Zenquito

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#45
gaetan8888 said:

Surfing on the diyaudio forum, I found your thread.
Here's an modified version of the Buzquito;
http://oamlabs.home.sapo.pt/oamlabs_a500d.html
Gaetan
Click to expand...
djk said:
Nice 50W amp.
R17, C15 would do more good on the other side of the relay.
Click to expand...
Leolabs said:
Wonder do u guys have the offset drifting problem???
Click to expand...


pantefeve original Buzquito (think it is)
is told to be biased 400mA and uses a paralleled pair of BUZ900/905 N+P
This means 200mA per BUX9xx transistor.
This buzquito is specified 150 Watt Class AB into a pair of LSP with 88dB SPL.
Offset drift when using more current = Class A should be less of a problem
than an amplifier 'running cold' ( class B, class AB low bias).

Of course also good temp compensation of input 2SK170/2SJ74
will effect eventual drift of offset.
Preferably they should be out together in close contact.
Yes, even the temperature of 2 VAS transistors in this diagram can effect offset!
In this following diagram, at plantefeve 😎 great website 😎

An externally hosted image should be here but it was not working when we last tested it.


Website:
http://perso.orange.fr/jm.plantefeve/sche.html


Regards 🙂 Lineup
 
#46
Hello lineup

What are the use of the two 220 ohm potentiometers ?

Any good replacements for the BUZ900/905 output transistors that can be found in north america ?

Anybody did made that Buzquito amp, how it sound ? and anybody compared it to Aska amp or any other excellent diy amp ?

Thank

Gaetan
 
#47
lineup said:


Of course also good temp compensation of input 2SK170/2SJ74
will effect eventual drift of offset.
Preferably they should be out together in close contact.
Yes, even the temperature of 2 VAS transistors in this diagram can effect offset!

Regards 🙂 Lineup
Click to expand...


Hello 😉 ,

Yes 😎 http://perso.orange.fr/pol.bct/JFG/Dsc02013.jpg

the thermal coupling improves the stability of the offset largely. To perfect that, drivers 2N3440/2N5416 would have to be also coupled, but it is difficult to find a radiator adapted to that (electric insulation), it would also preferably be necessary to modify the PCB.
example of radiator: to see datsheet 2SA607 http://pdf1.alldatasheet.com/datasheet-pdf/view/107665/ETC/2SA607.html

@ + Jean-François 😉
 
#49
gaetan8888 said:
Hello
Surfing on the diyaudio forum, I found your thread.
Here's an modified version of the Buzquito;
http://oamlabs.home.sapo.pt/oamlabs_a500d.html
Gaetan
Click to expand...


Hello 😉,

Pair 2SK170/2SJ74 is however better and however easier to pair, however that depends indeed on the recus batches... personellement, in spite of a number much more significant of 2SK246/2SJ103 (50 pairs) I had much more evil to make good pairs with those Ci. The BC550/BC560 save small a 0,1db. Work on the decoupling of the zéners of 10V is well seen, that gets along and strongly the noise decreases by it. Personally, 0,1µF MKT + 10µF Tantale solid Alusol Philips, the zéner of 10V consists of two zéners of 5,6V + 4,7V, which offers the advantage of making a zéner compensated in temperature. Thermal coefficient opposed below and to the top of 5V.

http://perso.wanadoo.fr/pol.bct/JFG/Dsc02013.jpg

http://perso.wanadoo.fr/pol.bct/JFG/Dsc02015.jpg

http://haute.fidelite.com.online.fr/coin-integriste/Jean-Francois-Gros/mosquito-JFgros.html

@ + Jean-François 😉
 
#52
hi

Think Leolabs is very correct.
Advice is this: Use the original 2SK1058 / 2SJ162, for Zenquito standard circuit!
They should not be too difficult to find and buy
in any part of world where you may live.


JFG67 said:

Hello 😉,

Pair 2SK170/2SJ74 is however better and somewhat easier to match,
but this can depend very much indeed, if buying them all from one same batch/package... or not.

Personally, even if having larger number of 2SK246/2SJ103 (50 pairs),
I had much more difficult to find good matching pairs with those.


The cascoding transistors, BC550/BC560 save small a 0,1db.
Work on the decoupling of the 10V zeners is recommended,
in that you can get a good noise reduction, decrease by doing so.

Personally, I use 100nF MKT + 10µF solid Tantale, Alusol Philips.
Each zener of 10V consists of two zeners of 5,6V + 4,7V,
which offers the advantage of making the zener having good compensation for temperature.
Thermal coefficient opposed below and to the top of 5V.
( makes combination almost zero temp drift coefficient )

http://perso.wanadoo.fr/pol.bct/JFG/Dsc02013.jpg

http://perso.wanadoo.fr/pol.bct/JFG/Dsc02015.jpg

http://haute.fidelite.com.online.fr/coin-integriste/Jean-Francois-Gros/mosquito-JFgros.html

@ + Jean-François 😉
Click to expand...


