QUASI Amplifier for Beginners - Page 73

olafk · 4th September 2012, 07:06 AM

Quote:

Originally Posted by joeyt

what is the power output of this compact module using -40v 0v +40v?

Please read the posts from #708.

regards, Olaf

joeyt · 4th September 2012, 12:23 PM

no answer from post no.708. i read in this forum that the power output of a PA comes from the supply voltage with adequate heat sink to its output transistor. -40v 0v +40v maybe i will get around 90 watts in 8 ohms. correct me pls.if i am wrong

thanks,joeyt

olafk · 4th September 2012, 01:05 PM

"+-30Vdc will sag to maybe around +-27Vdc when driving full power to a test resistor.
The voltage lost through the amplifier could be very approximately 3Vdrop when delivery that full power to the test load.
That leaves your maximum output voltage @ ~24Vpk.

Pmax = Vpk^2 / Rload / 2.
I predict your maximum power for a +-30Vdc supply as ~ 36W into 8r0"

-------------------------
I can not measure the output power of this module. But I hope the calculation from Andrew can give you a example.

regards

AndrewT · 4th September 2012, 03:31 PM

Joey,
why do you expect others to do your homework?
Read Olaf and read his reference post.

shravanth · 2nd December 2012, 03:07 PM

hello sir can any share amplifier bridging circuit

shravanth · 15th December 2012, 06:43 PM

Quote:

Originally Posted by apexaudio

I find paper with circuit of this amplifier with single pair 2N3773 and added VI limiter.

sir plz share pcb layout for this single pair amp

lelut · 14th January 2013, 05:56 AM

Quote:

Originally Posted by olafk

Hi,

I built the amplifier (picture see post #663) with two pairs of 2N3773 and I use +-60V DC. Now the Transistors MJE350/340 become to hot. I can touch them for only 3-4 seconds and I think it is a bit critical.
Should I reduce the voltage (have regulated power supply) or are there any other things I can do? I changed the heatsink to a bigger version for TO220 like the MJE15030, but gave no better result.
Can anybody help me?

regards
Olaf

Dear Sir Olaf,

How difference using +-60V or only using +-42V at sound (using 2N3773 final TR)?
more deep or more mid character?

And for your second kit, using 2n2922, how about sound character?

i will plan this schematic for outdoor PA using 8x2N3773 or 8x2N2922 per-channel.

thanks,

BR,
Made Sumber

olafk · 14th January 2013, 03:02 PM

Hi lelut,

I have not compared the sound with different voltages. But I think, there's not much difference.
For my taste the 2N2922 sound a little better and more balanced in the bass - but that is very subjective.
I built the amps for my sons to make noise ;-).
For hifi I use ax14. Next project is ax20 with 3 pairs.
Sorry for the only few informations.

regards Olaf

Vostro · 14th January 2013, 03:15 PM

Olafk if you build ax20, please comment on how it compares to ax14 in apex100w thread,
Im interested to know how they compare.

olafk · 14th January 2013, 04:37 PM

I will do so.

Regards Olaf

4th September 2012, 01:05 PM	#723
olafk diyAudio Member Join Date: Mar 2011 Location: germany	Andrew T. wrote in Post 700... "+-30Vdc will sag to maybe around +-27Vdc when driving full power to a test resistor. The voltage lost through the amplifier could be very approximately 3Vdrop when delivery that full power to the test load. That leaves your maximum output voltage @ ~24Vpk. Pmax = Vpk^2 / Rload / 2. I predict your maximum power for a +-30Vdc supply as ~ 36W into 8r0" ------------------------- I can not measure the output power of this module. But I hope the calculation from Andrew can give you a example. regards

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4th September 2012, 12:23 PM	#722
joeyt diyAudio Member Join Date: Aug 2012 Location: philippines pampanga	no answer from post no.708. i read in this forum that the power output of a PA comes from the supply voltage with adequate heat sink to its output transistor. -40v 0v +40v maybe i will get around 90 watts in 8 ohms. correct me pls.if i am wrong thanks,joeyt

4th September 2012, 03:31 PM	#724
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Joey, why do you expect others to do your homework? Read Olaf and read his reference post.

2nd December 2012, 03:07 PM	#725
shravanth diyAudio Member Join Date: Dec 2011 Location: hyderabad	hello sir can any share amplifier bridging circuit

14th January 2013, 03:02 PM	#728
olafk diyAudio Member Join Date: Mar 2011 Location: germany	Hi lelut, I have not compared the sound with different voltages. But I think, there's not much difference. For my taste the 2N2922 sound a little better and more balanced in the bass - but that is very subjective. I built the amps for my sons to make noise ;-). For hifi I use ax14. Next project is ax20 with 3 pairs. Sorry for the only few informations. regards Olaf

14th January 2013, 03:15 PM	#729
Vostro diyAudio Member Join Date: May 2012 Location: Other side of the fence	Olafk if you build ax20, please comment on how it compares to ax14 in apex100w thread, Im interested to know how they compare.

14th January 2013, 04:37 PM	#730
olafk diyAudio Member Join Date: Mar 2011 Location: germany	I will do so. Regards Olaf