QUASI Amplifier for Beginners

[olafk]

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

Please read the posts from #708.

regards, Olaf

 

[joeyt]

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]

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

 

[AndrewT]

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

 

[shravanth]

hello sir can any share amplifier bridging circuit

 

[shravanth]

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]

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]

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]

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

 

[olafk]

I will do so.

Regards Olaf

 

[lelut]

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

what voltage Sir have balance in the bass? +42V or +60V?
thanks sire for your information, i will try 8x2N2922 first with +42V,

Mr.Apex any advice?

ax14 to ax100 very complex schematic and made for expert DIYers

BR,

 

[olafk]

Amplifier with 2N2922 runs with +/- 45V DC.

regards Olaf

 

[djk]

The only 2N2922 I know of is a 25V 200mW device.

 

[Ian Finch]

It's probably a German-Indonesian version of 2SC2922. Now, how many years have they been obsolete?

 

[lelut]

It's probably a German-Indonesian version of 2SC2922. Now, how many years have they been obsolete?

Yes sir, i means 2SC2922,
i just see the last number of TR code,

sorry to make confuse,

BR,

 

[lelut]

Just share PCB layout,
let me know if there is an wrong place

 

[PetruV]

I want to squezze 300-500w 4r out of this thing using to 220 or to 264 packages what would be the cheapest to use and what voltage and layout and schematic
Sorry i asked for too much

 

[PetruV]

Has anybody tried this on perfboard

 

[amptech]

Hello Petruv, building power amp circuits on veroboard is ok for small amps using chip type amps but not for high powered ones as this is asking for trouble.

If you look over the forum there's many ideas along with foil lay outs to aid a building first class amplifiers.. Trying to get huge power from small power 220 packages at low 4 ohms is again not good and there for your better off using t0-3 or transistors such as 2sc5200.

Regards A.

 

[malik123]

BOS100

Here is pcb for BOS100 which is attached by Apex.
Which transistors can i use instead of BC639 and 2N3773

Tnx