Zenquito

[vizion]

Class A Profet

hello, is the Selectronic ProFet 15w a full Class A push pull amplifier ?

thanks.

 

[JFG67]

ProFet

Hello,

http://www.selectronic.fr/upload/produit/fichetechnique/7480MM.pdf

Yes, but 15W stéréo or 50W bridgé

PERFORMANCES
• Version STÉRÉO : 2 x 15 W RMS / 8 Ω
• Version bloc MONO (bridgé) : 50W RMS bridgé / 8 Ω


@ + JF

 

[lineup]

On amplifier Grande Audio Classe A Superb Quality
2 x 15 Watt pure Class A

Attachemente:
image de Zenquito 7480

Publicatione Article du originale
a la Monsieur Jean-Marc Plantefève
http://pagesperso-orange.fr/jm.plantefeve/

Zenotron by J M Plantefeve

Lineup Audio Lab
site du web - registrar por favor

 

[fab]

On amplifier Grande Audio Classe A Superb Quality
2 x 15 Watt pure Class A

Attachemente:
image de Zenquito 7480

Publicatione Article du originale
a la Monsieur Jean-Marc Plantefève
http://pagesperso-orange.fr/jm.plantefeve/

Zenotron by J M Plantefeve

Lineup Audio Lab
site du web - registrar por favor

Hi lineup

This shown Zenotron implementation does not have a very "dissipating" heatsink for a 15W stereo pure class A (even Push Pull)...
what is the thermal resistance?
or is the case very hot...

 

[JFG67]

Hi lineup

This shown Zenotron implementation does not have a very "dissipating" heatsink for a 15W stereo pure class A (even Push Pull)...
what is the thermal resistance?
or is the case very hot...

Hello Fab,

Rien n'indique que ce Zenotron soit en pure Classe A et tout dépend du réglage du courant de repos, certainement fait en fonction de la dissipation possible du boîtier

Nothing indicates that this Zenotron is in pure Classe has and all depends on the adjustment of the quiescent current, certainly made according to the possible dissipation of the case

http://www.atiresearch-anodized.com/products.html
http://www.hifi-2000.com/
http://www.seem-semrac.fr/seem/1Dissip/dissipat.htm

@ + JF

 

[lineup]

okay
ZENITRONt is one Classe AB
or even one Classe B .. id we bias for this

are you happy now
besserwisser

I am not happy

 

[lineup]

by that standard
no one of Nelson Pass
Class A amplifiers are anything but Class B
or Class AB and only in rare cases they happen to be Classs A

if it is all a matter of of bias and what load you use
so we can neve say one amplifier is any class
until we turn it on


this is something very new to me, and probably to many at this forum
that Class A NEVER is true Class A
even if the nominal specifications, instructions and other point this way and designer tells us so
... so Zenitron designer from France, Jean-Marc, is really not telling truth at hiswebsite.
Funny, he even does not sell amplifiers.
Wonder why he is not telling truth ... what is it in this for him.


I will consider this when using the term Class A in future
.. that this is a lie, until we set any bias and turnamplifier on


Lineup Class B Amplfiers - once they used to be Class A

 

[vizion]

Minimum Class A loosely defined would be 50% efficient and as low as 10% efficient.

So if you are putting out 15w (fully biased for minimum Class A), power draw should be at least 30w. And at a more extreme level (10% efficiency) 150w would be the power draw. Just a newbie. Is this correct ?

 

[JFG67]

by that standard
no one of Nelson Pass
Class A amplifiers are anything but Class B
or Class AB and only in rare cases they happen to be Classs A

if it is all a matter of of bias and what load you use
so we can neve say one amplifier is any class
until we turn it on


this is something very new to me, and probably to many at this forum
that Class A NEVER is true Class A
even if the nominal specifications, instructions and other point this way and designer tells us so
... so Zenitron designer from France, Jean-Marc, is really not telling truth at hiswebsite.
Funny, he even does not sell amplifiers.
Wonder why he is not telling truth ... what is it in this for him.


I will consider this when using the term Class A in future
.. that this is a lie, until we set any bias and turnamplifier on


Lineup Class B Amplfiers - once they used to be Class A

Hello,

http://pagesperso-orange.fr/jm.plantefeve/mont.html

Push Pull :

En classe B: Irepos=0, Pjmax=(2.Ualim²)/(pi².R), rendement max: 78%.

En classe A: Irepos=Ualim/2R, Pjmax=Ualim²/R, rendement max: 50%.

En classe AB les transistors sont polarisés à leur coude de conduction, la dissipation au repos n'est plus nulle comme typiquement en classe B, mais 2xUalimxIrepos (En A ou A SE celle-ci vaut Pjmax).
In class AB the transistors are polarized with their elbow of conduction, dissipation at rest is not null like typically in class B, but 2xUalimxIrepos (In class A Push or in class A Single this one is worth Pjmax).

Single Ended :

En Single Ended: Irepos=Ualim/R, Pjmax=2Ualim²/R, rendement max: 25%.

@ + JF

 

[lineup]

Zenquito, Mosquito

From what I've found on the internet I understand that Plantefève is called the french Nelson Pass.
His amps are known for their transparency, musicality and simplicity.
----------------
I have never had much interest in Passlabs amps.
Mainly because of their bad objective performance (they measure terribly).
However, I must admit that I have never heard any of them play...
----------------
ABo

You should give Nelson Pass amplifiers one ear, at least.
Two ears are even better when listen to Pass Amps

Plantefeve amplifiers are very high class.
You can do much more bad in the Diy Djungle of amplifiers.
Zenquito, Mosquito are good amplifiers.

