how do you measure your in put singal to the poweramp????

prorms · 19th December 2006, 03:20 PM

ever time i measure the in put singal to the power amp i keep get 47 v now iam measure the singal with the multimeter setting i just would like to make sure my input singnal does not go over the limt
what would be the right setting or correct way to measure the input singal could please draw it out on the schematic just to make more easyer to understand?????????????????

its circle in red

edl · 19th December 2006, 04:57 PM

The gain is determined by R9 and R6.
It's actually (22000+220)/220=101, equals 40dB.
It's way too large!

If your amp is rated 100W-RMS, than the input sensitivity is sqrt(100*8)/101=280mV. Its attenauted by R1, so it's 290mV.

edl · 19th December 2006, 04:58 PM

Hey, if you measure 47V-DC on the output, then...

prorms · 19th December 2006, 07:29 PM

say if wanted to hook up a singal generator if i measure in dc i get 0.1 mv
if measure in ac i get 1v

edl · 19th December 2006, 07:32 PM

Sorry, your english is too bad to understand.

jleaman · 19th December 2006, 07:56 PM

Quote:

Originally posted by edl
Sorry, your english is too bad to understand.

LMAO

prorms · 19th December 2006, 09:11 PM

is your input singal measured in ac volts or dc volts?????
going into the power amp??????????????????????????????????????????????? ?????????????????????????

adason · 20th December 2006, 01:44 AM

??????????????????????????????????????????????????

ReidK · 20th December 2006, 04:26 AM

Input is AC. DC should be 0 or close to it, though the input cap will block any DC.

AndrewT · 20th December 2006, 02:02 PM

Hi Prorm,
I see you schematic has taken on board most of the earlier suggestions.

I still ask.
What is c6 doing?
Where is the resistor between the emitters of q9 & q11?
Disconnect or remove the output protection in the simulator (until you understand the operation of the amplifier and what the simulator predicts).

C3 forces the DCgain=1(one).
AC gain as Edl says. Reduce it to somewhere between 20 (+26db) and 50 (+34db) times.

The AC input signal should be 1mV to 100mV for non-clipping output.
Or, a little higher for examining the clipping behaviour (is a simulator any good at modelling clipping behaviour?).

What is your mother tongue? I and a few others are having a lot of difficulty translating your posts into plain English.

19th December 2006, 07:29 PM	#4
prorms diyAudio Member Join Date: Nov 2006	... say if wanted to hook up a singal generator if i measure in dc i get 0.1 mv if measure in ac i get 1v

19th December 2006, 09:11 PM	#7
prorms diyAudio Member Join Date: Nov 2006	.... is your input singal measured in ac volts or dc volts????? going into the power amp??????????????????????????????????????????????? ?????????????????????????

20th December 2006, 02:02 PM	#10
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi Prorm, I see you schematic has taken on board most of the earlier suggestions. I still ask. What is c6 doing? Where is the resistor between the emitters of q9 & q11? Disconnect or remove the output protection in the simulator (until you understand the operation of the amplifier and what the simulator predicts). C3 forces the DCgain=1(one). AC gain as Edl says. Reduce it to somewhere between 20 (+26db) and 50 (+34db) times. The AC input signal should be 1mV to 100mV for non-clipping output. Or, a little higher for examining the clipping behaviour (is a simulator any good at modelling clipping behaviour?). What is your mother tongue? I and a few others are having a lot of difficulty translating your posts into plain English. __________________ regards Andrew T.

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19th December 2006, 04:57 PM	#2
edl diyAudio Member Join Date: Oct 2004	The gain is determined by R9 and R6. It's actually (22000+220)/220=101, equals 40dB. It's way too large! If your amp is rated 100W-RMS, than the input sensitivity is sqrt(100*8)/101=280mV. Its attenauted by R1, so it's 290mV.

19th December 2006, 04:58 PM	#3
edl diyAudio Member Join Date: Oct 2004	Hey, if you measure 47V-DC on the output, then...

19th December 2006, 07:32 PM	#5
edl diyAudio Member Join Date: Oct 2004	Sorry, your english is too bad to understand.

20th December 2006, 01:44 AM	#8
adason diyAudio Member Join Date: Nov 2004 Location: home sweet home	??????????????????????????????????????????????????

20th December 2006, 04:26 AM	#9
ReidK diyAudio Member Join Date: Jan 2006 Location: Los Angeles (a.k.a. Hell on Earth)	Input is AC. DC should be 0 or close to it, though the input cap will block any DC.

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