please comment my pcb

[sakis]

this is the schematic

and this the pcb ....your comments are very welcome

thank you

[nigelwright7557]

More copper and a ground plane covering any empty space.

[sakis]

your comment but dont you think tha a graound palne will mess up with my so nice ground rooting ????

[nigelwright7557]

Originally posted by sakis
your comment but dont you think tha a graound palne will mess up with my so nice ground rooting ????

A ground plane would make your ground even less impedance.

[djk]

R1 is too high of a value for the 5534 input off-set current.

Do you think you can get away with not using a compensatin cap for the opamp? It's de-compensated and not stable at gains of less than x5.

No temperature compensation for the bias, Suggest you look at the NJL0281/0302 ThermalTrac devices as drivers (as you need to track driver temp with this kind of output stage).

http://www.onsemi.com/pub_link/Colla...1D-D.PDF<br />

Only two pair of plastic outputs on ±74V? Resistive 8R load only please!

[sakis]

Originally posted by djk
R1 is too high of a value for the 5534 input off-set current.

No temperature compensation for the bias, Suggest you look at the NJL0281/0302 ThermalTrac devices as drivers (as you need to track driver temp with this kind of output stage).

http://www.onsemi.com/pub_link/Colla...NJL0281D-D.PDF

djk thanks for your comment ......

though the question is about the pcb since this is a comercial allready working amplifier

the only issues where about the original pcb since it was made very messy and disigned to fit inside a sassi with comfort but without any consideration to earth& signal rooting signal cables mixed with ac or dc cables and so on and on

this particular working amplifier has only stability and ocilation issues and has only thermostat and ventilators to preserve thermal stability ( dont know if its enough though )

the only question is about the pcb .... the circuit it shelf as we speak is not on judjment at least at this point

[djk]

R20, R21 need only be 1/2W with a 1K feedback resistor.

No resistor to damp L1?

No zobel on the amplifier output?

"though the question is about the pcb since this is a comercial allready working amplifier "

All sorts of marginal stuff finds its way to the marketplace.

[fotios]

I suggest you to mitter all corners on the tracks and round them after to avoid any parasitic capacitance (electrons concentrated in peaks). Also you may fill with copper triangles each vertical branch in the "T" point in each side of branch.

Fotios

[alex mm]

Hello Sakis ,
At the first look , I see pin nr. 6 and 7 from IC connected nowhere , so PCB no good to me . You can replace PCB whith my PCB if correct . I keep same places for the componnents with smalls changes any comment ? http://i27.tinypic.com/vxlso2.jpg . all the best alex mm

sorry for same bad english

[sakis]

Originally posted by alex mm
Hello Sakis ,
At the first look , I see pin nr. 6 and 7 from IC connected nowhere , so PCB no good to me . You can replace PCB whith my PCB if correct . I keep same places for the componnents with smalls changes any comment ? http://i27.tinypic.com/vxlso2.jpg . all the best alex mm

sorry for same bad english

at this point i am not willing to mess up with the circuit ...... this i will find later ...the question was only about the pcb

fotios thanks man