Walt Jung Class A preamp

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leiade, what are you after really? Of cource you can enhance the JC-amp. It can be a good start to start with something that actually works. Then when you have got it working, modify the design. If you can't design yourself, it's better to ask around and also look at other designs, as many as possible.

There are thousands of ideas and there are none which is absolutely right.

If you have concrete questions I think there are plenty of us who wants to help you.
 
sholud

I invented a new word " sholud" maybe to much Rioja I also suffers from keyboard afasi, but I'm Ok now, peranders can you help me with the JC-2 problem hook an output stage with low imp driving capability it sholud be something like the erno class a buffer output I think he use mosfet right ? or... maybe it's better to try the Walt Jung discete opamp buffer the one with LED's.

Peter Daniel, yes I will check some Swedish pages and it would be nice if you check som Canadian pages and when we have done this we can mail each other to change some interesting about electronics. 🙂
 
Re: sholud

leiade said:
I invented a new word " sholud" maybe to much Rioja I also suffers from keyboard afasi, but I'm Ok now, peranders can you help me with the JC-2 problem hook an output stage with low imp driving capability it sholud be something like the erno class a buffer output I think he use mosfet right ? or... maybe it's better to try the Walt Jung discete opamp buffer the one with LED's.

Walter Jung's design is very universal. You can use any transistor type you like.

What data should the output stage have?

How much gain?

How low noise?

Maximum supply voltage etc.

Have you checked integrated buffers?

LT1010, BUF6xx etc. Check http://www.elfa.se since you live in Sweden.

Integrated buffers are quite OK if you are satisfied with their data.
 
IC audio amplifiers

No, no, no, I do not want any IC, I want a low impedance driver at the output of the JC-2 output amplifier wich consists of in my case two jfet dual devices like the 2sk389 and 2sj109 and output devices is the wellknown 2n4401 and 2n4403 I think that it would be nice to end this amplifier with a mosfet design á la Erno
the old German fet amplifier guru "TOGFAG".

If any can check the schematics of the JC-2 and help me with an upgrade with the above mentioned output I would appreciate it very much.

I think Erno use 2sk216 and 2sj79 but I'm not sure.😎
 
Rioja

Oh no ! another bottle og Conde de Valdemar Reserva is on the table I have to run, if I don't get away I maybe invent some more peculiar words again like the "sholud" maybe this word can be the synonym for the JC-2 upgrade struggle. :innocent:
 
something about making

As I am an elder swedish guy not so upp to date as many of the youngsters here on the Web I will yet remember a story about bulding railways in the world Swedish,Norwegian and Finnish was often the guys who made it, here is the story in swedish.
Förmannen till beställaren ge mig snus,mus och brännvin samt svenskar, norrmän och finnar och jag skall bygga en järnväg till helvetet.

Goodbye gentlemen🙂
 
JFET MOSFET

My last question before I fall off the chair, what !!!! is the devices Erno use in his class a design obsolete can't be true if so subsitute it with IRF devices and please go on with the upgrade.

Sholud😎
 
Re: JC-2 Tune up

leiade said:
Nelson Pass I agree about the JC-2 how can we tune it up ? make a better output low impedance driving capablility and so on come on amateurs take this challenge.😎
Hi Leiade,
See the following thread at AA for tune up of the JC-2 and to see what is really inside the modules.
http://db.audioasylum.com/cgi/m.pl?forum=tweaks&n=35230&highlight=elso+mpsu56&r=&session=
Finally my own JC-2 was so tuned up that it was literally my own design preamplifier. Then I went for the Shallco 47 position volume switch and sold the JC-2.😉
 
tuning preamps

Hi Elso,

Can you show your jc-2 upgrade to this forum it woul be nice to se.

I have listened to a clone jc-2 for many years now and it's still working, but I wanted a remote controlled preamp so I bought a used Linn LK-1 and I must say this preamp has nothing do do in the high end area.

Lots of problems Ok it's old, the LK-1 was broken 5 -6 times I dont remember exactly, fortunatly I own a copy af the schematics, people!! lots of junk in this construction.
Maybe I can show some part of this LK-1 schematics here but I have to make xerox first I will show the output stage I think it is class A.🙂
 
MOSFET

Peranders,

They are available in Sweden and the price is about $10 for a pair of 2sk216 and 2sj79.

Can you attach them to the JC-2 output it would be very nice to get lower driving capability to this eminent design.😎
 
Preamp boxes

I'm searching for a nice box that can house my preamp pcb's it have to be SOTA I also want links to a machine shop that can make nice faceplates 🙂

Power supply not to forget any good idéa or link to a reliable power supply🙂
 
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