Your pcb design for stereo preamp from post #57 is OK, I suggest to use stereo buffer as preamp.
Attachments
TEF Configuration
I want to know the correct placement of bd139 for correct thermal compensation in tef configuration.should it be mount on on the first stage of tef configuration ? shuold all these transistor in tef configuration be mount on the same heatsink along with the output transistor together with bd139?
regards,
drowranger
I want to know the correct placement of bd139 for correct thermal compensation in tef configuration.should it be mount on on the first stage of tef configuration ? shuold all these transistor in tef configuration be mount on the same heatsink along with the output transistor together with bd139?
regards,
drowranger
BD139 must be mounted on the same heatsink together with drivers and outputs, only predrivers can be placement separate,
Regards
Ok Dear Mr. Apex. I will take a picture and post it...later...I put B1 buffer. It's a little bit difficult to find good caps with higher votage more than 63 volt. I plan to supply 45 - 0 - 45 Vac. Some suppliers only have 50 volt as a common. Now it is operating in 40 - 0 - 40 Vac.
Best Regards,
Arif
Best Regards,
Arif
Hi Mr. Damanhuri, one of my best friends in local audio community forum. I am still courious with this amplifier reproduction. With some components up grades I hope it will make better sound.
Dear Mr. Slavkovic./ Apex:
How about changing the transformer into toroidal type? Will it make a lot of improvements? My friend has some bad experiences using toroidal transformers, 2 times blew up after 2 hours operation. There were because of the toroidal quality I supposed. Now he is trying to make his own toroidal.
Dear Mr. Slavkovic./ Apex:
How about changing the transformer into toroidal type? Will it make a lot of improvements? My friend has some bad experiences using toroidal transformers, 2 times blew up after 2 hours operation. There were because of the toroidal quality I supposed. Now he is trying to make his own toroidal.
Hello Sir Arif Budiyanto. glad to see you here.
I find his name APEX. but I do not use artificial APEX protect the speakers, because componennya too much. I use the speaker protect locally made and it was a good friend of my design.
I find his name APEX. but I do not use artificial APEX protect the speakers, because componennya too much. I use the speaker protect locally made and it was a good friend of my design.
Toroidal type transformer have adventages but problem can be high voltage from turn to turn in primary wireing (over 200vac).
Symetrical Descrite Amplifier
B500 with single pair of outputs can be use as Hi-Fi amplifier. Basicly B500 is symetrical descrite amplifier with common base input stage. OP amp is for DC servo and AC input buffer for low impedance emiter amp input.
B500 with single pair of outputs can be use as Hi-Fi amplifier. Basicly B500 is symetrical descrite amplifier with common base input stage. OP amp is for DC servo and AC input buffer for low impedance emiter amp input.
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AX17 Full Discrete Symmetrical Amplifier
I like this one, I'm interesting to built one...🙂
Can you tell me the minimal & maximal voltage to this amp without any component value changing?
with 2 pair of output & the minimal load?
Thanks you Mr Mile
Regards
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