100W Ultimate Fidelity Amplifier

[shravanth]

What is this pcb version, there is some mistakes...

Apex ax-11 mk2 sir

 

[shravanth]

dear sravanth,
ur pcb looks good.from where u get it.how can u measure output voltage.would u like to tell me the procedure to check out put voltage thanks

Hi masood u can measure it by using multimeter

Just put multimeter in 200mv dc and check across speakers terminal

 

[masood]

Hi masood u can measure it by using multimeter

Just put multimeter in 200mv dc and check across speakers terminal

dear srawnth,
thank u i have assembelled this circuit pcb by silheg.but protection relay is not availabe here.for this reason my project is pending.thanks regard

 

[apexaudio]

Apex ax-11 mk2 sir

BD139 is not darlington, replace 4k7 with 1k5 in bias circuit and measure voltages on 47R and 680R resistors

 

[shravanth]

BD139 is not darlington, replace 4k7 with 1k5 in bias circuit and measure voltages on 47R and 680R resistors

Apex sir

I have changed 4.7k with 1.5k

Voltage across 680ohm is 1v
Voltage across 47ohm is 0.4v

With 30-0-30 VDC

 

[arasuk]

dear srawnth,
thank u i have assembelled this circuit pcb by silheg.but protection relay is not availabe here.for this reason my project is pending.thanks regard

Masood,

use-DoublePole,58series,Those-2legs-of-the-relay,behind,,cut-them,,
285ohms-are12v,,1150ohms-are-24v

 

[duyphuong2287]

It just works the way it is . For bias , here....

yes! I changed 1k to 1.5k and 100R to 200R resistor. Thank you so much sir Apex and sir Alex mm!

 

[panggih]

Hi Mr.Mile.
I build ax-11 MK2 and I am very happy with the sound, the bass and middle and high tones to detail, but I got the same problem with vargas Mongos, where the transistors heat up quickly. I use 25-0-25 voltage vac, what should I do so that the transistor does not heat up quickly and be stable?

 

[vargasmongo3435]

Hi Mr.Mile.
I build ax-11 MK2 and I am very happy with the sound, the bass and middle and high tones to detail, but I got the same problem with vargas Mongos, where the transistors heat up quickly. I use 25-0-25 voltage vac, what should I do so that the transistor does not heat up quickly and be stable?




View attachment 420340

I forgot to mention that I place small heat sink for MJE350/40 and I also add a coil and a 10 ohm 7W wire wound resistors in parallel with the coil 18AWG about 22 turns on a 8 mm diameter cylinder and I notice that the amp stabilize I do not have any scope so I do heat feeling "touch" notice that the heat was lower and stable I did not have a darlington so I just drop a BD139 I mean this is me because I do not have much parts or better test tools I did as test and it works

Regards
Juan

 

[panggih]

thanks a lot juan for your explant..i will try to put 10R/7or 5W parallel with the coil 22 turns 8mm diameter.

can i use 25-0-25 volt vac,juan?

 

[vargasmongo3435]

thanks a lot juan for your explant..i will try to put 10R/7or 5W parallel with the coil 22 turns 8mm diameter

let me know your finds after you add the zobel network

Regards
Juan

 

[AndrewT]

amplifier Output Zobel is the R+C that connects the amplifier output back to the amplifier Ground.

The Thiele Network adds a R||L to the Output Zobel to create a 4 component output Network.

 

[vargasmongo3435]

so L+R parallel is not call it that way "zobel network" ?

 

[panggih]

amplifier Output Zobel is the R+C that connects the amplifier output back to the amplifier Ground.

The Thiele Network adds a R||L to the Output Zobel to create a 4 component output Network.

is this you call zobel network,Andrew T?



Tomorrow i try to put zobel network or coil with R and i will post result immediately

 

[AndrewT]

That is the Thiele Network.
It has an R+C in series to Ground
and
an R||L to the speaker load.

An Output Zobel has only the R+C part to Ground.

 

[panggih]

let me know your finds after you add the zobel network

Regards
Juan

Hi juan
I put R ll L already.but after 5 minute with minimum input,transistor still geting hot.
So what else should i do?

 

[vargasmongo3435]

on the load are you using 8 ohms speakers ?

Juan

 

[panggih]

on the load are you using 8 ohms speakers ?

Juan

yes,,the load i am using 8ohms speaker
vcc 25vac is it too high?

 

[apexaudio]

Hi juan
I put R ll L already.but after 5 minute with minimum input,transistor still geting hot.
So what else should i do?

What is size of your heatsink and bias current?

 

[panggih]

What is size of your heatsink and bias current?

mr.mile.
current measurement is 21.9 mV at R0.22. but not constant...the size heatsink is 20cm x 8cm for tes only.