poweramp as good as gets for 350w

[prorms]

iam very sure that this power amp doesnt need any other modifcations to it
it has 1v max input and the same way the singal goes in it comes
out even louder Iam running this amp at 2 ohm load
i included in the winzip a circuit maker schematic and
a bmp file of the schematic

[lineup]

1. By lowering value of R6
until you get just about same voltage across R18 and R14
you will let Q1 and Q2 have exactly same current.

2. After this
you should hopefully have around 0.0 volt at the output.
If not you will go on and adjust for ZERO output
elsewhere in circuit.
We will tell you how to do this.

But first try to set Q1 / Q2 to share the current from R6
exactly 50%-50%

[prorms]

moedl are in pspice format
mje150034
mje150035
mj15003
mj15004
bd139
they also
have models in saber ,spice2 spice3

the datasheet at www.onsemi.com
http://www.onsemi.com/pub/Collateral/BD135-D.PDF
http://www.onsemi.com/pub/Collateral/MJ15003-D.PDF
http://www.onsemi.com/pub/Collateral/MJE15034-D.PDF

[prorms]

schematic is simulated in circuit maker 2000

[lineup]

Originally posted by seanmacss
schematic is simulated in circuit maker 2000

so wont be difficult to change and adjust resistor R6
to achieve a balanced input stage
and get close to 0.00 volt at the loudspeaker output.

Just ( right- ) click on R6 ( 468 Ohm ) and set a new value.
I would guess a better value would ~220-270 Ohm

then run a new simulation
to get new voltages at your testpoints

lineup long since I used Circuit Maker, but it is nice software!

[AndrewT]

Hi Seanm,
the bias pot is in the wrong side of the Vbe multiplier.

The driver emitter resistor is far too big.

A 2ohm load on two pair of 15003/4!

Input ground reference on the chassis earth needs to be moved to the audio ground.

The input RF filter is set a bit high @ 100nS.

All the other grounds need to be moved to the audio ground not the chassis earth.

Get that long tail pair (LTP) in balance.

If C3 needs to be that big then there is something wrong with your implementation.

C12 & 13 will just about suit 4ohm speakers but the RC time constant (4r * 33mF) of 130mS should be longer than R15 & C8 @ 1S. A bit of adjustment needed here as well.

[MikeB]

Sean, why did i send you schematics ?

Mike

[prorms]

change i made

just download

[kalmara]

Do you have any PCB design for this circuit?

[prorms]

iam not sure if i can find a beter transistor for q1 q2 q3 q4 q5
i wana keep them at least 80v
iam looking for ones that keep the sound qualty hifh
hi mike that before i built on a bread board sound great but
was engough watts for thanks for help than and now
no I am just at simulaton stage for this poweramp
need it to be 480 watts rms max but I wana keep at 350
iam using cpu fan heat sink with an alum 1/4 plate as the heat sinks
as far as i get it to 294 for r6 but i also change the transistor to
bc489 bbut am not sure how good they are