Zenquito

Wavebourn · 2006-12-19 1:02 am

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

Do you mean weight, or length? :scratch:

gaetan8888 · 2007-06-20 10:34 pm

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

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

Gaetan

djk · 2007-06-20 11:42 pm

Nice 50W amp.

R17, C15 would do more good on the other side of the relay.

Leolabs · 2007-06-21 3:45 am

Wonder do u guys have the offset drifting problem???

lineup · 2007-06-21 7:24 am

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

djk said:
Nice 50W amp.
R17, C15 would do more good on the other side of the relay.

Leolabs said:
Wonder do u guys have the offset drifting problem???

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

gaetan8888 · 2007-06-21 5:14 pm

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

JFG67 · 2007-06-22 6:04 am

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

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

lineup · 2007-06-22 6:29 am

Zenquito par Boris et Patrick G.

.

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)

JFG67 · 2007-06-22 6:42 am

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

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

gaetan8888 · 2007-06-22 4:07 pm

Can I replace the 2SK1058 by The FQA7N80C and the 2SJ162 by the FQA9P25 ?

They cost much less.

Thank

Gaetan

Leolabs · 2007-06-23 2:34 am

Can I replace the 2SK1058 by The FQA7N80C and the 2SJ162 by the FQA9P25 ?

Those are Fairchilds' QFETs,dont think they are for audio.

lineup · 2007-06-23 6:41 am

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

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

lineup

JFG67 · 2007-06-23 4:39 pm

lineup said:
hi

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

lineup

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

JFG67 · 2007-06-23 5:04 pm

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

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

JFG67 · 2007-06-23 7:11 pm

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)

,

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

G33/33 · 2007-06-26 2:42 am

JFG67 said:
Mosquito, in use 2SK170/2SJ74 + BC550c/BC560c + 2N3440/2N5416 + 3x 2SK1058/2SJ162

@ + JF

Hi,

I can not find 2N3440/2N5416 around here. any suggestion for their substitution ?

rgds,
G33/33

djk · 2007-06-26 5:44 am

MJE340/350, but remember the pin-out is different.

MPSW92/42 are 2.5W, or 1W in 25*C ambient, they would probably work too (same pin-out as the 2N3440/5415)

JFG67 · 2007-06-27 6:35 am

G33/33 said:
Hi, I can not find 2N3440/2N5416 around here. any suggestion for their substitution ?
rgds, G33/33

hello

,

MJE340/MJE350

@ + JF

G33/33 · 2007-06-28 3:01 am

Thanks alot :cheerful:

I have some in my drawer

G33/33

JFG67 · 2007-06-28 6:26 am

G33/33 said:
Thanks alot
I have some in my drawer G33/33

Hello

,

Not to forget their to put a good radiator (the transistors heat much, diagram JMP), the advantage of cases TO126 is that one can thermically couple the two transistors on the same radiator what reinforces still a little the stability of the offset

@ + JF

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