GAS - Global Amplification Stage

[Stee]

Hello!

this important schematic is a World Heritage
please add your modification

Regards

[lineup]

thanks, Stee
nice schematic

what tests have you done:
- as buffer, Gv=1
- at Gv=10 (+20dB)
- with different loads
- with different input AC levels
- with different output AC levels
- with different Voltage Supply

what is the recommended nominal Power Supply to use?
2 x 20 VDC max ... or

what transistors you use - you recommend
NPN? PNP?

thanks lineup is interested

[lineup]

Stee

I see you have already this GAS amplifier schematic
at your website
http://www.esafono.it/hindex_file/image003.jpg
http://www.esafono.it/hindex.htm

Have you joined my Audio Forum?
here it is http://lineupaudio.freehostia.com/forum/index.php
very small forum - me as moderator

We can post New Project & Discuss your GAS.
then later we come back here to www.diyaudio.com
and present our result from Project design!


===================================

Click my www below my post
= audio forum ... easy to join

[Stee]

Originally posted by lineup
thanks, Stee
nice schematic

what tests have you done:
- as buffer, Gv=1
- at Gv=10 (+20dB)
- with different loads
- with different input AC levels
- with different output AC levels
- with different Voltage Supply

what is the recommended nominal Power Supply to use?
2 x 20 VDC max ... or

what transistors you use - you recommend
NPN? PNP?

thanks lineup is interested

never tested, it's a fresh idea

think is better use power bipolar as 2SA5200 & C TOSHIBA
and his drive can be MJE340 & C
just to start at Gv=10 (+20dB) with dual 30V

do you have a simulator?
Regards

[Stee]

NFB partition ( 560 and 8K2 )

[Stee]

GAS is an ambitious project
to have Class A sound with AB class biasing

without bridge and OPA
with complementary and balanced criterion
in very simply design

I have found now a good simulator
http://www.catena.uk.com/cgi-bin/download1.pl?id=125930

[lineup]

I have installed SIMetrix maybe 2 months ago.
I have not learned how to use.

Have we some good transistors in SIMetrix?
What we want is simulation software (freeware)
with many AUDIO transistors, mosfet and bipolar.

People often use these free simulators & schematics designers:
- LTspice/SwitcherCAD III
http://www.linear.com/designtools/software/
- Eagle CADsoft
http://www.cadsoftusa.com/freeware.htm
- B2 Spice A/D v4 Lite, which can work with Eagle
http://www.beigebag.com/adv4_lite.htm
How to build a schematic in Eagle and export it to B2 Spice A/D v4 for simulation:
http://www.beigebag.com/eagle.htm


Lineup
Lineup Audio Blog & Audio projects Forum for members

[lineup]

I am sure GAS and also UAS will work well.
You do work now. Will later be final versions.

Did see you have a nice circuit here (UAS)
http://www.diyaudio.com/forums/attac...amp=1219024318
2SJ160 / 2SK1056 as driving 2SC5200 / 2SA1943
... this is a new idea for me .. but think is not bad
maybe will work perfect!

Lineup
http://lineupaudio.freehostia.com/forum/

[Giaime]

It won't work in real life. Output transistor Ic will be different (because of different beta and different Ib) so one transistor will saturate and stop working.

[Stee]

think Giaime is right