JLH 10 Watt class A amplifier

[marconi118]

any schema of your 4 resistor 3 transistor amplifier?

 

[cumbb]

;-)
This would be not the correct way.
Try;-)
And think.-)))
And tell;-)

 

[huggygood]

it's on my list

 

[Wierd]

No schema? or just thoughts?

 

[cumbb]

After a warm up it does run with 3 resistors only;-)))

YouTube

 

[Wierd]

Can you explain (technical or schema)?

 

[Ian Finch]

After a warm up it does run with 3 resistors only;-)))
.....

You will know that a music recording played back at You-tube MP3 quality on some arbitrary internet audio system has nothing to do with your reference amplifier.

We'd like to understand what you are talking about in your posts, so what is the circuit you refer to? You could sketch a simple schematic with free programs like MS paint if you don't have a circuit drawing program but here is a link to a free drawing program, with a tutorial in English to help get started: Circuit Diagram Maker | Free Download & Online App
Of course, there are more if you search - some harder, some too simple and some cost $$.

 

[nigelwright7557]

In 69 there weren't the choice of transistors we have today so its possible less than ideal transistors were used.

Even in 1980 Maplin were using 60 volt transistors on 100 volts supplies !
I used one for a mobile disco for at least 5 years before selling it on with no problems.

 

[cumbb]

And? Has anybody removed the bootstrap and listened;-? Or does listen, is listening;-?
Does anybody venture a step into acoustic, audio-physics, electrophysics;-?

 

[cumbb]

The TE13003 sound finer and more natural than the BD441. Much more again;-) Huiuiui;-)
The TO-3, in compare, sound like a rosty bended distorting steelplate, or similar;-)-;

 

[Wierd]

Have you a schema for the physics-model ?

 

[Juergen Knoop]

100V 2N3055 did exist in those days and you can even buy them today

 

[Nico Ras]

What is cumbb drivel about - is he doing listening tests with different output devices. How does he claim day/night differences among all the devices or does he just have 22 ct gold ears?

 

[Ian Finch]

The TE13003 sound finer and more natural than the BD441. Much more again;-) Huiuiui;-)
The TO-3, in compare, sound like a rosty bended distorting steelplate, or similar;-)-;

This has no meaning without a schematic diagram. TE or MJE13003 is a small (TO126) switching transistor for power supplies. Unless you tell us it is a substitute for the driver transistor, your amplifier will be much smaller than JLH 1969. Perhaps it is a headphone amplifier or just a very different design, since you say it has very few parts.

 

[Nico Ras]

If cumbb profile shows every item as different/relative, then I would not even bother to read his comments. Can one still block seeing comments made by someone?

I viewed the 365 threads submitted by cumbb and find them just a load of rubbish.

 

[huggygood]

you think of a troll?

 

[cumbb]

32 V, 1 A at moment. The TE13003;-)
I will higher the bias next days;-)
A dream;-)

... do you have soldering bolts;-?

 

[fredbloggstwo]

... do you have soldering bolts;-?

excuse my ignorance - what is a 'soldering bolt'.

Mike

 

[sergiu2009]

32 V, 1 A at moment. The TE13003;-)
I will higher the bias next days;-)
A dream;-)

... do you have soldering bolts;-?

Cumbb even though your transistors are (maybe) genuine telefunken parts i cannot see how can you dissipate all that heat... The on semi mje's have better dissipation from what datasheets show. Can you show us your cooling sollution??
32w disipation for a bd139 like transistor is like melting hot capsule dont you think? Could you show us some pics with temp measurements with the amp running after 30mins? I am really curious.
I have an almost 3kg of aluminium blocs per each transistor (with direct contact) to passivelly cool 45w dissipation in my modified Hiraga amplifier with TO264 cases (wich have way better dissipation than bd139 like capsule), and they are still hot in the summer days...

 

[cumbb]

I meant the TEs run as power transes in the/my 32-V-JLH: 2 x 16 V. Fan at moment. Passive later.
The Hiraga sounds very very ugly. No reason to use 3 kg alu for horrible sound. No modify sensible. No doubt. Cause: 4-stage-complementary-parts and "2-rail-psu". Sorry. Had have any, tuned too, had built any. Trust me.-)
Build a JLH;-)