not sure what class this poweramp is?

prorms · 20th September 2006, 11:45 PM

iam not sure what class this poweramp is
also for this type of amp ?Iam looking for the
math and a description of it fuctions are?

can anyone point me to the right direction?

lineup · 21st September 2006, 01:05 AM

no doubt a Class AB

you dont build Class A using as high as +- 55 Volt

the quiescense, idle, current going in Ouput transistors
in each is according to Ohm's Law
0.0137 V / 0.1 Ohm = 0.137 Ampere ( 137 mA )

this is typical for Class AB
for Class B would have been near to 0 mA
for Class A several Amperes

137 mA is towards high Class AB
normal values like 40-50 mA are not unusual

Leolabs · 21st September 2006, 02:36 AM

A slightly high bias class AB.

AndrewT · 21st September 2006, 07:09 AM

Hi,
Can anyone explain why the sim is indicating very low Vbe on both the output devices and the drivers? Vbe~=400mV

Forgot the output offset,

Quote:

0.0137 V / 0.1 Ohm = 0.137 Ampere ( 137 mA )

0.157V/0.2r=78mA through each output = a lot of heat to dissipate ~=26W

jacco vermeulen · 21st September 2006, 07:37 AM

Quote:

Originally posted by seanmacss
not sure what class this poweramp is

It's called: a Piece of S***

pinkmouse · 21st September 2006, 09:15 AM

Language, Jacco!

ilimzn · 21st September 2006, 11:15 AM

Jacco seems to have woken up on the wrong foot

but his post has elements of truth

There are a couple of resistors that have no function (and may be detrimental to the performance of the amp), some mistakes in wiring that will do the same, and for god sake PLEASE redraw that circuit with straight lines, I still feel dizzy!

edl · 21st September 2006, 11:48 AM

Quote:

Originally posted by jacco vermeulen

It's called: a Piece of S***

I'm agree...

anatech · 21st September 2006, 01:51 PM

Hi seanmacss,
There is nothing wrong with jacco's eye sight and mind.

I agree with him. I might be best if jacco had a coffee before posting though!

(language, as Al said).

-Chris

jacco vermeulen · 21st September 2006, 02:08 PM

Al is more than gentle with me, and has been on many occasion.

Bad timing, Rod Elliot's April Fools item doesn't even come close to this, besides the lack of drawing skills.
This schematic has the scent of gratuity Spice disease, lacking any respect for the true audio designers with a ton of knowledge.

(you're right about the morning stuff, i'm a regular sunshine...at night. I had 1 coffee before i posted)

21st September 2006, 01:05 AM	#2
lineup diyAudio Member Join Date: Dec 2005 Location: the north	no doubt a Class AB you dont build Class A using as high as +- 55 Volt the quiescense, idle, current going in Ouput transistors in each is according to Ohm's Law 0.0137 V / 0.1 Ohm = 0.137 Ampere ( 137 mA ) this is typical for Class AB for Class B would have been near to 0 mA for Class A several Amperes 137 mA is towards high Class AB normal values like 40-50 mA are not unusual __________________ lineup

21st September 2006, 09:15 AM	#6
pinkmouse diyAudio Moderator Join Date: Apr 2002 Location: Chatham, England	Language, Jacco! __________________ Al I conceive of nothing, in religion, science or philosophy, that is more than the proper thing to wear, for a while. Charles Fort

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21st September 2006, 02:36 AM	#3
Leolabs diyAudio Member Join Date: Dec 2004 Location: Bukit Mertajam	A slightly high bias class AB.

21st September 2006, 11:15 AM	#7
ilimzn diyAudio Member Join Date: Feb 2005 Location: Zagreb	Jacco seems to have woken up on the wrong foot but his post has elements of truth There are a couple of resistors that have no function (and may be detrimental to the performance of the amp), some mistakes in wiring that will do the same, and for god sake PLEASE redraw that circuit with straight lines, I still feel dizzy!

21st September 2006, 01:51 PM	#9
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi seanmacss, There is nothing wrong with jacco's eye sight and mind. I agree with him. I might be best if jacco had a coffee before posting though! (language, as Al said). -Chris

21st September 2006, 02:08 PM	#10
jacco vermeulen diyAudio Member Join Date: Oct 2004 Location: At the sea front, just under Rotterdam	Al is more than gentle with me, and has been on many occasion. Bad timing, Rod Elliot's April Fools item doesn't even come close to this, besides the lack of drawing skills. This schematic has the scent of gratuity Spice disease, lacking any respect for the true audio designers with a ton of knowledge. (you're right about the morning stuff, i'm a regular sunshine...at night. I had 1 coffee before i posted)

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