Thanks J-F.
Very good information, indeed,
for building BUZquito or ZENquito.

🙂 lineup
 
#53
lineup said:
hi

Thanks J-F.
Very good information, indeed,
for building BUZquito or ZENquito.

🙂 lineup
Click to expand...


Hello 😉,

Mosquito, in use 2SK170/2SJ74 + BC550c/BC560c + 2N3440/2N5416 + 3x 2SK1058/2SJ162

Simulations : (Francis Brooke) http://monsite.wanadoo.fr/francis.audio
Linearite, Distorsion H2/H1=-61.8dB et H3/H1=-76.0dB pour Us=4V a 1kHz sur R=5.5ohm Zenquito Evolution
Linearite, Distorsion H2/H1=-83.0dB, H3/H1=-93.3dB et H4/H1=-115.4dB pour Us=4V a 1kHz sur R=5.5ohm Zenquito Evolution

H2/H1=-84dB H3/H1=-94dB H4/H1=-128dB Mosquito schéma de base JMP http://perso.orange.fr/jm.plantefeve/sche.html

H2/H1=-93dB H3/H1=-102dB H4/H1=-140dB Mosquito JFG67 classe A 25WA/80WB/8ohms Alim +-42V 8x47000µF/Pi R=0,47ohm/11W

The very first original diagram of Mosquito is at the foot of the page.
http://haute.fidelite.com.online.fr/coin-integriste/Jean-Francois-Gros/mosquito-JFgros.html

R Pro2 = 2W
Modifications :
+-50V = +-42V
R 82 ohms in drivers = 120ohms because I drivers = 10/12 mA for I = 1,25A in 3x 2SK1058/2SJ162 for 25W classe A
Zéner 10V = zéner 5,6V+4,7V + 0,1µF MKT + 10µF Tantale Alusol
100µF = 220µF 105° C136 Philips + 1000µF FRS 105° Roedertein

@ + JF 😉
 
#54
lineup said:
hi
Advice is this: Use the original 2SK1058 / 2SJ162, for Zenquito standard circuit!
They should not be too difficult to find and buy
in any part of world where you may live.

🙂 lineup
Click to expand...


Hello 😉

Extreme Attention for 😡 BBM audio & electronics 😡 :

the 2SK1058 are not 2SK1058 drain and source is reversed

http://forums.delphiforums.com/n/mb/message.asp?webtag=haute_fidelite&msg=21770.1

vvvvvvvvvvvvv

De: Philby11 22-févr 11:22
À: Plantefève Jean-Marc (PJeanMarc) non-lu 11 de 12

21770.11 en réponse à 21770.10

Bonjour Jean François et Jean Marc,

On a eu aussi des soucis avec des mosfets 1058 Selectronic sur HC FR,
mais ils ont été très corrects, et ont changé tous les transistors
de ce lot.

http://www.homecinema-fr.com/forum/viewtopic.php?p=169818391#169818391

Ces mosfets sont inversés en Drain et source (ce ne sont pas des
1058!!!) et la diode en inverse drain source fait des dégats...

Et il y en a encore dans la nature, attention!!! :

http://cgi.ebay.fr/ws/eBayISAPI.dll...Sell_LogicX&refwidgettype=cross_promot_widget

Philippe

AAAAAAAA

@ + JF 😉
 
#55
Re: Zenquito par Boris et Patrick G.

lineup said:
.

Bon! Great Work trabajeuir, par Amplificados!
😎 boris et patrick
An externally hosted image should be here but it was not working when we last tested it.

!Muchos! Tre, Tre! Regardes
a la 🙂 Le Mounseir Lineup (suedoise)
Click to expand...

😉,

http://perso.orange.fr/jm.plantefeve/boris.html Boris
http://perso.orange.fr/jm.plantefeve/Garaud.html Patrick
http://perso.orange.fr/pol.bct/BuzKito.jpg and Pol
http://perso.orange.fr/pol.bct/exemples/DIY.htm Pol

http://haute.fidelite.com.online.fr/JFgros/JFG.html
http://perso.orange.fr/pol.bct/JFG/Dsc02020.jpg Zenquito Boris
http://perso.orange.fr/pol.bct/JFG/Dsc02011.jpg
http://perso.orange.fr/pol.bct/JFG/GdMos18.jpg GrandMos & Mosquito

@ + JF 😉
 
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