Anybody know this Amp

[Aniket]

Hi Andrew,

Multisim results are very much close to the actual working circuit. As i stated in the previous post, there were only minor differences, also tested voltages at various points but there weren't much difference between simulation and working circuit.
To my experience multisim is a very simple and easy to use simulator and its PowerPro version has spice models for almost all the components required to simulate a discrete amplifier.
Good luck for your amp.

Regards,
Aniket

 

[dipolar]

Hi ,
This schematic along with PCB and construction guide was published in EFY magazine about 25 yrs ago (when I was born) . It was rated or advertised at 120W@4ohms .I was looking into my old stuff when i found the PCB and schematic. I made this amplifier about 8-9 yrs ago when I was in school and amazingly IT Worked for about an hour or so till the outputs and drivers burned out(i used 2n3773 and tip122 maybe). I remember it was my fault, as I used tiny heat sinks and didn't know how to set bias and other things. I abandoned this project and made a nice and working STK465 amp, using its power supply and transformer(30-0-30V,8A).
As i found the PCB and got some 2n3773's, ttc5200's, 2sc4793,sa1837, tip41,42c and bd139,40's I am looking forward to rebuild this amp.
Any advice and if anybody know this amp are welcome.

Regards,
Aniket

I have made this amp using 2n3773 . it doesn't sound great in full range.sounds muddy.
I Bridged those two channels and used as sub amp for an 8 inch driver
Almost 280 watts into 8inch 8 ohms with 40 volts into a 14 litre vented boom box.
It was a star of that time.approx 8 years back.

 

[Aniket]

I have made this amp using 2n3773 . it doesn't sound great in full range.sounds muddy.
I Bridged those two channels and used as sub amp for an 8 inch driver
Almost 280 watts into 8inch 8 ohms with 40 volts into a 14 litre vented boom box.
It was a star of that time.approx 8 years back.

being a TEF design, it's a nice sub amp. 2N3773 are great transistors but are Vce limited. Which driver transistors did u used?
also which 8 inch driver u have that could handle 280W continuous ????

Regards,
Aniket

 

[dipolar]

being a TEF design, it's a nice sub amp. 2N3773 are great transistors but are Vce limited. Which driver transistors did u used?
also which 8 inch driver u have that could handle 280W continuous ????

Regards,
Aniket

I had stock of original toshiba transistor pulled out of a Japanese Ups.The Amp worked quite well and never got anything above warm. I think components were what was in the circuit ,I didnt have knowledge or skills to alter at that age or point of time.

Side by side I had Tda7250+TIP transistors amp which sounded much better than this quasi complimentary amp.

8 inch woofer were made by myself. I used to buy magnets,aluminium foil,cone ,spiders from Ritchie street Chennai and wind it by hand.
This one had 3 inch voice coil 150mm magnet.

280 watts! hmm, may not be continues but a vague figure after measuring amp output voltage ,current of trafo, mathematic calculations by an amateur Diyer, that was at the age of 22.
as a general rule of thumb I used to follow Power=V^2/8x Rl
43 volts was dc output volt at no load made of 500 va trafo ,again the trafo was lifted from same Japanese ups.

it was the time when JBL differential drivers were seen around and me and friend trying to make similar motor at home.

 

[Aniket]

Side by side I had Tda7250+TIP transistors amp which sounded much better than this quasi complimentary amp.

8 inch woofer were made by myself. I used to buy magnets,aluminium foil,cone ,spiders from Ritchie street Chennai and wind it by hand.
This one had 3 inch voice coil 150mm magnet.

That's really cool. making your own speakers.

Regards,
Aniket