Class A/B folded cascode amp

roender · 24th May 2007, 01:37 PM

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

Leolabs · 25th May 2007, 02:36 AM

Do the small signal transistors have to be matched???

roender · 25th May 2007, 06:39 AM

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

Samuel Jayaraj · 25th May 2007, 07:15 AM

Is the voltage for the input stage +-47volts?

roender · 25th May 2007, 08:06 AM

Input stage is boosted with 8V (regulated) over output stage which have 32V unregulated power supply

darkfenriz · 26th May 2007, 10:42 AM

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!

lineup · 26th May 2007, 11:52 AM

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

Khron · 26th May 2007, 03:21 PM

Greetings, mr roender

I sent you an email about 2 weeks ago, through diyaudio. Have you received it?

bogdan_borko · 26th May 2007, 04:04 PM

any photos??

roender · 27th May 2007, 05:24 PM

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

25th May 2007, 07:15 AM	#4
Samuel Jayaraj diyAudio Member Join Date: May 2001 Location: Bangalore, India	Is the voltage for the input stage +-47volts? __________________ Sam

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Folded cascode headphone amp	nelsonvandal	Headphone Systems	266	28th March 2009 07:12 PM
folded cascode	the_tool	Chip Amps	1	27th June 2006 09:53 PM
Symmetrical folded cascode.	Mr Evil	Solid State	195	1st April 2005 03:15 AM
folded cascode puzzling	drakonis	Pass Labs	6	30th March 2002 09:04 PM
Folded cascode question	Won	Solid State	3	11th January 2002 07:10 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

25th May 2007, 02:36 AM	#2
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	Do the small signal transistors have to be matched???

25th May 2007, 06:39 AM	#3
roender diyAudio Member Join Date: Sep 2006	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

25th May 2007, 08:06 AM	#5
roender diyAudio Member Join Date: Sep 2006	Input stage is boosted with 8V (regulated) over output stage which have 32V unregulated power supply

26th May 2007, 03:21 PM	#8
Khron diyAudio Member Join Date: Jul 2005 Location: Finland	Greetings, mr roender I sent you an email about 2 weeks ago, through diyaudio. Have you received it?

26th May 2007, 04:04 PM	#9
bogdan_borko diyAudio Member Join Date: Nov 2005 Location: serbia, zajecar	any photos??

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)