SE 1.5W OTL

[reinhard]

no reply

Not any info about

LED Magazine?

Reinhard

 

[Beato]

LED magazine is a French magazine mainly involved in DIY tubes products.

 

[reinhard]

How to order?

Is there a web page?

Reinhard

 

[Beato]

No web page. It's a small diffusion magazine.

I have some LED magazines, I will check.

You can find a post about KTR preampli with schematics on a french forum :

http://www.homecinema-fr.com/forum/viewtopic.php?t=29805486

 

[tubetvr]

From what I can see from the circuit diagram it consist of a SRPP DC connected to a cathode follower with active load. The output impedance of a cathode follower approaches 1/Gm and for the SRPP direct it is higher but it is fair to compare a circuit using 2 tubes to one using 4?

Regards Hans

 

[Beato]

You can find the complete description of the LED magazine at the following link :

http://www.isasarl.com/ --> PUBLICATION --> PREAMPLIFICATEUR and OPTIMISATION

 

[guglielmope]

I've scanned today but I've see that you can find the schematic in the indicated site but best in the first part of "Home cinema project" where there are more indications of how to calculate.
Ciao
Guglielmo

 

[reinhard]

1,5 Watt OTL SE

Hello,

maybe this french preamp is very good, but it is not

1,5 WATT OTL SE

We are speaking of power amplifiers here

Reinhard

 

[fdegrove]

Hi,

maybe this french preamp is very good, but it is not

No, it's not even very good either.😉


Cheers, 😎

 

[guglielmope]

What are you thinking is truee, but i think that this topology is interesting if used with power tubes for power amplification.
Ciao
Guglielmo

 

[reinhard]

maybe,

but the efficiency is very poor,
please make the math and let us know, think under 2 percent.

Reinhard

 

[tubetvr]

but i think that this topology is interesting if used with power tubes for power amplification.

What is interesting about it? Using a fancy name doesn't make it perform in any better way than what it really is, a SRPP DC connected to a cathode follower with an active load. For a power amplifier it wouldn't perform better than any other CF with active load and if you stick to single ended design this would give lowest possible output impedance, (except for inverted operation.)

Regards Hans

 

[reinhard]

SRPP

In my opinion an SRPP is not single ended, it´s push pull,

you can see that when you look at the possible output current.

As a reference: www.tubecad.com

There it is discussed in lenght.

Original US patent Nr. 2,310,342

Reinhard

 

[audio3chung]

CCS for SE OTL

Hi Reinhard
Have you ever use CCS to replace the inductor at the cathode of
6c19 of the output stage of the SE OTL?
If not, do you think it's OK.
Thank you for your constructive opinion!

CHOW

 

[audio3chung]

se otl

Hi Andrew
I got no idea on the higher power version,
but have you try use CCS instead of the inductor.

Regards CHOW

 

[Fuling]

I just ordered a bunch of Noval sockets, feels like it´s time to put those 6C19´s into service!

 

[reinhard]

SE OTL

Hello,

a good idea maybe an activated current source ala Nelson Pass´s
Aleph patent. Because of the special usage it must be mirrored,
P-channel instad of n-channel and so on.

Reinhard

 

[Fuling]

Not a bad idea!
A dynamic CCS would allow higher output power from a given bias current, and we all know that current is the limiting factor here.

 

[Fuling]

As far as I can tell the schematic posted in this thread is a mirrored Aleph CCS. Ignore the IRF540 follower.

http://www.diyaudio.com/forums/showthread.php?threadid=61624&highlight=

 

[Fuling]

Something like this:

I´m gonna ask the guys in teh Pass labs forum to fill in the resistor values🙂