Ironamp Video Posted

[Soundhappy]

Mike R. gave me in a private e-mail the hint that 1.75V/47000R gives a current of 0,000037234042553 A
So we have only 37 uV gate leakage. Under 100uV is o.k.

Long live Sun Pec!

And thanks Mike.....!

Yes i join Generg say thanks Mike for great beauty photos
of psu very appreciated

I'm happy to see that the Tokin SITs might be at least semi-legit. I might buy some, I might emulate them with big mosfets....

Generg have inspire Wrenchone to play with Tokin's.
After emulation amp name from Vfet it be V'fake ?
I like Your style 1

stop the blahblah!
it's time for you to build something with the 2SK82 , so much way to do it , single ended , pushpull, active load , choke load , resistor load ,bulb load . fixed bias , source resistor bias , etc...
you 'v got many days of happiness and headache with it.
and let the big boys play with Tokin Sit ( i'm not included)

Juanitox yes you have reason i am in and try push-pull,
and Ironamp first after choke maybe but actually is Aleph J.
I must wait to run Vfets hot and collect parts to be ready.

In spare find caps 4700uF | 385 Vcc for Ironamp prototype is to much ? Voltage normaly 160 Vcc it be around four time.

Thanks guys for useful informations
Best regards

 

[juanitox]

this caps are perfect for the job , better be safer than playing with fire like me with 35V power cap with 34V rail

 

[juanitox]

finally on the sound side the CSX1 ( single ended mod ) is the most pleasant of the 2SK82 sitamp i have built . the only concern is about the shy bass . bass are there but with no punch or power has i had with the inductor SITamp .. so i have two way to search , changing the 600ohm input transformer with a 10K 1:1 and search a better CCS load than the 2SJ28 ..

what about the bass with the Ironamp and it"s transformer output better damping i presume ?

 

[Soundhappy]

the only concern is about the shy bass . bass are there but with no punch or power has i had with the inductor SITamp
rolleyes:

Hi Juanitox
Do your psu filter caps banque is 120 000uF or more ?
What source impedance ? Hors or speakers is 4 Ohm ?

 

[Soundhappy]

what about the bass with the Ironamp and it"s transformer output better damping i presume ?

Let's come back to Ironamp
20Hz have -0,1 dB roll off so is great score for low frequency response. Damping ??
Two amp's Iron and Sony have possibility to configurate primary
maybe this is game to play.
Joint images extracted from Mr Rothacher video.
Anyway we must wait for precise informations from Mike : http://www.audiohobby.com/
Hope You have find solution.
Greeting

 

[Soundhappy]

Juanitox = Nath

 

[juanitox]

my 1/2 CSX1 running fine , it"s time to go to attack the ironamp

my plan is to use only 2 MKP caps for it in a CLC power supply
500u 4H 500u will do the job ..
i have a 1:1 cinemag for input
i need to find a suitable 240V 80/90V power transfo
and the last but more important is the output power transfo..

i could go with edcor but to simple , i will try to find a EU Custom alternative.
with tube the common rule as 5x the anode/cathode resistance ..
what will be the best primary resistance value for the 2SK82 with 95V on it?

 

[Soundhappy]

my 1/2 CSX1 running fine , it"s time to go to attack the ironamp

and the last but more important is the output power transfo..

what will be the best primary resistance value for the 2SK82 with 95V on it?

Hi Juanitox
On schematic output transformer primary have 150 Ohms
with 8 Ohms secondaire but 100 V tension.
Imho if Mr Rothacher made this choice it was calculated
around best sweet spot , why make modifications ?
Lundahl distributor in France give you informations
contact him if interested correct prices :

Lundahl1

contact e-mail : info@ceresaudio.com

Nice you enjoy it sound from your 1/2 CSX1
Greetings

 

[juanitox]

i think michael use 150ohm because he find only this kind of primary on the market transformer avalaible. you can use a 7k transformer to load a 300B but it will not sound a good as a 5K or 3.5K.

that"s why i want to know the internal resistance of the 2SK82 at 95V to make the right custom made transformer

 

[Soundhappy]

Lundahl realise customs transformers just my
With little chance maybe response is on audiohobby chanel
Juanitox what is your prefered outputs transformers brand ?
Kindly regards

 

[Soundhappy]

Find this table with 2SK82 resistance but ask more experienced diyers

 

[juanitox]

but ask more experienced diyers

that's was my initial plan

 

[Soundhappy]

i think michael use 150ohm because he find only this kind of primary on the market transformer avalaible.

From last update Michael say he was wait for specialy made
Edcor for this project output transformers
What is internal resistance ?
Simple ohm mesure between drain source et gate without courent , tension applied ?
Greetings

 

[juanitox]

ok! i quit...

 

[Soundhappy]

ok! i quit...

Sorry after verification this morning from update Ironamp video and is about customised INPUT transformer.
Probably output signal transformer data change too ....wait and see.

 

[Zen Mod]

it will be hard to find proper info , considering all posts with funny pictures and expression of unrestrained joy ....

 

[juanitox]

it will be hard to find proper info , considering all posts with funny pictures and expression of unrestrained joy ....

damn right , i know a method to find tube internal resistance with the load lines but here with the 2SK82 we have no load lines on the high voltage side available in data sheet..

but we have soundhappy

 

[Zen Mod]

damn right , i know a method to find tube internal resistance with the load lines but here with the 2SK82 we have no load lines on the high voltage side available in data sheet..

but we have soundhappy

I believe iilimzn already posted some snaps of curve tracer

even if he didn't , he's da Man to ask

 

[Soundhappy]

it will be hard to find proper info , considering all posts with funny pictures and expression of unrestrained joy ....

Hi Mighty
What is 2SK82 R=1 Ohm from "funny picture" data sheet post#151 ?
Handlebar mustache resistance for load lines ?

damn right , i know a method to find tube internal resistance with the load lines but here with the 2SK82 we have no load lines on the high voltage side available in data sheet..

Wish You receive Tektronix
Last Mr Rothacher update video about curves was made for request of diyer named Jama from Spain
he have lab at home and work with Sony and Tokin Vfets too.

but we have soundhappy

But i dont have any response from #150.
This is frogy company who make your custom transformers ?
Could i ask name or link ?
Thanks ZM and Juanitox
Best regards

 

[DIYspaceW]

What is your intendet operation point for the 2sk82?
I guess 400-500mA and 90-100V. You are good here whit 80-100R load.