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Old 17th May 2012, 12:48 PM   #3771
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Quote:
Originally Posted by NMOS View Post
Im sorry, I was a nice time but I do not longer build and support NMOS Amp

because

I habe now very much better sounding quasicomplementary BJT Design including all protections and relay free turn on delay, this design beat NMOS Amp,

its much clearer very transparent with imaging and depth so vivid you can “see” into the actual sound track. You’re going to hear every inner detail of the music the way the producer intended it to be heard and will playback any style of music in a Flawless manor.

I will share with Diy
can u upload a image of this amp
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Old 21st July 2012, 05:37 PM   #3772
Kapkan is offline Kapkan  Russian Federation
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Default NMOS200

Hi, everybody.

Prompt please: what standing current at NMOS200?

And that I bring together the amplifier, I do not know what current to expose.

Whether also it is possible to use condensers to 1000 pF on tension of 50 volts in case of a power +-35 volts? Or it is not enough?

PS If not so expressed I am sorry, I from Russia, know English badly, I use the translator.
PSS Yet up to the end completed, I look for angular heat sinks.
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Old 22nd July 2012, 07:30 AM   #3773
SaMaHa is offline SaMaHa  Russian Federation
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You should read this:
????????? ?? Mosfet ? ???????? ???????? ?? ?? ?????? ???????????????? - ????? ?? ????????????????
Chuvak, idi a vegalab ili na cxem.net
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Old 22nd July 2012, 07:55 AM   #3774
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I know you can't do anything about the link, but could you please post the rest in English. Thanks.
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Old 22nd July 2012, 08:38 AM   #3775
SaMaHa is offline SaMaHa  Russian Federation
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Quote:
Originally Posted by pinkmouse View Post


I know you can't do anything about the link, but could you please post the rest in English. Thanks.
No problem.
Quote:
Originally Posted by Kapkan View Post
Prompt please: what standing current at NMOS200?
Constant current is about of 30 mA.
Quote:
Originally Posted by Kapkan View Post
Whether also it is possible to use condensers to 1000 pF...
Yes it is.
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Old 22nd July 2012, 08:48 AM   #3776
Kapkan is offline Kapkan  Russian Federation
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SaMaHa
Спасибо за ссылки, нашел ответы на все вопросы.
Лучше на радиокот, cxem.net не очень нравится.
(Thanks for the link, found the answers to all questions.
It is better to radiokot, cxem.net do not really like.)
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Old 22nd July 2012, 08:49 AM   #3777
Kapkan is offline Kapkan  Russian Federation
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Update:
SaMaHa , thank you.
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Old 9th August 2012, 10:57 PM   #3778
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Default Biasing amp

I am building the Quasi NMOS 500. I used .15 ohm resistors instead of the .47 ohm Quasi used as emitter resistors. In the construction guide Quasi states that the amp should be biased to 30 ma per output transistor.
5. If everything seems ok adjust VR2 to set the output stage bias current, by measuring the
voltage across the positive rail resistor. Adjust for a reading of 3 volts per output FET pair. I.e.
For a 6 FET board set for a voltage of 9 volts. This equates to a bias current of 30mA per
FET pair or 90 mA total. For a 10 FET board set for a voltage of 15 volts.
6. If everything seems ok, check the output offset voltage and adjust VR1 to achieve an offset of
less than 10 mV.
7. All being well switch off, back off the bias control trimmer (VR2) and replace the 100 ohm
resistors with 10 ohm 1 watt resistors. Switch on again and re-adjust VR2 to get 0.3 volts per
per FET pair across the positive rail 10 ohm resistor.

Is this final setup still correct even though I used .15 ohm resistors instead of the .47 ohm Quasi used?
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Old 10th August 2012, 08:16 AM   #3779
AndrewT is offline AndrewT  Scotland
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Try using the same Vre value, i.e. 30mA across 0r47 = 14mVre
Using this value of Vre will result in ~100mA of output bias current per output pair.

This may be too much both for heat dissipation and to minimise crossover distortion, but it is a starting point to work from.
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Old 11th August 2012, 09:27 AM   #3780
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is there anyone out there try using ferrite beads at fets gate?
how to implement this which is directly connected to fets gate,is it the ferrite or gate resistor?
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