It's stable now.This is not DC pulses,this is very low frequency output.
My phone is offender.This is not happened by amp.Use smaller input cap to remove this
Today I worked on very simple amplifier.Tomorrow I'll upgrade it and maybe post new topic.It uses only two (maybe 4 for higher current) transistors on output and VAS is changed with transformer.
Hi Acca,
can I used your schema using ziklai output? Can you draw for this? No available here in our local store bdx33c/34c. Thanks in advance.
Regards,
Boyet
I have problem with bias.It's 0V at start,but after few min's it's 50mV.
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Check this:
http://www.diyaudio.com/forums/solid-state/242641-vstt.html
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Check this:
http://www.diyaudio.com/forums/solid-state/242641-vstt.html
Little up-date : BG1-BJT (MJL4281/4302) is up to day in my audio systeme. Last week i swap from CD to computer with Jriver software as player and music tracks on FLAC form. Computer is configurated in Bit perfect mode (wasapi under W7). What i can say is that the back return to CD source is quite impossible as the rendering is pleasent. All previous qualtities i have reported with BG1 introduction are magnified by source modifcation...really, really good music moments...
Marc
Marc
Hi Acca,
Its playing now your circuit using sziklai output with 2sa970/2sc2240 input.
Bias only 1 diode 1N4148 and some modification of the value of parts. And the result? Sounds great.
Dead silent if no signal compare to my lafet version.Regards,
Boyet
Hi Acca,
Its playing now your circuit using sziklai output with 2sa970/2sc2240 input.
Bias only 1 diode 1N4148 and some modification of the value of parts. And the result? Sounds great.
Dead silent if no signal compare to my lafet version.Regards,
Boyet
As I say,sound is perfect.Hi Acca,
Its playing now your circuit using sziklai output with 2sa970/2sc2240 input.
Bias only 1 diode 1N4148 and some modification of the value of parts. And the result? Sounds great.
Regards,
Boyet
Little progress in versatil 50 building process : speaker delay and dc protection board. This must be feed by 0/+12Vdc PSU.
I re-etch new versatil 50 board as i gave an evolution to the board by reduce the whole size. I am waitjing some SMD resistors to populate them.
I re-etch new versatil 50 board as i gave an evolution to the board by reduce the whole size. I am waitjing some SMD resistors to populate them.
Attachments
Nice work. But there is very simple way to add very small psu circuit. Only few resistors, one npn tranistor with zener diode and there is no need separate transformer for protection board. Speaker protect can be supplied directly from amp psu voltage.
Hi folks, I have been following this thread for a while and have decided to build my own. I have created the attached schematic based on Borys earlier schematic except with partys that I have. Can you have a quick glance over it for any mistakes before I create the board etc?
Thanks
Much appreciated.
Dom
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Thanks
Much appreciated.
Dom
Hi folks, I have been following this thread for a while and have decided to build my own. I have created the attached schematic based on Borys earlier schematic except with partys that I have. Can you have a quick glance over it for any mistakes before I create the board etc?
Thanks
Much appreciated.
Dom
[/URL][/IMG]
If I am not mistaken , at first sight , you have a positive feedback amp
here...check output stage transistors configuration... Also feedback return point should be taken at output of amp and not source resistor...Fab
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