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Old 24th May 2007, 01:37 PM   #1
roender is offline roender  Romania
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Default Class A/B folded cascode amp

This is the best sounding amplifier I'v ever constructed!
It don't measure very well but it sound so gooood
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Old 25th May 2007, 02:36 AM   #2
Leolabs is offline Leolabs  Malaysia
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Do the small signal transistors have to be matched???
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Old 25th May 2007, 06:39 AM   #3
roender is offline roender  Romania
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Hi Leo,

You must match the following transistors:
J1-J2, BL version, matched at 6mA Ids
Q16-Q14, matched for Vbe
Q19-Q20, it is not really necessary but it's a good thing to do it at the same hfe
Q7-Q6-Q15, matched for hfe

Mihai
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Old 25th May 2007, 07:15 AM   #4
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Is the voltage for the input stage +-47volts?
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Old 25th May 2007, 08:06 AM   #5
roender is offline roender  Romania
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Input stage is boosted with 8V (regulated) over output stage which have 32V unregulated power supply
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Old 26th May 2007, 10:42 AM   #6
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Default Re: Class A/B folded cascode amp

Quote:
Originally posted by roender
It don't measure very well but it sound so gooood
Don't be so shy.
It probably still measures way better than any gainclone ever built.
Nice one!
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Old 26th May 2007, 11:52 AM   #7
lineup is offline lineup  Sweden
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Default Re: Class A/B folded cascode amp

Quote:
Originally posted by roender

This is the best sounding amplifier I'v ever constructed!
It don't measure very well but it sound so gooood
.

great amplifier, roender

what i have in 'your folder' is something about SymaSym
so i think you have built one MikeB amp, before

( lineup has got one special folder for each interesting diyAudio member
in his harddrive.
Example this time:
C:/My Documents/diyAudio-persons/roender/070127a_powerstage.jpg
See my attachment below
for this powerstage from 27th of January )

If I have a 'NelsonPass' folder ?
Of course, I have!!!!!
... and you may guess it has got plenty of stuff ... as Nelson IS a very interesting diyAudio profile
C:/My Documents/diyAudio-persons/NelsonPass/



Regards
lineup

... will be back with one more post, lineup comment,
after studying this Folded Cascode amp a bit more
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Old 26th May 2007, 03:21 PM   #8
Khron is offline Khron  Romania
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Greetings, mr roender

I sent you an email about 2 weeks ago, through diyaudio. Have you received it?
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Old 26th May 2007, 04:04 PM   #9
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any photos??
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Old 27th May 2007, 05:24 PM   #10
roender is offline roender  Romania
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Quote:
Originally posted by Khron
Greetings, mr roender

I sent you an email about 2 weeks ago, through diyaudio. Have you received it?
No, sorry.
If you want, make your whish public ...

Mihai
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