tube (i have 4-125 sitting on shelf) i just want 1500v

according to ds, 600v max g2... but when he puts 2kv , then it must be fine.. i guess..
to 4-400a 800v max

 

[Shinja]

I guess there is a limit, e.g, 15%, on how much you can lower the filament voltage before shortening the life of the tube. I think his experiments basically confirmed what the old texts said.

Thank you. I found old Hitachi's article on the internet. Although it is very small voltage and current amplification application, it suggest operationg point of 12AX7
Ip 1mA Vh 6.3V or 12.6V
Ip 100uA Vh 4.5V or 9.0V
Ip 10uA Vh 3.4V or 6.8V
This is more steep change than I thought. Lowering heater voltage seems not a good thing.

 

[jazbo8]

Lowing the heater voltage is sometimes done in mic preamp applications, but just not with the 12AX7... 😉

 

[Soundhappy]

I do make little exception and show Tamasan 22 Diy works :
Tamasan 22
We can find few schematics inside of his blog but not so many.
Amplifiers are from tiny battery powered , OTL's to huge transmitter tubes monsters.
Extraordinary and out of limits. Attention !!!! 😀

 

[Soundhappy]

Bunch of schematics from sensei Susumu Sakuma

Schematics sensei Sakuma

Direct Heating

GM70 triode Amplifier Kit

YouTube

sensei Sakuma video

 

[hpeter]

tamasan likes hazardous things

 

[Soundhappy]

Feerless amplifier Diyer
not much LTSpice 🙂