Nice 50W Amp

[Woots29]

Blameless nga di ba?
The ckt caters all the possible areas where distortion may occur.

so did you personally tried it?

[Johannah Aleksandria]

so did you personally tried it?

Di pa, balak pa lang.
Nadala lang ako sa nabasa ko tungkol dito. Naniwala.
IMO, mganda pagka-design.

[Woots29]

Blameless nga di ba?
The ckt caters all the possible areas where distortion may occur.

so panu kung i-overdrive ko itong amplifer

magdidistort kaya?

[Johannah Aleksandria]

so panu kung i-overdrive ko itong amplifer

magdidistort kaya?

Bah, gusto ko yan sir ah, overdrive.
Palagay ko di na magdidistort, distorted na eh.

[Mayalin22]

May I make and assertion that the amplifier performance cannot be judged by (how well) the circuit (was designed) alone. There is one equally important component that is generally not given due attention by casual builders: the PCB Layout. Two identical circuits laid out differently will not give identical performance.

Take this as a preview of my upcoming thread  150W+150W Class D Amplifier. SHAMELESS PLUG
Yes, I am joining the audio amplifier craze!

start na yan sis born SHAMELESS PLUG 

[insomartin]

5.7 DISTORTION 7: NFB Takeoff point distortion.
There is a subtle trap in applying global NFB. Class-B output stages are awash with large halfwave-rectified currents, and if the feedback takeoff point is in slightly the wrong place, these currents contaminate the feedback signal, making it an inaccurate representation of the output voltage, and so introducing distortion; Fig 29 shows the problem.



At these current levels, all wires and PCB tracks must be treated as resistances, and it follows that point C is not at the same potential as point D whenever TR2 conducts. If feedback is taken from D, then a clean signal is established here, but the signal at output point C has a half- wave rectified sinewave added to it, due to the resistance C-D. The output will be distorted but the feedback loop does nothing about it as it does not know about the error. Fig 30 shows the practical result for an amplifier driving 100W into 8-Ohm. The resistive path C-D that did the damage was a mere 6mm length of heavy-gauge wirewound resistor lead.
To eliminate this distortion is easy, once you are alert to the danger. Taking the NFB feed from D is not advisable as D is not a mathematical point, but has a physical extent, inside which the current distribution is unknown. Point E on the output line is much better, as half-wave currents do not flow through this arm of the circuit.




 pcb layout pa lang pamatay na.

[Woots29]

Bah, gusto ko yan sir ah, overdrive.
Palagay ko di na magdidistort, distorted na eh.

since itong amplifier eh 1Vrms ang input

panu kaya kung 2V na-input ko? magdidistort kaya?

[Johannah Aleksandria]

since itong amplifier eh 1Vrms ang input

panu kaya kung 2V na-input ko? magdidistort kaya?

Hindi pa.
Kasi 2v p-p eh.

[tony]

this is a typical 3 stage ss amp.....

input impedance is about 10k, midband gain is 20 or 21 if you will......so that at 2volts rms input, output is supposed to be 42volts rms, question is will the output be distorted?

let us see.....with rails of +/- 37 volts, assuming that this rail will not sag with load.....and that collector saturation voltage is 2 volts, and that negligible ang drop sa 0.1ohm emitter degeneration resistors....

peak voltage then is 35volts peak or 24.5 volts rms....so that our output is severely distorted as you try to increase output voltage beyond 26volt say....

so answer is yes, it will be distorted....

[tony]

2 volt peak to peak is 1 volt peak and 0.7volts rms.....

with a gain of 21 output becomes 14volts.....kaya pa nung amp....

[Woots29]

wel said sir tony +1

[tony]

i used the mj4502 and mj802 to build DAN Meyer's Tigersaurus amps back in the 80's, i get them from Variproducts......now obsolete....

the MJ15003/15004 are better subs....

[Johannah Aleksandria]

2 volt peak to peak is 1 volt peak and 0.7volts rms.....

with a gain of 21 output becomes 14volts.....kaya pa nung amp....

Tumama ako dahil ginawang p-p.

[Woots29]

since the given input of amplifer is in Vrms

my question is also is in Vrms also

[Johannah Aleksandria]

since the given input of amplifer is in Vrms

my question is also is in Vrms also

Eh may sumalo eh, nkalusot ako.

[Johannah Aleksandria]

Ito na lang gawin natin.
Could anybody suggest a Class-G output out of this amp?

[???]

Galing ba ito ng libro talaga ni doug sarili?

Meron naglagay nyan dito.

[tony]

Ito na lang gawin natin.
Could anybody suggest a Class-G output out of this amp?

bakit pa? gawin mo na lang....ikaw ang nangmention, ikaw ang gumawa....

[Johannah Aleksandria]

Galing ba ito ng libro talaga ni doug sarili?

Meron naglagay nyan dito.

Galing nga to kay Douglas Self.
It is a nice book i acquired. I think i may start my learning from that book.

[Johannah Aleksandria]

bakit pa? gawin mo na lang....ikaw ang nangmention, ikaw ang gumawa....

Oo nga eh.
Kaya lang baka gusto rin ng iba gumawa, pwede kaming magtulungan.