There are also a number of modified Plantefeve amps done by good Diy Builders.
See the Plantefeve Gallery, for links to those projects:
http://pagesperso-orange.fr/jm.plantefeve/gale.html

Lineup

 

[JFG67]

... so Zenitron designer from France, Jean-Marc, is really not telling truth at hiswebsite.
Funny, he even does not sell amplifiers.
Wonder why he is not telling truth ... what is it in this for him.

Hello,

I am not on including/understanding well what you want to say concerning JMP.

Indeed JMP does not sell anything, it is a researcher. Its trade it is professor of electronics, teacher.

Zenotron is the version with negative feedback of Ampérotron.

ProFet is commercial realization of Sélectronic

JMP Zenotron = ProFet Sélectronic
JMP Mosquito = GrandMos (full mosfet) Sélectronic

@ + JF

 

[EUVL]

> I have never had much interest in Passlabs amps.
> Mainly because of their bad objective performance (they measure terribly).

Take an hour or so to read the F5 thread on the Pass forum.
The topology is very similar to that from ProFet.
0.003% distortion low enough ?
600kHz bandwidth high enough ?

Above all, try to do some long-period listening.
I used to own a Krell.
I sold it within a week of my 100W Class A working, without any regret.


Patrick

 

[lineup]

that's right, EUVL

there is something really good for every one
at nelson pass websites

 

[Machina]

Hi
How many bias should be on one transistor in class A? (Zenquito 2 pairs 2sk1058/2sj162)
I have almost 560mA in single transistor, supply voltage is +-26V.

 

[JFG67]

Hi
How many bias should be on one transistor in class A? (Zenquito 2 pairs 2sk1058/2sj162)
I have almost 560mA in single transistor, supply voltage is +-26V.

Hello,

1,12A bias current this gives 20W on a load of 8 ohms (10W / 4ohms)

Increasing a little bit ... at 1.25A it's 25W

and more ... at 1.77A it's 50W

Class A only depends on the bias current in the load

For max power, in class B. It depends on the supply voltage ...

The higher the voltage, the higher the output power (in class B). It can far exceed the power of Class A ...
But this tension is also to be multiplied by the current flowing through the chips. This dissipated power is pure loss in heat. And she uses fleas

For power calculations, see the website of my friend Jean-Marc
2A & DIY

 

[Machina]

Oh TY Very Much

 

[JFG67]

Oh TY Very Much

Hello,

But nothing, it was with pleasure.

If you will, you will show me your work.
Seeing the amp design still interests me.

At the beginning of the subject, which is already old, the photos have been deleted.
On the site of Jean-Marc, the photos of the amps of the friends of the time were removed. But they are still elsewhere for mine.

On the website of: Bienvenue sur Haute Fidelite.net

http://haute.fidelite.com.online.fr/JFgros/Dsc02015.jpg
http://haute.fidelite.com.online.fr/JFgros/Dsc02018.jpg
http://haute.fidelite.com.online.fr/JFgros/Dsc02013.jpg

The original diagram of Jean-Marc Plantefève
http://haute.fidelite.com.online.fr/coin-integriste/Jean-Francois-Gros/Mosquito.gif

So much for the work:
http://haute.fidelite.com.online.fr/coin-integriste/Jean-Francois-Gros/mosquito-JFgros.html
(No need to send emails on the address at the beginning of the link, it is deactivated and no longer works)

This Mosquito amp delivers 25W in pure Class A and beyond in class B up to 80W ... Under 8 ohms load ... Call this class AB, if you want.

The heatsinks are at 70 ° ... The diagram is somewhat different from the original diagram by the choice of components ... Resistors of different value to adapt to the current of rest. The input stage, the four transistor are capped with a long heatsink that keeps them at the same temperature. So you can put your fingers on it, without the output zero point Volt being changed. To further improve this, the 10V zener diode is actually two zener diodes. One negative coefficient and the other positive.
See all these precautions, to gain stability ... although this is not advisable ... but here it works very well ... the six output Mosfet are mounted without insulator on a copper plate. This is possible because Drain and Source of the Mosfets are reversed, compared to bipolar transistors. here all the Sources are electrically together

http://haute.fidelite.com.online.fr...Francois-Gros/06montage-sur-cu-radiateurs.jpg
http://haute.fidelite.com.online.fr/coin-integriste/Jean-Francois-Gros/07montage-avec-qpad.jpg

greetings

 

[JFG67]

Hi
How many bias should be on one transistor in class A? (Zenquito 2 pairs 2sk1058/2sj162)
I have almost 560mA in single transistor, supply voltage is +-26V.

Hello,
Given the power supply asser weak your amp. You can, perhaps, set the class A to the maximum possible of the power of Class B. Determined by the voltage + -26V. (I have not calculated how much that makes). The best are measurements in the laboratory. But you have to be well equipped for that.

 

[JFG67]

Hello
By the way, I did not pay attention to your flag, lol ... Yesterday, I went to see your countryman Kinga Glyk in Pforzheim in Germany ... and it was fantastic ... a lot of emotions in his music.
YouTube
And personally, I work in the computer banking in Strasbourg (Ibm Z14), I have two Polish colleagues, one of which is the city next to that of Kinga. lol
It's a pleasure to work with them

 

[Machina]

Hi JFG67
I have bias set to 0,7A on single transistor, heatsink have 63°C. I dont have this amplifier here, my friend borrowed him to compare with what he has No pic right now ;/